Self-Sacrificial\nAntibacterial Coating with Photothermal\nResponse for Inhibiting Implant Infection

Currently, titanium (Ti) metal implantation has become\none of the\nhottest surgeries. However, implant-related infections caused by drug-resistant\nbacteria are a serious problem facing clinical treatment. Therefore,\nmodifying the surface of the implant to endow it with the ability\nto destroy the biofilm on the implant surface and to kill bacteria\nat the infection site is an effective strategy for controlling drug-resistant\nbacterial infection on the implant surface. In this work, a Ti implant\n(M-Ti) was achieved by preparing two layers of coating on the surface\nof Ti. Specifically, the first coating comprised vancomycin (Van)\nand zeolitic imidazolate framework-8 (ZIF-8) nanoparticles. Then,\nthe second self-sacrificial coating with photothermal response based\non hexadecanol and Cu<sub>2</sub>O nanoparticles was encapsulated\non the first coating. After that, the M-Ti implant was applied to\ninhibit implant-related infection caused by methicillin-resistant Staphylococci aureus (MRSA). The results indicated\nthat under the irradiation of a near-infrared region 2 (NIR-II) laser,\nthe self-sacrificial coating could disintegrate the mature biofilm\nthrough mechanical stress generated by phase transition of hexadecanol.\nThe Van released from the first coating could kill bacteria synergistically\nwith photothermal therapy. The in vitro experimental results showed\nthat the killing efficiency of M-Ti against MRSA reached over 99.99%.\nThe implant-related infection model in mice implied that M-Ti was\nable to effectively destroy the biofilm and kill bacteria, thereby\nhindering the occurrence of inflammatory reactions and accelerating\nthe integration between tissues and implant. The advantages of facile\npreparation and favorable overall performance predicated the tremendous\npotential application of M-Ti in the fields of orthopedics, dentistry,\nand plastic surgery.