KR20090107429A - Medical device with antibacterial polyurethaneurea coating - Google Patents

Abstract

The present invention relates to a medical device having at least one coating obtained from an aqueous dispersion comprising at least one nonionic stabilized polyurethaneurea and at least one silver-containing component.

Description

Medical device with antibacterial polyurethaneurea coating {MEDICAL DEVICES WITH AN ANTIBACTERIAL POLYURETHANEUREA COATING}

This application claims the benefit of European Patent Application No. 08 154 208.6 of April 8, 2008, which is hereby incorporated by reference in its entirety for all useful purposes.

The present invention relates to a medical device having an antibacterial (antibacterial) polyurethane coating. The present invention also provides a method of making a medical device having an antibacterial (antibacterial) polyurethane coating and its use.

Articles made of plastic and metal are very frequently used in the medical sector. Examples of such materials are, for example, implants, cannula or catheter. The problem associated with the use of this product is that pathogens can easily colonize the surface of the material. A common consequence of using bacteria-collected articles, such as implants, cannula or catheter, is infection through biofilm formation. This infection is particularly severe in the field of central venous catheter and in the urology of which the catheter is used.

To date, several attempts have been made to prevent bacterial colonization and consequent infection. Often attempts have been made to impregnate the surface of a medical implant or catheter with antibiotics. In this case, however, the development and selection of resistant bacteria should be anticipated.

Another approach to preventing infection when using implants or catheters is to use metals or metal alloys, for example for catheters.

Of particular importance in this respect is the antibacterial effect of silver. Silver and silver salts have already been known as antimicrobial actives for many years. The antimicrobial effect of the surface containing silver is due to the release of silver ions. The advantage of silver is that it is highly toxic to bacteria even at very low concentrations. Hardes et al., Biomaterials 28 (2007) 2869-2875 report low concentrations of silver bactericidal activity of 35 ppb. In contrast, even at significantly higher concentrations, silver is still not harmful to mammalian cells. A further advantage is the low tendency of bacteria to develop resistance to silver.

Various approaches for providing silver to medical devices, such as catheters, have been described in the literature. One approach is to use metallic silver on the catheter surface. Thus, for example, US 3,800,087 discloses a method of metallization of surfaces which may also be used in medical instruments, for example catheters, according to DE 43 28 999. A disadvantage here is that the silver has poor surface adhesion upon stimulation to the catheter, for example, storage in body fluids such as urine, friction during infusion and removal in the body, or repeated refraction of the catheter.

However, metal coatings of medical devices have the disadvantage that in addition to poor adhesion to the catheter material, application to the inner surface of the catheter is very difficult.

The improvement of the adhesion of the silver coat to the catheter plastic by the application of the metal layer between the silver coat and the plastic with better adhesion is described in DE 43 28 999 A above. For the described products, silver is applied by vapor deposition in a vacuum chamber, by sputtering or ion implantation. This method is very complicated and expensive. A further disadvantage is that the amount of elemental silver applied by vapor deposition is relatively high, while only very small amounts of active silver ions are transferred to the surrounding fluid. In addition, this method can only be used to coat the exterior of an implant or catheter. However, it is known that bacteria also adhere easily inside the catheter, causing the formation of biofilms and infection of the patient.

Many applications relate to the use of silver salts in antimicrobial coatings applied to medical implants or catheters. Compared with metallic silver, silver salts have the disadvantage that in the impregnated coating there is an anion that can be toxic in certain circumstances, such as nitrate in silver nitrate, for example with active silver. Another problem is the release rate of silver ions from silver salts. Some silver salts, such as silver nitrate, dissolve very well in water and can transfer too quickly from the surface coating to the surrounding medium. Other silver salts, such as silver chloride, are so soluble that silver ions may be delivered to the fluid too late.

Accordingly, US 6,716,895 B1 relates to an antimicrobial composition comprising a hydrophilic polymer which can be selected as one component, in particular from polyether polyurethanes, polyester polyurethanes and polyurethaneureas. Antimicrobial coatings are achieved with oligodynamic salts, such as through the use of silver salts. The composition is used to coat the medical device. A disadvantage of this coating and the use of the silver salts described above is that they originate from a solution of the polymer component, so in many cases it is not possible to prevent residues of toxic solvents from entering the human body after implantation of a medical device provided with this coating. to be.

Other publications, for example WO 2004/017738 A, WO 2001/043788 A and US 2004/0116551 A, describe the concept of combining different silver salts to obtain a silver-containing coating that continuously releases silver ions. Various silver salts are mixed with different polymers, such as polyurethane, and the combination of silver salts with different water solubility is adjusted so that silver release is constant over the entire period of time that the coated apparatus is used.

Other methods of using silver ions are described in WO 2001/037670 A and US 2003/0147960 A. WO 2001/037670 A describes an antimicrobial agent which complexes silver ions to zeolites. US 2003/0147960 A describes a coating in which silver ions are bonded to a mixture of hydrophilic and hydrophobic polymers.

The above methods using silver salts have the above-mentioned disadvantages, and are further complicated to carry out, resulting in high production costs, and thus still needing an improved silver-containing coating in terms of manufacturing process and activity.

One interesting possibility for the antibacterial treatment of plastics is the use of nanocrystalline silver particles. An advantage over metallic silver coatings is that the surface area of the nanocrystalline silver is much larger than its volume, which results in increased release of silver ions compared to metallic silver coatings.

Furno et al., Journal of Antimicrobial Chemotherapy 2004, 54, pp. 1019-1024 describe a method of using supercritical carbon dioxide to impregnate nanocrystalline silver into the silicon surface. Given the complex impregnation process and the essential use of supercritical carbon dioxide, this method is expensive and not easy to apply.

In addition, there are a variety of known methods for incorporating nanocrystalline silver into plastics. See, for example, WO 01/09229 A1, WO 2004/024205 A1, EP 0 711 113 A and Muenstedt et al., Advanced Engineering Materials 2000, 2 (6), pages 380 to 386. Incorporation into urethanes is described. Pellets of a commercially available thermoplastic polyurethane are immersed in a solution with colloidal silver. In order to increase the antimicrobial activity, it is also mentioned in WO 2004/024205 A1 and DE 103 51 611 A1 that barium sulfate can be used as an additive. A corresponding product, such as a catheter, is then produced from the doped polyurethane pellets by extrusion. This procedure described in this publication furthermore has disadvantages due to the fact that the amount of silver remaining in the polyurethane pellets after dipping is not constant and / or cannot be measured in advance. Therefore, the effective silver content of the resulting product must be measured post-production, ie after production of the final product. In contrast, no procedure is known from these documents to ensure that an effective amount of silver is accurately provided in the resulting final product.

Similar procedures are described in EP 0 433 961 A. Here too, a mixture of thermoplastic urethane (Pellethane), silver powder and barium sulfate is mixed and extruded.

The disadvantage of this method is that a relatively large amount of silver is dispersed throughout the plastic element. Thus, this method is expensive and the incorporation of colloidal silver into the entire plastic matrix results in slow release of silver and in some cases insufficient activity. Improving the release of silver through the addition of barium sulphate requires additional costly processing steps.

Coating solutions comprising nanocrystalline silver and thermoplastic polyurethanes for the production of vascular prosthesis are described in WO 2006/032497 A. The structure of the polyurethane is not further specified, but since thermoplastics are claimed, one can assume the use of a polyurethane without urea. Antibacterial effect was determined by comparing the growth of Staphylococcus epidermidis cells attached to the surface of the test element compared to the control. However, anti-bacterial action detected in silver-containing coatings can be estimated to be low, since growth delays of only 33.2 h (starting from defined threshold growth) were observed at most compared to the control surface. Thus, this coating formulation is unsuitable for long time application as an implant or catheter.

A further problem is the use of solvents for the preparation of coating solutions. WO 2006/032497 A1 describes an antimicrobial implant having a flexible porous structure made from a biocompatible plastic in the form of a nonwoven structure. The components used include thermoplastic polyurethane solutions in chloroform. Chloroform is known to be a very toxic solvent. When coating a medical product implanted in the human body, there is a risk due to the residue of the toxic solvent after implantation in the human body.

A further disadvantage of colloidal silver in organic coating solutions is the common low stability of silver nanoparticles. In the organic solution, there may be aggregation of silver particles, so it is impossible to provide reproducible silver activity. Thus, in order to ensure unchanged silver activity between the batch, the organic solution with the addition of colloidal silver should be processed into the finished coating as soon as possible after its preparation. However, due to process practices, this procedure is sometimes not possible.

Thus, an aqueous polyurethane coating containing colloidally distributed silver is preferred as an antimicrobial coating.

US 2006/045899 describes antimicrobial agents using an aqueous polyurethane system. Antimicrobial agents are mixtures of different substances, which make the production of this product difficult. Except that the aqueous polyurethane system is a cationic or anionic stabilized dispersion, the properties of the aqueous polyurethane system are not precisely described.

CN 1760294 likewise refers to anionic polyurethane dispersions with silver powder having a particle size of 0.2 to 10 μm. According to the prior art, these particle sizes are not sufficient for high antimicrobial activity.

