CN110124115A - Hydrophobic coating, its preparation method, application and absorbable implantable device - Google Patents

Abstract

The invention relates to a hydrophobic coating, a preparation method and application thereof, and an absorbable implantable device. When the hydrophobic coating provided by the invention covers the surface of the degradable material, the hydrophobic block can enable the hydrophobic coating to play a good water-resisting role in the early stage, so that the degradable material is hardly degraded; in the later stage, the degradable blocks are degraded, so that the porosity of the hydrophobic coating is improved, body fluid can contact with the degradable matrix material through the pores of the hydrophobic coating, and the degradation of the matrix material is promoted.

Description

Hydrophobic coating, its preparation method, application and absorbable implantable device

technical field

The invention belongs to the technical field of degradable materials, and in particular relates to a hydrophobic coating, its preparation method, application and absorbable implantable device.

Background technique

In the medical field, degradable materials can be degraded and absorbed by the body after serving in the body, which can avoid the negative effects caused by secondary surgical removal and long-term existence of materials, so they are widely used in orthopedic internal fixation, drug slow and controlled release carriers, Tissue engineering stents, cardiovascular stents and other fields.

The degradation rate and mechanical properties of degradable materials are two important properties that are concerned when they are applied clinically. Ideal implantable devices (such as degradable vascular stents, absorbable bone plates, bone nails, etc.) usually need to maintain good mechanical support for a period of time in the early stage of implantation, and then be degraded and absorbed. Therefore, achieving a good match between the degradation rate of degradable materials, mechanical properties, and the time required for implant site repair is a key problem to be solved in the development of new implantable devices.

At present, the degradable materials used in the matrix of absorbable implantable devices mainly include degradable polymers (such as polylactic acid, poly(lactic-co-glycolic acid), polycaprolactone, etc.) and corrodible metals (such as magnesium and magnesium alloys). , iron and iron alloys, zinc and zinc alloys, etc.). Among them, the mechanical properties of degradable polymers are generally poor. When used in degradable stents, to achieve sufficient mechanical support, it is necessary to increase the thickness of the device as a cost, which not only limits the application range of its devices to a certain extent , At the same time, it may also lead to risks such as slow endothelial crawling. For example, in order to realize the mechanical support effect of coronary stents on blood vessels in the early stage, the stent rod of Abbott's polylactic acid coronary stent has a thickness of 156 μm, which limits its use in the field of small blood vessels. Corrosionable metals have better mechanical properties than degradable polymers, but metals or alloys such as magnesium and zinc are difficult to meet the requirements of mechanical support in the early stage of implantation due to their fast corrosion rate.

Patent CN 105327397 A discloses the preparation of a mesoporous calcium silicate coating degradable implant material on the surface of a medical magnesium alloy, which is compounded with a mesoporous calcium silicate coating material on the surface of the magnesium alloy to isolate the magnesium alloy from corrosion The contact with the medium improves the problem of too fast corrosion of the magnesium alloy and controls its degradation rate in the organism.

Patent CN 107789665 A discloses a method for preparing a superhydrophobic hydroxyapatite film layer on the surface of a magnesium alloy. A hydrothermal method is used to prepare a rod-shaped hydroxyapatite crystal layer with a length of micron scale and a diameter of nanoscale on the surface of magnesium alloy. Then prepare a stearic acid film on the surface of the nanostructured hydroxyapatite film to form a hydrophobic film with a static droplet contact angle of 153°, which can reduce the corrosion current density of magnesium alloys by 2 orders of magnitude. The layer impedance modulus increases from 2029Ω.cm2 to 117674Ω.cm2, which delays the corrosion of magnesium alloys.

Patent CN105420789A discloses a hydrophobic composite bioactive coating on the surface of pure magnesium or magnesium alloy and its preparation method. The composite bioactive coating is prepared by combining micro-arc oxidation coating, electrodeposited hydroxyapatite coating and magnesium alloy base material. It has the advantages of high density, good biocompatibility and good osteoinductive ability. On this basis, the composite bioactive coating is treated with a hydrophobic treatment agent to prepare a hydrophobic composite bioactive coating. The obtained The hydrophobic composite bioactive coating has greatly improved the corrosion resistance of simulated body fluids and enhanced the osteoinductive ability.

However, most of the existing published patents use coatings based on inorganic materials to reduce the degradation rate of degradable matrix materials, and inorganic material coatings are often brittle, so they are only suitable for orthopedic implants. It is difficult to use degradable cardiovascular stents and cerebrovascular stents with high requirements; in addition, the inorganic material coatings in the published patents have special requirements for the preparation process and matrix materials, which are limited to magnesium and magnesium alloy materials. deal with. However, the cross-linked hydrophobic coating in this patent has good strength and toughness, and can be used in various devices such as cardiovascular and cerebrovascular stents, orthopedic implants; and the hydrophobic cross-linked coating in this patent is universal and can be used The degradation rate of various degradable matrix materials is controlled by coating on the surface of various degradable matrix materials by common coating preparation methods.

Contents of the invention

The object of the present invention is to provide a hydrophobic coating, its preparation method, application and absorbable implantable device in order to solve the above problems.

The object of the present invention is achieved through the following technical solutions:

A hydrophobic coating covering the surface of a degradable material, characterized in that the hydrophobic coating is a coating formed by cross-linking a hydrophobic monomer, or a cross-linking coating formed by blending a hydrophobic monomer and a non-degradable component layer, wherein the hydrophobic monomer is a block copolymer comprising a hydrophobic block, a degradable block and a cross-linking functional group.

Preferably, the hydrophobic block is formed by a hydrophobic polymer, the degradable block is formed by a degradable polymer, and the hydrophobic polymer and the degradable polymer undergo a polymerization reaction to form a hydrophobic block connected by a chemical bond and In the degradable block, the cross-linking functional group is connected with the hydrophobic block and/or the degradable block through chemical bonds to promote cross-linking between hydrophobic monomers to form a hydrophobic coating.

Preferably, the hydrophobic block is composed of at least a formation.

Preferably, the degradable block is formed of a degradable polymer selected from the group consisting of polyglycolide, polyglycolic acid, poly-L-lactide, poly-D,L-lactide, poly At least one of hydroxybutyrate, polyε-caprolactone, polyε-alkyl substituted caprolactone, polyδ-valerolactone, polyβ-hydroxybutyrate, polycarbonate or polyetherester;

Alternatively, the degradable polymer is polyglycolide, polyglycolic acid, poly L-lactide, poly D,L-lactide, polyhydroxybutyrate, polyε-caprolactone, polyε - A copolymer of at least two of the monomers of alkyl substituted caprolactone, polydelta-valerolactone, polybeta-hydroxybutyrate, polycarbonate or polyetherester.

Preferably, the molecular weight of the degradable block is 500-20000, and the degree of polymerization of the degradable block is 20-40.

Preferably, the crosslinking functional group is selected from at least one of allyl group, acryloyl group, methacryloyl group, epoxy group, oxazoline group, cyanate group, silanol group or siloxyl group.

Preferably, the non-degradable component is selected from at least one of silicone rubber, polysiloxane, polysilazane or fluoropolymer. Preferably, the thickness of the hydrophobic coating is 0.01-100 μm, more preferably 1-20 μm.

A method for preparing a hydrophobic coating, comprising:

providing a hydrophobic monomer, applying an initiating condition to the hydrophobic monomer, so that the hydrophobic monomer is cross-linked to form the hydrophobic coating;

Alternatively, a mixture of hydrophobic monomers and non-degradable components is provided, triggering conditions are applied to the mixture of hydrophobic monomers and non-degradable components, so that the non-degradable components are cross-linked or the hydrophobic monomers are combined with Cross-linking occurs between the non-degradable components to form the hydrophobic coating.

The triggering condition is ultraviolet light irradiation, heat treatment or moisture action.

The ultraviolet light irradiation includes: after mixing the hydrophobic monomer and the photoinitiator, irradiating with 365nm ultraviolet light for 30min to 2h; the photoinitiator is 2-hydroxyl-2-methyl-1-phenyl-1- Acetone, the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer.

The heat treatment includes: treating the hydrophobic monomer or the mixture of the hydrophobic monomer and the non-degradable component at 20-150°C for 30min-72h;

Moisture action includes: reacting the hydrophobic monomer or the mixture of hydrophobic monomer and non-degradable component in a humid environment for 1-5 days.

The hydrophobic coating is used to delay the degradation behavior of degradable materials.

An absorbable implantable device includes an absorbable base, and the surface of the absorbable base is covered with a hydrophobic coating.

Preferably, the material of the absorbable matrix is a degradable polymer, a corrodible metal or a composite material of a corrodible metal and a degradable polymer.

Preferably, the absorbable implantable device further comprises an adhesive layer located between the absorbable matrix and the hydrophobic coating.

Preferably, the material of the adhesive layer is selected from at least one of dopamine and silane coupling agents.

The absorbable implantable device is a cardiovascular stent, a cerebrovascular stent, a peripheral vascular stent, a biliary stent, an esophageal stent, an airway stent, a urethral stent, an occluder, an orthopedic implant or an absorbable suture.

The hydrophobic coating provided by the present invention is a coating formed by cross-linking between hydrophobic monomers or hydrophobic monomers and non-degradable components. The hydrophobic monomers include degradable blocks, hydrophobic blocks and cross-linking functional groups. When When the hydrophobic coating is covered on the surface of the degradable material (such as a degradable matrix material), the hydrophobic block can make the hydrophobic coating play a good role in water barrier in the early stage, so that the degradable material hardly degrades. In the later stage, the degradable block degrades and its degradation products slowly penetrate the hydrophobic coating, which increases the porosity of the hydrophobic coating, allowing body fluids to contact the degradable matrix material through the pores of the hydrophobic coating. At this time, the degradable matrix Material begins to degrade. Therefore, the hydrophobic coating can delay the degradation of the degradable material.

Description of drawings

Fig. 1 is a schematic cross-sectional view of an absorbable implantable device in one embodiment;

Figure 2 is a schematic cross-sectional view of an absorbable implantable device in another embodiment;

Fig. 3 is the molecular formula of the hydrophobic monomer of embodiment 1;

Fig. 4 is the physical state figure of the hydrophobic monomer of embodiment 1;

Fig. 5 A is the surface contact angle test result figure of the PLA coating of embodiment 1;

Fig. 5 B is the surface contact angle test result figure of the hydrophobic coating of embodiment 1;

Fig. 6 is the iron sheet containing the hydrophobic coating of different thicknesses of embodiment 1 and the corrosion topography figure that only contains the iron sheet of PLA coating;

Fig. 7 is the molecular formula of the hydrophobic monomer of embodiment 2;

Fig. 8 is the physical state figure of the hydrophobic monomer of embodiment 2;

Fig. 9 is the atomic force microscope (AFM) scanning figure of the hydrophobic coating of embodiment 2;

Fig. 10 is the iron sheet containing the hydrophobic coating of different thicknesses of embodiment 2 and the corrosion topography figure of the iron sheet containing only PLA coating;

Fig. 11 is the atomic force microscope (AFM) scanning figure of the hydrophobic coating of embodiment 8;

Fig. 12 is a comparison diagram of the amount of hydrogen released in the corrosion test of the magnesium alloy sheet containing the hydrophobic coating of Example 8, the magnesium alloy sheet containing the hydrophobic coating of Example 8, and the bare magnesium alloy sheet;

13A-13B are diagrams showing the distribution of surface elements of the organopolysilazane of Example 11 at different curing times.

In the figure: 100-absorbable matrix; 200-hydrophobic coating; 300-adhesive layer; 110-outer surface; 120-inner surface; 130-side.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, the specific implementation manners of the present invention will be described in detail below in conjunction with the accompanying drawings. The following description sets forth numerous specific details in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

A hydrophobic coating according to one embodiment, the hydrophobic coating is a cross-linked coating formed by cross-linking hydrophobic monomers. The hydrophobic monomer is a block copolymer comprising hydrophobic blocks, degradable blocks and cross-linking functional groups. Among them, the hydrophobic block, the degradable block and the cross-linking functional group are connected by chemical bonds. Hydrophobic monomers exist in the form of crosslinks. Cross-linking occurs between hydrophobic monomers to form a hydrophobic coating.

The hydrophobic block is formed by a hydrophobic polymer, the degradable block is formed by a degradable polymer, and the hydrophobic polymer and the degradable polymer are polymerized to form a hydrophobic block and a degradable block connected by chemical bonds. The cross-linking functional group is connected with the hydrophobic block and/or the degradable block through a chemical bond to promote the cross-linking of the hydrophobic monomer.

A represents a hydrophobic block, B represents a degradable block, and C represents a crosslinking functional group. In one embodiment, the hydrophobic monomer is C-B-A-B-C or C-A-B-A-C. In another embodiment, the cross-linking functional group C is not necessarily located at the terminal, but can be located at any position of the hydrophobic monomer molecular chain except the terminal.

In one embodiment, the hydrophobic block is made of polydimethylsiloxane, perfluoropolyether, polydifluoroethylene, polytetrafluoroethylene, polyhexafluoropropylene, and polyvinylidene fluoride-hexafluoropropylene copolymer. At least one form.

