Creation of polylactide vascular scaffolds with high compressive strength using a novel melt-tube drawing method

Abstract

Tubular scaffolds have been commonly used for vascular stents, grafts, and replacement of the trachea. Common scaffolds are built from non-biodegradable synthetic polymers that have superior mechanical properties; these polymers include expanded poly(tetrafluoroethylene), poly(ethylene terephthalate), and poly(urethane). Unfortunately, biodegradable polymers are rarely used for vascular scaffolds due to their inferior mechanical properties. To overcome the current limitations of biodegradable tubular scaffolds, a novel polymer melt-tube drawing (MD) process that allows the fabrication of biodegradable vascular scaffolds with high compressive strength has been developed. The machine designed for the MD process uses a combination of melt extrusion and tube-drawing. In comparison to the scaffold prepared by conventional techniques, the poly(lactide) tubular scaffold fabricated using the MD process showed improved compressive strength and recovery ability as well as a smooth surface. Furthermore, the MD-tube displayed extensive chain orientation and increased crystallinity. As a result, this novel MD process has the potential to permit fabrication of biodegradable vascular scaffolds with excellent mechanical properties. It provides an opportunity to greatly expand the application of biodegradable polymeric tubes.