C.-W. Chou et al., Polymer Degradation and Stability 91 (2006), 1017-1024, describe sulfonate modified dispersions of polyether polyurethanes incorporating very small amounts (0.00151% to 0.0113% by weight) of colloidal silver. The purpose of this study was to improve the thermal and mechanical properties of the polyurethanes used. Antimicrobial activity has not been investigated and given this very small amount of silver, any such action is unlikely.

Starting from the prior art, it is an object of the present invention to provide a medical device having a coating exhibiting satisfactory antimicrobial activity.

One embodiment of the invention is a medical device comprising a coating obtained from an aqueous dispersion comprising at least one nonionic stabilized polyurethane urea and at least one silver-containing component.

Another embodiment of the invention is a macropolyol wherein said at least one nonionic stabilized polyurethane urea is selected from the group consisting of polyester polyols, polycarbonate polyols, polyether polyols and mixtures thereof It is the said medical apparatus containing a synthetic component.

Another embodiment of the invention is said medical device wherein said macropolyol synthesis component is selected from the group consisting of polyether polyols and polycarbonate polyols.

Another embodiment of the invention is that the polyurethaneurea of the coating is at least

a) at least one macropolyol;

b) at least one polyisocyanate;

c) at least one diamine or amino alcohol;

d) at least one monofunctional polyoxyalkylene ether; And

h) antimicrobial activity

It is the said medical apparatus synthesize | combined from.

Another embodiment of the invention is the medical device wherein the at least one silver-containing component is a highly porous silver powder, silver on a support material, or a colloidal silver sol.

Another embodiment of the invention is the medical device wherein the coating comprises nanocrystalline silver particles in an average size ranging from 1 to 1000 nm.

Another embodiment of the invention is characterized in that the amount of silver present in the coating is 0.1% to 10% by weight based on the amount of nonionic stabilized solid polyurethaneurea and calculated as Ag and Ag ⁺ It is the medical apparatus that is the scope.

Another embodiment of the present invention includes one or more coatings comprising applying to the medical device an aqueous dispersion comprising at least one nonionic stabilized polyurethaneurea and at least one silver-containing component. It is a manufacturing method of the said medical apparatus.

Another embodiment of the invention is the above method comprising applying the aqueous dispersion to the medical device by knife coating, printing, transfer coating, spraying, spin coating or dipping.

Another embodiment of the present invention is a medical device comprising a coating obtained by the above method.

Another embodiment of the invention is a contact lens, cannula, catheter, urology catheter, urinary catheter, ureteric catheter, central venous catheter, venous catheter, inlet catheter, outlet catheter, dilation balloon, angioplasty Catheter, biopsy catheter, stent introduction catheter, embolism filter introduction catheter, catheter filter introduction catheter, balloon catheter, inflatable medical device, endoscope, laryngoscope, tracheal instrument, endotracheal tube, respirator, tracheal aspiration Instruments, bronchoalveolar lavage catheters, catheters used for angioplasty, guide rods, insertion guides, vascular stoppers, pacemaker parts, cochlear implants, dental implants, drainage tubes, guide wires , Gloves, stents, implants, extracorporeal blood vessels, membranes, dialysis membranes, blood filters, circulatory aids, dressings for wound care, urine bags, stomach bags, medical The medical device is selected from the group consisting of an implant comprising an active agent, a stent comprising a medical active agent, a balloon surface comprising a medical active agent, a contraceptive agent comprising a medical active agent, an endoscope, a laryngoscope, and an infusion tube.

This object is achieved through the provision of a medical device having at least one coating obtained starting from an aqueous dispersion comprising at least one nonionic stabilized polyurethaneurea and at least one silver-containing component.

According to the present invention, it has been found that polyurethaneurea coatings comprising silver exhibit effective silver release when the polyurethane is nonionic modified and the coating is obtained starting from an aqueous dispersion. Corresponding experiments and corresponding comparative experiments according to the present invention supporting this finding are described below.

Polyurethane urea for the purposes of the present invention

의 우레탄기를 2개 이상 함유하는 반복 단위, 및(a) general structural formula

A repeating unit containing two or more urethane groups, and

를 함유하는 하나 이상의 반복 단위(b) urea

One or more repeating units containing

It is a polymer compound having.

Coating compositions for use according to the invention are based on polyurethaneureas that are not substantially ionic modified. This means, in the present invention, that the polyurethaneurea for use according to the invention is essentially free of ionic groups, for example more particularly sulfonate, carboxylate, phosphate and phosphonate groups.

As used herein, the term "substantially free of ionic groups" means that the resulting polyurethaneurea coating is generally at most 2.50% by weight, more particularly at most 2.00% by weight, preferably at most 1.50% by weight, particularly preferably It is meant to contain at most 1.00% by weight, in particular at most 0.50% by weight, and even more particularly free from ionic groups. Accordingly, it is particularly preferred that the polyurethaneurea does not contain any ionic groups.

Polyurethaneureas provided for the coating of medical devices according to the invention are preferably substantially linear molecules and may also be less preferred but branched. Substantially linear molecules are those having an average functionality of 1.7 to 2.3, more preferably 1.8 to 2.2, preferably selected from the group consisting of polyether polyols, polycarbonate polyols and polyester polyols as synthetic components. More preferably, it means a system having a slight degree of initial crosslinking comprising a macropolyol component of 1.9 to 2.1.

If a mixture of macropolyols and, if appropriate, polyols were used in the polyurethaneurea as described in more detail below, the average functionality represents the average value resulting from the entire macropolyol and / or polyol.

The number average molecular weight of the polyurethaneurea which is preferably used according to the present invention is preferably 1000 to 200,000, more preferably 5000 to 100,000. The number average molecular weight here is measured for polystyrene as standard material in dimethylacetamide at 30 ° C.

Polyurethane Urea

Polyurethaneurea based coating systems for use according to the invention are described in more detail below.

Polyurethaneureas used in the coating of medical devices according to the present invention are preferably at least one macropolyol component, at least one polyisocyanate component, at least one polyoxyalkylene ether, at least one diamine and / or amino alcohol, and preferably If formed by reaction of polyol components. Additional synthetic components may be present in the polyurethaneureas of the invention.

(a) macropolyol component

The composition of the polyurethaneurea coating provided according to the invention has units derived from at least one macropolyol component as a synthetic component.

This macropolyol component is generally selected from the group consisting of polyether polyols, polycarbonate polyols, polyester polyols and any desired mixtures thereof.

In one preferred embodiment of the invention, the synthetic component of the polyol is formed of a polyether polyol or polycarbonate polyol and also a mixture of polyether polyols and polycarbonate polyols.

In another embodiment of the invention, the synthetic component of the macropolyols is formed of polyether polyols, more particularly polyether diols. Polyether polyols and especially polyether diols are particularly preferred in terms of silver release. Corresponding experiments according to the invention supporting this finding are shown below.

In the following text, the individual macropolyol synthetic components are described in more detail, and the present invention generally includes only one synthetic component selected from polyether polyols, polyester polyols and polycarbonate polyols, Polyurethaneureas comprising a mixture. The polyurethaneurea provided according to the invention may also comprise one or more different representatives of this type of synthetic component.

The above defined functionality of the polyurethaneurea provided according to the invention is understood to be the average functionality if at least two different macropolyols and polyols or polyamines (described further in c) and e) are present in the polyurethaneurea do.

Polyether polyols

Hydroxyl-containing polyethers are self-polymerized by cyclic ethers such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin in the presence of BF3 or a basic catalyst. Or, for example, these ring compounds, if appropriate in a mixture or sequentially, starting components containing reactive hydrogen atoms, for example alcohols and amines or amino alcohols, for example water, ethylene glycol, propylene 1,2-glycol or These are prepared by addition reaction with propylene 1,3-glycol.

Preferred hydroxyl-containing polyethers are those based on ethylene oxide, propylene oxide or tetrahydrofuran or mixtures of these cyclic ethers. Particularly preferred hydroxyl-containing polyethers are those based on polymerized tetrahydrofuran. It is also possible to add other hydroxyl-containing polyethers, such as those based on ethylene oxide or propylene oxide, in which case the polyether based on tetrahydrofuran is preferably at least 50% by weight. It exists more than.

Polycarbonate polyols

Suitable for the introduction of units based on hydroxyl-containing polycarbonates in principle are polyhydroxy compounds having an average hydroxyl functionality of 1.7 to 2.3, preferably 1.8 to 2.2, more preferably 1.9 to 2.1.

Suitable hydroxyl-containing polycarbonates can be formulated with OH numbers, which can be obtained, for example, by reaction of carboxylic acid derivatives, for example diphenyl carbonate, dimethyl carbonate or phosgene with a polyol, preferably diol. The molecular weight measured through is preferably polycarbonate with 400 to 6000 g / mol, more preferably 500 to 5000 g / mol, more particularly 600 to 3000 g / mol. Examples of suitable diols include ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, 2-methyl-1,3-propanediol, 2,2,4-trimethylpentane-1,3-diol, di-, tri- or tetraethylene glycol, dipropylene glycol , Polypropylene glycol, dibutylene glycol, polybutylene glycol, bisphenol A, tetrabromobisphenol A, and also lactone modified diols.

