Preparation And Application Of Hydrogels With Nitric Oxide Enhanced Reactive Oxygen Species

Bacterial infection has become a severe health problem worldwide.The conventional method to cure bacterial infections is to use antibiotics.However,the efficacy of antibiotics is threatened,due to the increased resistance of bacteria to antibiotics.The continuous emergence of drug-resistant bacteria not only leads to the failure of antibiotic treatment but also increases the economic burden of patients due to the prolonged hospital stay.Therefore,it is urgent to develop original antibacterial strategies to treat drug-resistant bacterial infections.In this paper,the CS was nitrated to obtain water-soluble nitrate-containing CS(CSNO)and mixed with photosensitizer meso-tetra(4carboxyphenyl)porphine(TCPP)and salmon sperm DNA(ssDNA)through electrostatic forces to form biomass hydrogels(CSNO-TCPP-ssDNA).When the hydrogels were co-cultured with cultured Gram-negative bacteria,the CSNO-TCPP-ssDNA hydrogel with the ratio of CSNO and ssDNA of 2:1 and 1:1 shows the antibacterial effect of NO enhanced ROS,thereby improving the antibacterial ability of photodynamic therapy against Gram-negative bacteria.Mechanism research findings,under the solar-simulator irradiation,the hydrogels can simultaneously release reactive oxygen species(ROS)and nitric oxide(NO),thereby producing highly reactive peroxynitrite ions.Furthermore,when used to treat animal models of skin infections caused by drug-resistant bacteria,the proposed hydrogel exhibits excellent antibacterial activity in vivo.Altogether a biomass antibacterial material that releases ROS and NO synergistically can open up new possibilities for effectively killing drugresistant bacteria,making it of value in antibacterial wound dressings and other fields.