Near-infrared responsive quaternized chitosan-coated MoS2/poly(vinyl alcohol) hydrogel with improved mechanical and rapid antibacterial properties

Hydrogel is an ideal biomedical material because of its 3D network structure. However, their applications are greatly limited due to their poor mechanical strength and antibacterial property. Herein, a physically cross-linked and light-responsive poly(vinyl alcohol) (PVA) hydrogel embedded with quaternized chitosan-coated molybdenum disulfide (QCS-MoS2) nanomaterials was successfully prepared. The photothermal performance of QCS-MoS2 was studied with the results that QCS-MoS2 could be employed as a superior photothermal agent for light responsive hydrogels. After being incorporated with QCS-MoS2, a hydrogen bonding network could be formed in the hydrogel matrix, significantly increasing the mechanical properties. Moreover, the hybrid hydrogels exhibited excellent antibacterial properties. 95.6 % of Staphylococcus aureus (S. aureus) and 98.8 % of Escherichia coli (E. coli) were killed in 15 min due to the synergistic effects of the high temperature and the reactive oxygen species (ROS) generated by the irradiation of 808 nm near-infrared (NIR) light. No cytotoxicity was found by the introduction of QCS-MoS2, suggesting a great potential in photothermal antibacterial application for biomedical materials.