Method of manufacturing a medicated porous metal prosthesis

Abstract

A method of manufacturing a medicated prosthesis such as a stent. The method includes forming a stent out of porous metal and loading a therapeutic agent into the pores of the metal. In one embodiment the stent is formed from a sintered metal wire, sheet, or tube and can include adding a coating to the stent. When the stent is implanted into the vasculature of a patient, the therapeutic agent in the stent dissipates into the tissue of the vasculature proximate the stent.

What is claimed is:  
     
         1 . A method of manufacturing a prosthesis, comprising: 
 providing a porous metal material having a plurality of porous cavities;    forming the material into a prosthesis having a plurality of porous cavities; and    loading a therapeutic agent into the pores of the prosthesis.    
     
     
         2 . The method of    claim 1   , wherein the forming step comprises forming the metal into a stent.  
     
     
         3 . The method of    claim 1   , wherein the providing step comprises providing a sintered metallic material.  
     
     
         4 . The method of    claim 1   , wherein the providing step comprises weaving metallic fibers and sintering the metallic fibers to form a sintered metallic material.  
     
     
         5 . The method of    claim 2   , wherein: 
 the providing step includes providing a sheet of porous metal material; and    the forming step includes chemical etching the sheet into the form of an expandable stent.    
     
     
         6 . The method of    claim 5   , wherein the providing step includes sintering metallic particles into said sheet of porous metal material.  
     
     
         7 . The method of    claim 5   , wherein the providing step includes weaving metallic fibers into a sheet of porous metal material and sintering the woven metallic fibers into said sheet.  
     
     
         8 . The method of    claim 2   , wherein: 
 the providing step comprises providing a sheet of porous metal; and    the forming step includes cutting the sheet with a laser into the form of a stent.    
     
     
         9 . The method of    claim 8   , wherein the providing step comprises sintering metallic particles into said sheet.  
     
     
         10 . The method of    claim 8   , wherein the providing step comprises weaving metallic fibers into a sheet of porous metal.  
     
     
         11 . The method of    claim 10   , wherein the providing step further comprising sintering the woven metallic fibers.  
     
     
         12 . The method of    claim 2   , wherein the providing step further comprises providing a porous metal wire.  
     
     
         13 . The method of    claim 12   , wherein the providing step further includes sintering particles to form the wire.  
     
     
         14 . The method of    claim 12   , wherein the providing step comprises weaving metallic fibers into a sheet of porous metal.  
     
     
         15 . The method of    claim 14   , wherein the providing step further comprises sintering the metallic fibers.  
     
     
         16 . The method of    claim 15   , wherein the providing step further comprises: 
 arranging large diameter particles in a first horizontal plane;    arranging small diameter particles on both sides of the plane; and    sintering the large and small diameter particles into a sheet.    
     
     
         17 . The method of    claim 2   , wherein the providing step further comprises: 
 arranging large diameter particles along a first axis;    arranging small diameter particles radially outward from and coaxial to the large diameter particles; and    sintering the large and small diameter particles into a wire.    
     
     
         18 . The method of    claim 2   , wherein the step of loading the therapeutic agent comprises immersing the stent in a liquid solution containing the therapeutic agent.  
     
     
         19 . The method of    claim 2   , wherein the stent is emersed for a period of time sufficient to permit a therapeutic agent to be absorbed into the porous cavities of the stent.  
     
     
         20 . The method of    claim 2   , wherein the therapeutic agent is an anti-fibrin agent.  
     
     
         21 . The method of    claim 2   , wherein the therapeutic agent is an antithrombin agent.  
     
     
         22 . The method of    claim 2   , wherein the therapeutic agent is an anti-proliferative agent.  
     
     
         23 . The method of    claim 2   , wherein the therapeutic agent is an anti-coagulant.  
     
     
         24 . The method of    claim 2   , wherein the therapeutic agent is a GPII 6 III a  blocker.  
     
     
         25 . The method of    claim 2   , wherein the therapeutic agent is of the group comprising forskolin, aspirin, dipyridamole, coumadin, ticlopodine, or heparin.  
     
     
         26 . The method of    claim 2   , wherein the therapeutic agent is a vaso-active drug.  
     
     
         27 . The method of    claim 2   , wherein the therapeutic agent is an anti-inflammatory agent.  
     
     
         28 . The method of    claim 2   , wherein the therapeutic agent promotes endothelialization.  
     
     
         29 . The method of    claim 2   , further comprising coating the stent with a polymer.  
     
     
         30 . The method of    claim 29   , wherein the coating step occurs after the loading step.  
     
     
         31 . The method of    claim 29   , wherein the polymer is configured to release the therapeutic agent at a substantially constant rate.  
     
     
         32 . The method of    claim 29   , wherein the polymer is a biopolymer.  
     
     
         33 . The method of    claim 32   , wherein the polymer is a poly lactic acid or fibrin.  
     
     
         34 . The method of    claim 29   , wherein the polymer is a synthetic polymer.  
     
     
         35 . The method of    claim 33   , wherein the polymer is of the group comprising polyurethane, polyethylene teraphthalate tetrafluoride, polyethylene, polyethylene oxide (PEO) or silicone.  
     
     
         36 . The method of    claim 34   , wherein the polymer is a hydrogel.  
     
     
         37 . The method of    claim 29   , wherein the polymer is a heparin coating.  
     
     
         38 . The method of    claim 29   , wherein the polymer is mixed with the therapeutic agent.  
     
     
         39 . The method of    claim 29   , wherein the polymer is degradable.  
     
     
         40 . A method of manufacturing a stent comprising: 
 sintering the metalic fibers into a sintered stent material;    forming the sintered stent material into a stent; and    loading a therapeutic agent into porous cavities of the sintered metal stent.    
     
     
         41 . A method of manufacturing a sintered metal stent, comprising: 
 sintering metal particles into a sheet;    cutting the sheet into a porous metal stent; and    loading medication into porous cavities of the metal stent.    
     
     
         42 . The method of    claim 41   , wherein the sintering step includes weaving the metalic fibers into a sheet of porous metal and sintering the woven metalic fibers.