Biodegradable galactitol based crosslinked polyesters for controlled release and bone tissue engineering.

Various classes of biodegradable polymers have been explored towards finding alternates for the existing treatments for bone disorders. In this framework, two families of polyesters using an array of crosslinkers were synthesized. One was based on galactiol/adipic acid and the other based on galactitol/dodecanedioic acid. The structures of the polymers were confirmed by FTIR and further confirmed by 1H NMR. DSC showed that the polymers were amorphous and the glass transition temperature increased with increase in crosslinking. DMA and contact angle analysis revealed that the modulus and hydrophobicity increased with increase in crosslinking. Swelling studies demonstrated that %swelling decreased with increase in crosslinking. The in vitro hydrolytic degradation studies and dye release studies of all the polymers exhibited that the degradation and release rate decreased with increase in crosslinking, hydrophobicity and modulus. Degradation and release followed first order kinetics and Higuchi kinetics, respectively. The preliminary in vitro cytotoxicity studies proved that this array of polymers was not cytotoxic. Osteogenic differentiation of pre-osteoblasts was observed in three dimensional (3D) porous scaffolds prepared using these polymers. This study demonstrates the ability to modulate the physical properties, degradation and release kinetics of these biodegradable polymers through smart selection of crosslinkers. The findings of these studies have important implications for developing novel biodegradable polymers for drug delivery and tissue engineering applications.