TiO2 Nanotubes Guided Pt Nanorods Growth via Atomic Layer Deposition for Mild Photothermal Antibacterial Activity and Enhanced Fibroblast Response

Huan Liu¹Wangle Zhang²Boya Xu³Dongxuan Cai⁴Haochen Wang⁵Xiaofeng Chang¹Qin Zhou⁶Hao Feng⁷Wen Song⁸Zhe Li^6,9*

• ¹Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi'an, China
• ²Laboratory of Material Surface Engineering and Nanofabrication, National Key Laboratory of Energetic Materials, Xi’an Modern Chemistry Research Institute, Xi'an, China
• ³Department of Stomatology, The 941 Hospital of the Joint Service Support Force of the People's Liberation Army of China, Xining, China
• ⁴Department of stomatology, The 908th Hospital of the Chinese People's Liberation Army Joint Logistic Support Force, Nanchang, China
• ⁵State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Department of Prosthodontics，School of Stomatology , The Fourth Military Medical University, Xi’an, China
• ⁶Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, China
• ⁷Laboratory of Material Surface Engineering and Nanofabrication, Xi’an Modern Chemistry Research Institute, Xi’an, China
• ⁸State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration,Department of Prosthodontics, The Fourth Military Medical University, Xi'an, China
• ⁹Department of digital oral implantology and prosthodontics, College of Stomatology, Xi’an Jiaotong University, Xi’an, China

Soft tissue integration (STI) and antibacterial capability are critical for the long-term success of dental implants. However, achieving both simultaneously remains a major clinical challenge. In this study, we fabricated a novel nanostructured coating by embedding hollow platinum nanorods (PtNRs) into titania nanotubes (TNTs) via atomic layer deposition (ALD), resulting in a PtNR@TNT platform with stable architecture and dual biofunctionality. Structural characterizations confirmed that PtNRs were uniformly deposited along the inner walls of TNTs without compromising nanotopography or hydrophilicity. Long-term in vitro degradation studies demonstrated sustained Pt retention and minimal release (<50 μg L-1 over 12 weeks), indicating excellent safety. Under mild near-infrared (NIR) irradiation (0.5 W cm-², 42 °C - 45 °C), PtNR@TNT exhibited superior antibacterial performance against S. aureus and P. gingivalis, achieving over 99 % bacterial reduction via synergistic photothermal and photodynamic effects. Meanwhile, human gingival fibroblasts (HGFs) showed enhanced adhesion, proliferation, and migration on PtNR@TNT surfaces, with additional promotion observed after NIR exposure. qPCR analysis revealed that mPTT further upregulated related genes expressions including COL-1, FAK, ITGβ1, and VCL. Overall, our findings demonstrate that PtNR@TNT offers a promising surface modification strategy for dental implants by combining robust antibacterial efficacy with favorable soft tissue responses under clinically safe photothermal conditions.