Biomimetic Surface Modification to Mitigate Bacterial Adhesion and Improve the Antibacterial Efficacy of Titanium Implants

Implanted medical devices often face the challenge of infections, which can compromise their successful integration and use. To address this issue, we have covalently grafted a tannin-based antimicrobial biopolymer tanfloc (TAN) and a self-assembling dipeptide N-fluorenylmethyloxycarbonyl-diphenylalanine (Fmoc-FF) onto the titania nanotube arrays (TiNTs) surface to enhance antibacterial properties. Due to its polyphenolic and ionic structural configuration, tanfloc possesses unique properties that enable it to interact with and disrupt bacterial cell walls and membranes. Fmoc-FF peptides, in conjugation with TiNT, can inhibit biofilm formation, eradicate pre-existing biofilms, and kill bacteria. A synergistic effect can be achieved by combining the topographical features of TiNTs with the inherent antibacterial characteristics of tanfloc and Fmoc-FF. This synergy can potentially mitigate bacterial threats and prevent bacterial colonization on medical implants, enhancing their safety and efficacy. The successful attachment of tanfloc and Fmoc-FF on TiNTs was confirmed through X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The antibacterial and antibiofilm efficacy of the tanfloc- and Fmoc-FF-functionalized TiNTs was evaluated against Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria. The findings suggest that the covalent conjugation of tanfloc and Fmoc-FF onto TiNTs is a promising approach to improve the infection resistance of titanium-based medical implants, with potential applications in orthopedic, dental, and other biomedical device areas.