In one embodiment, the degradable block is formed from a degradable polymer. In one embodiment, the degradable polymer is capable of degrading to produce acidic products. In one embodiment, the degradable polymer is selected from polyglycolide, polyglycolic acid, poly L-lactide, poly D,L-lactide, polyhydroxybutyrate, polyε-caprolactone, At least one of polyε-alkyl substituted caprolactone, polyδ-valerolactone, polyβ-hydroxybutyrate, polycarbonate and polyetherester.

In further embodiments, the degradable polymer is polyglycolide, polyglycolic acid, poly-L-lactide, poly-D,L-lactide, polyhydroxybutyrate, polyε-caprolactone , A copolymer formed of at least two monomers in polyε-alkyl substituted caprolactone, polyδ-valerolactone, polyβ-hydroxybutyrate, polycarbonate and polyether ester.

In one embodiment, the crosslinking functional group is selected from at least one of allyl group, acryloyl group, methacryloyl group, epoxy group, oxazoline group, cyanate group, silanol group and siloxyl group.

In one embodiment, the hydrophobic coating comprises a hydrophobic monomer, and the same hydrophobic monomer is cross-linked to form the hydrophobic coating. In another embodiment, the hydrophobic coating comprises at least two different hydrophobic monomers, and the at least two different hydrophobic monomers are cross-linked with each other to form the hydrophobic coating. Also, the mass ratio of at least two different hydrophobic monomers can be any ratio.

The above-mentioned hydrophobic coating is covered on the surface of the degradable material, for example, when the hydrophobic coating is arranged on the surface of the substrate formed by the degradable material, the hydrophobic block can make the hydrophobic coating play a better role in the early stage. The water barrier effect makes the matrix formed by the degradable material hardly corrode or degrade in the water environment (for example, the blood environment). In the later stage, the degradable block degrades and its degradation products slowly penetrate the hydrophobic coating, which increases the porosity of the hydrophobic coating, allowing body fluids to contact the degradable material through the pores of the hydrophobic coating. At this time, the degradable material start to degrade. Therefore, the hydrophobic coating can delay the degradation of degradable materials.

Moreover, when the degradable block is formed by a degradable polymer capable of degrading to generate acidic products, the degradable block degrades to generate acidic products, which can generate a local slightly acidic environment around the degradable material, further promoting the degradable material. Degradation, accelerating the degradation of degradable materials in the later stage.

In one embodiment, the molecular weight of the degradable block is 500-20000. In another embodiment, the molecular weight of the degradable block is 1440-4080. In one embodiment, the degree of polymerization of the degradable block in the hydrophobic monomer is 20-40. In this way, it is beneficial to control the degradation products of the degradable block in the hydrophobic monomer, thereby further regulating the degradation behavior of the degradable material.

In another embodiment, the hydrophobic coating further comprises a non-degradable component. The non-degradable components are cross-linked to form a cross-linked network, and the hydrophobic monomers are dispersed in the cross-linked network. The non-degradable components are cross-linked to form a cross-linked network, which makes the hydrophobic coating have better hydrophobic properties, which can delay the corrosion or degradation of degradable materials in the early stage, and in the later stage, with the degradation of the degradable block in the hydrophobic monomer , the porosity of the hydrophobic coating is increased, so that the body fluid can contact the degradable matrix material through the pores of the hydrophobic coating, and the degradable matrix material begins to degrade at this time. In this example, no crosslinking occurs between hydrophobic monomers. In another embodiment, the hydrophobic monomers are cross-linked with each other, and the non-degradable components are cross-linked with each other.

Specifically, the non-degradable component is selected from at least one of silicone rubber, polysiloxane, polysilazane and fluoropolymer. In one embodiment, the silicone rubber is Dow Corning 184 silicone rubber, and the polysilazane is organopolysilazane.

In one embodiment, the hydrophobic coating is a coating formed by cross-linking hydrophobic monomers and non-degradable components. The cross-linking between the hydrophobic monomer and the non-degradable component means that the molecular chain of the hydrophobic monomer and the molecular chain of the non-degradable component are cross-linked, but the hydrophobic monomer itself does not cross-link, and the non-degradable component itself does not cross-link. couplet.

In one embodiment, whether it exists in a non-cross-linked form or in a cross-linked form, that is, whether the hydrophobic monomer is dispersed in the non-degradable component to form a cross-linked network to form a hydrophobic coating, or the hydrophobic monomer is combined with For the coating formed by cross-linking of non-degradable components, the mass ratio of hydrophobic monomers to non-degradable components is 1:100-1:0.01.

In one embodiment, the thickness of the hydrophobic coating is 0.01-100 μm. By setting the thickness of the hydrophobic coating reasonably, the degradation behavior of the degradable material can be further regulated, so that the degradation behavior of the degradable material can meet expectations. For example, when the hydrophobic coating is placed on the matrix of the absorbable vascular stent, in the early stage of implantation, the hydrophobic coating can play a water-proof role, thereby delaying the time point when the matrix starts to corrode or initiate degradation, and avoids premature corrosion of the matrix. Therefore, it is ensured that the matrix can maintain sufficient radial support performance during the repair period of the vascular lesion. In the later stage of implantation, when the repair of the lesion is completed, the degradable block degrades to produce acidic degradation products, which can promote the corrosion or degradation of the matrix, so that the metal can be degraded as soon as possible and absorbed by the matrix, which is beneficial to Avoid long-term clinical risks.

In one embodiment, the thickness of the hydrophobic coating is 1-20 μm.

When the degradable block is formed of a degradable polymer capable of degrading to produce acidic products, the above-mentioned hydrophobic coating can regulate the behavior of the degradable material, that is, delay the early degradation of the degradable material and accelerate the later degradation of the degradable material. Therefore, the hydrophobic coating can be applied in fields where the degradation behavior of degradable materials needs to be regulated. For example, the hydrophobic coating finds application in the field of absorbable implantable devices.

The preparation method of the hydrophobic coating of an embodiment, comprises the steps:

Step 110: providing a hydrophobic monomer, which is a block copolymer comprising a hydrophobic block, a degradable block and a cross-linking functional group.

The hydrophobic monomer is the same as above, and will not be repeated here.

In one embodiment, the following method is used to prepare hydrophobic monomers:

Use a polymer containing terminal hydroxyl groups to form a hydrophobic block (that is, A-OH, both ends contain hydroxyl groups, the following expressions represent the same meaning, and will not be described in detail below) as an initiator to synthesize a hydrophobic block containing terminal hydroxyl groups And the polymer of the degradable block (ie B-A-B-OH), and then use acryloyl chloride to react with the terminal hydroxyl group of the polymer containing the hydrophobic block and the degradable block at the end to obtain the hydrophobic monomer containing the acryloyl group at the end . The hydrophobic monomer synthesized by this method is C-B-A-B-C, and C is an acryloyl group.

For example, the hydrophobic block-forming polymer containing terminal hydroxyl groups is PDMS ₇₆ -OH, using PDMS ₇₆ -OH as an initiator to synthesize PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -OH, and then using acryloyl chloride and PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -OH reacts to generate PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA, which is a hydrophobic monomer. Among them, DA represents that the two ends of the molecular chain of the hydrophobic monomer are acryloyl groups, and PDMS ₇₆ represents the existing form (ie, hydrophobic block) in the hydrophobic monomer after PDMS ₇₆ participates in the reaction. For convenience, PDMS is still used to represent the participation of PDMS. The PDMS block formed after the reaction. The expressions below are all the same, and will not be repeated here.

In a specific embodiment, the polymer (HO-B-A-B-OH) containing a hydroxyl group at the end comprising a hydrophobic block and a degradable block is synthesized according to the literature G.M.Zentner, R.Rathi, C.Shih, J.C.McRea, M.H. Seo, H.Oh, B.G.Rhee, J.Mestecky, Z.Moldoveanu, M.Morgan, S.Weitman, Biodegradable blockcopolymers for delivery of proteins and water-insoluble drugs, J.Control.Release 72(2001)203-215 synthetic method. The specific method for the reaction of acryloyl chloride with terminal hydroxyl groups of polymers containing hydrophobic blocks and degradable blocks is based on the literature Z.S.Ge, Y.M.Zhou, J.Xu, H.W.Liu, D.Y.Chen, S.Y.Liu, High-Efficiency Preparation of Macrocyclic Diblock Copolymers via Selective Click Reaction in Micellar Media, J.Am.Chem.Soc.131 (2009) 1628-1629 method.

In another embodiment, a polymer containing a terminal hydroxyl group forming a degradable block (i.e. B-OH) is used as an initiator to synthesize a polymer containing a terminal hydroxyl group comprising a degradable block and a hydrophobic block (i.e. HO -A-B-A-OH), and then use acryloyl chloride to react with the terminal hydroxyl group of the polymer containing a degradable block and a hydrophobic block at the end to obtain a hydrophobic monomer. The hydrophobic monomer synthesized by this method is C-A-B-A-C, wherein, C is an acryloyl group.

In other embodiments, when C is another cross-linking functional group, the corresponding compound is used to react (HO-A-B-A-OH) or Reaction with the terminal hydroxyl group of a polymer containing a hydrophobic block and a degradable block containing a hydroxyl group (HO-B-A-B-OH), for example, using epichlorohydrin with a hydroxyl group containing a degradable block and a hydrophobic block at the end The terminal hydroxyl group of the segmented polymer reacts to generate a hydrophobic monomer whose cross-linking functional group is an epoxy group. Using triethoxysilylpropyl isocyanate to react with the terminal hydroxyl group of a polymer containing a degradable block and a hydrophobic block at the end to generate a hydrophobic monomer whose crosslinking functional group is a siloxane group.

In another embodiment, when the cross-linking functional group C can be located at any position of the hydrophobic monomer molecular chain except the end, references T.Wang, M.Yan, X.Sun, D.Quan, Polymer 57 ( 2015) 21-28 to synthesize hydrophobic monomers.

In one embodiment, the hydrophobic monomer is dissolved in a solvent to prepare a solution containing the hydrophobic monomer. The solution is applied to the surface of a substrate formed of a degradable material to form an uncrosslinked coating on the surface of the substrate. The solvent is a solvent capable of dissolving the hydrophobic monomer, such as ethyl acetate, acetone, acetonitrile and the like. The coating method is any method mastered by those skilled in the art, such as ultrasonic spray coating, spin coating, dip coating or drop coating and the like.

It should be noted that, in one embodiment, one hydrophobic monomer is dissolved in a solvent to prepare a solution containing only one hydrophobic monomer. In another embodiment, at least two different hydrophobic monomers can be dissolved in a solvent to prepare a solution containing at least two different hydrophobic monomers, and the at least two different hydrophobic monomers can be any formulation Compare.

Step 120: Applying triggering conditions to the hydrophobic monomers to cross-link the hydrophobic monomers to form a hydrophobic coating.

Initiating conditions are applied to the uncrosslinked coating on the surface of the substrate, that is, the initiating conditions are applied to the hydrophobic monomers, so that the hydrophobic monomers are crosslinked to form an elastic, rubbery hydrophobic coating.

In one embodiment, the triggering condition is ultraviolet light irradiation, heat treatment or moisture action.

In one embodiment, the method for initiating crosslinking by ultraviolet light irradiation includes: after mixing the hydrophobic monomer and the photoinitiator, irradiating with 365nm ultraviolet light for 30 minutes to 2 hours. Specifically, after dissolving the hydrophobic monomer in a solvent and preparing a solution containing the hydrophobic monomer, before performing crosslinking, adding a photoinitiator to the solution containing the hydrophobic monomer, and after mixing evenly, coating on the The surface of the substrate formed by the degradable material is then irradiated with 365nm ultraviolet light for 30 minutes to 2 hours, so that the hydrophobic monomers are cross-linked with each other to form a hydrophobic coating.

In one embodiment, the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone. It can be understood that in other embodiments, other photoinitiators capable of initiating crosslinking of hydrophobic monomers under the action of ultraviolet light can be used. Irradiate under ultraviolet light with an intensity of 5000-15000μW/ ^cm2 for 30min-2h, the amount of photoinitiator should be enough to fully cross-link the hydrophobic monomer to form an elastic, rubbery hydrophobic coating, so that the hydrophobic coating Layers have sufficient strength. In one embodiment, the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer.

In one embodiment, the method for initiating crosslinking by heat treatment includes: treating the hydrophobic monomer at 20-150° C. for 30 minutes-72 hours. That is, apply a solution containing hydrophobic monomers on the surface of the substrate, and after forming an uncrosslinked coating on the surface of the substrate, treat it at 20-150°C for 30 minutes to 72 hours to cross-link the hydrophobic monomers on the surface of the substrate Instead, a hydrophobic coating covering the surface of the substrate is formed.

In one embodiment, the step of initiating crosslinking by moisture includes: reacting the hydrophobic monomer in a humid environment for 1-5 days. Wherein, the humid environment is an air environment or an atmosphere with a certain humidity.

In one embodiment, when the hydrophobic coating contains non-degradable components, heat treatment is used to cross-link the non-degradable components. The method for initiating cross-linking of non-degradable components by heat treatment includes: dissolving hydrophobic monomers in a solvent, preparing a solution containing hydrophobic monomers, adding non-degradable components to the solution containing hydrophobic monomers, mixing evenly, coating Cover the surface of the matrix formed by degradable materials, and then treat it at 20-150°C for 30min-72h, so that the non-degradable components are cross-linked with each other to form a cross-linked network, and the hydrophobic monomer is dispersed in the cross-linked network , resulting in a hydrophobic coating.

