Biological response of human osteoblasts cultured on magnesium-doped hydroxyapatite coatings on Ti6Al7Nb alloy substrates

Titanium–niobium alloys are increasingly recognised as promising materials for biomedical applications due to their favourable mechanical properties and biocompatibility. However, their limited bioactivity necessitates surface modification to enhance cellular interactions, particularly in dental and maxillofacial contexts where soft tissue integration is critical. In this study, magnesium-doped hydroxyapatite (HAp + Mg) coatings were deposited onto Ti6Al7Nb alloy substrates via RF magnetron sputtering, aiming to improve the cytocompatibility and biological performance of the metallic interface. Surface morphology, roughness, phase, and chemical composition of the coatings were investigated. This study aimed to evaluate in vitro biocompatibility and inflammatory potential of titanium-niobium based alloy and magnesium-doped hydroxyapatite-coated Ti6Al7Nb (Ti6Al7Nb/HAp + Mg) alloys, with a view toward their application in dental implants. In accordance with ISO 10993–5:1999 standards for biological evaluation of medical devices, both materials demonstrated good biocompatibility, exhibiting no cytotoxic effects on the proliferation of human osteoblasts. Importantly, while both surfaces supported cell viability, nitric oxide (NO) and interleukin-6 (IL-6) assays indicated that the Ti6Al7Nb/HAp + Mg surface did not trigger inflammatory responses, in contrast to the uncoated Ti6Al7Nb alloy. This finding suggests a beneficial immunomodulatory effect of the HAp + Mg coating. Collectively, these results support the cytocompatibility and reduced inflammatory potential of the Ti6Al7Nb/HAp + Mg alloy, encouraging its further development for clinical applications in dental implantology.