Characterization of biodegradable poly(l‐lactide) tube over accelerated degradation

The next‐generation bioresorbable polymeric stents are undergoing continual research and development, especially how to control and optimize their degradation behaviors. The aim of this paper is to study the properties of a poly(l‐lactide) (PLLA) tube over accelerated degradation in vitro. Spherical nanoindentation was particularly adopted to measure the mechanical properties of PLLA tube; while differential scanning calorimetry and gel permeation chromatography were used for crystallinity and molecular weight measurements. Overall, the material degradation was captured by the local stress‐strain response obtained with spherical nanoindentation, and further confirmed with chemical analyses. The results are particularly useful for development of bioresorbable polymeric stents with improved performance.