CN115192764A

CN115192764A - Preparation method and application of degradable and absorbable surgical suture based on casein

Info

Publication number: CN115192764A
Application number: CN202211118230.9A
Authority: CN
Inventors: 高光辉; 李林虎
Original assignee: Jilin Haizhuo Biotechnology Co ltd
Current assignee: Jilin Haizhuo Biotechnology Co ltd
Priority date: 2022-09-15
Filing date: 2022-09-15
Publication date: 2022-10-18
Anticipated expiration: 2042-09-15
Also published as: CN115192764B

Abstract

The invention discloses a preparation method and application of a casein-based degradable and absorbable surgical suture, and belongs to the technical field of preparation of biomedical materials. The invention solves the problems that the existing fiber taking casein as a main body has low mechanical strength, is easy to swell and has high degradation speed, and cannot maintain enough strength before wound healing when being used as a suture. The invention adopts aldehyde sodium alginate and polyethylene glycol diglycidyl ether as cross-linking agents, improves casein fibers, and prepares the degradable absorption surgical suture line based on casein by a wet spinning process. The suture provides enough mechanical strength for wound suture, has good biocompatibility and degradability, and can meet the requirements of practical application of absorbable sutures. Meanwhile, the practical application scene of the casein is widened, and a new preparation idea is provided for the field of absorbable suture lines.

Description

Preparation method and application of degradable and absorbable surgical suture based on casein

Technical Field

The invention relates to a preparation method and application of a casein-based degradable and absorbable surgical suture, belonging to the technical field of preparation of biomedical materials.

Background

The operation suture line is one of the necessary materials for suturing the incision after clinical operation, and plays a vital role in the initial healing of the wound. The existing operation suture lines are generally divided into absorbable lines and non-absorbable lines, and the non-absorbable lines need to be removed after the wound is healed, so that the pain is brought to patients and even secondary wound is formed; the absorbable suture line has stable absorption, good elasticity, knotting property and holding property, does not have great change in mechanical property before wound healing, has good biocompatibility, does not need to be torn off, and has more and more extensive application in clinic.

Casein is natural polymer derived from milk, comprises various amino acids, calcium, phosphate, etc. required by human body, does not cause any tissue reaction in vivo, has good compatibility and no side effect, and is a degradable biological material based on casein, which is a natural polymer material and is a preferable suture material. However, since casein-based fibers generally have problems such as low mechanical strength, easy swelling, and excessively high degradation rate, and cannot maintain sufficient strength before wound healing when used as sutures, there has been no absorbable surgical suture based on casein in the prior art.

Although chinese patent CN109735948B discloses a casein-chitosan composite fiber, in which casein is used as the main component and no chemical fiber component is added, the fiber can be woven into textile fabrics with a plurality of excellent properties. However, the silane coupling agent and glutaraldehyde are used for crosslinking, so that high biocompatibility cannot be guaranteed, and the biocompatibility is a prerequisite which must be met by development of absorbable surgical sutures, so that the fiber cannot be used as surgical sutures. Therefore, it is necessary to provide a degradable casein-based biomaterial which can be used as a surgical suture.

Disclosure of Invention

The invention provides a preparation method and application of a casein-based degradable and absorbable surgical suture line with excellent mechanical property and degradation property of a biological material, aiming at solving the problems that the existing fiber taking casein as a main body has low mechanical strength, is easy to swell and has an excessively high degradation speed, and cannot keep enough strength before wound healing when being used as the suture line.

The technical scheme of the invention is as follows:

a preparation method of a casein-based degradable and absorbable surgical suture line comprises the following steps:

s1, preparing aldehydic sodium alginate by using a sodium alginate aqueous solution and sodium periodate as raw materials;

s2, preparing wet spinning stock solution by using casein, sodium carbonate, sodium bicarbonate, aldehyde sodium alginate and water;

s3, placing the wet spinning solution obtained in the S2 into an injector, extruding fibers from a spinneret orifice and injecting the fibers into a first coagulating bath, enabling the fibers to enter a second coagulating bath under the traction of a roller, and finally winding the fibers on a collecting roller;

and S4, taking down the fibers and the collecting roller together, soaking the fibers and the collecting roller in an ethanol water solution containing polyethylene glycol diglycidyl ether, taking out the fibers, and sequentially washing, drying, sterilizing and disinfecting to obtain the casein-based degradable absorption surgical suture.