The diol component preferably contains 40% to 100% by weight of hexanediol, preferably 1,6-hexanediol and / or hexanediol derivatives, preferably those containing ether or ester groups as well as terminal OH groups , Examples are products obtained by the reaction of 1 mole of hexanediol with at least 1 mole, preferably 1 to 2 moles of caprolactone, or through the self-esterification of hexane diols giving di- or trihexylene glycol. It is likewise possible to use polyether-polycarbonate diols. The hydroxyl polycarbonate should be substantially linear. However, if desired, they may be slightly branched due to the incorporation of multifunctional components, more particularly low molecular weight polyols. Examples of those suitable for this purpose are glycerol, trimethylolpropane, hexane-1,2,6-triol, butane-1,2,4-triol, trimethylolpropane, pentaerythritol, quinitol, mannitol, sorbitol , Methylglycoside or 1,3,4,6-dihydrohexitol. Preferred polycarbonates are those based on hexane-1,6-diol, and also co-diols with modifying action, for example butane-1,4-diol, or for example ε-caprolactone. More preferred polycarbonate diols are those based on mixtures of hexane-1,6-diol and butane-1,4-diol.

The polycarbonates are preferably substantially linear in structure and have only some three-dimensional crosslinking, resulting in a polyurethane having the same specifications as above.

Polyester polyol

Suitable hydroxyl-containing polyesters are, for example, reaction mixtures of polyhydric, preferably dihydric alcohols with polybasic, preferably dibasic polycarboxylic acids. Instead of the free carboxylic acid, it is also possible to prepare the polyester using the corresponding polycarboxylic anhydrides or the corresponding polycarboxylic acid esters of lower alcohols, or mixtures thereof.

Polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and / or heterocyclic in nature and may be substituted and / or unsaturated, for example by a halogen atom, as appropriate. Aliphatic and cycloaliphatic dicarboxylic acids are preferred. Examples of these include succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, tetrachlorophthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, itaconic acid, sebacic acid, Glutaric acid, suberic acid, 2-methylsuccinic acid, 3,3-diethylglutaric acid, 2,2-dimethylsuccinic acid, maleic acid, malonic acid, fumaric acid or dimethyl terephthalate. Anhydrides of these acids can also be used when present. Examples thereof include maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, glutaric anhydride, hexahydrophthalic anhydride and tetrachlorophthalic anhydride.

As polycarboxylic acids for use in small amounts, trimellitic acid can be mentioned here as appropriate.

The polyhydric alcohols used are preferably diols. Examples of such diols are, for example, ethylene glycol, propylene 1,2-glycol, propylene 1,3-glycol, butane-1,4-diol, butane-2,3-diol, diethylene glycol, triethylene glycol, hexane -1,6-diol, octane-1,8-diol, neopentyl glycol, 2-methyl-1,3-propanediol or neopentyl glycol hydroxypivalate. Polyester diols formed from lactones such as ε-caprolactone can also be used. Where appropriate, examples of polyols that can likewise be used are trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate.

(b) polyisocyanates

The composition of the polyurethaneurea coating provided according to the invention comprises units derived from at least one polyisocyanate as a synthetic component.

As the polyisocyanate (b), it is known to the person skilled in the art and the average NCO functionality of each or any of the preferred mixtures of each other, whether produced by a phosgene process or a phosgene free process, is at least 1, preferably at least 2 It is possible to use all aromatic, araliphatic, aliphatic and cycloaliphatic isocyanates. They may also contain iminooxadiazinedione, isocyanurate, uretdione, urethane, allophanate, biuret, urea, oxadiazinetrione, oxazolidinone, acylurea and / or carbodiimide structures. have. The polyisocyanates can be used individually or in admixture with one another in any desired mixture.

Preference is given to using isocyanates from a series of aliphatic or cycloaliphatic representatives having a carbon backbone (without NCO groups present) having 3 to 30, preferably 4 to 20 carbon atoms.

Particularly preferred compounds of component (b) are those of the above types having aliphatic and / or cycloaliphatic attached NCO groups, for example bis (isocyanatoalkyl) ethers, bis- and tris (isocyanatoalkyl) benzenes, -Toluene and -xylene, propane diisocyanate, butane diisocyanate, pentane diisocyanate, hexane diisocyanate (eg hexamethylene diisocyanate, HDI), heptane diisocyanate, octane diisocyanate, nonane diisocyanate (eg Trimethyl-HDI (TMDI) as a mixture of 2,4,4 and 2,2,4 isomers in general, nonane triisocyanate (eg, 4-isocyanatomethyl-1,8-octane diisocyanate), Decane diisocyanate, decane triisocyanate, undecane diisocyanate, undecane triisocyanate, dodecane diisocyanate, dodecane triisocyanate Carbonate, 1,3- and 1,4-bis (isocyanatomethyl) cyclohexane in hexanes (H ₆ XDI), 3- isocyanatomethyl -3,5,5- trimethyl cyclohexyl isocyanate (isophorone Isocyanate, IPDI), bis (4-isocyanatocyclohexyl) methane (H ₁₂ MDI) or bis (isocyanatomethyl) norbornane (NBDI).

Very particularly preferred compounds of component (b) are hexamethylene diisocyanate (HDI), trimethyl-HDI (TMDI), 2-methylpentane 1,5-diisocyanate (MPDI), isophorone diisocyanate (IPDI), 1,3 And 1,4-bis (isocyanatomethyl) cyclohexane (H ₆ XDI), bis (isocyanatomethyl) norbornane (NBDI), 3 (4) -isocyanatomethyl-1- Methyl-1-methylcyclohexyl isocyanate (IMCI) and / or 4,4'-bis (isocyanatocyclohexyl) methane (H ₁₂ MDI) or mixtures of these isocyanates. Further examples are derivatives of the above diisocyanates having uretdione, isocyanurate, urethanes, allophanates, biurets, iminooxadiazinedione and / or oxadiazinetrione structures and more than two NCO groups.

The amount of component (b) in the coating of the invention is in each case preferably 1.0 to 3.5 moles, more preferably 1.0 to 3.3 moles, more particularly 1.0 to based on component (a) of the coating for use according to the invention 3.0 moles.

(c) diamine or amino alcohol

The composition of the polyurethaneurea coating provided according to the invention comprises units derived from one or more diamines or amino alcohols as synthetic components and acting as so-called chain extenders.

Such chain extenders are for example diamines or polyamines and also hydrazides such as hydrazines, 1,2-ethylenediamine, 1,2- and 1,3-diaminopropane, 1,4-diaminobutane, 1 Isomeric mixtures of, 6-diaminohexane, isophoronediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylenetriamine, 1,3- and 1 , 4-xylylenediamine, α, α, α ', α'-tetramethyl-1,3- and -1,4-xylylenediamine and 4,4'-diaminodicyclohexylmethane, dimethylethylene Diamine, hydrazine, adipic dihydrazide, 1,4-bis (aminomethyl) cyclohexane, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane and other (C ₁ -C ₄ ) Di- and tetraalkyldicyclohexylmethanes, for example 4,4'-diamino-3,5-diethyl-3 ', 5'-diisopropyldicyclohexylmethane.

Suitable diamines or amino alcohols generally contain low molecular weight diamines or amino alcohols containing active hydrogens having different reactivity with different NCO groups, for example primary amino groups as well as secondary amino groups or amino groups (primary or secondary) But also compounds containing OH groups. Examples of such compounds are primary and secondary amines such as 3-amino-1-methylaminopropane, 3-amino-1-ethylaminopropane, 3-amino-1-cyclohexylaminopropane, 3-amino- 1-methylaminobutane, and also amino alcohols such as N-aminoethylethanolamine, ethanolamine, 3-aminopropanol, neopentanolamine and particularly preferably diethanolamine.

Component (c) of the coating composition for use according to the invention can be used as a chain extender in view of the preparation of the coating composition.

The amount of component (c) in the coating composition for use according to the invention is in each case preferably 0.1 to 1.5 moles, more preferably 0.2 to 1.3 based on component (a) of the coating composition for use according to the invention Moles, more particularly 0.3 to 1.2 moles.

(d) polyoxyalkylene ethers

The polyurethaneurea used in the present invention has units derived from polyoxyalkylene ethers as synthetic components.

The polyoxyalkylene ether is preferably a copolymer of polyethylene oxide and polypropylene oxide. These copolymer units exist in the form of terminal groups in the polyurethaneurea and have the effect of hydrophilizing the coating composition of the present invention.

Suitable nonionic hydrophilic compounds which conform to the definition of component (d) are, for example, polyoxyalkylene ethers containing at least one hydroxyl group or amino group. These polymers contain units derived from ethylene oxide in a proportion of generally 30% by weight to 100% by weight.

