In vivo degradation characteristics of poly(glycerol sebacate).

We have developed a series of biodegradable elastomers, poly(glycerol sebacate) (PGS), based on glycerol and sebacic acid. The polymers are potentially useful in soft tissue regeneration and engineering. To evaluate the performance of PGS in a physiological environment, we compared their degradation profiles with poly(DL-lactide-co-glycolide) (50:50, carboxyl ended, M(w) 15,000) in vivo. Among the parameters examined are changes in weight and mechanical strength with time, implant geometry, surface characteristics, and degree of swelling. Unlike poly(DL-lactide-co-glycolide), PGS primarily degrades by surface erosion, which gives a linear degradation profile of mass, preservation of geometry and intact surface, and retention of mechanical strength.