Further limited, the specific operation process of S1 is: adding sodium periodate into a sodium alginate aqueous solution, stirring for 8-12h at normal temperature in the dark, adding ethylene glycol to terminate the reaction, purifying the product by a precipitation method, and finally drying the product to obtain the aldehyde sodium alginate.

Further limiting, the concentration of the sodium alginate aqueous solution is 2 to 3wt%.

Further limiting, the adding amount of the sodium periodate is 0.8 to 1.2 times of the mass of the sodium alginate.

More specifically, the amount of the ethylene glycol added is the same as the sodium periodate.

Further, the specific operation process of S2 is as follows: adding sodium carbonate and sodium bicarbonate into water, dissolving, adding casein, stirring to disperse uniformly, adding aldehyde sodium alginate, and stirring to dissolve completely to obtain viscous wet spinning stock solution.

Further limiting, the mass part ratio of the sodium carbonate, the sodium bicarbonate, the casein and the aldehyde sodium alginate in the wet spinning solution is (0.25 to 1): (0.25 to 1): (10 to 20): (1~3).

Further limited, the concentration of sodium carbonate is 0.25 to 1wt%.

Further, the concentration of sodium bicarbonate is 0.25 to 1wt%.

Further, in S3, the first coagulation bath is an ammonium sulfate solution having a pH of 4.1 to 5.3 and a concentration of 20 to 40wt%.

More particularly, the pH of the ammonium sulfate solution is adjusted using acetic acid.

Further defined, the second coagulation bath in S3 is a mixture of ethanol and polyethylene glycol.

More particularly, the concentration of ethanol in the second coagulation bath is 75vol%.

Further, the concentration of the polyethylene glycol in the second coagulation bath is 3 to 6wt%.

In step S3, the wet spinning dope obtained in step S2 is placed in a syringe and then subjected to defoaming treatment.

Further, the defoaming treatment conditions are as follows: rotating at 3000rpm, and centrifuging for 15min.

Further, in S3, the fiber is extruded from the spinneret orifice to be finally wound and passes through 5 rollers.

Further defined, the rollers are each 8cm in diameter.

More specifically, the rotation speed of the drum is increased in the order of the fiber passing.

More particularly, the draw ratio of the fiber is 1.2.

Further, the epoxy value of the polyethylene glycol diglycidyl ether in S4 is 0.7 to 0.8mol/100g.

Further, the concentration of the polyethylene glycol diglycidyl ether is 0.4 to 1vol%.

Further, the concentration of ethanol in the ethanol aqueous solution is limited to 75 to 95vol%.

Further limited, the soaking temperature in S4 is 40 to 60 ℃, and the soaking time is 3 to 12h.

More specifically, the washing in S4 is rinsing with clean water.

Further limited, the sterilization conditions in S4 are: ethylene oxide with a concentration of 250mg/L was sterilized for 4h.

The invention also claims the application of the casein-based degradable and absorbable surgical suture obtained by the preparation method for wound suturing.

The invention has the following beneficial effects:

the invention adopts aldehyde sodium alginate and polyethylene glycol diglycidyl ether as cross-linking agents, improves casein fibers, and prepares a degradable absorption surgical suture line based on casein through a wet spinning process. The preparation method of the fiber provided by the invention improves the mechanical property and stability of the original casein fiber, provides enough mechanical strength for wound suture, and has the characteristics of uniform wire diameter, firm knotting, no cytotoxicity, no sensitization and the like.

Compared with the prior art, the invention also has the following advantages:

(1) The invention adopts two crosslinking agents to form crosslinking of casein, the stability of the casein in the in vivo environment is enhanced by a crosslinking structure, the mechanical strength based on casein fiber is improved, and the invention also has good biocompatibility and degradability, and can meet the requirement of the practical application of absorbable suture lines.

