Medical devices with porous polymeric structures

Abstract

Medical articles with porous polymeric structures and methods of forming thereof are disclosed. The porous structure can have pores sizes that are nanoporous or greater than nanoporous. The porous structure can be a coating or layer of a medical device such as a stent, stent graft, catheter, or lead for pacemakers or implantable cardioverter defibrillators. Additionally, the body of the medical device can be a porous polymeric structure. The porous structure can be made from bioabsorbable polymers. The porous structures can be formed by contacting a polymer with a supercritical fluid.

What is claimed is: 
     
         1 . A stent comprising:
 a stent body; and   a coating disposed above at least a portion of the stent body, wherein the coating comprises a porous bioabsorbable polymer.   
     
     
         2 . The stent of  claim 1 , wherein the porous bioabsorbable polymer is nanoporous. 
     
     
         3 . The stent of  claim 1 , wherein the porous bioabsorbable polymer comprises pores greater than 1 μm and less than and equal to 10 μm. 
     
     
         4 . The stent of  claim 1 , wherein the porous coating comprises a closed cell porous structure. 
     
     
         5 . The stent of  claim 1 , wherein the porous coating comprises an open cell porous structure. 
     
     
         6 . The stent of  claim 1 , wherein the porous coating is impregnated with a therapeutic agent. 
     
     
         7 . The stent of  claim 1 , wherein the stent body is composed of a bioabsorbable polymer. 
     
     
         8 . The stent of  claim 1 , wherein the stent body is metal. 
     
     
         9 . The stent of  claim 1 , wherein the porous coating is disposed above an entire surface of the stent body. 
     
     
         10 . A stent comprising a stent scaffolding formed from a porous bioabsorbable polymer. 
     
     
         11 . The stent of  claim 10 , wherein the porous scaffolding comprises a closed cell porous structure. 
     
     
         12 . The stent of  claim 10 , wherein a coating is disposed above the porous scaffolding. 
     
     
         13 . The stent of  claim 12 , wherein the coating comprises a porous bioabsorbable polymer. 
     
     
         14 . The stent of  claim 10 , wherein the porous scaffolding is impregnated with a therapeutic agent. 
     
     
         15 . A stent comprising a stent scaffolding formed of an abluminal layer, a luminal layer, and optionally an inner layer, wherein at least one of the layers is a porous bioabsorbable polymer. 
     
     
         16 . The stent of  claim 15 , wherein the porous bioabsorbable polymer is nanoporous. 
     
     
         17 . The stent of  claim 15 , wherein the porous bioabsorbable polymer comprises pores greater than 1 μm and less than and equal to 10 μm. 
     
     
         18 . The stent of  claim 15 , wherein the porous layer comprises a closed cell porous structure. 
     
     
         19 . The stent of  claim 15 , wherein the porous layer comprises an open cell porous structure. 
     
     
         20 . The stent of  claim 15 , wherein the porous layer is impregnated with a therapeutic agent. 
     
     
         21 . The stent of  claim 15 , wherein the stent scaffolding comprises two layers, one layer being the porous layer comprising a therapeutic agent and the other layer being a nonporous polymer or a metal, the outer layer being adapted to provide structural support to a lumen upon implantation of the stent. 
     
     
         22 . The stent of  claim 15 , wherein the abluminal and luminal layers are the porous polymer layers comprising therapeutic agent and the inner layer is a nonporous polymer or metal being adapted to provide structural support to a lumen upon implantation of the stent. 
     
     
         23 . The stent of  claim 15 , wherein the inner layer is the porous polymer layer comprising therapeutic agent and the abluminal and luminal layers are nonporous polymer or metal being adapted to provide structural support to a lumen upon implantation of the stent.