Biomimetic hydroxyapatite/gelatin composites for bone tissue regeneration: Fabrication, characterization, and osteogenic differentiation in vitro

Abstract

Herein, we prepared a series of novel hydroxyapatite (HA) nanowire and gelatin composite films with varying HA to gelatin ratios, attempting to simulate the major features of the natural extracellular matrix of bone. The results showed that the ratio of HA nanowires to gelatin had a great influence on the physicochemical and biological properties of the composites. The morphology of the HA/gelatin 7/3 composite film had a fibrous and porous architecture, while the 5/5 and 3/7 samples led to the formation of non-porous rough surfaces. Additionally, an increase in HA content enhanced the composite mechanical properties, with a maximum tensile strength of 114 ± 8 MPa, respectively. The HA/gelatin composite films exhibited good cell adhesion and proliferation. Osteogenic differentiation of mouse bone marrow mesenchymal stem cells on the 7/3 composite film was superior to that of the remaining films, as evident by alkaline phosphatase activity, calcium deposition, and gene expression. Thus, the HA/gelatin 7/3 composite film prepared herein has potential as a bone substitute for bone repair and regeneration.