Construction And Antibacterial Properties Research Of Nano-compound System And Smart Release System Of Antibiotic

Antibiotics have been a powerful weapon in saving human beings from bacterial infection,but drug abuse has evoked bacterial drug resistance.Several new antibacterial materials have been researched for reducing bacterial drug resistance.However,these new antibacterial methods cannot completely replace antibiotics for clinical application,because they have their own problems.Therefore,a rational use of antibiotics is the most rapid and simple way to resolve the increasingly serious issue of bacterial drug resistance.In our work,Vancomycin-hybrid bimetallic Au/AgNPs were prepared by chemical reduction,Van as model antibiotic.The bimetallic Au/AgNPs@Van had the best antibacterial activity when the Ag-Au ratio was 2:1.Vancomycin could double the adhesion between bacteria and the Au/AgNPs@Van.The MIC of Au/AgNPs@Van was as low as 30 nmol/mL,and 99% of the bacteria were killed within 5 h.The Au/AgNPs@Van also showed better antibacterial activity than free vancomycin and Au/AgNPs,and have a low drug resistance and cytotoxicity.First,PDMAEMA was synthesized by carrying out RAFT polymerization.A new pH-sensitive and bacterial concentrationsensitive hydrogel was formed using PAA cross-linked with PDMAEMA by hydrogen bonds.The hydrogel was found to decompose and release antibiotic under the acidic environment of a bacterial infection,to decompose more rapidly as the bacterial concentration was increased,to have excellent and lasting antibacterial activities according to bacterial proliferation experiments,and to display low cytotoxicity.A more simple,rapid and green method was used to prepare a pH-sensitive natural hydrogel for the smart controlled release of an antibiotic focussed on bacterial infection.Sodium alginate and citric acid monohydrate solution were mixed rapidly by the formation of hydrogen bend and then the hydrogels were obtained.The natural hydrogel showed better biocompatibility and low cytotoxicity than synthesized hydrogel,achieving a smart release of its contents at the bacterial infection site.Its advantages could reduce the inappropriate and disproportionate use of antibiotics for clinical application.