Physicochemical characterization and in vitro biocompatibility assessment of hydrothermally synthesized hydroxyapatite from oyster shells

Abstract

Naturally produced Hydroxyapatite (HAP) yields beneficial attributes with regards to its biological functions including cell compatibility, proliferation and osteoinduction. This study synthesized HAP from oyster shells as a calcium source with multiple hydrothermal reaction times including 1 h, 6 h and 24 h at 150℃. A wet precipitated control sample was produced at room temperature. Characterization using FTIR, XRD, SEM-EDX and BET were conducted, followed by a degradation analysis. Bio-compatibility study of Oys-HAP was performed against Saos-2 osteoblast-like cells. The results showed nano scaled elongated and oval-shaped Oys-HAP particles with high crystallinity, beta-type carbonated, non-stoichiometric Ca/P ratio with a maximum surface area of 41.39 m2·g‒1. Furthermore, Oys-HAP samples were non-toxic and significantly enhanced Saos-2 cell proliferation by 65.6% compared to the negative control. These findings demonstrate the potential of oyster shell-derived Oys-HAP as a sustainable and effective biomaterial for biomedical applications.