Synthesis and characterization of biodegradable and thermoresponsive poly(1,8-Octanediol-glycerol-1,12-Dodecanedioate) and its composites for tissue engineering applications

Abstract

Biodegradable polyesters, poly(1,8-octanediol–glycerol–1,12-dodecanedioate)s (POGDA)s, were synthesized via polycondensation polymerization method without solvent and catalyst and with different monomer molar ratios. Formation of POGDA was confirmed with structural analysis by Fourier transform infrared spectroscopy. The effects of varying the monomer molar ratio on POGDA properties were illustrated in the gel content and swelling analysis, ultraviolet–visible spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, x-ray diffraction, tensile test and in vitro degradation tests. In vitro degradation tests were performed in phosphate-buffered solution at 37 °C for 60 days. Thermoresponsive behavior was revealed by POGDA with 0.5 mole ratio of glycerol (Gly), and bending tests were performed to study the shape memory effect. In vitro cytotoxicity tests and cell proliferation tests suggested that these POGDA polymers have potential applications in biomedical fields such as tissue engineering. POGDA (0.5 Gly) loading with hydroxyapatite (HA) were prepared using similar polycondensation polymerization method. Addition of HA improved the mechanical properties and decreased the degradation rate of the composites. Scaffolds were fabricated from POGDA/HA composites using solvent-free salt leaching method. Pore structure in scaffold was visualized with field emission scanning electron microscope and porosities were measured using liquid displacement test. The porous scaffolds fabricated from POGDA/HA composites were found to exhibit thermoresponsive behavior. The cell proliferation tests suggested that the scaffolds have good biocompatibility with fibroblast cells and have potential to be used in tissue engineering.