Extraction and characterization of biocompatible hydroxyapatite (Hap) from red big eye fish bone: Potential for biomedical applications and reducing biowastes

In this study, nanostructured hydroxyapatite (HAp) was successfully extracted from the bones of Priacanthus macracanthus (Red Big Eye), a species commonly processed in the fish industry, generating significant waste. The extraction process utilized an alkaline hydrolysis method optimized with 2 M sodium hydroxide at 250 °C for 5 h, producing high-purity HAp. Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of characteristic phosphate peaks at 1044 cm⁻¹ and 963 cm⁻¹, and hydroxyl peaks at 632 cm⁻¹. Powder X-ray diffraction (XRD) analysis showed prominent peaks at 2θ values of 25.9°, 32.2°, 39.8°, and 46.7°, corresponding to the crystalline planes of HAp. Field-emission scanning electron microscopy (FESEM) revealed spherical HAp particles with sizes ranging from 50 to 80 nm. Biocompatibility was assessed using human osteoblast-like MG-63 cells, showing a proliferation rate of 92 % compared to the control. Cytotoxicity tests indicated no significant adverse effects, supporting the potential use of this HAp in biomedical applications. Importantly, this method offers a sustainable solution for managing fish bone waste, contributing to pollution control by reducing environmental burdens associated with discarded bone wastes. Future research will focus on in vivo biocompatibility studies and exploring applications in pollution mitigation and tissue engineering. This study highlights the dual benefits of utilizing biowaste for valuable HAp production and addressing environmental pollution challenges, making it a promising approach for sustainable material synthesis and environmental management. The cost-effective and environmentally friendly process further underscores the feasibility of scaling up this method for industrial applications, providing a greener alternative to conventional HAp synthesis.