Construction of chitosan-based thermosensitive composite hydrogels for recognizing and combined chemo-photodynamic elimination of Gram-negative bacterial infections

Release time:2023-10-19 Hits:

Key Words:INACTIVATION; CHALLENGES; ATTACHMENT; DISCOVERY

Abstract:Recently, rapid acquisition of bacterial resistance and consequent slow healing of infected wounds threaten human life and health. In this study, chitosan-based hydrogels and nanocomplexes ZnPc(COOH)8:PMB composed of photosensitizer ZnPc(COOH)8 and antibiotic polymyxin B (PMB) were integrated into a thermosensitive antibacterial platform ZnPc(COOH)8:PMB@gel. Interestingly, fluorescence and reactive oxygen species (ROS) of ZnPc(COOH)8:PMB@gel can be triggered by E. coli bacteria at 37 degrees C, but not by S. aureus bacteria, which gave the potential to simultaneously detect and treat Gram-negative bacteria. The survival rate for a certain amount of E. coli bacteria treated with ZnPc(COOH)8:PMB (ZnPc(COOH)8 2 & mu;M) was decreased by approximately fivefold than that with either ZnPc(COOH)8 or PMB alone, indicating combined antibacterial efficacy. ZnPc(COOH)8: PMB@gel facilitated the complete healing of wounds infected with E. coli bacteria in about seven days, while over 10 % wounds treated with ZnPc(COOH)8 or PMB remained unhealed on the 9th day. ZnPc(COOH)8:PMB resulted in a threefold increase of ZnPc(COOH)8 fluorescence in E. coli bacteria suggesting enhanced uptake of ZnPc(COOH)8 for the intervention of PMB on membrane permeability. The construction principle of the ther-mosensitive antibacterial platform and the combined antimicrobial strategy can be applied to other photosen-sitizers and antibiotics for detection and treatment of wound infections.

Volume:242

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Translation or Not:no