Method for producing a bioactive surface on an endoprosthesis or on the balloon of a balloon catheter

Abstract

In a method for producing a bioactive surface on an endoprosthesis or on the balloon of a balloon catheter, the surface of the endoprosthesis or the surface of the balloon is softened. The surface of the endoprosthesis or of the balloon is moistened with a solution of an active ingredient and the solvent is separated from the active ingredient. The solvent can be a water-miscible solvent.

What is claimed is:  
     
         1 . A method for producing a bioactive surface on an endoprosthesis or on a balloon of a balloon catheter, comprising the steps of:
 softening a surface of the endoprosthesis or a surface of the balloon;   wetting the surface of the endoprosthesis or the surface of the balloon with a solution of an active ingredient in a solvent;   separating the solvent from the active ingredient;   wherein the surface of the endoprosthesis or the surface of the balloon is softened with a water-miscible solvent;   wherein the surface of the endoprosthesis or the surface of the balloon is softened with the solution of the active ingredient;   wherein the surface of the endoprosthesis or the surface of the balloon comprises a polymer.   
     
     
         2 . The method according to  claim 1 , wherein the solvent is dimethyl sulfoxide (DMSO), dioxane, dimethyl formamide (DMF), tetrahydrofuran (THF), methylene chloride or chloroform. 
     
     
         3 . The method according to  claim 1 , wherein the endoprosthesis or the balloon consists of a polymer. 
     
     
         4 . The method according to  claim 3 , wherein the balloon consists of nylon or of a nylon Pebax mixture. 
     
     
         5 . The method according to  claim 1 , wherein in the step of wetting the solvent of the solution of the active ingredient is miscible with water, wherein the active ingredient has a solubility of maximally 0.9 mg/ml in distilled water; and wherein the solvent of the solution is separated from the active ingredient in that the wetted endoprosthesis or the wetted balloon is immersed in water, wherein the active ingredient that is insoluble in water precipitates and partially deposits on the surface of the endoprosthesis or the surface of the balloon. 
     
     
         6 . The method according to  claim 1 , comprising the step of functionally coating the surface of the endoprosthesis or the surface of the balloon with a polymer layer prior to the step of softening, wetting, and separating. 
     
     
         7 . The method according to  claim 1 , wherein the active ingredient is selected from the group consisting of tretinoin, tretinoin derivatives, orphan receptor agonists, elafin derivatives, corticosteroids, steroid hormones, paclitaxel, taxol, taxol derivatives, rapamune, tacrolimus, hydrophobic proteins, and substances that change cell proliferation. 
     
     
         8 . The method according to  claim 7 , wherein the steroid hormones are selected from methyl prednisolone, dexamethasone and estradiol. 
     
     
         9 . The method according to  claim 7 , wherein a surface area of the endoprosthesis or the balloon is enlarged before softening. 
     
     
         10 . The method according to  claim 9 , wherein the surface area is mechanically, thermally, or chemically enlarged. 
     
     
         11 . The method according to  claim 1 , comprising the step of enlarging a surface area of the endoprosthesis or of the balloon by structuring or profiling before the step of softening. 
     
     
         12 . The method according to  claim 11 , wherein structuring or profiling is carried out by roughening. 
     
     
         13 . The method according to  claim 10 , wherein the step of enlarging the surface area generates depressions with a depth of 5-50 μm and a width of 5-50 μm on the surface of the endoprosthesis or the surface of the balloon. 
     
     
         14 . The method according to  claim 1 , wherein the endoprosthesis is a stent. 
     
     
         15 . A balloon of a balloon catheter that comprises a bioactive surface prepared according to  claim 1 . 
     
     
         16 . A balloon catheter comprising a balloon according to  claim 15 . 
     
     
         17 . An endoprothesis that comprises a bioactive surface prepared according to  claim 1 .