(2) The invention firstly utilizes the o-diol structure on the sodium alginate structural unit to be oxidized by sodium periodate to form aldehyde functional groups to obtain the aldehyde sodium alginate, when the aldehyde group meets the amino functional groups on the molecular chain of the protein to generate Schiff base reaction to generate dynamic imine groups, namely, the aldehyde sodium alginate is utilized to carry out one-stage crosslinking on casein to form dynamic chemical crosslinking, then the epoxy group carried by polyethylene glycol diglycidyl ether is utilized to form stable chemical covalent bonds with the amino, hydroxyl and carboxyl of the protein to realize two-stage crosslinking on the casein, thereby improving the mechanical property and the degradation property of the product and obtaining the absorbable casein suture line which can be used for operation.

(3) The invention takes casein as a main body to prepare the absorbable suture line for operation, widens the actual application scene of the casein, and provides a new preparation idea for the field of absorbable suture lines.

Drawings

Fig. 1 is a graph showing the result of cytotoxicity test of the casein-based suture prepared in example 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The experimental procedures used in the following examples are conventional unless otherwise specified. The materials, reagents, methods and apparatus used, unless otherwise specified, are conventional in the art and are commercially available to those skilled in the art.

The polyethylene glycol in the following examples is specifically polyethylene glycol 4000.

Example 1:

the method for preparing the casein-based degradable and absorbable surgical suture line comprises the following steps:

(1) Preparing the aldehyde sodium alginate: 3g of sodium alginate was added to 100mL of deionized water and stirred until completely dissolved. Then, 3g of sodium periodate was added thereto, and the mixture was stirred at normal temperature in the dark to react for 12 hours. After the reaction is finished, ethylene glycol with the same mass as sodium periodate is added for reaction for 1 hour, and the unreacted sodium periodate is consumed. And then adding 3 parts of sodium chloride and 100 parts of ethanol by taking the sodium alginate solution as 100 parts by weight, precipitating a crude product, dissolving the precipitated product in 100 parts of water again, adding 3 parts of sodium chloride and 100 parts of ethanol again, collecting the precipitated precipitate, and drying to obtain the aldehyde sodium alginate.

(2) Preparing a spinning solution: and (2) sequentially adding 0.5 part of sodium carbonate, 0.5 part of sodium bicarbonate, 20 parts of casein and 2 parts of aldehyde sodium alginate prepared in the step (1) into 77 parts of deionized water by weight, and mechanically and uniformly stirring to form a viscous spinning solution.

(3) And (3) wet spinning: centrifuging the spinning solution in a centrifuge at 3000rpm for 15min, removing bubbles, injecting into an injector, uniformly extruding the solution by using a peristaltic pump, injecting the fiber extruded from a spinneret orifice into a first coagulating bath, wherein the first coagulating bath is an aqueous solution of ammonium sulfate with the concentration of 30wt%, and adding a small amount of acetic acid to adjust the pH value to 4.6. After the fiber passes through the first coagulating bath, the fiber continuously enters a second coagulating bath under the drawing action of a roller, wherein the components of the second coagulating bath are aqueous solutions of ethanol and polyethylene glycol, the ethanol content is 75vol%, and the polyethylene glycol content in the solutions is 5wt%. The fibers are drawn off again by the drum after exiting the second coagulation bath and then wound on a collecting roll. The fiber is extruded from a spinneret orifice to the final winding and passes through 5 rollers, the diameters of the rollers are 8cm, the rotating speed of the rollers is increased along the passing sequence of the fiber, and the drawing ratio (the ratio of the speed of the final winding to the speed of the initial extrusion) of the fiber is 1.2.

(4) And (3) secondary crosslinking strengthening: and taking down the fiber together with the collecting roller, and soaking the fiber in an ethanol water solution of polyethylene glycol diglycidyl ether. The epoxy value of the polyethylene glycol diglycidyl ether is 0.7mol/100g, the concentration in the solution is 0.4vol%, the ethanol concentration in the ethanol water solution is 75vol%, the soaking temperature is 40 ℃, and the reaction time is 12 hours, so that the fibers form certain covalent crosslinking. Rinsing with clear water for 2 hours, and air drying the fiber to obtain the medical absorbable suture.

