Bio-compatible poly(ester-urethane)s based on PEG–PCL–PLLA copolymer with tunable crystallization and bio-degradation properties

Abstract

Multi-block copolymer poly(ester-urethane)s with ethoxy or polyhedral oligomeric silsesquioxane (POSS) terminal functional groups were designed and synthesized by using polyethylene glycol–poly(ε-caprolactone)–poly(L-lactide) (PEG–PCL–PLLA) diols via urethane linkages. In addition, an efficient and green catalyst, bismuth ethylhexanoate, was used to prepare high molecular weight copolymers, and the influences of molecular compositions on the crystallinity, mechanical properties, biodegradability, cytocompatibility and blood-compatibility were systematically studied. By varying the terminal functional groups, as well as PEG, PCL and PLLA segment ratios, the materials exhibited highly tunable properties, especially including crystallinity, mechanical properties and degradation rate. Notably, these new functional materials may effectively be applied in the treatment of blood vessels because of the mentioned tunable properties.