Study On Construction And Antibacterial Activity Of Novel Selenium Loaded Composite Nanomaterials

The aggravation of bacterial resistance caused by the abuse of antibiotics has become a global public health problem,which seriously affects human health and medical treatment.It is urgent to find new non-antibiotic-dependent antibacterial methods.The emergence of existing nanomaterials with photodynamic activity,photothermal activity and enzyme-like activity provides a new idea for the design of new antibacterial agents.These nanomaterials can use light or heat to destroy bacterial cell membranes or structures to achieve antibacterial effects.At the same time,they can also catalyze the redox reaction through enzyme-like activity,produce substances harmful to bacteria,and further enhance the antibacterial effect.This new antibacterial agent with multiple activities can exert a variety of antibacterial effects at the same time,including photodynamic activity,photothermal activity and enzyme-like activity.These effects cooperate with each other to achieve the best bactericidal effect.In this study,Se nanoparticles-loaded and Mo-doped Fe Pc nanorods（Se-Mo-Fe Pc NRs）were successfully constructed.The study of light absorption capacity showed that Se-Mo-Fe Pc NRs had a good near-infrared light response.Under the irradiation of 808nm near-infrared light Se-Mo-Fe Pc NRs could efficiently catalyze endogenous H₂O₂ to generate amount of·OH,and exhibit photodynamic performance with ¹O₂ and more·OH production.The produced ROS induced membrane stress and damage the bacteria integrity.Besides,it also possessed good NIR photothermal conversion efficiency,the induced hyperthermia could promote the peroxidase-like catalytic activity of Se-Mo-Fe Pc NRs and effectively accelerate GSH oxidation,breaking down the protection system of bacteria.Based on the synergistic mechanism of NIR regulated photodynamic/photothermal effect and peroxidase-like activity of Se-Mo-Fe Pc,it exhibitd excellent anti-E.coli and anti-S.aureus efficiency through damaging cell membrane and inhibiting biofilm formation with low hemolysis and cytotoxicity.Animal experiments further suggested that Se-Mo-Fe Pc NRs could effectively treat S.aureus-infected wounds and promote their healing in the presence in the presence of H₂O₂ and NIR irradiation,without obvious lesions and inflammation in tissues and organs.The above results indicated that Se-Mo-Fe Pc NRs had photoresponsive peroxidase-like activity and could be used as an effective antibacterial agent.