(5) And (3) disinfection and sterilization: the suture thread is sterilized by ethylene oxide, the sterilization concentration of the ethylene oxide is 250mg/L, the sterilization time is 4 hours, and the suture thread after the sterilization treatment can be used for wound suture.

The obtained medical absorbable suture line is subjected to performance test, and the test method and the test result are as follows:

1. and (3) testing mechanical properties:

the measuring method comprises the following steps: the temperature is 20 ℃, the humidity is 65%, and the fiber is drawn at a constant speed of 50mm/min by a drawing machine until the fiber is broken, so that the breaking strength and the breaking elongation are obtained. The mechanical property data of the wet fiber are measured after the suture sample is soaked in phosphate buffer for 5 minutes. Each data was obtained from the same four samples.

The results are shown in the following table:

fineness (dtex)	8.10±0.45
		Dry Strength (cN/dtex)	2.93±0.44
Elongation at Break in Dry State (%)	16.1±3.0
		Wet strength (cN/dtex)	1.88±0.61
Elongation at Break in Wet State (%)	49.8±12.2
		Dry Strength after knot tying (cN/dtex)	1.64±0.45
Elongation at break in the Dry State after knot (%)	18.0±5.5
		Wet strength after knotting (cN/dtex)	1.35±0.29
Elongation at break in Wet State after knot (%)	35.9±6.4

As can be seen from the above table, the fiber prepared by the invention meets the mechanical requirements of the medical absorbable suture.

2. Cytotoxicity test:

the measuring method comprises the following steps: soaking the suture sample in DMEM culture solution, and culturing at 37 deg.C for 2 days to obtain the leaching solution of suture. Subsequently, the cell extract was mixed with a culture solution of fibroblasts, and the culture was continued at 37 ℃ for 1, 4, and 7 days. Thereafter, a small amount of CCK-8 reagent was added, the mixture was incubated at 37 ℃ for 1 hour, and finally the absorbance at a wavelength of 450nm (OD =450 nm) was measured by a microplate reader. The control group is prepared by changing the leaching solution into pure DMEM culture solution, and other conditions are not changed. Higher absorbance indicates more cells. Cell viability (%) = absorbance of experimental group/absorbance of control group × 100%.

The test results are shown in fig. 1, and it can be seen from fig. 1 that the fibers prepared by the present invention have no significant cytotoxicity.

3. And (3) testing the degradation performance:

the measuring method comprises the following steps: PBS buffer (pH = 7.4) was prepared and a small amount of lysozyme (concentration 1 mg/mL) was added to simulate the environment of body fluid. A sufficient amount of the suture sample was soaked in the solution, and the temperature of the solution was maintained at 37 ℃. Taking 4 fibers every day to measure the mechanical strength, sucking off surface water drops by using filter paper before measurement, measuring the mechanical strength by using a drawing machine, and finally counting. Complete absorption is considered when no more formed suture sample is present in the solution.

The results are shown in the following table:

when the mechanical strength is reduced by half	11-13 days
		Mechanical strength reduction 7At 5% time of use	17-20 days
When mechanical strength is completely lost	24-31 days
		When it is completely absorbed	For 49 days

Example 2:

the method for preparing the casein-based degradable and absorbable surgical suture comprises the following steps:

(2) Preparing a spinning solution: and (2) sequentially adding 1 part of sodium carbonate, 1 part of sodium bicarbonate, 15 parts of casein and 2.5 parts of aldehyde sodium alginate prepared in the step (1) into 80.5 parts of deionized water in parts by weight, and mechanically and uniformly stirring to form a viscous spinning stock solution.

(3) And (3) wet spinning: centrifuging the spinning solution in a centrifuge at 3000rpm for 15min, removing bubbles, injecting into an injector, uniformly extruding the solution by using a peristaltic pump, injecting the fiber extruded from a spinneret orifice into a first coagulating bath, wherein the first coagulating bath is an aqueous solution of ammonium sulfate with the concentration of 25wt%, and adding a small amount of acetic acid to adjust the pH value to 4.6. After the fiber passes through the first coagulating bath, the fiber continuously enters a second coagulating bath under the drawing action of a roller, and the components of the second coagulating bath are aqueous solutions of ethanol and polyethylene glycol, wherein the ethanol content is 75vol%, and the content of the polyethylene glycol in the solution is 5wt%. The fibers are drawn off again by the drum after exiting the second coagulation bath and then wound on a collecting roll. The fiber is extruded from a spinneret orifice to the final winding and passes through 5 rollers, the diameters of the rollers are 8cm, the rotating speed of the rollers is increased progressively along the passing sequence of the fiber, and the drawing ratio (the ratio of the speed of the final winding to the speed of the initial extrusion) of the fiber is 1.2.

