JI Jian, Zhejiang University, the research team series Jinqiao progress in the \”use\” and \”reform\” microenvironment anti-bacterial bio film was made

biofilm is the main form of bacteria survive in nature, more than 65% of clinical infections associated with biofilm. Affected bacterial growth and reproduction of bacteria and biofilm normal tissues having different specific microenvironments, such as acidic pH, hypoxia, high concentration of GSH, overexpression of specific enzymes, the group effect gradient. Biofilm special microenvironment of resistant bacteria, fungi and other support formation of stay has important implications. For bacterial biofilm that anti-infective therapy problems, Zhejiang University JI Jian , Jinqiao team and transformation through the use of biofilm microenvironment designed a series of drug delivery systems to overcome bacterial biofilm resistance, advances have been achieved series:

First, the use of biofilm slightly acidic environment designed to simultaneously azithromycin nanocarriers intelligent control the size and charge, to enhance antibiotic penetration and retention in the biofilm improve the antibacterial properties of azithromycin

azithromycin is commonly used in clinical antibiotics can inhibit the formation of bacterial biofilm, having an excellent bactericidal effect. However, biological efficacy of azithromycin for the film has been formed is very obvious. In order to increase azithromycin efficacy of biofilm already formed, the research team from covalently bonded azithromycin dendrimer PAMAM starting designed simultaneously azithromycin nanocarriers intelligent control size and surface charge, the use of bacterial biofilm acidic microenvironment environment to achieve the size of the nanoparticles from large to small and the charge from negative to positive, the azithromycin enhanced penetration and retention nanocarriers in bacteria in the biofilm, and the use of increased membrane permeability PAMAM bacteria, increased bacterial neomycin Neie Qi content, improved bactericidal properties azithromycin, to increase the ability of anti-biofilm three orders of magnitude , and reduces the generation of bacterial resistance, bacterial pneumonia treatment on mice We achieved excellent results. This antibiotic delivery strategies developed a new method to improve the macrolide antibiotic anti-biofilm ability of , relevant research results to \”Size and Charge Adaptive Clustered NanoparticlesTargeting Biofilm Microenvironment for Chronic Lung Infection Management \”in the title published online in the ACS Nano (DOI: 10.1021 / acsnano.0c00269), the first author doctoral High Yi Fan , corresponding author for the Professor Jin Qiaofu and JI Jian, a professor .

Second, the use of infected tissue slightly acidic environment design of intelligent nano-carrier, in improving the biological safety without affecting the bactericidal properties of polymyxin B of

polymyxin B has a very good bactericidal action against Gram negative bacteria, Gram-negative bacteria is called preventive infection last line of defense. However, polymyxin B in the human body can cause serious kidney toxicity and neurotoxicity, which makes polymyxin B can not be injected intravenously, limiting its application in clinical practice. for polymyxa serious side effects polymyxin B, the research team designed a pH-sensitive chitosan – polymyxin B nanocomposites improve biosafety polymyxin B by protecting chitosan, infection under acidic environment to stimulate tissue, polymyxin B can effectively release, exhibit excellent bactericidal properties , the relevant research results \”polymyxin B-polysaccharide polyion nanocomplex with improved biocompatibility and unaffected antibacterial activity for acute lung infection management\” in the title published in the Advanced Healthcare Materials (2020, 9, 1901542), the first author is graduate students Chaimeng Ying , corresponding author for the Professor Jin Qiaofu . [ 123]

Third, to improve biofilm hypoxic microenvironment by delivering oxygen to overcome the resistance to biofilmOf the is one of many bacterial biofilm mainly refractory infections, including drug efflux through, obstacles extracellular matrix, a series of mechanisms sleep effect, and other groups to achieve the effect of resistance to antibiotics. Inherent resistance mechanisms associated with these important in the pathology and biofilm hypoxic microenvironment. Based on this principle pathology, the research team

proposed a new model to improve the bacterial envelope hypoxic microenvironment and then treated with antibiotics creatures . By perfluorocarbon treatment with liposomes, the bacterial biofilm improve hypoxic microenvironment, inhibiting the expression of resistance genes drug efflux pumps, etc. group effect, resistance against biofilm, greatly improved bactericidal effect of various antibiotics ceftazidime, aztreonam. Improve biofilm hypoxic microenvironment as a new antibiotic disinfection method of improving a broad spectrum of , will respond to antibiotic era after bacterial biofilm drug resistance problem of providing a simple and effective solution and it has great potential, relevant research results to \”Relief of Biofilm Hypoxia Using an Oxygen Nanocarrier: a New Paradigm for Enhanced Antibiotic Therapy\” in the title is Advanced Science receiving (DOI: 10.1002 / advs.202000398) , the first author doctoral Hu Dengfeng , corresponding author for the Professor Jin Qiaofu and JI Jian, a professor .

Fourth, by a high-GSH microenvironment nitric transformation biofilm, synergistically increased ability photodynamic anti-biofilm Since no resistance, photodynamic treatment coating film has a great potential in anti-bacterial organisms. Then, bacterial biofilm in a high concentration of GSH is consumed active oxygen generated by photodynamic therapy affect bactericidal properties. To solve this problem, research groups

pH responsive design of reversing the charge of nitric oxide and a photosensitizer were transferred Ce6 nanocarrier, the reverse of the charge biofilm nanocarriers in response to high pH permeate through. Meanwhile, the released nanocarrierNitric oxide can be consumed in the biofilm GSH, effectively prevent the reaction with the active oxygen generated photodynamic therapy GSH is consumed, the improved photodynamic scavenging biofilm , the relevant research in \”Surface Charge Switchable Supramolecular Nanocarriers for Nitric Oxide Synergistic Photodynamic Eradication of Biofilms \”was published in ACS Nano on (2020, 14, 347-359), the first author doctoral Hu Dengfeng and Tang Wing Yan , corresponding author for the Professor Jin Qiaofu and JI Jian, a professor .