The nonionic hydrophilization component (d) has an average of 5 to 70, preferably 7 to 55 ethylene jade, per molecule, of the type available in a conventional manner, for example via alkoxylation of suitable starter molecules. Monofunctional polyalkylene oxide polyether alcohols containing seed units (see, for example, Ullmanns Enzyklopaedie der technischen Chemie, 4th Edition, Volume 19, Verlag Chemie, Weinheim pp. 31-38).

Examples of suitable starting molecules are saturated monoalcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, isomeric pentanol, hexanol, octanol and nonanol, n -Decanol, n-dodecanol, n-tetradecanol, n-hexadecanol, n-octadecanol, cyclohexanol, isomeric methylcyclohexanol or hydroxymethylcyclohexane, 3-ethyl-3- Hydroxymethyloxetane or tetrahydrofurfuryl alcohol, diethylene glycol monoalkyl ether, for example diethylene glycol monobutyl ether, for example unsaturated alcohols such as allyl alcohol, 1,1-dimethylallyl alcohol or Oleyl alcohol, aromatic alcohols such as phenol, isomeric cresol or methoxyphenol, araliphatic alcohols such as benzyl alcohol, anylyl alcohol or cinnamil alcohol, secondary monoamines such as dimethylamine, di Ethylamine, dipropyl Min, diisopropylamine, dibutylamine, bis (2-ethylhexyl) amine, N-methyl- and N-ethylcyclohexylamine or dicyclohexylamine, and also heterocyclic secondary amines such as mor Pauline, pyrrolidine, piperidine or 1H-pyrazole. Preferred starting molecules are saturated monoalcohols. Particular preference is given to using diethylene glycol monobutyl ether as starting molecule.

Alkylene oxides suitable for the alkoxylation reaction are especially ethylene oxide and propylene oxide, which can be used in any order or in a mixture in the alkoxylation reaction.

Polyalkylene oxide polyether alcohols are mixed polyalkylene oxide polyethers in which the pure polyethylene oxide polyether or alkylene oxide units consist of ethylene oxide in the range of at least 30 mol%, preferably at least 40 mol%. . Preferred nonionic compounds are monofunctional mixed polyalkylene oxide polyethers containing at least 40 mol% ethylene oxide units and up to 60 mol% propylene oxide units.

If alkylene oxides, ethylene oxides and propylene oxides are used, they can be used in any order or in a mixture in the alkoxylation reaction.

The average molar weight of the polyoxyalkylene ether is preferably 500 g / mol to 5000 g / mol, more preferably 1000 g / mol to 4000 g / mol and more particularly 1000 to 3000 g / mol.

The amount of component (d) in the coating composition for use according to the invention is in each case preferably 0.01 to 0.5 moles, more preferably 0.02 to 0.4 based on component (a) of the coating composition for use according to the invention Moles, more particularly 0.04 to 0.3 moles.

(e) polyols

In a further embodiment, the composition of the polyurethaneurea coating provided according to the invention further comprises units derived from at least one polyol as a synthetic component. Compared to the macropolyols, these polyol synthetic components are relatively short chain synthetic components that can cause hardening through additional hard segments.

Low molecular weight polyols (e) used to synthesize polyurethaneureas generally have the effect of hardening and / or branching polymer chains. The low molecular weight is preferably 62 to 500 g / mol, more preferably 62 to 400 g / mol and more particularly 62 to 200 g / mol.

Suitable polyols may contain aliphatic, cycloaliphatic or aromatic groups. For example, low molecular weight polyols having up to about 20 carbon atoms per molecule, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4 Butanediol, 1,3-butylene glycol, cyclohexanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, neopentyl glycol, hydroquinone dihydroxyethyl ether, bisphenol A (2,2-bis (4-hydroxyphenyl) propane), hydrogenated bisphenol A (2,2-bis (4-hydroxycyclohexyl) propane), and also trimethylolpropane, glycerol or pentaerythritol and mixtures thereof, and if desired, Other low molecular weight polyols may be mentioned here. In addition, ester diols such as α-hydroxybutyl-ε-hydroxycaproic acid esters, ω-hydroxyhexyl-γ-hydroxybutyric acid esters, adipic acid β-hydroxyethyl esters or terephthalic acid bis (β- Hydroxyethyl) esters can be used.

The amount of component (e) in the coating composition for use according to the invention is in each case preferably 0.05 to 1.0 mole, more preferably 0.05 to 0.5 based on component (a) of the coating composition for use according to the invention Moles, more particularly 0.1 to 0.5 moles.

(f) additional amine- and / or hydroxy-containing units (synthetic components)

The reaction of the isocyanate containing component (b) with the hydroxy- or amine-functional compounds (a), (c), (d) and (e), if used, is typically observed in slightly excess relative to the reactive hydroxy or amine compound Is performed using NCO. In this case, at the end of the reaction through the attainment of the desired viscosity, there are always residues of active isocyanates. These residues must be blocked so that there is no reaction with the macromolecular chains. This reaction leads to three-dimensional crosslinking and gelation of the batch. Treatment of such coating solutions is no longer possible or only limitedly possible. The batch typically contains a large amount of water. Over the course of several hours, upon stirring or waiting of the batch at room temperature, water causes the remaining isocyanate groups to be consumed by the reaction.

However, if it is desired to quickly block the remaining residual isocyanate content, the polyurethaneurea coatings provided according to the invention may also comprise monomers (f) which in each case are located at the chain ends and capping them. have.

These units are derived on the one hand from monofunctional compounds which are reactive with NCO groups, for example monoamines, more particularly mono-secondary amines, or monoalcohols. For example ethanol, n-butanol, ethylene glycol monobutyl ether, 2-ethylhexanol, 1-octanol, 1-dodecanol, 1-hexadecanol, methylamine, ethylamine, propylamine, butylamine, octyl Amine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, N-methylaminopropylamine, diethyl (methyl) aminopropylamine, morpholine, Mention may be made of piperidine and suitable substituted derivatives thereof.

Since unit (f) is used essentially to destroy excess NCO in the coating of the invention, its required amount depends essentially on the excess NCO amount and cannot generally be specified.

Preferably this unit is not used during synthesis. In this case, unreacted isocyanate is preferably hydrolyzed by the dispersion water.

(g) additional ingredients

Antibacterial (antibacterial) polyurethaneurea coatings already provide sufficient functionality for the medical device of the present invention, but in certain cases it may be advantageous to incorporate additional functionality into the coating. Further possible such functionality is now described in more detail below.

In addition, the polyurethaneurea coatings provided according to the invention may comprise further components typical of the intended purpose, for example additives and fillers. Examples of such are active pharmacological substances, medicaments, and additives (drug-eluting additives) which promote the release of the active pharmaceutical substance.

Active pharmaceutical substances and medicaments that can be used for coating on the medical device of the invention generally include, for example, thromboresistant agents, antibiotics, anticancer agents, growth hormones, antiviral agents, angiantogenic agents, Angiogenesis agents, antimitotic agents, anti-inflammatory agents, cell cycle regulators, genetic agents, hormones, and their analogs, derivatives, fractions, pharmaceutical salts and combinations thereof.

Thus, specific examples of such agents and active pharmaceutical agents include thrombosis (non-thrombogenic) agents and other agents for inhibiting acute thrombosis, stenosis or late restenosis of the arteries, such as heparin, streptokinase. ), Urokinase, tissue plasminogen activator, antithromoxane-B ₂ agent, anti-B-thromboglobulin, prostaglandin-E, aspirin, dipyridimol, anti-trimoxane-A ₂ agent, murine Monoclonal antibody 7E3, triazolopyrimidine, cyprosten, hirudin, ticlopidine, nicolandil and the like. Growth factors can be used as a medicament for inhibiting subendometrial fibromyaloid hyperplasia at the site of arterial stenosis, or any other cell growth inhibitor can be used at the stenosis site.

The pharmaceutical or active pharmaceutical substance may also consist of vasodilators, such as vasodilators, for neutralizing anticonvulsants such as papaverine. The medicament may itself be an vascular agent, for example a calcium antagonist, or an α- and β-adrenene agonist or antagonist. The therapeutic agent can also be a biological adhesive such as medical grade cyanoacrylate, or fibrin, for example used to attach a tissue valve to the wall of a coronary artery.

The therapeutic agent may further be an anti-tumor agent, for example 5-fluorouracil, preferably in combination with a controlled release vehicle of the formulation (e.g., for use of a sustained controlled release anti-tumor agent at the tumor site. ).

The therapeutic agent may preferably be an antibiotic in combination with a controlled release vehicle for sustained release from the medical device coating at a local infection lesion in the body. Similarly, the therapeutic agent may include a steroid for suppressing inflammation of local tissue or for other reasons.

