No abstract

Antibiotic-resistant bacteria and biofilms are among the most difficult challenges in infection treatment. Herein, lignin-copper sulfide (LS-CuS) nanocomposites were incorporated into a poly­(vinyl alcohol) (PVA) hydrogel to fabricate a LS-CuS@PVA composite hydrogel with near-infrared-activated photothermal, photodynamic, and peroxidase-like performance. The antibacterial tests of LS-CuS@PVA exhibited the highest antibacterial rate that caused 3.8-log and 4.8-log reductions of colony forming units (CFUs) against Escherichia coli and Staphylococcus aureus in the presence of H2O2 under near-infrared (NIR) light irradiation for 10 min. The significantly improved bactericidal performance could be attributed to the synergistic effects of hyperthermia and reactive oxygen species (ROS). Furthermore, the LS-CuS@PVA hydrogel could eradicate the already formed biofilm and inhibit biofilm formation. Considering the highly effective antibacterial and antibiofilm activity of the LS-CuS@PVA hydrogel, this work could provide new insights for the design of poly­(vinyl alcohol)-based composite hydrogels for wound healing and wound dressing.

Lignin has been considered to be an ideal carrier for the construction of lignin-based antibacterial materials by its biocompatibility and environmentally benign feature. Herein, lignosulfonate (LS) was utilized as a growth template and a stabilizing agent to synthesize lignin-copper sulfide (LS-CuS) nanocomposites. Interestingly, the as-prepared LS-CuS nanocomposites show enhanced photothermal performance and peroxidase-like activity with nearinfrared (NIR) light activation, which benefits highly efficient bacteria-killing via synergistic photothermal−catalytic effects. The bactericidal tests indicated that LS-CuS nanocomposites (100 μg/mL) cause 5.9-log 10 and 5.4-log 10 CFU/mL reductions against Escherichia coli and Staphylococcus aureus under NIR light irradiation (808 nm, 1.8 W/cm 2 ) for only 5 min in the presence of H 2 O 2 . Moreover, LS-CuS nanocomposites can be blended with waterborne polyurethane (WPU) to obtain hybrid films, which also achieves a bactericidal efficacy of more than 90% in 5 min. Considering the low cost, easy preparation, and environmental friendliness of LS-CuS nanocomposites, this study may provide new insights into the design of lignin-based inorganic nanocomposites with high bacteria-killing efficiency in a sustainable manner.