Silver nanoparticle-embedded hydrogel as a photothermal platform for combating bacterial infections

Because of the indiscriminate use of antibiotics and threats of the drug resistance, bacterial wound infection remains one of the most difficult medical issues. Therefore, it is of great significance to develop novel antibacterial platforms. In this work, we successfully prepared gallic acid functional silver nanoparticles (GA-Ag NPs) by a one-pot method and then embedded them into the network structure of a biocompatible polysaccharide to obtain a novel hydrogel (GA-Ag NP hydrogel) with outstanding bactericidal effect. In this system, the embedded GA-Ag NPs not only act as an antibacterial agent sustainably released from the matrix of the hydrogel to realize sterilization, but also act as a photothermal agent that effectively and controllably converts 808 nm near-infrared ray light into heat to kill bacteria. In vitro testing verified the outstanding broad-spectrum sterilization property of the GA-Ag NP hydrogel against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). In vivo wound healing experiments confirmed the practical potential of this hydrogel in combating bacterial infections and accelerating wound healing. Hemolysis and cytotoxicity experiments showed that it has good biocompatibility. The development of this novel antibacterial hydrogel opens a new way to strengthen the antimicrobial arsenal for fighting bacterial infections.