Specific examples of suitable agents are

(a) lytic agents, homologues, analogs thereof, including heparin, heparin sulfate, hirudin, hyaluronic acid, chondroitin sulfate, dermatan sulfate, keratan sulfate, urokinase and streptokinase Water, fragments, derivatives and pharmaceutical salts thereof,

(b) antibiotics such as penicillin, cephalosporin, bacomycin, aminoglycosides, quinolone, polymycin, erythromycin, tetracycline, chloramphenicol, clindamycin, lincomycin, sulfonamides, analogs thereof , Analogs, derivatives, pharmaceutical salts and mixtures thereof,

(c) paclitaxel, docetaxel, immunosuppressive agents, for example sirolimus or everolimus, mechlorethamine, chlorambucil, cyclophosphamide, melphalan and ifosfamide, alkylating agents, methotrexate, 6- Anti-metabolites including mercaptopurine, 5-fluorouracil and cytarabine, plant alkoids including vinblastine, vincristine and etoposide, doxorubicin, daunomycin, bleomycin and Antibiotics containing mitomycin, nitrosurea including carmustine and romustine, inorganic ions containing cisplatin, biological reaction modifiers containing interferon, angiostatin and endostatin, asparaginase Enzymes, including, and hormones, including tamoxifen and flutamide, homologues, analogs, fragments, derivatives, pharmaceutical salts thereof, and the like Mixtures, and

(d) antiviral agents, for example amantadine, rimantadine, rabavirin, idoxiuridine, vidarabine, trifluridine, acyclovir, gancyclovir, zidobudine, phosphonoformates, interferons, homologues thereof , Analogs, fragments, derivatives, pharmaceutical salts and mixtures thereof, and

(e) anti-inflammatory agents such as ibuprofen, dexamethasone or methylprednisolone

It includes.

In addition, typical additives and auxiliaries, such as thickeners, hand assistants, pigments, dyes, quenchers, UV stabilizers, phenolic antioxidants, light stabilizers, hydrophobicizing agents and / or flow control auxiliaries are likewise present. It can be used in coatings provided according to the invention.

(h) antibacterial silver

The polyurethaneurea dispersions used according to the invention comprise at least one silver-containing component in addition to the polyurethaneurea.

"Silver-containing component" means any component capable of releasing silver in elemental or ionic form for the purposes of the present invention resulting in an antimicrobial (sterilizing / antibacterial) effect.

The bactericidal effect of silver is due to the interaction of silver ions with bacteria. A large surface area of silver is advantageous so that the largest number of silver ions can be generated from elemental silver. As a result, mainly for antimicrobial applications, highly porous silver powders, silver or colloidal silver sol on support materials are used.

For example, Ag-Ion (silver in zeolite, Agion, Wakefield, Mass., USA), Ionpure® (Ag ^{+ in} glass, Ciba spegealititatenchememi) Ciba Spezialitaetenchemie GmbH, Lampertime, Germany, Alphasan® (AgZr phosphate, Milliken Chemical, Ghent, Belgium) Irgaguard® (zeolite / Ag in glass), Hygate® (silver powder, Bio-Gate, Nuremberg, Germany), Nanosilver® BG (silver in suspension) and Nanocid® (Silver on TiO ₂ , Pars Nano Nasb Co., Tehran, Iran) is currently commercially available.

Silver powder is preferably obtained from the gas phase and the silver melt is vaporized in helium. The resulting nanoparticles are obtained in the form of powders which immediately aggregate and are highly porous and easily filtered. However, a disadvantage of these powders is that the aggregates can no longer be dispersed into individual particles.

Colloidal silver dispersions are obtained by reducing silver salts in organic or aqueous media. Their preparation is more complicated than the preparation of silver powders, but offers the advantage that unaggregated nanoparticles are obtained. By incorporating unaggregated nanoparticles into the coating material, it is possible to produce transparent films.

For the silver-containing polyurethaneurea coatings of the present invention, it is possible to use any preferred silver powder or colloidal silver dispersion. Many of these silver materials are commercially available.

The silver sol, which is preferably used to prepare the silver-containing aqueous polyurethane dispersion of the present invention, is prepared by the pre-addition of the dispersing aid from Ag ₂ O followed by reduction with a reducing agent, for example an aqueous formaldehyde solution. For this purpose, Ag ₂ O sol is prepared, for example, in a batch manner, by rapid mixing of silver nitrate solution with rapid stirring with NaOH, or in a continuous manner using a micromixer according to DE 10 2006 017 696. The Ag ₂ O nanoparticles are then reduced by excess formaldehyde in a batch process and finally purified by centrifugation or membrane filtration, preferably by membrane filtration. This method of preparation is particularly advantageous because of the fact that it minimizes the amount of organic adjuvant bound on the surface of the nanoparticles. The product is a silver sol dispersion having an average particle size of approximately 10 to 150 nm, more preferably 20 to 100 nm.

It is possible to use nanocrystalline silver particles having an average size of 1 to 1000 nm, preferably 5 to 500 nm and very preferably 10 to 250 nm for the production of antimicrobial coated coatings. The silver nanoparticles can be dispersed in an organic solvent or water, preferably in a water miscible organic solvent or water, very preferably in water. The raw coating material is prepared by adding a silver dispersion to the polyurethane solution followed by homogenization by stirring or shaking.

The amount of nanocrystalline silver calculated on the basis of the amount of solid polymer and as Ag and Ag + may vary. Typical concentrations range from 0.1% to 10% by weight, preferably from 0.3% to 5% by weight, more preferably from 0.5% to 3% by weight.

Compared to many alternative methods, the advantage of the silver-containing polyurethanes of the present invention lies in the great ease of combining aqueous polyurethane dispersions with aqueous colloidal silver dispersions. Different silver concentrations can be easily and precisely set according to the requirements for different applications. Many methods of the prior art are substantially more complex and are not as precise as the methods of the present invention when it comes to metering the amount of silver.

In one particularly preferred embodiment, the antimicrobial silver is in the form of a highly porous silver powder, silver on the support material, or in the form of a colloidal silver sol, with 0.1% to 10% by weight of silver, based on the solid polyurethane polymer.

In a more particularly preferred embodiment, the antimicrobial silver is in the form of a colloidal silver sol in an aqueous medium or a water-miscible organic solvent having a particle size of 1 to 1000 nm, and the amount added is 0.3% to 5% by weight based on the solid polyurethane polymer. %to be.

In a more particularly preferred embodiment, the antimicrobial silver is in the form of a colloidal silver sol in an aqueous medium having an average particle size of 1 to 500 nm and the addition amount is 0.5% to 3% by weight based on the solid polyurethane polymer in the coating.

Coating composition

In one preferred embodiment, the coating composition provided according to the invention is at least

a) at least one macropolyol;

b) at least one polyisocyanate;

c) at least one diamine or amino alcohol; And

d) at least one monofunctional polyoxyalkylene ether; And also

h) at least one antimicrobial silver-containing component

Polyurethaneurea synthesized from.

In another embodiment of the invention, the coating composition provided according to the invention is at least

a) at least one macropolyol;

b) at least one polyisocyanate;

c) at least one diamine or amino alcohol;

d) at least one monofunctional polyoxyalkylene ether; And

e) at least one additional polyol; And also

h) at least one antimicrobial silver-containing component

Polyurethaneurea synthesized from.

In another embodiment of the invention, the coating composition provided according to the invention is at least

a) at least one macropolyol;

b) at least one polyisocyanate;

c) at least one diamine or amino alcohol;

d) at least one monofunctional polyoxyalkylene ether;

e) at least one additional polyol; And

f) at least one amine- or hydroxyl-containing monomer located at the polymer chain end; And also

h) at least one antimicrobial silver-containing component

Polyurethaneurea synthesized from.

Particularly preferred according to the invention for the coating of medical instruments is

a) at least one macropolyol having an average molar weight of 400 g / mol to 6000 g / mol and a hydroxyl functionality of 1.7 to 2.3;

b) at least one aliphatic, cycloaliphatic or aromatic polyisocyanate, or mixtures of such polyisocyanates, in an amount of 1.0 to 3.5 moles per mole of macropolyol;

c) at least one aliphatic or cycloaliphatic diamine or at least one amino alcohol, or a mixture of such compounds, in an amount of 0.1 to 1.5 moles per mole of the macropolyol as so-called chain extenders;

d) at least one monofunctional polyoxyalkylene ether having an average molar weight of 500 g / mol to 5000 g / mol, or a mixture of such polyethers, in an amount of 0.01 to 0.5 moles per mole of macropolyol;

e) if desired, at least one short-chain aliphatic polyol having a molar weight of 62 g / mol to 500 g / mol in an amount of 0.05 to 1 mole per mole of macropolyol; And

f) if desired, amine- or OH-containing units located at the polymer chain ends and capping them; And also

h) at least one antimicrobial silver-containing component

Polyurethaneurea dispersion synthesized from.

Particularly preferred according to the invention for the coating of medical instruments is

a) at least one macropolyol having an average molar weight of 500 g / mol to 5000 g / mol and a hydroxyl functionality of 1.8 to 2.2;

b) one or more aliphatic, cycloaliphatic or aromatic polyisocyanates, or mixtures of such polyisocyanates, in an amount of 1.0 to 3.3 moles per mole of macropolyol;

c) at least one aliphatic or cycloaliphatic diamine or at least one amino alcohol, or a mixture of such compounds, in an amount of 0.2 to 1.3 moles per mole of the macropolyol as so-called chain extenders;

d) at least one monofunctional polyoxyalkylene ether having an average molar weight of 1000 g / mol to 4000 g / mol, or a mixture of such polyethers, in an amount of 0.02 to 0.4 moles per mole of macropolyol;

e) if desired, at least one short-chain aliphatic polyol having a molar weight of 62 g / mol to 400 g / mol in an amount of 0.05 to 0.5 moles per mole of macropolyol; And

f) if desired, amine- or OH-containing units located at the polymer chain ends and capping them; And also

h) at least one antimicrobial silver-containing component

Polyurethaneurea dispersion synthesized from.