In one embodiment, when the hydrophobic coating contains non-degradable components, the non-degradable components are cross-linked by the action of moisture. The step of initiating crosslinking by the action of moisture includes: dissolving the hydrophobic monomer in a solvent, preparing a solution containing the hydrophobic monomer, adding non-degradable components to the solution containing the hydrophobic monomer, mixing evenly, and coating on The degradable material is placed on the surface of the matrix, and then placed in a humid environment for 2 to 5 days to react, so that the non-degradable components are cross-linked to form a cross-linked network, and the hydrophobic monomer is dispersed in the cross-linked network. Wherein, the humid environment is an air environment or an atmosphere with a certain humidity.

It should be noted that when the hydrophobic coating contains hydrophobic monomers and non-degradable components, the non-degradable components can be made Cross-linking between components and hydrophobic monomers, or only cross-linking between non-degradable components, and no cross-linking between hydrophobic monomers.

The preparation method of the above-mentioned hydrophobic coating has a simple process and low equipment requirements, and can directly form a hydrophobic coating on the substrate that needs to be regulated for degradation behavior, and complete it in one step. Compared with preparing the hydrophobic coating first, and then combining the hydrophobic coating with the required The regulated degradable substrate binding method has high efficiency.

Further, an absorbable implantable device is provided. Please refer to FIG. 1 , an absorbable implantable device according to an embodiment includes an absorbable matrix 100 and a hydrophobic coating 200 disposed on the surface of the absorbable matrix 100 .

Wherein, the absorbable matrix 100 is formed of a bioabsorbable material (that is, a degradable material). In one embodiment, the material of the absorbable matrix 100 is a degradable polymer, a corrodible metal, or a composite material of a corrodible metal and a degradable polymer.

In one embodiment, the degradable polymer is selected from at least one of degradable polyester and degradable polyanhydride. Wherein, the degradable polyester is selected from polyglycolide, polyglycolic acid, poly L-lactide, poly D, L-lactide, polyhydroxybutyrate, polyε-caprolactone, polyε-alkane At least one of caprolactone, poly δ-valerolactone, poly β-hydroxybutyrate, polycarbonate and polyether ester is substituted with radicals. The degradable polyanhydride is at least one selected from poly-1,3-bis(p-carboxyphenoxy)propane-sebacic acid, polyerucic acid dimer-sebacic acid and polyfumaric acid-sebacic acid.

In another embodiment, the degradable polymer is a copolymer formed by copolymerization of at least two of the aforementioned degradable polyester and degradable polyanhydride monomers.

Corrosionable metals refer to corrodible pure metals or corrodible alloys. In one embodiment, the corrodible metal is pure iron, iron-based alloy, pure magnesium, magnesium-based alloy, pure zinc or zinc-based alloy. In one embodiment, the corrodible metal is treated corrodible metal, for example, the corrodible metal is nitrided pure iron.

In one embodiment, the corrodible metal and degradable polymer composite material refers to a material that is blended with a corrodible metal and a degradable polymer and then pressed into shape. The press-formed material is further processed to form the absorbable matrix 100 .

In another embodiment, the corrodible metal and degradable polymer composite material refers to a material in which corrodible metal and degradable polymer are combined in a layered structure. For example, the substrate is formed of corrodible metal, and the degradable polymer is attached to the surface of the substrate in the form of a coating or a film to form the absorbable substrate 100 . Alternatively, the matrix is formed of a degradable polymer, and the corrodible metal is attached to the surface of the matrix in the form of a coating or a film to form the absorbable matrix 100 .

In one embodiment, the corrodible metal is pure iron or iron alloy, the degradable polymer is selected from at least one of degradable polyester and degradable polyanhydride, and the degradable polymer is in the form of a coating or a film The form is attached to the surface of the iron matrix to form an absorbable matrix 100 . The hydrophobic coating 200 covers the degradable polymer coating. During the early stages of implantation, the hydrophobic coating 200 protects the absorbable matrix 100 from degradation. When the degradable block in the hydrophobic coating 200 degrades to form pores, the degradable polymer in the absorbable matrix 100 begins to degrade, and the acidic degradation products produced by the degradation of the degradable block in the hydrophobic coating 200 and the absorbable matrix 100 The acidic degradation products produced by the degradable polymer can accelerate the corrosion of the iron matrix, so as to control the early corrosion of absorbable medical devices and accelerate the corrosion in the later stage.

Referring again to FIG. 1 , the absorbable matrix 100 has an outer surface 110 , an inner surface 120 and side surfaces 130 . Wherein, when the absorbable implantable device is implanted into the lesion, for example, when the absorbable implantable device is implanted into a blood vessel, the outer surface 110 is the surface in contact with the blood vessel wall, and the inner surface 120 is the surface in direct contact with the blood . The outer surface 110 is opposite to the inner surface 120 , and the side surface 130 connects the outer surface 110 and the inner surface 120 . When the absorbable implantable device is implanted in other non-vascular diseased sites, the inner surface 120 is the surface that directly contacts the body fluid at the implanted site. The hydrophobic coating 200 covers at least the inner surface 120 of the absorbable matrix 100. In the early stage after implantation, the hydrophobic coating 200 can better isolate the inner surface 120 of the absorbable matrix 100 from body fluids, so as to prevent the premature absorption of the absorbable matrix 100. Initiate corrosion or prematurely initiate degradation.

As shown in FIG. 1 , in one embodiment, the hydrophobic coating 200 completely covers all surfaces of the absorbable substrate 100 , that is, the outer surface 110 , the inner surface 120 and the side surfaces 130 of the absorbable substrate 100 are completely covered by the hydrophobic coating 200 covered by. In this way, on the one hand, the hydrophobic coating 200 is a complete and continuous coating, which helps to prevent the hydrophobic coating 200 from falling off during the expansion of the absorbable matrix 100 after implantation; on the other hand, the hydrophobic coating 200 is completely Covering the entire surface of the absorbable matrix 100 is beneficial to better protect the absorbable matrix 100 in the early stage after implantation, and promote uniform corrosion or uniform degradation of the absorbable matrix 100 in the later stage.

In another embodiment, the hydrophobic coating 200 only covers the inner surface 120 of the absorbable substrate 100 , and there is no distribution of the hydrophobic coating 200 on both the outer surface 110 and the side surface 130 of the absorbable substrate 100 . In other embodiments, the hydrophobic coating 200 covers both the outer surface 110 and the inner surface 120 of the absorbable substrate 100 . Alternatively, the hydrophobic coating 200 covers both the inner surface 120 and the side surfaces 130 of the absorbable substrate 100 . Setting the hydrophobic coating 200 in this way can also delay the initiation of corrosion or degradation of the absorbable matrix 100 in the early stage of implantation, and the degradation of the degradable block in the hydrophobic coating 200 in the later stage The generation of acidic products promotes rapid corrosion or rapid degradation of the absorbable matrix 100 .

The material of the hydrophobic coating 200 is the same as that described above, and will not be repeated here. It should be noted that when the degradable blocks in the hydrophobic coating 200 are degraded to produce acidic products, in the later stage of implantation, as the degradable blocks continue to degrade, acidic products are continuously produced, and the acidic products can be removed from the The hydrophobic coating 200 permeates to the exterior of the absorbable implantable device, thereby creating a lower pH environment at the implantation site of the absorbable implantable device, thereby further promoting rapid corrosion or degradation of the absorbable matrix 100 . The hydrophobic coating 200 can not only delay the initiation of corrosion or degradation of the absorbable matrix 100, but also continuously regulate the degradation behavior of the absorbable matrix 100 from the early stage to the late stage after implantation. That is, the hydrophobic coating 200 delays the time point at which the absorbable matrix 100 starts to corrode or initiates degradation in the early stage after implantation, and prevents the absorbable matrix 100 from prematurely initiating corrosion or initiating degradation, so that before the repair of the lesion is completed, avoid Absorbable matrix 100 loses mechanical support properties prematurely. After the repair of the lesion is completed, the acidic products continuously produced by the degradable block can promote the rapid corrosion or rapid degradation of the absorbable matrix 100, which is beneficial to avoid the occurrence of long-term clinical risks.

By providing a hydrophobic coating 200 with a thickness of only 0.01-100 μm on the surface of the absorbable matrix 100, the degradation behavior of the absorbable matrix 100 from the early stage after implantation to the late stage after implantation can be regulated, so that the absorbable matrix 100 ( The degradation rate of the degradable material) can be well matched with the mechanical properties and the time required for implant site repair, so that the absorbable implantable device can meet the requirements of early support and later rapid corrosion or degradation.

It should be noted that, when the thickness of the hydrophobic coating 200 is less than 0.01 μm, the hydrophobic coating 200 will be degraded prematurely, resulting in an insignificant effect of delaying the time point at which the absorbable matrix 100 starts to corrode or starts to degrade; When the thickness of the layer 200 is greater than 100 μm, it may adversely affect the adherence of the absorbable implantable device to a certain extent, and may also increase the sheathing resistance of the absorbable implantable device and cause difficulty in delivery. Therefore, in one embodiment, the thickness of the hydrophobic coating 200 is 0.01-100 μm. The hydrophobic coating 200 with a thickness of only 0.01-100 μm can regulate the degradation behavior of the absorbable matrix 100 from the early post-implantation to the late post-implantation, and the thickness of the hydrophobic coating 200 within the range of 0.01-100 μm will not Significantly increasing the radial dimension of the absorbable implantable device after compression, thus not significantly increasing the sheathing resistance of the absorbable implantable device, nor causing difficulty in delivery.

Integrating the early water-repelling effect, the later promoting degradation or corrosion, the smoothness of delivery, and the adherence after implantation, in one embodiment, the thickness of the hydrophobic coating 200 is 1-20 μm.

In one embodiment, please refer to FIG. 2 , the absorbable implantable device further includes an adhesive layer 300 . The adhesive layer 300 is located between the absorbable substrate 100 and the hydrophobic coating 200 . The adhesive layer 300 is provided to improve the binding force between the hydrophobic coating 200 and the absorbable matrix 100, so that the hydrophobic coating 200 can be more reliably attached to the surface of the absorbable matrix 100, which is beneficial to avoid The hydrophobic coating 200 falls off during the expansion process of the implantable device, thereby improving the reliability of the absorbable implantable device.

In one embodiment, the material of the adhesive layer 300 is selected from at least one of dopamine and silane coupling agent. In another embodiment, the material of the adhesive layer 300 is not limited to dopamine and silane coupling agent, and any material with adhesive properties and good biocompatibility can be used in the adhesive layer 300 .

It can be understood that the distribution of the adhesive layer 300 on the surface of the absorbable matrix 100 is the same as the distribution of the hydrophobic coating 200 on the surface of the absorbable matrix 100 .

The above-mentioned absorbable implantable devices are any implantable devices that need to meet the requirements of early support and later rapid corrosion or degradation. For example, absorbable implantable devices are cardiovascular stents, cerebrovascular stents, peripheral vascular stents, biliary stents, esophageal stents, airway stents, urethral stents, occluders, orthopedic implants, or absorbable sutures, etc.

The preparation method of the above-mentioned absorbable implantable device is as follows: after preparing the absorbable matrix 100 according to the methods mastered by those skilled in the art, the hydrophobic coating 200 is formed on the absorbable matrix 100 by the same method as the above-mentioned method for preparing the hydrophobic coating, that is, The solution containing the hydrophobic monomer is coated on the surface of the absorbable matrix 100 by means of ultrasonic spraying, spin coating, dipping or drop coating, and then the absorbable matrix 100 is cross-linked by ultraviolet light irradiation, heat treatment or moisture action. The hydrophobic monomers and/or non-degradable components on the surface of the absorbent matrix 100 are cross-linked to form a hydrophobic coating 200 on the surface of the absorbent matrix 100 .

It can be understood that when the absorbable implantable device further includes the adhesive layer 300 , the adhesive layer 300 is prepared on the absorbable base 100 first, and then the hydrophobic coating 200 covering the adhesive layer 300 is prepared. The adhesive layer 300 can be prepared by methods mastered by those skilled in the art, such as ultrasonic spray coating, spin coating, dip coating or drop coating. In one embodiment, before preparing the adhesive layer 300 , a step of surface treatment of the absorbable base 100 is further included, so that the adhesive layer 300 can be more reliably disposed on the surface of the absorbable base 100 . For example, oxygen plasma treatment is performed on the surface of the absorbable matrix 100 to form hydroxyl groups on the surface of the absorbable matrix 100 , so that the hydroxyl groups react chemically with the silane coupling agent to form the adhesive layer 300 .

The above-mentioned hydrophobic coatings and absorbable implantable devices are further described with specific examples below. The components of the hydrophobic coatings in Examples 1-19 are shown in Table 1.

Embodiment 20～embodiment 24 and comparative example 1～comparative example 4 adopt following test method:

In vivo sample metal weight loss measurement method: the absorbable implantable device is implanted in the animal body for a period of time, and then the animal is sacrificed, and the absorbable implantable device is taken out. Micro-CT with a resolution of 5 μm was used for high-resolution scanning, and the results were processed to calculate the volume of undegraded metal, so as to calculate weight loss=1-volume of undegraded metal/initial metal volume.

