Synthesis, characterization and in vitro degradation of a biodegradable elastomer

An elastorner was prepared front biodegradable components as a potential biomaterial for drug delivery and tissue engineering applications. The elastomer was synthesized in two steps. First, a star copolymer (SCP) was manufactured via ring opening polymerization of epsilon-caprolactone (epsilon-CL) with D,L-lactide using glycerol as initiator and stannous 2-ethylhexanoate as catalyst. This living SCP was further reacted with different ratios of a crosslinking nionorner, 2,2-bis(epsilon-CL-4-yl)-propane in the presence of epsilon-Cl as a solvent and co-monomer. The elastomers had very low glass transitions (-32degreesC), sol contents ranging from 17% to 37%, and were soft and weak with physical properties similar to those of natural elastomers such as elastin. The physical properties decreased in a logarithmic fashion with time when degraded in phosphate buffered saline, indicative of first-order degradation kinetics. The elastomers degraded relatively slowly, with degradation being incomplete after 12 weeks. (C) 2003 Elsevier Ltd. All rights reserved.