In situ synthesis of amply antimicrobial silver nanoparticle (AgNP) by polyzwitterionic copolymers bearing hydroxyl groups

Zwitterionic monomer methyacryloxyethyl sulfobetaine (MAES) copolymerized with hydroxyethyl methacrylate (HEMA) forming random copolymer with some block characteristics in a controlled manner. The polyzwitterionic copolymer P(MAESx-ran-HEMAy) (PMxHy, where x and y were the degrees of polymerization of MAES and HEMA, respectively), which bearing hydroxyl groups that served as both reducing and capping reagent for in situ AgNPs synthesis without exogenous additions. The in situ formed uniform AgNPs composites adopted a typical “core-shell” structure where AgNPs served as cores, and PMH were shells. The stability of the AgNPs composites was promoted by chelation of AgNPs core and the generated aldehyde on PMH during silver ions (Ag+ ions) reduction. Size of the AgNPs composites directly correlated with [MAES] to [HEMA] ratio in PMH and the highest yield of AgNPs composites was achieved when PM20H27 to AgNO3 weight ratio equaled 30%. The AgNPs composites originating from PM50H26 showed the most potent bactericidal activity through the membrane perturbation mechanism. Besides, the AgNPs composites confirmed safe for mammalian cells by hemolysis and cytotoxicity tests.