Table 1 Embodiment 1-19 hydrophobic coating components

Example 1

Cut a pure iron sheet with a thickness of 200 μm (purity >99.9%) into 22mm×26mm, polish it with 800, 1500, 2000, and 3000 mesh sandpaper in sequence, and put the polished iron sheet in acetone and absolute ethanol for ultrasonic cleaning in sequence 10min, then dry the surface of the iron sheet with nitrogen, and place the iron sheet in an oven at 60°C to fully dry.

Dissolve polylactic acid (PLA) with a molecular weight of 60,000 in ethyl acetate to prepare a polylactic acid solution with a concentration of 0.01 g/mL. The polylactic acid solution was sprayed on the surface of the treated iron sheet by an ultrasonic spraying method to prepare an iron sheet with a PLA coating on the surface with a thickness of 4 μm. During the spraying process, the flow rate of the pump liquid is 0.1mL/min, and the ultrasonic power is 5.0W. Place the PLA-coated iron sheet in a fume hood to fully evaporate the ethyl acetate solvent.

With reference to the method in the above-mentioned literature, first synthesize the PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -OH with two hydroxyl groups at the end with the polydimethylsiloxane (PDMS ₇₆ -OH) containing two alkyl hydroxyl groups at the end as the initiator, and then refer to the literature The method in the method uses acryloyl chloride to react with terminal hydroxyl groups to obtain acryloyl-terminated polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate, that is, PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA. The structural formula and physical state of PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA are shown in Figures 3 and 4, respectively.

Macromonomer PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA (i.e. hydrophobic monomer) is dissolved in ethyl acetate, and preparation concentration is the solution containing hydrophobic monomer of 0.02g/mL; A photoinitiator 2-hydroxyl-2-methyl-1-phenyl-1-propanone is added to the solution to obtain a mixed solution, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. The above-mentioned mixed solution was sprayed on the PLA-coated surface of the above-mentioned PLA-coated iron sheet by an ultrasonic spraying method. During the spraying process, the flow rate of the pump liquid was 0.1 mL/min, and the ultrasonic power was 4.75 W. By controlling the number of spraying, samples with different thicknesses of uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA coatings on the surface were prepared.

The above-mentioned uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA coating was irradiated with ultraviolet light at 365 nm and an intensity of 8000 μW/cm ² for 1 h to react the acryloyl group at the end of PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA, Thus cross-linking the hydrophobic monomers. After ultraviolet light, it can be clearly observed that the PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA coating has changed from a weak coating to a rubbery coating with certain elasticity, that is, formed on the surface of the PLA coating of the iron sheet. Hydrophobic coating. The water contact angle test was carried out on the surface of the PLA coating and the hydrophobic coating. The results are shown in Figure 5A and Figure 5B, respectively. The contact angle of the PLA coating is 100°, and the contact angle of the hydrophobic coating is 114°. Therefore, the hydrophobic coating is more hydrophobic than the PLA coating. The thickness of the hydrophobic coatings was characterized by a scanning electron microscope, and the thicknesses of the hydrophobic coatings were 0.5 μm, 1.0 μm and 1.5 μm, respectively.

Use 704 silica gel to seal the edge of the iron sheet with only PLA coating on the surface and the iron sheet with both PLA coating and hydrophobic coating on the surface, so that only the coated side is exposed to the outside. After the 704 silica gel is completely cured, put the edge-sealed sample in Hank’s solution, and conduct a corrosion test in a water-bath shaker (50rpm, 37°C). Take pictures of the sample every week to observe the corrosion situation. The results are shown in Figure 6. Among them, 0 μm represents the iron sheet with only PLA coating on the surface, 0.5 μm, 1.0 μm and 1.5 μm represent the iron sheet with both PLA coating and hydrophobic coating on the surface, and the thickness of the hydrophobic coating is respectively 0.5μm, 1.0μm and 1.5μm. It can be seen intuitively from Figure 6 that the hydrophobic coating can inhibit the corrosion of early iron and PLA coating composites, and as the thickness of the hydrophobic coating increases, the time for which the iron corrosion is inhibited is prolonged. When the thickness of the hydrophobic coating is 1.5 μm, the iron sheet has only very slight corrosion after soaking for 28 days.

Example 2

Iron sheets of the same specifications were processed in the same manner as in Example 1 and PLA coatings of the same thickness were prepared on the surface of the iron sheets.

Polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromer (i.e. hydrophobic monomer) synthesized by the same method as in Example 1, PLA The structural formula and physical state of ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA are shown in Figure 7 and Figure 8, respectively.

Dissolve PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA in ethyl acetate to prepare a hydrophobic monomer solution with a concentration of 0.02 g/mL; add photoinitiator 2-hydroxyl-2- Methyl-1-phenyl-1-propanone is used to obtain a mixed liquid, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. The above mixed solution was sprayed onto the PLA-coated surface of the PLA-coated iron sheet by the ultrasonic spraying method. During the spraying process, the flow rate of the pump liquid was 0.1ml/min, and the ultrasonic power was 4.50W. Spray once and twice, respectively, to form two different thicknesses of uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coatings on the PLA coatings of different iron sheets.

The above-mentioned uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating was irradiated with ultraviolet light at 365 nm and an intensity of 8000 μW/cm ² for 1 h, so that the acryloyl group at the end of PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA reacted, Thus cross-linking the hydrophobic monomers. It can be observed that after ultraviolet light, the coating changes from the original sticky state to a smooth rubbery state with a certain degree of toughness, that is, a hydrophobic coating is formed on the surface of the PLA coating on the iron sheet. Scanning the surface of the cross-linked coating with an atomic force microscope, it can be seen that the PLA block (degradable block) and the non-degradable PDMS block (hydrophobic block) have phase-separated, and the PLA phase is dispersed in the PDMS phase. , as shown in Figure 9. The thicknesses of the two hydrophobic coatings were 0.5 μm and 1 μm, respectively, as characterized by scanning electron microscopy.

Use 704 silica gel to seal the edge of the iron sheet with only PLA coating on the surface and the iron sheet with both PLA coating and hydrophobic coating on the surface, so that only the coated side is exposed. After the 704 silica gel is solidified, put the iron sheet in a 6-well culture plate, add 5mL Hank's solution to each well, and then put the culture plate in a water bath shaker (50rpm, 37°C) for corrosion experiments, and replace the Hank's solution every 24 hours . After the corrosion experiment was carried out for 1 day, 2 days, 3 days and 5 days, the iron sheets with different coatings were photographed and observed. The results are shown in Figure 10, where 0 μm represents the iron sheet with only PLA coating on the surface, 0.5 μm and 1.0 μm represent the iron sheet with both PLA coating and hydrophobic coating on the surface, and the thickness of the hydrophobic coating is 0.5 μm respectively and 1.0 μm. It can be seen from Figure 10 that the hydrophobic coating significantly inhibited the corrosion of the iron sheet under the PLA coating when it was degraded for 3 days. On the 5th day, the iron sheet with the hydrophobic coating also experienced obvious corrosion, but the corrosion degree was still lower than that without Hydrophobic coated, PLA coated iron sheet only.

Example 3

Iron sheets of the same specifications were processed in the same manner as in Example 1 and PLA coatings of the same thickness were prepared on the surface of the iron sheets.

With reference to the method in the above-mentioned literature, the polydimethylsiloxane (PDMS ₇₆ -OH) containing two alkyl hydroxyl groups at the end is used as an initiator to react with 2-methyl, 2-methyl acrylate group-dimethyl carbonate Synthesize HO-Ac-PDMS ₇₆ -Ac-OH with functional groups at the end; then use HO-Ac-PTMC ₁₀ -Ac-OH as an initiator to react with trimethylene carbonate to obtain propylene in the molecular chain side group Acyloxy polytrimethylene carbonate-Ac-polydimethylsiloxane-Ac-polytrimethylene carbonate (PTMC ₂₀ -Ac-PDMS ₇₆ -Ac-PTMC ₂₀ ) macromers (i.e. hydrophobic monomer).

Dissolve PTMC ₂₀ -Ac-PDMS ₇₆ -Ac-PTMC ₂₀ in ethyl acetate, prepare a solution containing a hydrophobic monomer with a concentration of 0.02g/mL; add photoinitiator 2- Hydroxy-2-methyl-1-phenyl-1-propanone is used to obtain a mixed solution, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. The above mixed solution was sprayed onto the PLA-coated surface of the PLA-coated iron sheet by an ultrasonic spraying method to obtain an uncrosslinked PTMC ₂₀ -Ac-PDMS ₇₆ -Ac-PTMC ₂₀ coating.

Irradiate the above-mentioned uncrosslinked PTMC ₂₀ -Ac-PDMS ₇₆ -Ac-PTMC ₂₀ coating with 365nm ultraviolet light with an intensity of 10000μW/cm ² for 2h, so that Ac in PTMC ₂₀ -Ac-PDMS ₇₆ -Ac-PTMC ₂₀ The double bonds of the pendant groups react, thereby cross-linking the hydrophobic monomers with each other. It can be observed that after ultraviolet light, the coating changes from the original sticky state to a smooth rubbery state with a certain degree of toughness, that is, a hydrophobic coating is formed on the surface of the PLA coating on the iron sheet. The thickness of the hydrophobic coating was 5 μm as characterized by scanning electron microscopy.

Use 704 silica gel to seal the edge of the iron sheet with only PLA coating on the surface and the iron sheet with both PLA coating and hydrophobic coating on the surface, so that only the coated side is exposed. After the 704 silica gel is solidified, put the iron sheet in a 6-well culture plate, add 5mL Hank's solution to each well, and then put the culture plate in a water bath shaker (50rpm, 37°C) for 28 days of corrosion experiment, Hank's solution every 24 Replace every hour. The samples were photographed every 7 days to record the corrosion situation. The results showed that after 7 days of immersion, severe corrosion had occurred on the surface of the iron sheet containing only the PLA coating. However, when there is a hydrophobic coating on the outside of the PLA coating, there is still almost no corrosion on the surface of the iron sheet after immersion for 28 days, showing a metallic luster.

Example 4

Iron sheets of relevant specifications were processed in the same manner as in Example 1 and PLA coatings of the same thickness were prepared on the surface of the iron sheets.

Synthesize the polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate (PTMC ₁₅ -PDMS ₇₆ -PTMC ₁₅ -DA) macromer of acryl terminated by the same method as in Example 1 (i.e. hydrophobic monomer).

Prepare the PTMC ₁₅ -PDMS ₇₆ -PTMC ₁₅ -DA with a concentration of 0.02g/mL and the Dow Corning 184 silicone rubber precursor with a concentration of 0.02g/mL (in Dow Corning 184 silicone rubber, the mass ratio of the basic component to the crosslinking agent is 10:1) ethyl acetate solution, the two solutions were blended at a volume ratio of 1:5 to obtain a mixed solution, and the mixed solution was sprayed onto the PLA coating surface of the iron sheet by ultrasonic spraying. Place in a fume hood for 12 hours to continue to volatilize ethyl acetate, and then place in an oven at 60°C for 12 hours to cross-link the silicone rubber precursor to form a hydrophobic coating. The results of characterization under scanning electron microscope showed that the thickness of the hydrophobic coating was 2.5 μm.

Use 704 silica gel to seal the edge of the iron sheet with only PLA coating on the surface and the iron sheet with both PLA coating and hydrophobic coating on the surface, so that only the coated side is exposed. Put the iron sheet in a 6-well culture plate, add 5mL Hank’s solution to each well, then place the culture plate in a water bath shaker (50rpm, 37°C) for 28 days of corrosion experiment, and replace Hank’s solution every 24 hours. The samples were photographed every 7 days to record the corrosion condition. The results showed that after 7 days of immersion, severe corrosion had occurred on the surface of the iron sheet containing only the PLA coating. However, when there is a hydrophobic coating on the outside of the PLA coating, there is still almost no corrosion on the surface of the iron sheet after immersion for 21 days, showing a metallic luster, and the surface of the iron sheet begins to darken on the 28th day, showing signs of corrosion.

Example 5

Iron sheets of the same specifications were processed in the same manner as in Example 1 and PLA coatings of the same thickness were prepared on the surface of the iron sheets.

The iron sheet with PLA coating on the surface was treated under oxygen plasma, the gas pressure was 50Pa, the plasma power was 100W, and the treatment time was 30min. Draw 50 μL of KH-570 silanized coupling agent with a 100 μL pipette gun, put the tip containing KH-570 inside and the iron sheet with PLA coating on the surface after plasma treatment into the desiccator, and vacuumize , placed for 12 hours, the KH-570 is volatilized and adsorbed on the surface of the PLA coating, and a KH-570 layer is formed on the PLA coating.

Acryloyl-terminated poly(lactic acid)-polydimethylsiloxane-poly(lactic acid) (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromers (ie, hydrophobic monomers) were synthesized in the same manner as in Example 1.

