Lipase mediated functionalization of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with ascorbic acid into an antioxidant active biomaterial.

Naturally produced polyhydroxyalkanoates (PHAs) biopolymers have limited medical applications due to their brittle and hydrophobic nature. In this study poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV) copolymer was produced using engineered Escherichia coli YJ101, and further functionalized with ascorbic acid using Candida antarctica lipase B mediated esterification. Copolymer P(3HB-co-3HV)-ascorbic acid showed lower degree of crystallinity (9.96%), higher thermal degradation temperature (294.97 °C) and hydrophilicity (68°) as compared to P(3HB-co-3HV). Further, P(3HB-co-3HV)-ascorbic acid biomaterial showed 14% scavenging effect on 1,1-diphenyl-2-picryl-hydrazyl (DPPH), and 1.6 fold increase in biodegradability as compared to P(3HB-co-3HV). Improvement of PHAs polymer properties by adding functional groups could be a good approach to increase their biodegradability, economic value and important applications in the medical field.