Stent with nanoporous surface

Abstract

Methods for fabricating a medical device having at least one porous layer include providing a medical device having at least one alloy and removing at least one component of the alloy to form the porous layer. Although methods may be used to make stent devices with porous layers, any other suitable medical device may be made having one or more porous layers. An alloy may include any suitable combination of metals and sometimes a combination of metal and non-metal. In some embodiments, one or more of the most electrochemically active component(s) of an alloy are removed by the dissolving (or “dealloying”) process, to leave a porous matrix behind. The porous matrix layer may then be infused with one or more therapeutic agents for enhancing treatment of a patient.

1 . A method of fabricating an implantable medical device having at least one porous layer for releasably containing at least one therapeutic agent, the method comprising: providing an implantable medical device comprising at least one alloy; and dealloying at least a portion of the implantable medical device to form at least one porous layer.  
     
     
         2 . A method as in  claim 1 , wherein the at least one alloy is cobalt-chromium.  
     
     
         3 . A method as in  claim 1 , wherein providing the implantable medical device comprises providing a stent having an outer surface and an inner surface.  
     
     
         4 . A method as in  claim 1 , wherein the stent is integrally formed from the at least one alloy.  
     
     
         5 . A method as in  claim 4 , wherein the stent comprises cobalt-chromium.  
     
     
         6 . A method as in  claim 1 , wherein providing the implantable medical device includes depositing the at least one alloy on at least one surface of the medical device.  
     
     
         7 . A method as in  claim 1 , wherein the alloy is disposed along an outer surface of the implantable medical device, such that the removing step forms the porous layer on the outer surface of the device.  
     
     
         8 . A method as in  claim 1 , wherein the alloy comprises at least one metal selected from the group consisting of gold, silver, nitinol, steel, chromium, iron, nickel, copper, aluminum, titanium, tantalum, cobalt, tungsten, palladium, vanadium, platinum and niobium.  
     
     
         9 . A method as in  claim 1 , wherein dealloying comprises dissolving a most electrochemically active component of the alloy.  
     
     
         10 . A method as in  claim 1 , further comprising introducing the at least one therapeutic agent into the porous layer.  
     
     
         11 . A method as in  claim 10 , wherein the at least one therapeutic agent comprises at least one anti-restenosis agent or anti-inflammatory agent for inhibiting restenosis of a coronary artery.  
     
     
         12 . A method as in  claim 3 , further comprising forming a porous layer on the inner surface of the stent.  
     
     
         13 . A method for treating a blood vessel using a stent, the method comprising: providing a dealloyed stent having at least one porous layer for releasably containing at least one drug; and placing the stent within the blood vessel at a desired location, wherein the stent releases the at least one drug from the at least one porous layer after placement.  
     
     
         14 . An implantable medical device having at least one porous layer, at least one the at least one porous layers comprising: at least one remaining metal component of an alloy comprising at least two metal components; and interstitial spaces, wherein the interstitial spaces comprise at least one removed metal component space of the alloy.  
     
     
         15 . An implantable medical device as in  claim 14 , wherein at least one of the at least two metal components is selected from the group consisting of gold, silver, nitinol, steel, chrome, iron, nickel, copper, aluminum, titanium, tantalum, cobalt, tungsten, palladium, vanadium, platinum and niobium.  
     
     
         16 . An implantable medical device as in  claim 14 , wherein the at least one removed metal component comprises a most electrochemically active component of the alloy.  
     
     
         17 . A method for forming a porous medical component, comprising: 
 providing a medical device component comprising a metallic surface;    chemically dealloying the metallic surface; and    thermally annealing the metallic surface.    
     
     
         18 . The method for forming a porous medical component in  claim 17 , further comprising altering the surface charge of the metallic surface.  
     
     
         19 . The method for forming a porous medical component in  claim 17 , further comprising altering the hydrophobicity of the metallic surface.  
     
     
         20 . The method for forming a porous medical component in  claim 17 , further comprising applying a binder to the metallic surface.