Dissolve PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA in ethyl acetate to prepare a solution containing a hydrophobic monomer at a concentration of 0.02 g/mL, and add the photoinitiator 2-hydroxy-2-methyl-1-benzene base-1-acetone to obtain a mixed solution, wherein the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer. The mixed solution is sprayed on the PLA coating surface of the iron sheet treated with silanized coupling agent and the PLA coated surface of iron sheet not treated with silanized coupling agent by ultrasonic spraying method, and the ultrasonic spray head is along the x-axis The moving speed is 15mm/s, the step length moving along the y-axis direction is 2mm, the flow rate of the pump liquid is 0.1mL/min, and the ultrasonic power is 4.5W. Repeat the spraying five times according to these parameters. A coating of uncross-linked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA was formed on it.

The uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating was irradiated with ultraviolet light at 365 nm and an intensity of 8000 μW/cm ² for 1 hour, so that the terminal acryloyl group of PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA crossed. to form a hydrophobic coating. After exposure to light, it can be found that the coating has changed from the original sticky state to a rubbery coating with a certain degree of elasticity and toughness. The thickness of the hydrophobic coating is 3 μm, characterized by scanning electron microscopy.

Use 704 silica gel to seal the edge of the iron sheet with only PLA coating on the surface and the iron sheet with both PLA coating and hydrophobic coating on the surface, so that only the coated side is exposed. After the 704 silica gel is solidified, put each iron piece in a glass dish containing 50mL Hank’s solution, and place it in a water bath shaker (50rpm, 37°C) for corrosion experiments, and replace Hank’s solution every 24 hours. On the 0th day, 1st day, 3rd day, 5th day and 7th day of immersion, the iron sheets with different coatings on the surface were photographed to observe the corrosion situation. The results show that the iron sheet with only PLA coating has been severely corroded on the third day, and the surface of the entire iron sheet is black and green, while the iron sheet with a hydrophobic coating with a thickness of 3 μm on the surface has a corrosion effect on the surface of the iron sheet on the seventh day. Corrosion occurs only at individual sites.

Use tweezers to scrape the hydrophobic coating, compare the adhesion between the hydrophobic coating and the substrate of the sample treated with KH-570 and the sample without KH-570, and find that the sample treated with KH-570 is more difficult to scrape off . It shows that after treatment with KH-570, the binding force between the hydrophobic coating and the PLA coating is improved to a certain extent.

Example 6

The same method as in Example 1 is used to process iron sheets of the same specifications, and drip-coating 200 μL of PLA ( _Mw : 60kDa) ethyl acetate solution with a concentration of 0.02g/mL on each iron sheet, and place it in a fume hood for use. After the ethyl acetate was completely volatilized, a PLA coating with a thickness of 4 μm was formed on the surface of the iron sheet.

Acryloyl-terminated poly(lactic acid)-polydimethylsiloxane-poly(lactic acid) (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromers (ie, hydrophobic monomers) were synthesized in the same manner as in Example 1.

Dissolve PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA in ethyl acetate to prepare a solution containing a hydrophobic monomer at a concentration of 0.2 g/mL, and add the photoinitiator 2-hydroxy-2-methyl-1-benzene base-1-acetone to obtain a mixed solution, wherein the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer; at a low speed (1500r/min) rapidly (8s) 4 to 5 drops of the mixed solution are added dropwise to On the surface of the PLA coating of the iron sheet, and rotate at a speed of 3000r/min for 25s to complete the preparation of the coating, that is, to form uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ on the surface of the PLA coating of the iron sheet -DA coating.

The uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating was irradiated with ultraviolet light at 365 nm and an intensity of 8000 μW/cm ² for 1 hour, so that the terminal acryloyl group of PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA crossed. to form a hydrophobic coating. After light exposure, it can be observed that the PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating has changed from the original sticky state to a smooth rubbery state with a certain degree of toughness. Characterized by scanning electron microscope, the thickness of the hydrophobic coating was 5 μm.

Use 704 silica gel to seal the edge of the iron sheet with only PLA coating on the surface and the iron sheet with both PLA coating and hydrophobic coating on the surface, so that only the coated side is exposed. Put the iron sheet in a 6-well culture plate, add 10mL Hank’s solution to each well, then put the culture plate in a water bath shaker (50rpm, 37°C) for 14 days of corrosion experiment, and replace Hank’s solution every 24 hours. After soaking for 1 day, 3 days, 5 days, 7 days, and 14 days, the samples were photographed to record the corrosion conditions. The results showed that obvious corrosion had occurred on the surface of the iron sheet containing only the PLA coating after soaking for 1 day. However, when there is a hydrophobic coating with a thickness of 5 μm on the PLA coating, the surface of the iron sheet still has almost no corrosion after 7 days of immersion, showing a metallic luster, and individual corrosion sites appear on the surface of the iron sheet on the 28th day.

Example 7

Iron sheets of the same specifications were processed in the same manner as in Example 1 and PLA coatings of the same thickness were prepared on the surface of the iron sheets.

Synthesize polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DE) macromer (i.e. body), different from Example 1, using epichlorohydrin to react with terminally hydroxylated PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -OH to generate polylactic acid-polydimethylsiloxane terminally containing epoxy groups Alkane-polylactic acid macromer, that is, hydrophobic monomer. Among them, DE means that the two ends of the hydrophobic monomer molecular chain are epoxy groups.

Dissolve PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DE in ethyl acetate to prepare a solution containing a hydrophobic monomer with a concentration of 0.02 g/mL; ) was dissolved in ethyl acetate, and a solution with a concentration of 0.02g/mL was prepared; the above two solutions were mixed at a volume ratio of 1:1 to obtain a mixed solution, and the mixed solution was coated on the iron surface by ultrasonic spraying. On the surface of the PLA coating of the iron sheet, during the spraying process, the ultrasonic power is 4.5W, the flow rate of the pump liquid is 0.1mL/min, and the spraying is repeated 5 times. After the spraying is completed, an uncrosslinked Coating of PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DE.

Put the iron sheet coated with uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DE on the surface and heat it in an oven at 60°C for 12 hours, so that the terminal epoxy group of the macromer and the terminal hydroxyl group of PDMS-OH reaction to obtain a cross-linked hydrophobic coating, which can be observed to become stronger after heat treatment. Scanning electron microscopy showed that the thickness of the hydrophobic coating was 2.5 μm.

Carry out edge sealing to sample by the same method as embodiment 6 and carry out corrosion test in water-bath shaker, take pictures to observe the result of iron sheet corrosion appearance and show, when soaking for 3 days, only the whole surface of iron sheet that only contains PLA coating has all been destroyed. Corrosion occurred, and when there was a hydrophobic coating with a thickness of 2.5 μm outside the PLA coating, only some small corrosion spots appeared after 7 days of immersion, and most of the surface of the iron sheet remained uncorroded after 14 days of immersion.

Example 8

AZ31 magnesium alloy sheets with a thickness of 500 μm and a size of 22 mm×26 mm were polished with 800-mesh and 2000-mesh sandpaper in sequence, ultrasonically cleaned with acetone and absolute ethanol for 10 min, and dried with nitrogen.

Acryloyl-terminated polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₇ -PDMS ₇₆ -PLA ₁₇ -DA) macromers (ie, hydrophobic monomers) were synthesized in the same manner as in Example 1.

Dissolve PLA ₁₇ -PDMS ₇₆ -PLA ₁₇ -DA in ethyl acetate to prepare a solution containing hydrophobic monomers with a concentration of 0.1 g/mL, and add photoinitiator 2-hydroxy-2-methyl-1-phenyl -1-Acetone to obtain a mixed solution, wherein the quality of the photoinitiator is 1‰ of the weight of the hydrophobic monomer. Drop-coat 0.5mL of the above-mentioned mixture on each magnesium alloy sheet, and place it in a fume hood. After the ethyl acetate is volatilized, uncrosslinked PLA ₁₇ -PDMS ₇₆ -PLA ₁₇ -DA is formed on the surface of the magnesium alloy sheet. coating.

The uncrosslinked PLA ₁₇ -PDMS ₇₆ -PLA ₁₇ -DA coating was irradiated with 365nm ultraviolet light with an intensity of 8000μW/cm ² for 1 hour to react the terminal acryloyl groups to obtain a crosslinked hydrophobic coating. After ultraviolet light irradiation, it can be seen that a layer of rubbery coating with certain toughness is formed on the surface of the magnesium alloy sheet. From the scanning results of the coating surface by the atomic force microscope, it can be seen that the degradable PLA block and the non-degradable PDMS block in the hydrophobic coating have obvious phase separation, and the PLA phase is dispersed in the PDMS phase, as shown in Fig. 11. The thickness of the hydrophobic coating was determined to be 10 μm by scanning electron microscopy.

Use 704 silica gel to seal the edges of the bare magnesium alloy sheet and the magnesium alloy sheet with a hydrophobic coating. In the magnesium alloy sheet sample with a hydrophobic coating, the hydrophobic coating is exposed. After the 704 silica gel is solidified, put each piece of sample in a beaker with 200mL of PBS, place the beaker in a water bath shaker (50rpm, 37°C), and use the inverted funnel method to collect the amount of hydrogen generated by the corrosion of the magnesium alloy. The results are shown in Figure 12. In the 14-day corrosion of the magnesium alloy with a hydrophobic coating on the surface, the amount of hydrogen produced is significantly less than that of the no coating group (bare magnesium alloy sheet), which proves that the hydrophobic coating can be used to slow down the corrosion of magnesium alloys. corrosion.

Example 9

AZ31 magnesium alloy sheets of the same specification were processed in the same manner as in Example 8.

In the same manner as in Example 1, the perfluoropolyether (PFPE-OH) terminated by two hydroxyl groups is used as an initiator to synthesize polycaprolactone-PFPE-polycaprolactone (PCL ₂₀ -PFPE-OH) terminated by methacryl group. PCL ₂₀ -DMA) macromer (ie hydrophobic monomer).

Dissolve PCL ₂₀ -PFPE-PCL ₂₀ -DMA in ethyl acetate, prepare a solution containing hydrophobic monomers with a concentration of 0.1g/mL, add photoinitiator 2-hydroxy-2-methyl-1-phenyl- 1-Acetone obtains a mixture, wherein the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer. Drop-coat 0.5mL of the above-mentioned mixed solution on each magnesium alloy sheet, place it in a fume hood, and form uncrosslinked PCL ₂₀ -PFPE-PCL ₂₀ -DMA on the surface of the magnesium alloy sheet after volatilizing ethyl acetate. coating.

The uncrosslinked PCL ₂₀ -PFPE-PCL ₂₀ -DMA coating was irradiated with 365nm ultraviolet light with an intensity of 15000μW/ ^cm2 for 1 hour to react the terminal methacryloyl groups in the coating to obtain a crosslinked hydrophobic coating. After ultraviolet light, it can be seen that the coating has changed from the original state of being scratched with a slight touch of tweezers to a smooth coating with certain toughness. The thickness of the hydrophobic coating was determined to be 10 μm by scanning electron microscopy.

Use 704 silica gel to seal the edges of the bare magnesium alloy sheet and the magnesium alloy sheet with a hydrophobic coating. In the magnesium alloy sheet sample with a hydrophobic coating, the hydrophobic coating is exposed. After the 704 silica gel is cured, put each piece of sample in a beaker with 200mL of PBS, and place the beaker in a water bath shaker (50rpm, 37°C), and use the inverted funnel method to collect the amount of hydrogen generated by the corrosion of the magnesium alloy. The results show that the magnesium alloy without the coating group continuously releases hydrogen in a volume of about 10mL in 14 days, and the magnesium alloy with a hydrophobic coating on the surface hardly collects hydrogen during 14 days of corrosion, which proves that the hydrophobic coating is available. to slow down the corrosion of magnesium alloys.

Example 10

AZ31 magnesium alloy sheets of the same specification were processed in the same manner as in Example 8.

Synthesize the polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate (PTMC ₁₉ -PDMS ₇₆ -PTMC ₁₉ -DA) macromer of acryloyl terminated by the same method as in Example 1 (i.e. hydrophobic monomer).

Dissolve PTMC ₁₉ -PDMS ₇₆ -PTMC ₁₉ -DA in ethyl acetate, prepare a solution containing a hydrophobic monomer with a concentration of 0.1g/mL, add photoinitiator 2-hydroxy-2-methyl-1-phenyl -1-Acetone to obtain a mixture, wherein the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer. Drop-coat 0.5mL of the above-mentioned mixture on each magnesium alloy sheet, place it in a fume hood, and form uncrosslinked PTMC ₁₉ -PDMS ₇₆ -PTMC ₁₉ -DA on the surface of the magnesium alloy sheet after volatilizing ethyl acetate coating.

The uncrosslinked PTMC ₁₉ -PDMS ₇₆ -PTMC ₁₉ -DA coating was irradiated with ultraviolet light at 365 nm and an intensity of 5000 μW/cm ² for 1 hour to react the terminal acryloyl groups in the coating to obtain a cross-linked hydrophobic coating. Floor. After ultraviolet light, it can be seen that the coating has changed from the original state of being scratched with a slight touch of tweezers to a smooth coating with certain toughness. The thickness of the hydrophobic coating was determined to be 10 μm by scanning electron microscopy.

