Bioabsorbable stent with radiopaque layer and method of fabrication

Abstract

Embodiments of a stent and methods of fabricating the same with a bioabsorbable radiopaque layer are disclosed.

What is claimed is: 
     
         1 . A bioabsorbable stent comprising a stent scaffolding including a radiopaque layer and a support layer, the radiopaque layer comprising radiopaque material mixed within a first bioabsorable polymer, the support layer formed from a second bioabsorbable polymer. 
     
     
         2 . The stent of  claim 1 , wherein the support layer is adapted to be primarily responsible for maintaining patency within a vascular lumen. 
     
     
         3 . The stent of  claim 1 , wherein the second bioabsorbable polymer has a higher strength and modulus than the first bioabsorbable polymer. 
     
     
         4 . The stent of  claim 1 , wherein the radiopaque layer is a luminal or an abluminal layer. 
     
     
         5 . The stent of  claim 1 , wherein the radiopaque layer is an abluminal layer and the support layer is a luminal layer. 
     
     
         6 . The stent of  claim 1 , wherein the radiopaque layer is a luminal layer and the support layer is an abluminal layer. 
     
     
         7 . The stent of  claim 1 , further comprising a second support layer formed from the second bioabsorbable polymer, the radiopaque layer disposed between the first and second support layers. 
     
     
         8 . The stent of  claim 1 , further comprising a second radiopaque layer formed from the first bioabsorbable polymer, the support layer disposed between the first and second radiopaque layers. 
     
     
         9 . The stent of  claim 1 , wherein the radiopaque material comprises particles. 
     
     
         10 . The stent of  claim 9 , wherein the particles are nanoparticles. 
     
     
         11 . The stent of  claim 1 , wherein the radiopaque material comprises a corrodible metal, a biostable metal, metallic salts, or a combination thereof. 
     
     
         12 . The stent of  claim 1 , wherein the radiopaque material is selected from the group consisting of iodine, bromine, barium, tungsten, bismuth, magnesium, iron, zinc, ferrous sulfate, ferrous gluconate, ferrous carbonate, ferrous chloride, ferrous fumarate, ferrous iodide, ferrous lactate, ferrous succinate, barium sulfate, bismuth subcarbonate, bismuth potassium tartrate, bismuth sodium iodide, bismuth sodium tartrate, bismuth sodium triglycollamate, bismuth subsalicylate, zinc acetate, zinc carbonate, zinc citrate, zinc iodate, zinc iodide, zinc lactate, zinc phosphate, zinc salicylate, zinc stearate, zinc sulfate, and combinations thereof. 
     
     
         13 . The stent of  claim 1 , wherein the radiopaque material comprises between 5% and 40% by volume of the radiopaque layer. 
     
     
         14 . The stent of  claim 1 , wherein the support layer is 2 to 10 times thicker than the radiopaque layer. 
     
     
         15 . The stent of  claim 1 , wherein the thickness of the radiopaque layer is 5-100 μm. 
     
     
         16 . The stent of  claim 1 , further comprising a therapeutic layer disposed above or below the radiopaque layer.