More preferred according to the invention for the coating of medical instruments

a) at least one macropolyol having an average molar weight of 600 g / mol to 3000 g / mol and a hydroxyl functionality of 1.9 to 2.1;

b) at least one aliphatic, cycloaliphatic or aromatic polyisocyanate, or mixtures of such polyisocyanates, in an amount of 1.0 to 3.0 moles per mole of macropolyol;

c) at least one aliphatic or cycloaliphatic diamine or at least one amino alcohol, or a mixture of such compounds, in an amount of 0.3 to 1.2 moles per mole of the macropolyol as so-called chain extenders;

d) at least one monofunctional polyoxyalkylene ether having an average molar weight of 1000 g / mol to 3000 g / mol, or a mixture of such polyethers, in an amount of 0.04 to 0.3 mol per mole of macropolyol, more particularly preferably Is a mixture of polyethylene oxide and polypropylene oxide; And

e) if desired, at least one short-chain aliphatic polyol having a molar weight of 62 g / mol to 400 g / mol in an amount of 0.1 to 0.5 moles per mole of macropolyol; And also

h) at least one antimicrobial silver-containing component

Polyurethaneurea dispersion synthesized from.

Medical instruments

The term "medical device" should be understood broadly in the context of the present invention. Non-limiting examples of suitable medical instruments (including equipment) include contact lenses, cannula, catheter, for example urological catheter, for example urinary catheter or ureter catheter, central venous catheter, venous catheter or inlet or outlet catheter, expansion balloon Catheters, balloon catheters or other inflatable medical devices, endoscopes, laryngoscopes, tracheal instruments, for example endotracheal tubes, respiratory organs and other organ aspiration, for use in introducing catheters, stents, embolism filters or venous vein filters for angioplasty and biopsy Instruments, bronchial alveolar lavage catheters, catheters used in angioplasty, guide wires, insertion guide devices, etc., blood vessel closures, pacemaker parts, snail implants, dental implants, drainage tubes and guide wires.

The coating solutions of the present invention may also contain protective coatings such as gloves, stents and other implants, external (external) blood vessels (blood delivery tubes), membranes such as dialysis, blood filters, circulatory support devices, wound care It can be used to produce a dressing material, a urine bag and a gastric bag. Also included are implants comprising a medical active agent, such as a stent or balloon surface or a medical active agent for contraceptives.

Medical instruments are typically formed from catheters, endoscopes, laryngoscopes, endotracheal tubes, feed ducts, guide rods, stents and other implants.

There are many materials suitable as substrates for surfaces to be coated such as metals, textiles, ceramics or plastics, and the use of metals and plastics is preferred for the manufacture of medical instruments.

Examples of metals may include medical stainless steel or nickel-titanium alloys.

In the case of catheters, these are preferably plastics such as polyamides, styrene and unsaturated compounds such as ethylene, butylenes and isoprene block copolymers, polyethylene or copolymers of polyethylene and polypropylene, silicones, polyvinyl chloride (PVC) and And / or made from polyurethane. For improved adhesion of the coating composition essential for the present invention, the surface of the medical article may be coated with a surface treatment, such as an adhesion promoter, in advance.

Preparation of Coating Dispersions Used According to the Invention

The synthetic components (a), (b), (d) and, if desired, (e) are first reacted to produce an isocyanate-functional prepolymer free of urea groups, wherein the amount ratio of material of isocyanate groups to isocyanate-reactive groups Is 0.8 to 3.5, preferably 0.9 to 3.0, more preferably 1.0 to 2.5, after which the remaining isocyanate groups are amino-functional chain extension or chain termination in water before, during or after dispersion, wherein The ratio of equivalents of isocyanate-reactive groups of the compounds used for chain extension to free isocyanate groups of the prepolymer is 40% to 150%, preferably 50% to 120%, more preferably 60% to 120%.

The polyurethaneurea dispersions of the invention which serve as starting materials for the preparation of the coatings of the invention are preferably prepared by a process known as the acetone process.

For the preparation of polyurethaneurea dispersions by this acetone process, typically all or part of the synthetic components (a), (d) and (e) preferably not containing any primary or secondary amino groups, and polyisocyanates Component (b) is introduced for the preparation of isocyanate-functional polyurethane prepolymers and, where appropriate, diluted with a water miscible solvent which is inert to the isocyanate groups and the initial charge is heated to a temperature in the range of 50 to 120 ° C. In order to accelerate the isocyanate addition reaction, it is possible to use catalysts known in polyurethane chemistry, for example dibutyltin dilaurate. It is preferable to synthesize without a catalyst.

Suitable solvents are typical aliphatic keto-functional solvents such as acetone, butanone, which may be added not only at the beginning of the preparation, but if desired, also later. Acetone and butanone are preferred. Other solvents such as xylene, toluene, cyclohexane, butyl acetate, methoxypropyl acetate and solvents with ether units or ester units can likewise be used and can be removed in whole or in part by distillation or remain completely in the dispersion. Can be.

The components (a), (b), (d) not added at the start of the reaction and, if used, any component from (e) can then be metered in.

In the preparation of the polyurethane prepolymers, the ratio of the amount of material of isocyanate groups to isocyanate-reactive groups is between 0.8 and 3.5, preferably between 0.9 and 3.0, more preferably between 1.0 and 2.5.

The reactions of components (a), (b), (d) and (e), if used, to provide a prepolymer are carried out partially or completely, but preferably completely. In this way, polyurethane prepolymers containing free isocyanate groups are obtained in bulk or in solution.

In a further process step, the resulting prepolymer is then dissolved by aliphatic ketones such as acetone or butanone if the reaction has not yet been carried out or only partially.

The possible NH ₂ -and / or NH-functional components are then reacted with the residual isocyanate groups. This chain extension / termination can alternatively be carried out in a solvent before dispersion, or in water during or after dispersion takes place. It is preferable to carry out chain extension before dispersing in water.

When a compound conforming to the definition of (c) with NH ₂ or NH group is used for chain extension, the chain extension of the prepolymer is preferably carried out before dispersion.

The degree of chain extension, ie, the equivalent ratio of the NCO-reactive groups of the compounds used for chain extension to the free NCO groups of the prepolymer, is from 40% to 150%, preferably from 50% to 120%, more preferably from 60% to 120%.

The amine component (c) can be used individually or in mixtures in the process of the invention, preferably in water-dispersed or solvent-dispersed form, in which case in principle any order of addition is possible. When water or an organic solvent is used as the diluent, the diluent content is preferably 70% to 95% by weight.

Preparation of the polyurethane dispersion from the prepolymer takes place after chain extension. For this purpose, the dissolved and chain-extended polyurethane polymer can, if appropriate, be introduced into the dispersion with strong shear, such as vigorous stirring, or, conversely, the dispersion is stirred into the prepolymer solution. Preferably water is added to the dissolved prepolymer.

The solvent still present in the dispersion after the dispersion step is then typically removed by distillation. Its removal is likewise possible during the actual dispersion step.

The solids content of the polyurethane dispersion is 20% to 70% by weight, preferably 20% to 65% by weight. For coating experiments, this dispersion can optionally be diluted with water to vary the thickness of the coating.

The polyurethane dispersions used according to the invention are then obtained by mixing the above-mentioned nonionic stabilized polyurethaneureas and / or the obtained polyurethaneureas with the silver-containing components as defined above and stirring the mixture or It is possible to homogenize by shaking.

Preparation of the medical device of the present invention

The invention further provides a method of making an antimicrobial equipped medical device comprising applying at least the coating composition described above to the surface of the medical device and then curing the coating.

The polyurethaneurea dispersions of the invention can be used to coat various substrates such as metals, plastics, ceramics, paper, leather or textiles. This coating can be applied to any conceivable substrate by various techniques such as spraying, dipping, knife coating, printing, spin coating or transfer coating. The preferred application of the hydrophilic coating is to the surface of the medical device and the implant as already mentioned above.

The invention further provides for the use of the medical device according to any one of claims 1 to 7 or 10 in medical technology.

The advantages of the polyurethaneurea solution of the present invention are illustrated by comparative examples in the following examples.

All documents described above are incorporated by reference in their entirety for all useful purposes.

While some specific structures have been shown and described that implement the invention, some of the various modifications and rearrangements may be made without departing from the spirit and scope of the underlying inventive concept, which is not limited to the specific forms shown and described herein. The sound will be apparent to those skilled in the art.

Example

The NCO content of the resins described in the invention and comparative examples is determined by titration according to DIN EN ISO 11909.

Solid content is measured according to DIN-EN ISO 3251. 1 g of polyurethane dispersion was dried to constant weight at 115 ° C. using an infrared dryer (15-20 minutes).