(4) And (3) secondary crosslinking strengthening: and taking down the fiber together with the collecting roller, and soaking the fiber in an ethanol water solution of polyethylene glycol diglycidyl ether. The epoxy value of the polyethylene glycol diglycidyl ether is 0.7mol/100g, the concentration in the solution is 0.4vol%, the ethanol concentration in the ethanol water solution is 75vol%, the soaking temperature is 40 ℃, and the reaction time is 12 hours, so that the fibers form certain covalent crosslinking. Rinsing with clear water for 2 hours, and air-drying the fiber to obtain the medical absorbable suture.

Example 3:

(1) Preparing aldehyde sodium alginate: 3g of sodium alginate was added to 100mL of deionized water and stirred until completely dissolved. Then, 2.5g of sodium periodate was added thereto, and the mixture was stirred at normal temperature in the dark to react for 12 hours. After the reaction is finished, ethylene glycol with the same mass as sodium periodate is added for reaction for 1 hour, and the unreacted sodium periodate is consumed. And then adding 3 parts of sodium chloride and 100 parts of ethanol based on 100 parts by weight of sodium alginate solution to precipitate a crude product, dissolving the precipitated product in 100 parts of water, adding 3 parts of sodium chloride and 100 parts of ethanol again, collecting the precipitated precipitate, and drying to obtain the aldehyde sodium alginate.

(2) Preparing a spinning solution: and (2) sequentially adding 0.25 part of sodium carbonate, 0.25 part of sodium bicarbonate, 18 parts of casein and 1.5 parts of aldehyde sodium alginate prepared in the step (1) into 80 parts of deionized water in parts by weight, and mechanically and uniformly stirring to form a viscous spinning stock solution.

(3) And (3) wet spinning: centrifuging the spinning solution in a centrifuge at 3000rpm for 15min, removing bubbles, injecting into an injector, extruding the solution at constant speed by using a peristaltic pump, injecting the fiber extruded from a spinneret orifice into a first coagulating bath, wherein the first coagulating bath is an aqueous solution of ammonium sulfate, the concentration of the aqueous solution is 30wt%, and a small amount of acetic acid is added to adjust the pH value to 4.6. After the fiber passes through the first coagulating bath, the fiber continuously enters a second coagulating bath under the drawing action of a roller, and the components of the second coagulating bath are aqueous solutions of ethanol and polyethylene glycol, wherein the ethanol content is 75vol%, and the content of the polyethylene glycol in the solution is 5wt%. The fibers are drawn off again by the drum after exiting the second coagulation bath and then wound on a collecting roll. The fiber is extruded from a spinneret orifice to the final winding and passes through 5 rollers, the diameters of the rollers are 8cm, the rotating speed of the rollers is increased along the passing sequence of the fiber, and the drawing ratio (the ratio of the speed of the final winding to the speed of the initial extrusion) of the fiber is 1.2.

(4) And (3) secondary crosslinking strengthening: and taking down the fiber together with the collecting roller, and soaking the fiber in an ethanol water solution of polyethylene glycol diglycidyl ether. The epoxy value of the polyethylene glycol diglycidyl ether is 0.8mol/100g, the concentration in the solution is 0.4vol%, the ethanol concentration in the ethanol water solution is 75vol%, the soaking temperature is 40 ℃, and the reaction time is 6 hours, so that the fibers form certain covalent crosslinking. Rinsing with clear water for 2 hours, and air drying the fiber to obtain the medical absorbable suture.

