Biofilm ablation on titanium alloy surface by photothermal and chemotherapeutic synergistic therapy

With prolonged exposure in the human body, titanium alloy implants face challenges associated with bacterial attachment and proliferation, leading to implant failure and severe complications. Photothermal therapy (PTT) emerges as an efficient strategy for biofilm elimination. However, the local high temperature of PTT and incomplete bacteria ablation in low-temperature PTT pose risks of damage to normal tissues and biofilm recalcitrance, respectively. In this study, we synergistically combined photothermal therapy and chemotherapy to mildly disrupt biofilms of Staphylococcus aureus (S. aureus) to enhance the efficiency of biofilm ablation. The synergistic nanoplatform comprises near-infrared-light responsive conjugated polymers, heat-sensitive liposomes, and the antibiotic daptomycin for biofilm elimination. The heat generated by conjugated polymers, stimulated with 808 nm light, alters biofilm permeability and releases antibiotics locally to eradicate biofilm. The nanoparticles exhibit biofilm dispersion activity and can effectively inhibit biofilm growth for up to 5 days. Consequently, this nanoplatform based on conjugated polymers offers a reliable method for ablating biofilms on titanium alloy implant and exhibits potential in drug-resistant clinical applications.