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

Diseases caused by bacterial infection have resultedin seriousharm to human health. It is crucial to develop a multifunctional antibiotic-independentantibacterial platform for combating drug-resistant bacteria. Herein,titanium diboride (TiB2) nanosheets integrated with quaternizedchitosan (QCS) and indocyanine green (ICG) were successfully preparedas a synergetic photothermal/photodynamic antibacterial nanoplatform(TiB2-QCS-ICG). The TiB2-QCS-ICG nanocompositesexhibit effective photothermal conversion efficiency (24.92%) andexcellent singlet oxygen (O-1(2)) production capacitysimultaneously under 808 nm near-infrared irradiation. QCS improvedTiB(2) stability and dispersion, while also enhancing adhesionto bacteria and further accelerating the destruction of bacteria byheat and O-1(2). In vitro experimentsindicated that TiB2-QCS-ICG had excellent antibacterialproperties with an inhibition rate of 99.99% against Escherichiacoli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA), respectively. More importantly, in vivo studies revealed that the nanoplatform can effectivelyinhibit bacterial infection and accelerate wound healing. The effectivewound healing rate in the TiB2-QCS-ICG treatment groupwas 99.6% which was much higher than control groups. Taken together,the as-developed TiB2-QCS-ICG nanocomposite provides morepossibilities to develop metal borides for antibacterial infectionapplications.