Characterization of natural hydroxyapatite originated from fish bone and its biocompatibility with osteoblasts.

Hydroxyapatite (HAP) was very attractive for using as bone implant material for a long period due to the close similarity with natural bone in composition and osteoconductive properties. In this study, three kinds of natural HAP (nHAP) derived from rainbow trout (Onchorynchus mkiss), cod (Gadus) and salmon (Oncorhynchus keta) bones were prepared using thermal calcination method for the first time. Resultant nHAPs were characterized by fourier transform infrared spectroscopy (FT-IR), x-ray diffraction analysis (XRD), field-emission scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis. Biocompatibility of calcined nHAP was evaluated through MTT cell viability assay and alkaline phosphatase activity experiment using mouse preosteoblast MC3T3-E1. Results of cell experiment indicated that the nHAP originated from rainbow trout and salmon bones showed better biological compatibility compared with the nHAP originated from cod bone and chemical synthetic HAP (cHAP). This is most likely attributed to the different element composition in nHAP, i.e., the nHAP derived from rainbow trout and salmon bones showed the presence of CO3 2- and Mg2+ . Therefore, the nHAP originated from rainbow trout and salmon bones have a great potential for application as implant material substitute in bone tissue engineering and the natural waste fish bone product can be used for hydroxyapatite synthesis as a part of bio-waste management.