Role of poly (Propylene fumarate)(PPF) based scaffolds in bone regeneration

In tissue engineering applications, biomaterials have significant roles to support cells and promote cell growth, proliferation, and differentiation. The initial response of the cells to the scaffold directly affects the cell adhesion, growth, proliferation and differentiation. Therefore, biomaterials should be biocompatible, biodegradable, and have good mechanical properties. In recent years, natural polyesters and fumaric acid based polyesters have attracted a lot of interest in bone tissue engineering (BTE) applications because of their superior biocompatibility, biodegradability, and mechanical property. One of the extensively investigated polyester is poly (propylene fumarate) (PPF), an unsaturated linear polyester, which can be modified or crosslinked through its carbon-carbon double bonds and used in different composites in tissue engineering applications. The purpose of this study was to investigate the role of PPF based novel scaffolds in bone regeneration. For this purpose, synthesized PPF polymers were cured in the presence of two phosphonic acid based monomers; vinyl phosphonic acid (VPA) and vinyl phosphonic acid diethyl ester (VPES) at different concentrations with two methods: cure at body temperature (BT) in the presence of a suitable initiator and catalyst and UV cure at body temperature. Also, PPF/VPES based scaffolds were cured at different concentrations of beta-tricalcium phosphate (β-TCP, 0 per cent, 5 per cent, 10 per cent, 15 per cent, 20 per cent) at BT in order to support osteogenesis. Following analyses were carried out to indicate the osteoblast activity in the presence of this novel biomaterial. The morphology of the cell seeded scaffolds was analyzed by scanning electron microscopy (SEM). Biocompatibility, osteoblast cell attachment, proliferation, mineralization, alkaline phosphatase, and osteocalcin activities were evaluated. All experiments demonstrated that UV-cured and BT-cured PPF based scaffolds and its composites with β-TCP were biocompatible and promoted osteoblast cell attachment, proliferation, growth, and differentiation. Therefore, significant potential of the usage of crosslinked PPF/VPA and PPF/VPES based scaffolds in BTE applications was shown in this study.