The average particle size of the polyurethane dispersion was measured using a high performance particle size meter (HPPS 3.3) from Malvern Instruments.

Unless stated otherwise, the amounts expressed in% are by weight and relate to the total solution obtained.

Substances and Abbreviations Used:

Desmophen C2200: polycarbonate polyol, OH number 56 mg KOH / g, number average molecular weight 2000 g / mol (Bayer AG, Leverkusen, Germany)

Desmophen C1200: polycarbonate polyol, OH value 56 mg KOH / g, number average molecular weight 2000 g / mol (Bay Agesa, Leverkusen, Germany)

PolyTHF ^® 2000: polytetramethylene glycol polyol, OH number 56 mg KOH / g, number average molecular weight 2000 g / mol (BASF AG, Ludwigshafen, Germany)

Polyether LB 25: (monofunctional polyether based on ethylene oxide / propylene oxide, number average molecular weight 2250 g / mol, OH value 25 mg KOH / g (Bayer Agesa, Leverkusen, Germany)

Example 1:

This example describes the preparation of the polyurethaneurea dispersion of the present invention.

277.2 g desmophene C 2200, 33.1 g polyether LB 25 and 6.7 g neopentyl glycol were introduced at 65 ° C. and stirred for 5 minutes to homogenize. This mixture was first mixed with 71.3 g of 4,4′-bis (isocyanatocyclohexyl) methane (H ₁₂ MDI) and then 11.9 g of isophorone diisocyanate at 65 ° C. over 1 minute. The reaction mixture was heated to 110 ° C. The theoretical NCO value was reached after 3 hours 40 minutes. The finished prepolymer was dissolved in 711 g of acetone at 50 ° C. and then a solution of 4.8 g of ethylenediamine in 16 g of water at 40 ° C. was metered in over 10 minutes. The subsequent stirring time was 15 minutes. Then, over 15 minutes, 590 g of water was added to effect dispersion. Subsequently, the solvent was removed by vacuum distillation. This gave a storage-stable polyurethane dispersion with a solids content of 41.5% and an average particle size of 164 nm.

Example 2:

This example describes the preparation of the polyurethaneurea dispersion of the present invention.

277.2 g of Desmofen C 1200, 33.1 g of Polyether LB 25 and 6.7 g of neopentyl glycol were introduced at 65 ° C. and stirred for 5 minutes to homogenize. This mixture was first mixed with 71.3 g of 4,4′-bis (isocyanatocyclohexyl) methane (H ₁₂ MDI) and then 11.9 g of isophorone diisocyanate at 65 ° C. over 1 minute. The reaction mixture was heated to 110 ° C. After 2.5 hours the theoretical NCO value was reached. The finished prepolymer was dissolved in 711 g of acetone at 50 ° C. and then a solution of 4.8 g of ethylenediamine in 16 g of water at 40 ° C. was metered in over 10 minutes. The subsequent stirring time was 5 minutes. Then, over 15 minutes, 590 g of water was added to effect dispersion. Subsequently, the solvent was removed by vacuum distillation. This gave a storage-stable polyurethane dispersion with a solids content of 40.4% and an average particle size of 146 nm.

Example 3:

This example describes the preparation of the polyurethaneurea dispersion of the present invention.

277.2 g polyTHF 2000, 33.1 g polyether LB 25 and 6.7 g neopentyl glycol were introduced at 65 ° C. and stirred for 5 minutes to homogenize. This mixture was first mixed with 71.3 g of 4,4′-bis (isocyanatocyclohexyl) methane (H ₁₂ MDI) and then 11.9 g of isophorone diisocyanate at 65 ° C. over 1 minute. The reaction mixture was heated to 110 ° C. After 18 hours the theoretical NCO value was reached. The finished prepolymer was dissolved in 711 g of acetone at 50 ° C. and then a solution of 4.8 g of ethylenediamine in 16 g of water at 40 ° C. was metered in over 10 minutes. The subsequent stirring time was 5 minutes. Then, over 15 minutes, 590 g of water was added to effect dispersion. Subsequently, the solvent was removed by vacuum distillation. This gave a storage-stable polyurethane dispersion with a solids content of 40.7% and an average particle size of 166 nm.

Example 4:

This example describes the preparation of the polyurethaneurea dispersion of the present invention.

269.8 g polyTHF 2000, 49.7 g polyether LB 25 and 6.7 g neopentyl glycol were introduced at 65 ° C. and stirred for 5 minutes to homogenize. This mixture was first mixed with 71.3 g of 4,4′-bis (isocyanatocyclohexyl) methane (H ₁₂ MDI) and then 11.9 g of isophorone diisocyanate at 65 ° C. over 1 minute. The reaction mixture was heated to 110 ° C. After 17.5 hours the theoretical NCO value was reached. The finished prepolymer was dissolved in 711 g of acetone at 50 ° C. and then a solution of 4.8 g of ethylenediamine in 16 g of water at 40 ° C. was metered in over 10 minutes. The subsequent stirring time was 5 minutes. Then, over 15 minutes, 590 g of water was added to effect dispersion. Subsequently, the solvent was removed by vacuum distillation. This gave a storage-stable polyurethane dispersion with a solids content of 41.6% and an average particle size of 107 nm.

Example 5:

This example describes the preparation of the polyurethaneurea dispersion of the present invention.

282.1 g polyTHF 2000, 22.0 g polyether LB 25 and 6.7 g neopentyl glycol were introduced at 65 ° C. and stirred for 5 minutes to homogenize. This mixture was first added with 71.3 g of 4,4'-bis (isocyanatocyclohexyl) methane (H ₁₂ MDI) and then 11.9 g of isophorone diisocyanate at 65 ° C. over 1 minute. The reaction mixture was heated to 110 ° C. After 21.5 hours the theoretical NCO value was reached. The finished prepolymer was dissolved in 711 g of acetone at 50 ° C. and then a solution of 4.8 g of ethylenediamine in 16 g of water at 40 ° C. was metered in over 10 minutes. The subsequent stirring time was 5 minutes. Then, over 15 minutes, 590 g of water was added to effect dispersion. Subsequently, the solvent was removed by vacuum distillation. This gave a storage-stable polyurethane dispersion with a solids content of 37.5% and an average particle size of 195 nm.

Example 6:

The 0.054 M silver nitrate solution is mixed with a mixture of 0.054 M sodium hydroxide solution and dispersion preparation Disperbyk 190 (BYK Chemie) (1 g / L) in a volume ratio of 1: 1, and the mixture is Stir for 10 minutes. Brown Ag ₂ O nanosols were formed. To the reaction mixture was added an aqueous 4.6 M formaldehyde solution with stirring, resulting in a molar ratio of Ag ⁺ to reducing agent of 1:10. The mixture was heated to 60 ° C. and held at this temperature for 30 minutes before cooling. The particles were purified by centrifugation (60 minutes at 30,000 rpm) and redispersed in complete demineralized water by the introduction of ultrasound (1 minute). This operation was repeated twice. A colloidally stable sol having a solids content (silver particles and dispersion aid) of 5% by weight was obtained in this way. The yield was almost 100%. After centrifugation, according to the elemental analysis, the silver dispersion contained 3% by weight of Disperbike 190 based on the silver content. Analysis by laser correlation spectroscopy showed an effective diameter of the particles of 73 nm.

50 ml of the polyurethane dispersions from Examples 1 to 5 were mixed with the 15.1% aqueous colloidal silver dispersion prepared as above and the mixture was homogenized by shaking. The amount of silver dispersion added to the polyurethane dispersions of Examples 1-5 allowed the dispersion to contain 1 weight percent silver based on the solid polymer content.

Example 7:  Silver emission research, chemical

Silver-containing coatings for the measurement of silver release were applied on a glass slide with dimensions 25x75 mm using a spin coater (RC5 Gyrset® 5, Karl Suess, German teaching material). Generated. For this purpose, slides treated with 3-aminopropyltriethoxysilane to improve adhesion are clamped onto the sample plate of the spin coater and uniformly covered with about 2.5 to 3 g of an aqueous non-diluted polyurethane dispersion. It was. The sample plate was spun at 1300 revolutions per minute for 20 seconds to give a uniform coating, which was dried at 100 ° C. for 15 minutes and then at 50 ° C. for 24 hours. From the slide thus obtained, 4.5 cm ² fragments were generated and used to measure the amount of silver released.

Slide pieces with various silver-containing polyurethane coatings of Examples 6a to 6e were covered with 2.5 ml of distilled water in a tablet tube and stored in the incubator for one week at 37 ° C. Water was removed and the amount of silver transferred from the film to the liquid was measured by atomic absorption spectroscopy. The dry film on the glass piece was again covered with 2.5 ml of water and stored further at 37 ° C. The entire process was repeated five times to determine silver release for several weeks.

The results show that the coating delivers silver over a relatively long time.

