Method for fabricating medical devices with porous polymeric structures

摘要

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.

主权项

1. A method of fabricating a stent, comprising:
conveying a polymer gel comprising a bioabsorbable polymer dissolved in a solvent through an extruder, wherein the polymer gel allows coextrusion at a temperature below a melting point of the polymer; disposing a fluid into the extruder, wherein the fluid is supercritical in at least a portion of the extruder, the supercritical fluid being mixed or dispersed within the polymer, wherein a therapeutic agent is dissolved in the supercritical fluid, wherein the temperature is below a degradation temperature of the therapeutic agent; coextruding a tube comprising two layers, at least one layer being a porous layer formed from the polymer in the extruder, the porous structure of the layer being formed when the fluid becomes subcritical, wherein the therapeutic agent is impregnated within the porous layer; and forming a stent pattern in the coextruded tube.