Polymer metal and composite implantable medical devices

Abstract

A device and a method of manufacturing an implantable medical device, such as a stent, are described herein. The device includes a metallic region composed of a bioerodable metal and a polymer region composed of a biodegradable polymer contacting the metallic region. The metallic region may erode at a different rate when exposed to bodily fluids than the polymer region when exposed to bodily fluids. In certain embodiments, the polymer region is an outer layer and the metallic region is an inner layer of the device.

1 . A stent comprising:
 struts made of a metal comprising magnesium; and   a coating on the struts, wherein the coating comprises a biodegradable polymer.   
     
     
         2 . The stent of  claim 1 , wherein the biodegradable polymer is selected from the group consisting of polyanhydrides and polyorthoesters. 
     
     
         3 . The stent of  claim 1 , wherein the biodegradable polymer is selected from the group consisting of .poly(L-lactic acid) and poly(D,L-lactic acid). 
     
     
         4 . The stent of  claim 1 , wherein the coating completely surrounds the struts. 
     
     
         5 . The stent of  claim 1 , wherein the coating comprises a drug. 
     
     
         6 . A stent comprising a scaffolding including a pattern of interconnecting struts, wherein a cross section of a strut of the struts includes a core and a coating around the core, wherein the core is made of a bioerodible metal and the coating comprises a biodegradable polymer. 
     
     
         7 . The stent of  claim 6 , wherein the bioerodible metal comprises magnesium. 
     
     
         8 . The stent of  claim 6 , wherein the biodegradable polymer is selected from the group consisting of polyanhydrides and polyorthoesters. 
     
     
         9 . The stent of  claim 6 , wherein the biodegradable polymer is selected from the group consisting of .poly(L-lactic acid), poly(D,L-lactic acid), and poly(lactide-co-glycolide). 
     
     
         10 . The stent of  claim 6 , wherein the coating comprises a drug. 
     
     
         11 . The stent of  claim 6 , wherein upon implantation of the stent in a vessel, the core is configured to erode when erosion of the coating exposes a portion of the core to bodily fluids. 
     
     
         12 . The stent of  claim 6 , wherein upon implantation of the stent in a vessel, the coating inhibits or prevents direct contact or exposure of the core to a vascular environment. 
     
     
         13 . A stent comprising interconnecting struts, wherein a strut of the struts comprises a core comprising magnesium and a coating on the core, wherein the coating comprises a surface eroding polymer that prevents exposure of the core to a vascular environment for a selected time period upon implantation of the stent. 
     
     
         14 . The stent of  claim 13 , wherein the surface eroding polymer is selected from the group consisting of polyanhydrides and polyorthoesters. 
     
     
         15 . The stent of  claim 13 , wherein upon implantation of the stent in a vessel, the core erodes when erosion of the coating exposes a portion of the core to bodily fluids. 
     
     
         16 . A stent comprising interconnecting struts, wherein a strut of the struts comprises a core comprising magnesium and a coating over the core,
 wherein the coating includes a first layer over the core and a second layer over the first layer, wherein the first layer comprises a first biodegradable polymer and the second layer comprises a second biodegradable polymer, and   wherein the first biodegradable polymer has a different erosion rate than the second biodegradable polymer.   
     
     
         17 . The stent of  claim 16 , wherein the first biodegradable polymer is selected from the group consisting of polyanhydrides and polyorthoesters, and wherein the second biodegradable polymer is selected from the group consisting of .poly(L-lactic acid), poly(D,L-lactic acid), and poly(glycolic acid). 
     
     
         18 . A stent comprising interconnecting struts, wherein a strut of the struts comprises a core comprising magnesium and a bioerodible metal layer over the core, and wherein the core and the bioerodible metal layer have different erosion rates.