Example 8:

2.5 g of the silver-containing polyurethane dispersions of Examples 6b and 6d were weighed and dispensed into an aluminum container (6.4 cm in diameter, 1.3 cm in height). The aqueous dispersion was first left to dry at room temperature for 2 hours, then the still wet polymer was dried at 50 ° C. for 25 hours in a drying cabinet. The resulting polyurethane molded article was separated from the aluminum tray and cut into small plaques 5 mm in diameter. This silver-containing polyurethane plaque, 150 μm thick, was tested for its antimicrobial activity against Escherichia coli.

Polyurethane plaques comprising silver-containing polyurethane dispersions of Examples 6b and 6d with a diameter of 5 mm were investigated for their bactericidal action with a bacterial suspension of Escherichia coli ATCC 25922.

The colonies of Escherichia coli ATCC 25922 were colonized with colonies from Colombian agar (Colombia blood agar plate, Becton Dickinson, # 254071) and colonized from agar plates grown and grown overnight at 37 ° C. Was prepared by suspending in 0.9% sodium chloride solution. An aliquot of this solution was transferred to PBS (PBS pH 7.2, Gibco, # 20012) with 5% Muller Hinton medium (Becton Dickinson, # 257092) to give an OD600 of 0.0001. . This solution corresponded to the number of pathogens of 1 × 10 ⁵ pathogens per ml. The pathogen count was measured by performing a series of dilutions and plating out the dilution step on agar plates. Cell numbers were reported in the form of colony-forming units (CFU / ml).

Polyurethane plaques containing the silver-containing polyurethane dispersions of Examples 6b and 6d with a diameter of 5 mm were placed in each well of one of the 24-well microtiter plates. 1 ml E. coli ATCC 25922 suspension, 1 × 10 ⁵ pathogens per ml, was pipetted into each well on plaques and plates were incubated at 37 ° C. for 24 hours. Immediately after preparation of the experiment, and after 2, 4, 6 and 24 hours, 20 μl per well was recovered and the pathogen count measured. After 24 hours, sample plaques were removed and transferred to new 24-well microtiter plates. 1 ml of the bacterial suspension of E. coli ATCC 25922 prepared as described above was applied to the plaque again, followed by incubation at 37 ° C., and immediately after the experimental preparation and after 24 hours, 20 μl of each sample was removed to determine the number of pathogens. This was repeated for 10 days.

The results show more than one week of antibacterial coating. Freshly added bacterial suspensions were killed continuously with a very low pathogen count.

Example 9:

Silver-containing coatings for antimicrobial activity measurements were created on a glass slide with dimensions 25x75 mm using a spin coater (RC5 Girset 5, Karl Sauss, German teachings). For this purpose, slides treated with 3-aminopropyltriethoxysilane for improved adhesion were clamped onto the sample plate of the spin coater and uniformly covered with about 2.5 to 3 g of an aqueous undiluted polyurethane dispersion. . The sample plate was spun at 1300 revolutions per minute for 20 seconds to give a uniform coating, which was dried at 100 ° C. for 15 minutes and then at 50 ° C. for 24 hours. The resulting coated slides were used directly for antimicrobial activity measurement.

Testing of the antimicrobial activity was performed according to the following specifications:

The test pathogen E. coli ATCC 25922 was incubated overnight at 37 ° C. on Colombian agar (Colombia blood agar plate). Colonies were then suspended in PBS (PBS pH 7.2, Gibcosa, # 20012) with 5% Muller Hinton's medium (Becton Dickinson, # 257092) and set to a cell number of approximately 1 × 10 ⁵ pathogens / ml (“microbial suspension”). ). Test material was transferred to a Falcon tube filled with 30 ml of microbial suspension and incubated overnight at 37 ° C. After 24 hours, 20 μl of cell suspension was taken to monitor growth. Cell number was determined by serial dilution and plating out of the dilution step on agar plates. Cell numbers were reported in the form of colony-forming units (CFU / ml).

The coating of Example 6d was tested for antimicrobial action over 15 days. For this purpose the specification was continued so that known bacterial suspensions of known concentration were again applied to the coating after the determination of the pathogen count, and the pathogen count was again measured after 24 hours. The film was irrigated with PBS buffer on days 4-6 and 9-14.

Example 10-Comparative Experiment:

Silver Release from Sulfonate-Containing Dispersions

Dispercoll® U 53 and Impranil® DLN were used. Both were polyester containing polyurethaneureas based on aliphatic diisocyanates and stabilized with sulfonic acid groups.

Comparison of Nonionic Dispersions of the Invention:

Weeks 1 and 2 had relatively low levels of silver release compared to the nonionic dispersions of the present invention.

After 4-5 weeks of storage both sulfonate-containing coatings were hard and brittle. The sharp increase in silver release at 5 and 6 weeks can be explained by the degradation of the polymer matrix.

Example 14-Comparative Experiment

In addition, in the study of bacterial adhesion of E. coli on different polyurethane surfaces, it was evident that the two nonionic dispersions (Examples 2 and 4) had a relatively low affinity for E. coli without the use of Ag. This experiment was performed by a method based on Japanese standard JIS Z 2801.

For this purpose, the test pathogen E. coli ATCC 25922 was incubated at 37 ° C. on a Colombian agar. Multiple colonies were then suspended in phosphate-buffered saline (PBS) with 5% Muller Hinton's medium and a cell number of approximately 1 × 10 ⁵ pathogens / ml was set. 100 μl of each suspension was distributed onto the test material (in this case a coating free of nanocrystalline silver) using a piece of Parafilm with dimensions 20 × 20 mm to uniformly wet the surface with the cell suspension. Subsequently, the test substance with the bacterial suspension was incubated in a humidity chamber at 37 ° C. for 6 hours. After 6 hours, 20 μl of cell suspension was taken to monitor growth. Cell number was measured by performing a series of dilutions and plating out the dilution step on agar plates. In this case, only living cells were measured. For all materials studied, pathogen growth up to approximately 10 ⁷ to 10 ⁸ pathogens / ml was measured. Thus, the test material did not interfere with microbial growth without the addition of nanocrystalline silver.

The parafilm was then removed from the test material and the test material was washed three times with 4 mL of PBS to remove free-floating cells. The test material was then transferred to 15 ml of PBS and sonicated for 30 seconds in an ultrasonic bath to detach bacteria attached to the surface of the test material. Colony-forming units per ml are shown in logarithmic state.

From these results it can be inferred that the nonionic dispersions exhibit a relatively low E. coli affinity compared to sulfonate-containing dispersions (impranyl DLN) without additional adjuvant. However, it still does not provide protection against infection alone, but it can easily break down relatively low concentrations of bacteria on the surface into relatively low concentrations of silver.

Claims (11)

A medical device comprising a coating obtained from an aqueous dispersion comprising at least one nonionic stabilized polyurethaneurea and at least one silver-containing component. The macropolyol synthetic component according to claim 1, wherein said at least one nonionic stabilized polyurethaneurea is selected from the group consisting of polyester polyols, polycarbonate polyols, polyether polyols, and mixtures thereof. Medical apparatus comprising a. The medical device of claim 2, wherein the macropolyol synthetic component is selected from the group consisting of polyether polyols and polycarbonate polyols. The method of claim 1, wherein the polyurethaneurea of the coating is at least a) at least one macropolyol; b) at least one polyisocyanate; c) at least one diamine or amino alcohol; d) at least one monofunctional polyoxyalkylene ether; And h) antimicrobial activity A medical instrument synthesized from. The medical device of claim 1, wherein the at least one silver-containing component is a highly porous silver powder, silver on a support material, or a colloidal silver sol. The medical device of claim 1, wherein the coating comprises nanocrystalline silver particles having an average size in the range of 1 to 1000 nm. The medical device of claim 1 wherein the amount of silver present in the coating ranges from 0.1% to 10% by weight, based on the amount of nonionic stabilized solid polyurethaneurea and as Ag and Ag +. . A method of making a medical device comprising at least one coating comprising applying to the medical device an aqueous dispersion comprising at least one nonionic stabilized polyurethaneurea and at least one silver-containing component. The method of claim 8, comprising applying the aqueous dispersion to the medical device by knifecoating, printing, transfer coating, spraying, spin coating, or dipping. A medical device comprising a coating obtained by the method of claim 8. The catheter of claim 1, wherein the contact lens, cannula, catheter, urology catheter, urinary catheter, ureteric catheter, central venous catheter, venous catheter, inlet catheter, exit catheter, dilation balloon, angioplasty catheter, biopsy catheter , Stent introduction catheter, embolism filter introduction catheter, venous venous filter introduction catheter, balloon catheter, inflatable medical device, endoscope, laryngoscope, tracheal instrument, endotracheal tube, respirator, tracheal suction instrument, bronchial alveolar Cleaning catheter, catheter used for angioplasty, guide rod, insertion guide, vascular stopper, pacemaker parts, cochlear implant, dental implant, drain tube, guide wire, glove, stent Containing implants, extracorporeal circulating blood vessels, membranes, dialysis membranes, blood filters, circulatory support apparatus, wound care dressings, urine bags, stomach bags, medical active agents A graft, the balloon surface including stents, medical agent containing a medical active agents, is selected from the group consisting of a contraceptive, endoscope, laryngoscope, and an injection pipe which includes a medical active medical device.