Surface treatment of a polymeric stent

Abstract

Methods of treating the polymeric surfaces of a stent with a fluid including a solvent for the surface polymer are disclosed.

1 . A method for treating a polymeric surface of a stent comprising:
 contacting a polymeric surface of a stent with a first fluid, the first fluid comprising a solvent for the surface polymer, the solvent capable of dissolving the surface polymer;   allowing the solvent to modify at least a portion of the polymeric surface by dissolving at least a portion of the surface polymer; and   contacting the polymeric surface with a second fluid miscible with the solvent to remove all or a majority of the first fluid from the polymeric surface, the second fluid comprising a non-solvent for the surface polymer.   
   
   
       2 . The method of  claim 1 , wherein contacting the polymeric surface of the stent with the first fluid comprises immersing the stent in the first fluid. 
   
   
       3 . The method of  claim 1 , wherein contacting the polymeric surface of the stent with the first fluid comprises spraying the stent with the first fluid. 
   
   
       4 . The method of  claim 3 , wherein the second fluid removes all or a majority of dissolved surface polymer from the polymeric surface. 
   
   
       5 . The method of  claim 1 , wherein contacting the polymeric surface with a second fluid comprises immersing the stent in the second fluid. 
   
   
       6 . The method of  claim 5 , further comprising removing the second fluid from the polymer surface of the stent. 
   
   
       7 . The method of  claim 1 , wherein the surface comprises a surface of a coating layer including the surface polymer disposed over a substrate of the stent. 
   
   
       8 . The method of  claim 1 , wherein the surface comprises a surface of a substrate of the stent, the substrate comprising the surface polymer. 
   
   
       9 . The method of  claim 1 , wherein the solvent comprises chloroform and the surface polymer comprises poly(L-lactide). 
   
   
       10 . The method of  claim 1 , wherein the solvent is allowed to reduce or eliminate a surface imperfection. 
   
   
       11 . The method of  claim 1 , wherein the solvent is allowed to round edges of a structural element of the stent. 
   
   
       12 . The method of  claim 1 , wherein the portion of the surface polymer dissolved comprises at least a portion of a surface imperfection and/or a sharp edge of a strut. 
   
   
       13 . The method of  claim 1 , wherein the surface polymer is a biostable polymer, biodegradable polymer, or a combination thereof. 
   
   
       14 . The method of  claim 1 , wherein a region of the polymeric surface is selectively contacted with the treatment fluid. 
   
   
       15 . A method for treating a polymeric surface of a stent comprising contacting a polymeric surface of a stent with a gas stream, the gas stream comprising a solvent for the surface polymer, the solvent capable of dissolving the surface polymer, wherein the solvent in the gas is allowed to modify at least a portion of the polymeric surface by dissolving at least a portion of the surface polymer. 
   
   
       16 . The method of  claim 15 , wherein the gas stream selectively contacts a region a polymeric surface of a stent to selectively modify the region. 
   
   
       17 . The method of  claim 15 , wherein the gas stream contacts the polymeric surface with a nozzle directing the gas stream at the region. 
   
   
       18 . The method of  claim 15 , wherein the surface comprises a surface of a coating layer including the surface polymer disposed over a substrate of the stent. 
   
   
       19 . The method of  claim 15 , wherein the surface comprises a surface of a substrate of the stent, the substrate comprising the surface polymer. 
   
   
       20 . The method of  claim 15 , wherein the solvent comprises chloroform and the surface polymer comprises poly(L-lactide). 
   
   
       21 . The method of  claim 15 , wherein the solvent is allowed to reduce or eliminate a surface imperfection. 
   
   
       22 . The method of  claim 15 , wherein the solvent is allowed to round edges of a structural element of the stent. 
   
   
       23 . The method of  claim 15 , wherein the surface polymer is a biostable polymer, biodegradable polymer, or a combination thereof. 
   
   
       24 . The method of  claim 15 , wherein the portion of the surface polymer removed comprises at least a portion of a surface imperfection in the polymeric surface. 
   
   
       25 . The method of  claim 15 , wherein gas stream comprises particles, the particles modifying the surface by abrading the polymeric surface. 
   
   
       26 . A method for treating a polymeric surface of a stent comprising:
 contacting a polymeric surface of a stent with a fluid mixed with particles, the first fluid comprising a solvent for the surface polymer, the solvent capable of dissolving the surface polymer; and   allowing the solvent in the fluid and the particles to modify at least a portion of the polymeric surface, the solvent modifying the surface by dissolving at least a portion of the surface polymer, the particles modifying the surface by abrading the polymeric surface.   
   
   
       27 . The method of  claim 26 , further contacting the polymeric surface with a second fluid miscible with the solvent to remove all or a majority of the first fluid and the particles from the polymeric surface, the second fluid comprising a non-solvent for the surface polymer. 
   
   
       28 . The method of  claim 26 , wherein contacting a polymeric surface of a stent with a fluid mixed with the particles comprises flowing the fluid mixed with the particles over the polymeric surface. 
   
   
       29 . The method of  claim 26 , wherein the fluid mixture is flowed through a tube including the stent. 
   
   
       30 . The method of  claim 26 , wherein the polymeric surface of the stent is contacted with the stent by immersing the stent in the fluid mixture, wherein agitation of the fluid mixture causes the abrading of the polymeric surface. 
   
   
       31 . A method for treating a polymeric surface of a stent comprising:
 contacting a polymeric surface of a stent with a gas mixed with particles; and   allowing the particles to modify at least a portion of the polymeric surface, the particles modifying the surface by abrading the polymeric surface.