Biomimetic gelatin/chitosan/polyvinyl alcohol/nano-hydroxyapatite scaffolds for bone tissue engineering

Multi-component bone tissue engineering scaffolds are the dominant trend to address complex requirements of bone defect repair. In this study, to mimic component and microstructure of natural bone, polymers (natural and synthetic) and nano-hydroxyapatite (nHAp) were fabricated to form a porous composite scaffold. Gelatin (Gel), chitosan (CS) and polyvinyl alcohol (PVA) were first assembled to simulate extracellular matrix. The simulated matrix exhibited tunable pore size, porosity, swelling, pH, degradation and mechanical strength. After the incorporation of nHAp, the composite scaffolds showed improved compression resistance, pH adaptability, improved surface bioactivity and biomimetic structure. In addition, the composite scaffolds can effectively promote cell proliferation and adhesion, of which, scaffolds containing 12.5% of nHAp were demonstrated to have high osteogenic differentiation ability. Hence, these results suggest that Gel/CS/PVA/nHAp composite scaffolds could be a promising biomimetic scaffold for bone tissue engineering.