Use 704 silica gel to seal the edges of the bare magnesium alloy sheet and the magnesium alloy sheet with a hydrophobic coating. In the magnesium alloy sheet sample with a hydrophobic coating, the hydrophobic coating is exposed. After the 704 silica gel is cured, put each piece of sample in a beaker with 200mL of PBS, and place the beaker in a water bath shaker (50rpm, 37°C), and use the inverted funnel method to collect the amount of hydrogen generated by the corrosion of the magnesium alloy. The results are shown in Figure 12. During the 14-day corrosion of the magnesium alloy with a hydrophobic coating on the surface, the cumulative hydrogen release volume was about 1mL, and there was almost no hydrogen release in the first 6 days of the corrosion test, while the group without coating was in the 14-day period. The volume of sustained hydrogen release is about 10 mL, demonstrating that the hydrophobic coating can be used to slow down the corrosion of magnesium alloys.

Example 11

AZ31 magnesium alloy sheets of the same specification were processed in the same manner as in Example 8.

Acryloyl-terminated polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromers (ie, hydrophobic monomers) were synthesized in the same manner as in Example 1.

Blend PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA with organopolysilazane at a mass ratio of 1:10 to prepare a mixed solution of ethyl acetate with a total mass concentration of 0.2 g/mL; The magnesium alloy sheet is adsorbed on the sample stage of the spin coater, and 6-8 drops of the above mixed solution are dripped on the surface of the magnesium alloy sheet at a low speed (1500r/min, 10s), and then the speed is kept at 2000r/min, Rotate for 25s to form an uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating on the surface of the magnesium alloy sheet, then place the sample in the air to make the Si-N bonds and NH bonds in the polysilazane Under the action of humidity, react for 5 days. From the results of surface element analysis, it can be seen that compared with the first day of curing, no N element can be detected in the coating on the fifth day, as shown in Figures 13A and 13B, respectively, indicating that the polysilazane has been crosslinked at this time Completely, a hydrophobic coating is formed. The thickness of the hydrophobic coating was determined to be 8 μm by scanning electron microscopy.

Use 704 silica gel to seal the edges of the bare magnesium alloy sheet and the magnesium alloy sheet with a hydrophobic coating. In the magnesium alloy sheet sample with a hydrophobic coating, the hydrophobic coating is exposed. After the 704 silica gel is solidified, place the edge-sealed bare magnesium alloy sheet and the magnesium alloy sheet with a hydrophobic coating in six-well plates filled with 5mL Hank's solution, and place them on a water bath shaker (50rpm, 37°C) Corrosion experiments were carried out in the medium, and the Hank's solution was changed every 24 hours. On the 28th day, the corrosion solution was taken to test the concentration of magnesium ions in the solution with an inductively coupled plasma optical emission spectrometer (ICP-OES). The results show that after soaking for 28 days, the concentration of magnesium ions produced by the corrosion of the bare magnesium alloy sheet is 138.1 mg/L, and the concentration of magnesium ions produced by the corrosion of the magnesium alloy sheet under the hydrophobic coating is 30.4 mg/L. layer still has a significant inhibitory effect on the corrosion of magnesium alloy sheets.

Example 12

Cut the pure magnesium sheet with a thickness of 200μm into 22mm×26mm, and polish it with 800, 1500, 2000 and 3000 mesh sandpaper in sequence, put the polished pure magnesium sheet in acetone and absolute ethanol for 10 minutes, and then clean it with nitrogen gas. blow dry.

Synthesize acryl-terminated polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₀ -PDMS ₇₆ -PLA ₁₀ -DA) macromonomers (i.e. hydrophobic monomers) and propylene in the same manner as in Example 1 Acyl-terminated polytrimethylenecarbonate-polydimethylsiloxane-polytrimethylenecarbonate ( _PTMC20 - _PDMS76 - _PTMC20 -DA) macromer (ie, hydrophobic monomer).

PLA ₁₀ -PDMS ₇₆ -PLA ₁₀ -DA and PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA were dissolved in ethyl acetate at a mass ratio of 1:1, and a total mass concentration of 0.2g/mL containing two The solution of the hydrophobic monomer is added with a photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone to obtain a mixed solution, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. Utilize negative pressure to adsorb the processed pure magnesium sheet on the sample stage of the spin coater, drop 6 to 8 drops of the above-mentioned mixed solution on the surface of the pure magnesium sheet at a low speed (1500r/min, 8s), and then Keep the rotation speed at 2000r/min, rotate for 30s, place in a fume hood to volatilize ethyl acetate, and form uncrosslinked PLA ₁₀ -PDMS ₇₆ -PLA ₁₀ -DA and PTMC ₂₀ -PDMS ₇₆ on the surface of the pure magnesium sheet - Hybrid coating of PTMC ₂₀ -DA.

The mixed coating of uncrosslinked PLA ₁₀ -PDMS ₇₆ -PLA ₁₀ -DA and PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA was irradiated with ultraviolet light at 365 nm and an intensity of 8000 μW/ ^cm2 for 1 hour to make the end The acryl reacts to form a hydrophobic coating. After ultraviolet light irradiation, it can be seen that the coating has changed from the original sticky state to a rubbery state with a certain degree of toughness, indicating that the macromonomer has been cross-linked. Characterized under a scanning electron microscope, the thickness of the hydrophobic coating was 5 μm.

Use 704 silica gel to seal the edges of the bare magnesium alloy sheet and the magnesium alloy sheet with a hydrophobic coating. In the magnesium alloy sheet sample with a hydrophobic coating, the hydrophobic coating is exposed outside. After the 704 silica gel is solidified, put the edge-sealing sample in a beaker filled with 200mL Hank's solution, and use the inverted funnel method to measure the amount of hydrogen gas released by magnesium corrosion. The corrosion experiment is carried out in a water bath shaker (50rpm, 37°C) conduct. The results show that after 7 days of corrosion of the bare pure magnesium sheet, the cumulative release of hydrogen gas volume is about 12mL, and the cumulative release of hydrogen gas volume of the pure magnesium sheet with a hydrophobic coating is about 0.5mL, indicating that the hydrophobic coating can well inhibit Early corrosion of pure magnesium.

Example 13

Process the pure magnesium sheet of identical specification by the method identical with embodiment 12.

Synthesize polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate (PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DTS containing trimethoxysilyl group at the end in the same manner as in Example 1) ) macromonomer (i.e. hydrophobic monomer), different from Example 1, using trimethoxysilylpropyl isocyanate to react with hydroxyl-containing PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -OH at the end to generate a trimethoxy group at the end Silicon-based polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate macromer, ie hydrophobic monomer. Among them, DTS means that the two ends of the molecular chain of the hydrophobic monomer are trimethoxysilyl groups.

Dissolve PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DTS in ethyl acetate to prepare solutions containing hydrophobic monomers with mass concentrations of 0.1g/mL and 0.5g/mL respectively; drop-coat 0.2 mL of the above-mentioned two different concentrations of solutions containing hydrophobic monomers, and placed in a fume hood, after the ethyl acetate was volatilized, a coating of uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DTS was formed on the surface of the pure beauty sheet. Floor.

At room temperature, the pure magnesium sheet coated with uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DTS on the surface was placed in the air for 3 days, and the terminal trimethoxysilyl group was hydrolyzed by moisture to produce silanol , and use the dehydration reaction between silanol groups to achieve cross-linking of hydrophobic monomers to generate a cross-linked hydrophobic coating. The cross-linked coating changes from the original sticky state to a rubbery state with a certain degree of toughness. The thicknesses of the hydrophobic coatings prepared by the two concentrations of solutions were 20 μm and 100 μm, respectively, as characterized by scanning electron microscope.

Use 704 silica gel to seal the edges of the treated bare pure magnesium sheet and the pure magnesium sheet with a hydrophobic coating, so that the side with the hydrophobic coating is exposed outside. After the 704 silica gel is solidified, put the edge-sealing sample in a beaker filled with 200mL Hank's solution, and use the inverted funnel method to measure the amount of hydrogen gas released by magnesium corrosion. The corrosion experiment is performed on a water bath shaker (50rpm, 37°C) in progress. The results show that after 14 days of corrosion on the bare pure magnesium sheet, the cumulative volume of released hydrogen gas is about 23mL, and the cumulative volume of hydrogen gas released by corrosion of the pure magnesium sheet with a thickness of 20μm on the surface is about 0.8mL, and the surface has a thickness of 100μm hydrophobic coating. The coated pure magnesium sheets did not collect hydrogen. It shows that the hydrophobic coating can well inhibit the early corrosion of pure magnesium.

Example 14

Polyglycolide-lactide copolymer (PLGA, LA:GA=50:50) with a molecular weight of 60,000 was hot-pressed at 120°C to make a PLGA sheet with a thickness of 300 μm and a size of 22mm×26mm.

Synthesize the polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate (PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA) macromer of acryloyl terminated by the same method as in Example 1 (i.e. hydrophobic monomer).

Dissolve PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA in ethyl acetate to prepare a 0.5g/mL solution containing hydrophobic monomer, add photoinitiator 2-hydroxy-2-methyl-1-phenyl- 1-Acetone obtains a mixed solution, wherein the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer. Add 4-6 drops of the mixed solution dropwise at a low speed (1500r/min, 10s), and then spin-coat at a speed of 2000r/min for 25s to generate uncrosslinked PTMC ₂₀ -PDMS ₇₆ - on the surface of the PLGA sheet PTMC ₂₀ -DA coating.

The uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA coating was irradiated with ultraviolet light at 365nm and an intensity of 8000μW/ ^cm2 for 1 hour to react the terminal acryloyl group in the macromer to obtain a crosslinked hydrophobic coating. It can be seen that the hydrophobic coating formed after ultraviolet irradiation has certain toughness and elasticity. The thickness of the hydrophobic coating was 10 μm as characterized by scanning electron microscopy.

Seal the bottom surface and surrounding of the PLGA sheet with 704 silica gel to ensure that only the test surface or the side with a hydrophobic coating is exposed to the outside. After the 704 silica gel was completely cured, the PLGA sheet was soaked in Hank's solution, and the PLGA sheet without a hydrophobic coating was used as a control, and the degradation experiment was carried out in a water bath shaker at 37°C. After 28 days of degradation, the PLGA sheet was taken for permeation gel chromatography (GPC) test. The results of GPC showed that the molecular weight of PLGA with hydrophobic coating was higher than that of the group without coating (bare PLGA sheet). The method achieves the purpose of slowing down the degradation of PLGA by coating the surface of the PLGA sheet with a hydrophobic coating.

Example 15

A pure zinc sheet with a thickness of 200 μm and a size of 22 mm × 26 mm was polished with 800-mesh and 2000-mesh sandpaper in sequence, ultrasonically cleaned with acetone and absolute ethanol for 10 min, and the surface was blown dry with nitrogen.

Synthesize acryloyl-terminated polycaprolactone-polydimethylsiloxane-polycaprolactone (PCL ₁₅ -PDMS ₇₆ -PCL ₁₅ -DA) macromer (i.e. hydrophobic monomer).

Dissolve PCL ₁₅ -PDMS ₇₆ -PCL ₁₅ -DA in ethyl acetate to prepare a solution containing a hydrophobic monomer at a concentration of 0.02 g/mL, and add the photoinitiator 2-hydroxy-2-methyl-1-benzene Base-1-acetone to obtain a mixed solution, wherein the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer. Spray the mixed solution on the surface of the treated pure zinc sheet by ultrasonic spraying method. During the spraying process, the flow rate of the pump supply liquid is 0.1mL/min, and the ultrasonic power is 5.0W; the sample is placed in a fume hood to fully volatilize the ethyl acetate Finally, an uncrosslinked PCL ₁₅ -PDMS ₇₆ -PCL ₁₅ -DA coating was formed on the surface of the pure zinc sheet.

Irradiate the uncrosslinked PCL ₁₅ -PDMS ₇₆ -PCL ₁₅ -DA coating with ultraviolet light at 365nm and an intensity of 12000μW/cm ² for 40 minutes to make the acryloyl group in the coating react to obtain a crosslinked hydrophobic coating, which can be seen Until the coating changes from the original scratch-resistant state to a rubbery state with certain toughness. The thickness of the hydrophobic coating was determined to be 5 μm by scanning electron microscopy.

Use 704 silica gel to seal the edge of the bare pure zinc sheet and the pure zinc sheet with a hydrophobic coating on the surface, and only the test surface (that is, the corresponding surface of the hydrophobic coating and the bare pure zinc sheet) is exposed. After the 704 silica gel is cured, Each piece of sample was immersed in 10 mL of Hank's solution, and the corrosion test was carried out in a water-bath shaker (37° C., 50 rpm). The results showed that the surface of the bare pure zinc sheet was fully corroded when soaked for 1 day, but the surface of the pure zinc sheet with a hydrophobic coating had not yet been corroded by the 28th day.

Example 16

Process the pure zinc sheet of identical specification by the method identical with embodiment 15.

Acryloyl-terminated polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromers (ie, hydrophobic monomers) were synthesized in the same manner as in Example 1.

Blend PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA with organopolysilazane at a mass ratio of 1:100, and prepare an ethyl acetate solution with a total mass concentration of 0.02g/mL; The pure zinc sheet is adsorbed on the sample stage of the spin coater, and 6-8 drops of the above-mentioned ethyl acetate solution are dropped on the surface of the pure zinc sheet at a low speed (2000r/min, 10s), and then the speed is kept at 4000r/min , and rotated for 25s to form a blend coating of uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA and organopolysilazane on the surface of the pure zinc sheet.

