Development and Characterization of a Biocomposite Material from Chitosan and New Zealand-Sourced Bovine-Derived Hydroxyapatite for Bone Regeneration

A biocomposite scaffold was developed using chitosan (CS) and bovine-derived hydroxyapatite (BHA). The prepared CS-BHA biocomposite scaffold was characterized for its physiochemical and biological properties and compared against control BHA scaffolds to evaluate the effects of CS. Energy-dispersive X-ray analysis confirmed the elemental composition of the CS-BHA scaffold, which presented peaks for C and 0 from CS and Ca and P along with trace elements in the bovine bone such as Na, Mg, and Cl. Fourier transform infrared spectroscopy confirmed the presence of phosphate, hydroxyl, carbonate, and amide functional groups attributed to the CS and BHA present in the biocomposite scaffolds. The CS-BHA scaffolds demonstrated an interconnected porous structure with pore sizes ranging from 60 to 600 pm and a total porosity of similar to 64-75%, as revealed by scanning electron microscopy and micro-CT analyses, respectively. Furthermore, thermogravimetric analysis revealed that the CS-BHA scaffold lost 70% of its weight when heated up to 1000 degrees C, which is characteristic of CS phase decomposition in the biocomposite. In vitro studies demonstrated that the CS-BHA scaffolds were biocompatible toward Saos-2 osteoblast-like cells, showing high cell viability and a significant increase in cell proliferation across the measured timepoints compared to the controls.