Example 4:

(1) Preparing the aldehyde sodium alginate: 5g of sodium alginate was added to 200mL of deionized water and stirred until completely dissolved. Then, 4g of sodium periodate was added thereto, and the mixture was stirred at normal temperature in the dark to react for 12 hours. After the reaction is finished, ethylene glycol with the same mass as sodium periodate is added for reaction for 1 hour, and the unreacted sodium periodate is consumed. And then adding 3 parts of sodium chloride and 100 parts of ethanol by taking the sodium alginate solution as 100 parts by weight, precipitating a crude product, dissolving the precipitated product in 100 parts of water again, adding 3 parts of sodium chloride and 100 parts of ethanol again, collecting the precipitated precipitate, and drying to obtain the aldehyde sodium alginate.

(2) Preparing a spinning solution: according to the parts by weight, 77.5 parts of deionized water are sequentially added with 0.5 part of sodium carbonate, 0.5 part of sodium bicarbonate, 20 parts of casein and 1.5 parts of aldehyde sodium alginate prepared in the step (1), and the mixture is mechanically stirred uniformly to form viscous spinning stock solution.

(3) And (3) wet spinning: centrifuging the spinning solution in a centrifuge at 3000rpm for 15min, removing bubbles, injecting into an injector, uniformly extruding the solution by using a peristaltic pump, injecting the fiber extruded from a spinneret orifice into a first coagulating bath, wherein the first coagulating bath is an aqueous solution of ammonium sulfate with the concentration of 30wt%, and adding a small amount of acetic acid to adjust the pH value to 4.6. After the fiber passes through the first coagulating bath, the fiber continuously enters a second coagulating bath under the drawing action of a roller, and the components of the second coagulating bath are aqueous solutions of ethanol and polyethylene glycol, wherein the ethanol content is 75vol%, and the content of the polyethylene glycol in the solution is 5wt%. The fibers are drawn off again by the drum after exiting the second coagulation bath and then wound on a collecting roll. The fiber is extruded from a spinneret orifice to the final winding and passes through 5 rollers, the diameters of the rollers are 8cm, the rotating speed of the rollers is increased progressively along the passing sequence of the fiber, and the drawing ratio (the ratio of the speed of the final winding to the speed of the initial extrusion) of the fiber is 1.

(4) And (3) secondary crosslinking strengthening: and taking down the fiber together with the collecting roller, and soaking the fiber in an ethanol water solution of polyethylene glycol diglycidyl ether. The epoxy value of the polyethylene glycol diglycidyl ether is 0.8mol/100g, the concentration in the solution is 0.8vol%, the ethanol concentration in the ethanol water solution is 75vol%, the soaking temperature is 60 ℃, and the reaction time is 6 hours, so that the fibers form certain covalent crosslinking. Rinsing with clear water for 2 hours, and air drying the fiber to obtain the medical absorbable suture.

Example 5:

(1) Preparing the aldehyde sodium alginate: 3g of sodium alginate was added to 100mL of deionized water and stirred until completely dissolved. Then, 2.7g of sodium periodate was added thereto, and the mixture was stirred at normal temperature in the dark to react for 12 hours. After the reaction is finished, ethylene glycol with the same mass as sodium periodate is added for reaction for 1 hour, and the unreacted sodium periodate is consumed. And then adding 3 parts of sodium chloride and 100 parts of ethanol based on 100 parts by weight of sodium alginate solution to precipitate a crude product, dissolving the precipitated product in 100 parts of water, adding 3 parts of sodium chloride and 100 parts of ethanol again, collecting the precipitated precipitate, and drying to obtain the aldehyde sodium alginate.

(2) Preparing a spinning solution: and (2) sequentially adding 0.25 part of sodium carbonate, 0.25 part of sodium bicarbonate, 12 parts of casein and 2.5 parts of aldehyde sodium alginate prepared in the step (1) into 85 parts of deionized water in parts by weight, and mechanically and uniformly stirring to form a viscous spinning stock solution.

