Investigating the Biomedical Potential of Hydroxyapatite/Cerium oxide Nanocomposite: A Study on its Physicochemical, Antimicrobial, Anti-inflammatory and Cytotoxic Activities

Hydroxyapatite/Cerium oxide (HAp/CeO₂) nanocomposite was successfully synthesized via the hydrothermal method. The structural, spectroscopic, thermal, morphological, mechanical and biological characteristics of the as-prepared nanocomposite were comprehensively analyzed using various techniques. X-ray diffraction analysis confirmed the phase purity and crystallinity, with crystallite sizes estimated using the Scherrer equation and further evaluated through Williamson–Hall analysis. Fourier Transform Infrared spectroscopy validated the presence of characteristic functional groups, confirming interactions between HAp and CeO₂. Raman spectroscopy provided insights into vibrational characteristics, phonon modes and structural order. X-ray Photoelectron Spectroscopic Analysis revealed the elemental composition and oxidation states, providing a deeper understanding of surface chemistry. Thermogravimetric Analysis showed <5 % weight loss at high temperatures, indicating excellent thermal stability and confirming suitability for implant fabrication. BET surface area analysis revealed a high surface area of 74.902 m²/g for the composite material, surpassing pure HAp, suggesting enhanced reactivity and improved biological interactions. Morphological analysis by Field Emission Scanning Electron Microscopy (FE-SEM) coupled with Energy Dispersive X-ray (EDX) Analysis and Transmission Electron Microscopy (TEM) with Selected Area Electron Diffraction (SAED) pattern demonstrated well-dispersed CeO 2 nanoparticle distribution over HAp surface. In vitro cytocompatibility via MTT assay on 3T3-L1 fibroblast cells showed excellent cell viability across all concentrations, with high biocompatibility even at elevated dosages. The nanocomposite also exhibited potential anti-inflammatory activity, which could aid in reducing inflammatory responses, promoting osteointegration and accelerating tissue regeneration, making it highly beneficial for bone repair and post-implantation healing in biomedical applications. Antimicrobial activity against Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans demonstrated strong antibacterial and antifungal efficacy, reducing infection-related risks. Mechanical properties were evaluated to confirm suitability for bone-related applications. The synergistic combination of HAp and CeO₂ imparts multifunctional bioactivity, positioning the nanocomposite as a strong candidate for bone tissue engineering and biomedical implants.