Fabrication and characterization of nano-rod hydroxyapatite from fish bones with osteo-biocompatible features

In this study, we highlight the eco-friendly and cost-effective fabrication of Osteo-biocompatible nano-rod hydroxyapatite (FB-nHAp) from the fish bones of Cyprinus carpio using the ultrasonic-assisted dissolution-precipitation technique, a promising method for fabricating biomaterials with high efficiency and minimal chemical use. Further, phase purity and crystallographic parameters were consistent with the hydroxyapatite standard JCPDS 00–009–0432, as determined from an X-ray diffraction (XRD) pattern. The presence of functional groups such as PO 4 3- , OH - , and B form CO 3 2- were confirmed by Fourier-transform infrared (FT-IR). The zeta potential value of FB-nHAp is −27.1 mV, which confirms the colloidal stability of the sample. Thermogravimetric analysis (TGA) results showed an overall weight loss of 12.7% up to 1200 °C, confirming the high thermal stability. Transmission electron microscopy (TEM) revealed agglomerated nano-rod-shaped particles with an average diameter of 42.64 ± 1.4 nm. The presence of elements (Ca, P, O and C), trace elements (Na and Mg) and calcium/phosphorus (Ca/P) molar ratio (1.66) was examined using energy-dispersive X-ray spectroscopy (EDX). Cell viability of the fabricated materials was evaluated in MC3T3-E1 cells using the CCK-8 assay, which showed that FB-nHAp exhibited higher cell viability than the control, demonstrating superior biocompatibility. Besides, the staining results (ARS and ALP) showed greater calcium deposition (100 μg/mL: 42.5%; 200 μg/mL: 67.5%) and ALP staining areas (100 μg/mL: 55.7%; 200 μg/mL: 69.5%) than in the control groups (ARS: 5.2% and ALP:14.7%). These results highlight the promising Osteo-biocompatible potential of FB-nHAp for biomedical applications, including bone substitutes and bone regenerative therapies.