Effect of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/gelatin ratios on the characteristics of biomimetic composite nanofibrous scaffolds

Biomimetic composite nanofibrous scaffolds were fabricated via the growth of calcium phosphate (CaP) crystals on electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/gelatin (PHGE) nanofibers with different polymer ratio to mimic the composite nature of bone tissue as well as the nanoscale features of extracellular matrix (ECM). The resulting composite scaffolds exhibited three-dimensionally interconnected microporous structures. The CaP crystals were successfully formed on not only the external surface but also the interior of the scaffolds. The amount of CaP crystals fabricated and the surface roughness of the scaffolds increased with increasing the PHBV content because of the formation of bead-typed CaP aggregates. Higher amount of CaP crystals significantly accelerated the deposit rate of bone-like apatite on the surface of composite membrane. The results of cytocompatibility tests demonstrated that PHGE41 scaffold, composed of PHBV/gelatin (4:1), promoted more rapid MC3T3-E1 proliferation and differentiation compared with other scaffolds. These results suggest that the PHGE composite scaffolds are ideal biomaterials for bone tissue engineering.