Coating for a stent and a method of forming the same

Abstract

A coating for a stent and methods for coating a stent are provided. The coating may be used for the sustained delivery of an active ingredient or a combination of active ingredients.

What is claimed is:  
     
         1 . A method of coating a stent, comprising: 
 (a) forming a first layer supported by a stent substrate; and    (b) patterning said first layer by removing portions of said first layer.    
     
     
         2 . A coated stent produced in accordance with the method of  claim 1 .  
     
     
         3 . The method of  claim 1 , wherein said patterning comprises: 
 (a) forming a second layer on the surface of said stent prior to forming said first layer;    (b) patterning said second layer to form vias in said second layer, wherein said first layer is formed on the remaining portions of said second layer and in said vias; and    (c) patterning said second layer to remove portions of said the first layer disposed on the remaining portion of said second layer to pattern said first layer.    
     
     
         4 . The method of  claim 1 , additionally comprising forming a primer layer on the surface of said stent substrate prior to forming said first layer, wherein said patterning comprises: 
 (a) forming a second layer on said primer layer prior to forming said first layer;    (b) patterning said second layer to form vias in said second layer, wherein said primer layer remains essentially undisturbed on the surface of said stent substrate, and wherein said first layer is formed on the remaining portions of said second layer and in said vias on said primer layer; and    (c) removing the remaining portions of said second layer to remove portions of said first layer disposed on the remaining portions of said second layer to pattern said first layer.    
     
     
         5 . The method of  claim 1 , additionally comprising forming a second layer on the remaining portions of said first layer.  
     
     
         6 . The method of  claim 5 , wherein said first layer contains a first substance and said second layer contains a second substance different than said first substance.  
     
     
         7 . The method of  claim 6 , wherein said first or second substances are selected from a group of therapeutic agents, radiopaque elements and radioactive isotopes.  
     
     
         8 . The method of  claim 1 , wherein said patterning comprises: 
 (a) forming a second layer on the surface of said stent prior to forming said first layer;    (b) patterning said second layer to expose portions of the surface of said stent;    (c) forming depots in said stent between the remaining portions of said second layer, wherein said first layer fills said depots; and    (d) removing the remaining portions of said second layer to remove portions of said first layer disposed on the remaining portions of said second layer, wherein said first layer remains in said depots.    
     
     
         9 . The method of  claim 8 , additionally comprising reducing the profile of said first layer such that said first layer does not protrude out from said depots.  
     
     
         10 . The method of  claim 8 , additionally comprising forming a third layer over said first layer and on the surface of said stent.  
     
     
         11 . The method of  claim 10 , wherein said first layer contains a first substance and said third layer contains a second substance different from said first substance.  
     
     
         12 . The method of  claim 1 , wherein said patterning comprises: 
 (a) forming a second layer on said first layer;    (b) patterning said second layer to form vias in said second layer to expose portions of said first layer;    (c) removing the exposed portions of said first layer, wherein portions of said first layer positioned underneath the remaining portions of said second layer remain essentially undisturbed; and    (d) removing the remaining portions of said second layer to form a patterned first layer.    
     
     
         13 . The method of  claim 12 , additionally comprising forming a third layer on the remaining portions of said first layer.  
     
     
         14 . The method of  claim 13 , additionally comprising reducing the profile of said third layer so as to create an alternating pattern of said first layer and said third layer.  
     
     
         15 . The method of  claim 13 , wherein said first layer contains a first substance and said third layer contains a second substance different from said first substance.  
     
     
         16 . The method of  claim 12 , wherein the coating comprises a discontinuous first layer interrupted by a second layer.  
     
     
         17 . A coating for a stent comprising: 
 a first layer; and    a discontinuous second layer separated by said first layer.    
     
     
         18 . The coating of  claim 17 , wherein said first layer is a discontinuous layer separated by said second layer so as to create an alternating pattern of said first layer and said second layer disposed on the surface of the stent.  
     
     
         19 . The coating of  claim 17 , additionally comprising: 
 a primer layer disposed on the surface of the stent, wherein said first layer is a discontinuous layer separated by said second layer so as to create an alternating pattern of said first layer and said second layer disposed on said primer layer.    
     
     
         20 . The coating of  claim 17 , wherein said first layer contains a first substance and said second layer contains a second substance, and wherein the release rate of said first substance is different than the release rate of said second substance.  
     
     
         21 . The coating of  claim 17 , wherein said first substance is different than said second substance.  
     
     
         22 . The coating of  claim 17 , wherein the stent is a radially expandable stent.