Remove the prepared uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA and organopolysilazane blend coating sample, and place it in the air at room temperature to make the Si- The N bond and NH bond reacted under the action of moisture for 5 days to make the coating cross-linked to form a hydrophobic coating. The thickness of the hydrophobic coating was determined to be 0.01 μm by scanning electron microscopy.

Use 704 silica gel to seal the edge of the bare pure zinc sheet and the pure zinc sheet with a hydrophobic coating on the surface, and only the test surface (that is, the corresponding surface of the hydrophobic coating and the bare pure zinc sheet) is exposed. After the 704 silica gel is cured, Each piece of sample was immersed in 10 mL of Hank's solution, and the corrosion test was carried out in a water-bath shaker (37° C., 50 rpm). The results showed that the surface of the bare pure zinc sheet had been fully corroded after soaking for 1 day, but only a few sites of the pure zinc sheet with a hydrophobic coating on the surface were corroded by the 3rd day.

Example 17

Synthesize the polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate (PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA) macromer of acryloyl terminated by the same method as in Example 1 (i.e. hydrophobic monomer).

Dissolve PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA in ethyl acetate to prepare a solution containing a hydrophobic monomer with a concentration of 0.3 g/mL, and add the photoinitiator 2-hydroxy-2-methyl-1-benzene Base-1-acetone to obtain a mixed solution, wherein the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer. Immerse a PLA filament with a molecular weight of 100,000 and a diameter of 200 μm in the above solution for 10 seconds, and pull it at a rate of 2000 μm/s to form a layer of uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA on the surface of the PLA filament coating.

The uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA was irradiated with 365nm ultraviolet light with an intensity of 15000μW/cm ² for 30min to react the acryloyl group in the coating to obtain a crosslinked hydrophobic coating. The thickness of the hydrophobic coating was determined to be 5 μm by scanning electron microscopy.

Use 704 silica gel to seal the two ends of the PLA wire that is not covered by the hydrophobic coating. After the 704 silica gel is cured, soak the PLA wire with the hydrophobic coating on the surface in a glass dish containing 50mL Hank's solution, and use the surface without coating The PLA silk was used as a control, and the degradation experiment was carried out in a water bath shaker (50rpm, 37°C). After 28 days of degradation, the tensile properties of PLA filaments with different degradation times were tested. The results showed that the tensile strength of PLA filaments with hydrophobic coating on the surface was equivalent to that before the degradation test after 28 days of degradation, while the surface without The mechanical properties of the coated PLA filaments have been significantly reduced, indicating that the hydrophobic coating can delay the degradation of the PLA filaments, thereby maintaining the slow decline in the early mechanical properties of the PLA filaments.

Example 18

A pure iron wire with a diameter of 200 μm (iron content >99.9%) was polished with 800-mesh and 2000-mesh SiC sandpaper in sequence, and the pure iron wire was wound on a screw with a diameter of 5 mm to grow a spring of 3 cm, and ultrasonically cleaned with acetone and absolute ethanol in sequence 10min, then blow dry with nitrogen.

A PLA (M _w : 60kDa) ethyl acetate solution with a concentration of 0.1g/mL was prepared, and a spring made of pure iron wire was immersed in the PLA solution for 10s, then pulled at a speed of 2000μm/s, and the spring was hung on the After evaporating ethyl acetate in a fume hood, a PLA coating was formed on the surface of the spring.

Synthesize acryloyl-terminated polycaprolactone-polydimethylsiloxane-polycaprolactone (PCL ₁₅ -PDMS ₇₆ -PCL ₁₅ -DA) macromer (i.e. hydrophobic monomer).

Blend PCL ₁₅ -PDMS ₇₆ -PCL ₁₅ -DA with Dow Corning 184 silicone rubber precursor (in Dow Corning 184 silicone rubber, the mass ratio of the basic component to the crosslinking agent is 10:1) at a mass ratio of 1:5 to prepare A solution of ethyl acetate with a total concentration of 0.2 g/mL was prepared. Immerse the spring-shaped pure iron wire coated with PLA in the above solution, and pull it rapidly at a speed of 4000 μm/s, and form uncrosslinked PCL ₁₅ -PDMS ₇₆ - on the surface of the PLA-coated spring-shaped pure iron wire Blend coating of PCL ₁₅ -DA with Dow Corning 184 silicone rubber precursor.

Hang the spring-like pure iron wire with the blended coating of uncrosslinked PCL ₁₅ -PDMS ₇₆ -PCL ₁₅ -DA and Dow Corning 184 silicone rubber precursor on the surface for 24 hours, so that the blended coating on the surface crosses at room temperature. Linked to form a cross-linked hydrophobic coating, it can be seen that the coating changes from the original sticky state to a smooth rubbery state with certain toughness. The thickness of the hydrophobic coating was determined to be 4 μm by scanning electron microscopy.

The spring-shaped pure iron wire with only PLA coating on the surface and the spring-shaped pure iron wire with both PLA coating and hydrophobic coating on the surface were immersed in Hank’s solution, and the corrosion test was carried out in a water bath shaker (37°C, 50rpm). The results showed that after soaking for 7 days, the pure iron wire with only PLA coating on the surface had undergone severe corrosion and fractured at some points, while the spring-like pure iron wire with a hydrophobic coating on the surface had almost no corrosion, and until At 28 days, the spring-like pure iron wire still maintains the same mechanical properties as the initial state.

Example 19

Iron wires of the same specification were treated in the same manner as in Example 18 and the same PLA coating was prepared on the surface.

Synthesize polycaprolactone-polydimethylsiloxane-polycaprolactone (PCL ₁₀ -PDMS ₇₆ -PCL ₁₀ -DS) macromolecule containing triethoxysilyl propyl group at the end in the same manner as in Example 1 Monomer (i.e. hydrophobic monomer). Among them, DS means that the two ends of the molecular chain of the hydrophobic monomer are triethoxysilylpropyl groups.

Dissolve PCL ₁₀ -PDMS ₇₆ -PCL ₁₀ -DS in ethyl acetate to prepare a solution containing a hydrophobic monomer with a concentration of 0.5 g/mL. Immerse the spring-like pure iron wire coated with PLA in the above solution and pull it rapidly at a rate of 4000 μm/s to form uncrosslinked PCL ₁₀ -PDMS ₇₆ -PCL ₁₀ -DS on the surface of the spring-like pure iron wire coating.

At room temperature, hang the pure iron wire coated with uncrosslinked PCL ₁₀ -PDMS ₇₆ -PCL ₁₀ -DS on the surface for 48 hours, use the moisture in the air to hydrolyze the terminal triethoxysilylpropyl group to generate silanol, and The cross-linking of the coating is achieved through the dehydration reaction between the silanol groups to form a cross-linked hydrophobic coating. After cross-linking, the hydrophobic coating changes from a state that is easily scratched before cross-linking to a smooth coating with a certain degree of toughness. Characterized under a scanning electron microscope, the thickness of the hydrophobic coating was 5 μm.

Corrosion experiments were carried out in Hank's solution in the same manner as in Example 18. The results showed that after 7 days of immersion, the pure iron wire with only PLA coating on the surface had undergone serious corrosion, and fractures had occurred at individual sites, while the surface had The pure iron wire with hydrophobic coating has not been corroded when soaked for 7 days, and the pure iron wire still maintains the same radial strength as the initial state by 28 days.

Example 20

An absorbable iron-based coronary stent, the preparation method of which is as follows: providing a 30008 specification pure iron substrate with a quality of 3.8 mg, a wall thickness of 50 μm, and an inner diameter of 1.45 mm (the 30008 specification is defined as follows: at a nominal expansion pressure of 8 atm (nominal expansion Pressure refers to the pressure used when the stent is expanded to the nominal diameter), the nominal diameter after expansion is 3.0mm, and the nominal length is 8.0mm. The 30008 specifications in the following examples represent the same meaning, and will not be repeated below), Prepare an ethyl acetate solution of polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromer (i.e. hydrophobic monomer) with a concentration of 0.02 g/mL, and add The photoinitiator 2-hydroxyl-2-methyl-1-phenyl-1-propanone is used to obtain a mixed solution, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. Spray the mixed solution on all surfaces of the pure iron substrate by ultrasonic spraying method, and ventilate to completely volatilize the ethyl acetate, and form uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ - on all surfaces of the pure iron substrate DA coating. During the spraying process, the flow rate of the pump liquid was 0.1mL/min, and the ultrasonic power was 4.75W. Then, irradiate the uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating with ultraviolet light at 365 nm and an intensity of 8000 μW/cm ² for 30 min, so that the acryloyl group in the coating reacts to obtain a cross-linked hydrophobic coating, thereby A cross-linked hydrophobic coating is formed covering the exterior, interior and sides of the pure iron substrate. The thickness of the hydrophobic coating was determined to be 8 μm by scanning electron microscopy.

The multiple absorbable iron-based coronary stents of this batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio was kept within the range of 1.1:1 to 1.2:1 during the implantation process. Using micro-CT to calculate the iron weight loss, the iron was not corroded 1 month after implantation, 20% of the iron weight loss was 3 months after implantation, and 40% of the iron weight loss was 6 months after implantation.

Example 21

An absorbable iron-based coronary stent, the preparation method of which is as follows: providing a 30008 specification pure iron matrix with a mass of 3.8 mg, a wall thickness of 50 μm, and an inner diameter of 1.45 mm, dissolving PLA with a molecular weight of 60,000 in ethyl acetate, Prepare a PLA solution with a concentration of 2 mg/mL, and spray the PLA solution on the outer surface, inner surface and side of the pure iron substrate by ultrasonic spraying, and form on the outer surface, inner surface and side of the pure iron substrate after drying. PLA coating with a thickness of 4 μm. Prepare polytrimethylene carbonate-polydimethylsiloxane-polytrimethylene carbonate (PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA) (i.e. hydrophobic monomer) in ethyl acetate at a concentration of 0.02 g/mL ester solution, and adding a photoinitiator 2-hydroxyl-2-methyl-1-phenyl-1-propanone to obtain a mixed solution, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. Spray the mixed solution on the outer surface, inner surface and side of the pure iron substrate by ultrasonic spraying method, and ventilate to completely volatilize the ethyl acetate, and form uncrosslinked PTMC ₂₀ -PDMS ₇₆ on the inner surface of the pure iron substrate -PTMC ₂₀ -DA coating. During the spraying process, the flow rate of the pump liquid was 0.1mL/min, and the ultrasonic power was 4.75W. Then, irradiate the uncrosslinked PTMC ₂₀ -PDMS ₇₆ -PTMC ₂₀ -DA coating with 365nm ultraviolet light with an intensity of 8000μW/cm ² for 2h, so that the acryloyl group in the coating reacts to obtain a crosslinked hydrophobic coating, thereby A cross-linked hydrophobic coating is formed covering the exterior, interior and sides of the pure iron substrate. The thickness of the hydrophobic coating was determined to be 5 μm by scanning electron microscopy.

The multiple absorbable iron-based coronary stents of this batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio was kept within the range of 1.1:1 to 1.2:1 during the implantation process. Using micro-CT to calculate the weight loss of iron, the iron was not corroded at 1 month after implantation, the iron was not corroded at 3 months after implantation, and the iron lost 50% of its weight at 6 months after implantation.

Example 22

An absorbable iron-based coronary stent, the preparation method of which is as follows: provide a 30008 specification nitrided iron matrix with a mass of 3.8 mg, a wall thickness of 50 μm, and an inner diameter of 1.45 mm, and dissolve PLA with a molecular weight of 60,000 in ethyl acetate , prepare a PLA solution with a concentration of 2mg/mL, and spray the PLA solution on the outer surface, inner surface and side of the nitrided iron substrate by ultrasonic spraying method, and after drying, it will be applied on the outer surface and inner surface of the nitrided iron substrate and a PLA coating with a thickness of 4 μm was formed on the sides.

The nitrided iron substrate with PLA coating on the surface was treated under oxygen plasma, the gas pressure was 50Pa, the plasma power was 100W, and the treatment time was 30min. Draw 50 μL of KH-570 silanized coupling agent with a 100 μL pipette gun, put the tip containing KH-570 inside and the pure magnesium substrate with PLA coating on the surface after plasma treatment into the desiccator, and vacuumize After that, leave it for 12 hours to make KH-570 volatilize and adsorb on the surface of the PLA coating, forming an adhesive layer on the surface of the PLA coating.

Synthesize acryloyl-terminated polycaprolactone-polydimethylsiloxane-polycaprolactone (PCL ₁₀ -PDMS ₇₆ -PCL ₁₀ -DA) macromer (i.e. hydrophobic monomer).

Prepare polycaprolactone-polydimethylsiloxane-polycaprolactone (PCL ₁₀ -PDMS ₇₆ -PCL ₁₀ -DA) macromonomer (i.e., hydrophobic monomer) in ethyl acetate at a concentration of 0.02 g/mL solution, and adding a photoinitiator 2-hydroxyl-2-methyl-1-phenyl-1-propanone to obtain a mixed solution, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. The mixed solution is sprayed on all surfaces of the nitrided iron substrate by ultrasonic spraying method, and after ventilating to completely volatilize the ethyl acetate, an uncrosslinked (PCL) covering adhesive layer is formed on all surfaces of the pure iron substrate. ₁₀ -PDMS ₇₆ -PCL ₁₀ -DA) coating. During the spraying process, the flow rate of the pump liquid was 0.1mL/min, and the ultrasonic power was 4.75W. Then, irradiate the uncrosslinked (PCL ₁₀ -PDMS ₇₆ -PCL ₁₀ -DA) coating with ultraviolet light at 365 nm and an intensity of 8000 μW/cm ² for 1 h, so that the acryloyl group in the coating reacts to obtain a cross-linked hydrophobic coating , thereby forming a cross-linked hydrophobic coating covering the outer, inner and lateral surfaces of the pure iron substrate. The thickness of the hydrophobic coating was determined to be 20 μm by scanning electron microscopy.

