Novel branched poly(l-lactide) with poly(glycerol-co-sebacate) core

A series of biodegradable poly (glycerol-sebacate-l-lactide) (PGSLA) copolymers, with variable PLLA length, were synthesized and characterized. The copolymers comprised PGS backbone chain with a nominal molecular weight of 2,800 g/mol. The length of each PLLA side chain covered the 800–14,000 range, while the length of the PLLA was easily controlled by the feed molar ratio of the l-lactide to the PGS. The structure of the copolymer was studied by nuclear magnetic resonance spectroscopy and gel permeation chromatography. Differential scanning calorimetric measurements and thermal gravimetric analysis had been performed to indicate the glass transition temperature (Tg), melting point (Tm), and the degree of crystallinity (χc). It was also found that the onset decomposition temperature (Td) of the copolymers was lower than those of the linear polylactide (LPLLA). After solution casting and solvent evaporation, porous structures were found in the copolymer films by scanning electron microscope (SEM). Water contact angle results showed that the hydrophilicity of the copolymers was much higher than that of linear PLLA. In vivo, PGSLA copolymer demonstrated a favorable tissue response profile compared to PGS/LPLLA blend. There was also significantly less inflammation and fibrosis during degradation. PGSLA might therefore serve as an excellent candidate material for medical applications, given its minimal in vivo tissue response.