Research On Promoting Healing Of Infected Wounds And Antibacterial Mechanism Based On Nanozyme Synergistic Antibacterial Syste

Bacterial infectious wounds are usually affected by systemic chronic diseases,resulting in difficult wound healing,and currently mainly rely on the treatment of antibiotics.However,the abuse of antibiotics will lead to the emergence of multidrug-resistant bacteria.Therefore,the development of bacteriostatic agents with excellent bacteriostatic effect and avoiding bacterial drug resistance has become an urgent problem to be solved.At present,nanozymes,such as peroxidases（POD）,use broad-spectrum antibiotics mediated by reactive oxygen species（ROS）to replace antibiotics as a new antibacterial agent,which provides a new idea to solve the above problems,but there are still problems such as low treatment efficiency and exogenous addition of unstable H₂O₂.In order to improve the antibacterial performance of nanozyme,it is necessary to combine it with other antibacterial mechanisms of nanozyme,such as reactive oxygen free radical,mechanical action and so on.Based on this,we constructed a combination of multiple antibacterial mechanisms based on nanozymes to cooperate with antibacterial.A synergistic antibacterial system Fe₂（Mo O₄）₃@GOx with double enzyme activity nanozyme was developed.The starvation therapy produced by glucose oxidase（GOx）can cooperate with·OH produced by Fe₂（Mo O₄）₃against drug-resistant bacteria;An antibacterial system of molybdenum oxide cooperating with mechanical damage and reactive oxygen free radicals was constructed,and its antibacterial mechanism was deeply explored,mainly including the following aspects:1.In order to select materials with better peroxidase activity and realize efficient loading of glucose oxidase（GOx）,Fe₂（Mo O₄）₃with patterned multilayer structure formed by self-assembly of nano plates was synthesized by Fe（NO₃）₃and Na₂Mo O₄,which with strong negative potential,and its loading rate on GOx can reach 36.57 wt%.The obtained product Fe₂（Mo O₄）₃@GOx could consume the carbon source（glucose）of bacteria to produce starvation therapy,and the intermediate products H₂O₂and gluconic acid can stimulate the peroxidase activity of Fe₂（Mo O₄）₃to further produce·OH.The antibacterial results showed that it is effective for the extended-spectrumβ-lactamases producing Escherichia coli（ESBL-producing E.coli）and methicillin-resistant Staphylococcus aureus（MRSA）with lactamase have excellent antibacterial properties.In vivo wound healing experiment further confirmed Fe₂（Mo O₄）₃@GOx.The synergistic antibacterial system with high antibacterial activity,excellent biocompatibility and application potential.2.In order to study the main antibacterial mechanism of nanozymes,molybdenum trioxide nanowires（Mo O₃NWS）with POD enzyme activity were synthesized.The sharp end of Mo O₃NWS could pierce the cell wall of bacteria,which will directly cause mechanical damage to bacteria,and the contents of damaged bacteria will leak.At the same time,Mo O₃NWS with POD enzyme activity can convert H₂O₂into·OH,which further affected the structure of bacteria,and damage caused by leaked protein and DNA.The experimental results showed that Mo O₃NWS could produce excellent antibacterial properties against ESBL-producing E.coli.The bacterial morphology characterization results showed that Mo O₃NWS could effectively pierce the bacterial cell wall,and the experimental results showed that the protein leakage increases with the increase of the concentration of MoO₃NWS.