The multiple absorbable iron-based coronary stents of this batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio was kept within the range of 1.1:1 to 1.2:1 during the implantation process. Using micro-CT to calculate the iron weight loss, the iron was not corroded at 1 month after implantation, the iron was not corroded at 3 months after implantation, and the iron weight loss was 55% at 6 months after implantation.

Example 23

An absorbable zinc-based coronary stent, the preparation method of which is as follows: provide a 30008 specification pure zinc matrix with a mass of 6 mg, a wall thickness of 90 μm, and an inner diameter of 1.45 mm, and prepare PLA ₁₇ -PDMS ₇₆ - with a concentration of 0.02 g/mL The ethyl acetate solution of PLA ₁₇ -DA (hydrophobic monomer), add photoinitiator 2-hydroxyl-2-methyl-1-phenyl-1-acetone to obtain mixed solution, wherein, the quality of photoinitiator is hydrophobic mono 1‰ of body weight. Spray the above mixed solution on the inner surface of the above-mentioned pure zinc substrate by ultrasonic spraying method, and after ventilating to completely volatilize the ethyl acetate, an uncrosslinked PLA ₁₇ -PDMS ₇₆ -PLA ₁₇ -DA coating is formed on the surface of the pure zinc substrate. Floor. During the spraying process, the flow rate of the pump liquid was 0.1mL/min, and the ultrasonic power was 4.75W. Then, irradiate the uncrosslinked PLA ₁₇ -PDMS ₇₆ -PLA ₁₇ -DA coating with ultraviolet light at 365 nm and an intensity of 8000 μW/cm ² for 1 h, so that the acryloyl group in the coating reacts to obtain a cross-linked hydrophobic coating, thereby A hydrophobic coating is formed covering the inner surface of the pure zinc substrate. The thickness of the hydrophobic coating was determined to be 15 μm by scanning electron microscopy.

The multiple absorbable zinc-based coronary stents of this batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio range of 1.1:1 to 1.2:1 was kept during the implantation process. Using micro-CT to calculate the zinc weight loss, the zinc weight loss was 4% at 1 month after implantation, 25% at 3 months after implantation, and 70% at 6 months after implantation.

Example 24

An absorbable magnesium-based coronary stent, the preparation method of which is as follows: providing a 30008 specification pure magnesium matrix with a mass of 2 mg, a wall thickness of 100 μm, and an inner diameter of 1.45 mm.

Acryloyl-terminated polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromers (ie, hydrophobic monomers) were synthesized in the same manner as in Example 1.

Prepare an ethyl acetate solution of polylactic acid-polydimethylsiloxane-polylactic acid (PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA) macromer (i.e. hydrophobic monomer) with a concentration of 0.02 g/mL, and add The photoinitiator 2-hydroxyl-2-methyl-1-phenyl-1-propanone is used to obtain a mixed solution, wherein the mass of the photoinitiator is 1‰ of the mass of the hydrophobic monomer. Adopt ultrasonic spraying to spray this mixed solution on the surface of the magnesium substrate, the flow rate of the pump supply liquid is 0.1mL/min, the ultrasonic power is 4.5W, repeat the spraying five times according to these parameters, on the surface of the bonding layer of the pure magnesium substrate, no trace is formed. Cross-linked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating.

The uncrosslinked PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating was irradiated with 365nm ultraviolet light with an intensity of 10000μW/cm ² for 1.5h to cross the terminal acryloyl group of PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA to form a hydrophobic coating covering the outer, inner and side surfaces of the pure magnesium substrate. After exposure to light, it can be found that the PLA ₁₅ -PDMS ₇₆ -PLA ₁₅ -DA coating has changed from the original sticky state to a smooth rubbery state with certain elasticity and toughness. The thickness of the hydrophobic coating is 20 μm as characterized by the scanning electron microscope.

The multiple absorbable magnesium-based coronary stents of this batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio range of 1.1:1 to 1.2:1 was kept during the implantation process. Magnesium weight loss was calculated using micro-CT. Magnesium was not corroded 2 months after implantation, 40% of magnesium weight loss was 3 months after implantation, and 100% of magnesium weight loss was 6 months after implantation.

Comparative example 1

An absorbable iron-based coronary stent, the material is pure iron, the specification is 30008, the mass is 3.8mg, the wall thickness is 50μm, and the inner diameter is 1.45mm.

The multiple absorbable iron-based coronary stents of this batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio was kept within the range of 1.1:1 to 1.2:1 during the implantation process. Using micro-CT to calculate the weight loss of iron, the weight loss of iron was 8% at 1 month after implantation (it began to degrade when exposed to body fluid), 15% of iron weight loss at 3 months after implantation, and 30% at 6 months after implantation.

Compared with Comparative Example 1, the absorbable coronary iron-based stent of Example 20 started corrosion later, but the corrosion rate was significantly accelerated at the later stage of implantation.

Comparative example 2

An absorbable iron-based coronary stent, the preparation method of which is as follows: providing a 30008 specification pure iron matrix with a mass of 3.8 mg, a wall thickness of 50 μm, and an inner diameter of 1.45 mm, dissolving PLA with a molecular weight of 60,000 in ethyl acetate, A PLA solution with a concentration of 2mg/mL was prepared, and the PLA solution was sprayed on the outer surface, inner surface and side surfaces of the nitrided iron substrate by ultrasonic spraying method, and after drying, the PLA solution was sprayed on the outer surface, inner surface and side surfaces of the nitrided iron substrate. A PLA coating with a thickness of 4 μm was formed on it.

The multiple absorbable iron-based coronary stents of this batch were respectively implanted into the abdominal aorta of multiple rabbits, and the overexpansion ratio was kept in the range of 1.1:1 to 1.2:1 during the implantation process. Using micro-CT to calculate the weight loss of iron, the weight loss of iron was 20% at 1 month after implantation (degradation began after contact with body fluid), 40% of iron weight loss at 3 months after implantation, and 50% of iron weight loss at 6 months after implantation.

Compared with Comparative Example 2, the absorbable coronary iron-based stents of Example 21 and Example 22 started corrosion later, but the corrosion rate was significantly accelerated at the later stage of implantation.

Comparative example 3

An absorbable zinc-based coronary stent, the material is pure zinc, the specification is 30008, the mass is 6mg, the wall thickness is 90μm, and the inner diameter is 1.45mm.

The multiple absorbable zinc-based coronary stents of the batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio range of 1.1:1 to 1.2:1 was kept during the implantation process. Using micro-CT to calculate the weight loss of zinc, the weight loss of zinc was 12% within 1 month of implantation (degradation began after contact with body fluid), 30% of zinc weight loss after 3 months of implantation, and 60% of zinc weight loss after 6 months of implantation.

Compared with Comparative Example 3, the absorbable zinc-based coronary stent of Example 23 started corrosion later, but the corrosion rate was significantly accelerated at the later stage of implantation.

Comparative example 4

An absorbable magnesium-based coronary stent is made of pure magnesium, the specification is 30008, the mass is 2 mg, the wall thickness is 100 μm, and the inner diameter is 1.45 mm.

The multiple absorbable magnesium-based coronary stents of the batch were respectively implanted into the abdominal aortas of multiple rabbits, and the overexpansion ratio range of 1.1:1 to 1.2:1 was maintained during the implantation process. Using micro-CT to calculate the weight loss of magnesium, 30% of the weight loss of magnesium is 1 month after implantation (degradation begins after contact with body fluid), 80% of weight loss of magnesium is 3 months after implantation, and 100% of weight loss of magnesium is 4 months after implantation.

Compared with Comparative Example 4, the absorbable magnesium-based coronary stent of Example 24 started corrosion later, but the corrosion rate was significantly accelerated at the later stage of implantation.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (17)

1. A hydrophobic coating covering the surface of a degradable material, characterized in that the hydrophobic coating is a coating formed by the cross-linking of hydrophobic monomers, or a cross-linked coating formed by blending hydrophobic monomers and non-degradable components. joint coating, Wherein, the hydrophobic monomer is a block copolymer comprising a hydrophobic block, a degradable block and a cross-linking functional group. 2. a kind of hydrophobic coating according to claim 1, is characterized in that, described hydrophobic block is formed by hydrophobic polymer, and described degradable block is formed by degradable polymer, and the monomer of hydrophobic block Polymerize with the monomer of the degradable block to form a hydrophobic block and a degradable block connected by chemical bonds. Cross-linking occurs between them to form a hydrophobic coating. 3. A kind of hydrophobic coating according to claim 1, characterized in that, the hydrophobic block is made of polydimethylsiloxane, perfluoropolyether, polydifluoroethylene, polytetrafluoroethylene, polyhexa at least one of fluoropropylene or polyvinylidene fluoride-hexafluoropropylene copolymer. 4. A kind of hydrophobic coating according to claim 1, is characterized in that, described degradable block is formed by degradable polymer, The degradable polymer is selected from polyglycolide, polyglycolic acid, poly L-lactide, poly D, L-lactide, polyhydroxybutyrate, polyε-caprolactone, polyε-alkane At least one of substituted caprolactone, polyδ-valerolactone, polyβ-hydroxybutyrate, polycarbonate or polyetherester; Alternatively, the degradable polymer is polyglycolide, polyglycolic acid, poly L-lactide, poly D,L-lactide, polyhydroxybutyrate, polyε-caprolactone, polyε - A copolymer of at least two of the monomers of alkyl substituted caprolactone, polydelta-valerolactone, polybeta-hydroxybutyrate, polycarbonate or polyetherester. 5. A hydrophobic coating according to claim 4, characterized in that the molecular weight of the degradable block is 500-20000, and the degree of polymerization of the degradable block is 20-40. 6. A kind of hydrophobic coating according to claim 1, is characterized in that, described crosslinking functional group is selected from allyl, acryloyl, methacryloyl, epoxy, oxazoline, cyanide At least one of acid group, silanol group or silanoxy group. 7. A hydrophobic coating according to claim 1, characterized in that, the non-degradable component is selected from at least one of silicone rubber, polysiloxane, polysilazane or fluoropolymer. 8. A hydrophobic coating according to claim 1, characterized in that, the thickness of the hydrophobic coating is 0.01-100 μm. 9. the preparation method of a kind of hydrophobic coating as claimed in claim 1, is characterized in that, comprises: providing a hydrophobic monomer, applying an initiating condition to the hydrophobic monomer, so that the hydrophobic monomer is cross-linked to form the hydrophobic coating; Alternatively, a mixture of hydrophobic monomers and non-degradable components is provided, triggering conditions are applied to the mixture of hydrophobic monomers and non-degradable components, so that the non-degradable components are cross-linked or the hydrophobic monomers are combined with Cross-linking occurs between the non-degradable components to form the hydrophobic coating. 10 . The method for preparing a hydrophobic coating according to claim 9 , wherein the triggering condition is ultraviolet light irradiation, heat treatment or moisture action. 11 . 11. the preparation method of a kind of hydrophobic coating according to claim 10, is characterized in that, The ultraviolet light irradiation includes: after mixing the hydrophobic monomer and the photoinitiator, irradiating with 365nm ultraviolet light for 30min to 2h; the photoinitiator is 2-hydroxyl-2-methyl-1-phenyl-1- Acetone, the quality of the photoinitiator is 1‰ of the quality of the hydrophobic monomer. The heat treatment includes: treating the hydrophobic monomer or the mixture of the hydrophobic monomer and the non-degradable component at 20-150°C for 30min-72h; Moisture action includes: reacting the hydrophobic monomer or the mixture of hydrophobic monomer and non-degradable component in a humid environment for 1-5 days. 12. The application of the hydrophobic coating as claimed in claim 1 in delaying the degradation behavior of degradable materials. 13. An absorbable implantable device, comprising an absorbable matrix, characterized in that it further comprises a hydrophobic coating according to claim 1, the hydrophobic coating covering the surface of the absorbable matrix. 14. The absorbable implantable device according to claim 13, characterized in that, the material of the absorbable matrix is a composite of degradable polymer, corrodible metal or corrodible metal and degradable polymer Material. 15. An absorbable implantable device according to claim 13, characterized in that, the absorbable implantable device further comprises an adhesive layer, and the adhesive layer is located between the absorbable matrix and the between hydrophobic coatings. 16. An absorbable implantable device according to claim 15, wherein the material of the adhesive layer is selected from at least one of dopamine and silane coupling agents. 17. The absorbable implantable device according to claim 13, characterized in that, the absorbable implantable device is a cardiovascular stent, a cerebrovascular stent, a peripheral vascular stent, a biliary stent, an esophageal stent, Tractal stents, urethral stents, occluders, orthopedic implants, or absorbable sutures.