Electrophoretic Deposition of Green-Synthesized Hydroxyapatite on Thermally Oxidized Titanium: Enhanced Bioactivity and Antibacterial Performance

Titanium alloys such as Ti-6Al-4V are widely used in biomedical implants due to their excellent mechanical properties and biocompatibility, but their bioinert nature limits osseointegration and antibacterial performance. This study proposes a multifunctional surface coating system integrating a ther...

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Main Authors: Mariana Relva, Daniela Santo, Ricardo Alexandre, Pedro Faia, Sandra Carvalho, Zohra Benzarti, Susana Devesa
Format: Article
Language:English
Published: MDPI AG 2025-08-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/15/15/8598
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Summary:Titanium alloys such as Ti-6Al-4V are widely used in biomedical implants due to their excellent mechanical properties and biocompatibility, but their bioinert nature limits osseointegration and antibacterial performance. This study proposes a multifunctional surface coating system integrating a thermally oxidized TiO<sub>2</sub> interlayer with a hydroxyapatite (HAp) top layer synthesized via a green route using <i>Hylocereus undatus</i> extract. The HAp was deposited by electrophoretic deposition (EPD), enabling continuous coverage and strong adhesion to the pre-treated Ti-6Al-4V substrate. Structural, morphological, chemical, and electrical characterizations were performed using XRD, SEM, EDS, Raman spectroscopy, and impedance spectroscopy. Bioactivity was assessed through apatite formation in simulated body fluid (SBF), while antibacterial properties were evaluated against <i>Staphylococcus aureus</i>. The results demonstrated successful formation of crystalline TiO<sub>2</sub> (rutile phase) and calcium-rich HAp with good surface coverage. The HAp-coated surfaces exhibited significantly enhanced bioactivity and strong antibacterial performance, likely due to the combined effects of surface roughness and the bioactive compounds present in the plant extract. This study highlights the potential of eco-friendly, bio-inspired surface engineering to improve the biological performance of titanium-based implants.
ISSN:2076-3417