Method of coating a stent with a polysaccharide layer and associated stents

Abstract

The invention concerns methods of coating stents and stents produced in accordance therewith. The object of the invention is to provide methods of coating stents with a polysaccharide layer which has improved adhesion capacity on the substrate surface of the implant, and to afford correspondingly functionalized stents. That is achieved inter alia by covalent bonding of a non-crosslinked hyaluronic acid to a substrate surface of the stent with the formation of hyaluronic acid layer and crosslinking of the hyaluronic acid layer.

What is claimed is:  
     
         1 . A method of coating a surface of a stent with a polysaccharide layer, the method comprising the steps of: 
 providing a stent with a surface prepared for covalent bonding of a polysaccharide thereto; and    bonding a non-crosslinked polysaccharide covalently to the prepared surface, thereby providing a polysaccharide surface layer.    
     
     
         2 . The method of  claim 1 , comprising the further step of: 
 forming a cross-linked polysaccharide outer layer.    
     
     
         3 . The method of  claim 2 , wherein: 
 the non-crosslinked polysaccharide is hyaluronic acid; and    the crosslinked polysaccharide outer layer is formed by crosslinking the polysaccharide surface layer.    
     
     
         4 . The method of  claim 3 , wherein: 
 the step of providing the stent with a surface prepared for covalent bonding comprises bonding a bonding agent layer to the substrate surface.    
     
     
         5 . The method of  claim 2 , wherein: 
 the non-crosslinked polysaccharide is hyaluronic acid; and    the crosslinked polysaccharide outer layer is formed by covalently bonding a layer of a crosslinked hyaluronic acid to the polysaccharide surface layer.    
     
     
         6 . The method of  claim 2 , wherein: 
 the non-crosslinked polysaccharide is hyaluronic acid; and    the crosslinked polysaccharide outer layer is formed by the steps of covalently bonding a layer of a non-crosslinked hyaluronic acid to the polysaccharide surface layer and crosslinking the non-crosslinked hyaluronic acid layer.    
     
     
         7 . The method of  claim 1 , wherein: 
 the step of providing the stent with a surface prepared for covalent bonding comprises bonding a bonding agent layer to the substrate surface; and    the step of bonding a non-crosslinked polysaccharide covalently to the prepared surface is accomplished by the steps of: 
 bonding a non-crosslinked chitosan covalently to the bonding agent; and  
 bonding a layer of crosslinked hyaluronic acid covalently to the chitosan.  
   
     
     
         8 . The method of  claim 1 , wherein: 
 the step of providing the stent with a surface prepared for covalent bonding comprises bonding a bonding agent layer to the substrate surface; and    the step of bonding a non-crosslinked polysaccharide covalently to the prepared surface is accomplished by the steps of: 
 bonding a non-crosslinked chitosan covalently to the bonding agent; and  
 bonding a layer of non-crosslinked hyaluronic acid covalently to the chitosan.  
   
     
     
         9 . A stent, comprising a polysaccharide surface layer applied by the method of  claim 1.