(3) And (3) wet spinning: centrifuging the spinning solution in a centrifuge at 3000rpm for 15min, removing bubbles, injecting into an injector, uniformly extruding the solution by using a peristaltic pump, injecting the fiber extruded from a spinneret orifice into a first coagulating bath, wherein the first coagulating bath is an aqueous solution of ammonium sulfate with the concentration of 30wt%, and adding a small amount of acetic acid to adjust the pH value to 4.6. After the fiber passes through the first coagulating bath, the fiber continuously enters a second coagulating bath under the drawing action of a roller, wherein the components of the second coagulating bath are aqueous solutions of ethanol and polyethylene glycol, the ethanol content is 75vol%, and the polyethylene glycol content in the solution is 4.5wt%. The fibers are drawn off again by the drum after exiting the second coagulation bath and then wound on a collecting roll. The fiber extruded from the spinneret orifice to the final winding passes through 5 rollers with the diameter of 8cm, the rotating speed of the rollers is increased along the passing sequence of the fiber, and the drawing ratio (the ratio of the speed of the final winding to the speed of the initial extrusion) of the fiber is 1.25.

(4) And (3) secondary crosslinking strengthening: and taking down the fiber together with the collecting roller, and soaking the fiber in an ethanol water solution of polyethylene glycol diglycidyl ether. The epoxy value of the polyethylene glycol diglycidyl ether is 0.75mol/100g, the concentration in the solution is 0.4vol%, the ethanol concentration in the ethanol water solution is 75vol%, the soaking temperature is 40 ℃, and the reaction time is 8 hours, so that the fibers form certain covalent crosslinking. Rinsing with clear water for 2 hours, and air drying the fiber to obtain the medical absorbable suture.

The above description is intended to be illustrative of the preferred embodiment of the present invention and should not be taken as limiting the invention, but rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Claims

1. A preparation method of a casein-based degradable and absorbable surgical suture is characterized by comprising the following steps:

s1, preparing aldehydized sodium alginate by taking a sodium alginate aqueous solution and sodium periodate as raw materials;

s3, placing the wet spinning solution obtained in the S2 into an injector, injecting fibers extruded from a spinneret orifice into a first coagulating bath, allowing the fibers to enter a second coagulating bath under the traction of a roller, and finally winding the fibers on a collecting roller;

2. The preparation method of the casein based degradable and absorbable surgical suture line according to claim 1, wherein S1 is specifically: adding sodium periodate into a sodium alginate aqueous solution, stirring for 8-12h at normal temperature in the dark, adding ethylene glycol to terminate the reaction, purifying the product by a precipitation method, and finally drying the product to obtain the aldehyde sodium alginate.

3. The preparation method of the casein-based degradable and absorbable surgical suture line as claimed in claim 2, wherein the concentration of the sodium alginate aqueous solution is 2-3 wt%, the addition amount of the sodium periodate is 0.8-1.2 times of the mass of the sodium alginate, and the addition amount of the ethylene glycol is the same as the mass of the sodium periodate.

4. The preparation method of the casein based degradable and absorbable surgical suture line according to claim 1, wherein S2 is specifically: adding sodium carbonate and sodium bicarbonate into water, dissolving, adding casein, stirring to disperse uniformly, adding aldehyde sodium alginate, and stirring to dissolve completely to obtain a viscous wet spinning stock solution; the mass part ratio of sodium carbonate, sodium bicarbonate, casein and aldehyde sodium alginate in the wet spinning stock solution is (0.25 to 1): (0.25 to 1): (10 to 20): (1~3); the concentration of sodium carbonate is 0.25 to 1wt%, and the concentration of sodium bicarbonate is 0.25 to 1wt%.

5. The preparation method of the casein-based degradable and absorbable surgical suture line as claimed in claim 1, wherein the first coagulation bath in S3 is ammonium sulfate solution with pH of 4.1 to 5.3 and concentration of 20 to 40wt%.

6. The method for preparing a casein based degradable and absorbable surgical suture line according to claim 1, wherein the second coagulation bath in the S3 is a mixture of ethanol and polyethylene glycol.

7. The preparation method of the casein-based degradable and absorbable surgical suture line as claimed in claim 1, wherein the epoxy value of the polyethylene glycol diglycidyl ether in S4 is 0.7 to 0.8mol/100g.

8. The preparation method of the casein-based degradable and absorbable surgical suture line as claimed in claim 1, wherein the soaking temperature in S4 is 40 to 60 ℃, and the soaking time is 3 to 12h.

9. Use of a casein based degradable absorbable surgical suture obtainable by the process according to claim 1 as surgical suture material.