Biomimetic Reactor Loaded With Glucose Oxidase For Antibacterial Applications

Bacterial infection is one of the world’s problems that harm human health.Antibiotics are the main drugs used to treat bacterial infections.However,overuse of antibiotics can easily lead to the development of resistance in bacteria.Hydrogen peroxide（Hydrogen peroxide,H₂O₂）is a an inexpensive and widely used antibacterial agent.However,the high concentration of H₂O₂ required as an antibacterial agent often causes damage to normal cell tissue around the site of infection.Glucose oxidase（Glucose oxidase,GOx）can efficiently catalyse glucose reactions to produce gluconic acid and H₂O₂,avoiding the toxic side effects caused by direct contact with high concentrations of H₂O₂ in tissues and providing a safer antibacterial effect.However,the bacterial infection is difficult to be eradicated,and simply using H₂O₂ for antibacterial can not achieve good results.Therefore,it is particularly important to develop a cooperative antibacterial system based on GOx.（1）To achieve targeted antibacterial effects,we designed a cascade catalyst system that can be activated by adenosine triphosphate（Adenosine triphosphate,ATP）.Firstly,G4（G-quadruplex/hemin）was encapsulated in ZIF-8,and then GOx and G4@ZIF-8were embedded in hydrogel to construct the Gz Gp system.Among them,ZIF-8 can distort the spatial structure of G4 to inhibit its peroxidase activity after embedding G4.After co-cultivation with bacteria,ATP secreted by bacteria can activate the peroxidase activity of the Gz Gp system,leading to a cascade reaction between GOx and G4,which catalyses glucose to produce highly toxic hydroxyl radical（·OH）.In addition,the hydrogel structure of Gz Gp can shorten the transport distance of intermediates through domain confinement,improve the efficiency of the cascade reaction,and achieve high efficiency and on-demand slow release of·OH.The results of in vitro antibacterial experiment of Gz Gp and wound bacterial infection healing experiment of mice have reached the expected purpose.The system can provide a reference value for realizing efficient generation and transfer of highly toxic substances in a small space.（2）In order to further improve the antibacterial performance,we prepared a glucose-triggered silver ion sustained-release antibacterial system.GOx and the silver ion donor Ag NPs@Ui O-66 were co-embedded in the hydrogel to form the AUGP system.AUGP can be triggered by glucose to produce gluconic acid and H₂O₂,which further decompose Ag NPs into silver ions in the acidic environment to achieve metal ion targeting and on-demand antibacterial activity.The results of the antibacterial experiment of AUGP in vitro and wound bacterial infection in mice showed that AUGP has good potential for biomedical application.The antibacterial system provides a new idea for realising the slow release of large molecules on demand.