Near-Infrared Light-Responsive Multifunctional Photothermal/Photodynamic Titanium Diboride Nanocomposites for the Treatment of Antibiotic-Resistant Bacterial Infections.

Diseases caused by bacterial infection have resulted in serious harm to human health. It is crucial to develop a multifunctional antibiotic-independent antibacterial platform for combating drug-resistant bacteria. Herein, titanium diboride (TiB) nanosheets integrated with quaternized chitosan (QCS) and indocyanine green (ICG) were successfully prepared as a synergetic photothermal/photodynamic antibacterial nanoplatform (TiB-QCS-ICG). The TiB-QCS-ICG nanocomposites exhibit effective photothermal conversion efficiency (24.92%) and excellent singlet oxygen (O) production capacity simultaneously under 808 nm near-infrared irradiation. QCS improved TiB stability and dispersion, while also enhancing adhesion to bacteria and further accelerating the destruction of bacteria by heat and O. experiments indicated that TiB-QCS-ICG had excellent antibacterial properties with an inhibition rate of 99.99% against () and methicillin-resistant (MRSA), respectively. More importantly, studies revealed that the nanoplatform can effectively inhibit bacterial infection and accelerate wound healing. The effective wound healing rate in the TiB-QCS-ICG treatment group was 99.6% which was much higher than control groups. Taken together, the as-developed TiB-QCS-ICG nanocomposite provides more possibilities to develop metal borides for antibacterial infection applications.