Antibacterial activity evaluation of a novel triblock cationic copolymer (PHEMA-b-PNIPAM-b-PVEAH)

Abstract

Background and objective: Antibacterial compounds are considerably interested because of their importance in control of microbial outbreak. Various approaches are being developed for explore of novel and powerful antimicrobial agents. The aim of present work was to develop a durable cationic antibacterial based on triblock copolymer. Materials and methods: Novel poly(2-hydroxyethyl methacrylate)-b-poly(N-isopropyl acrylamide)-b-poly (N-4-vinylbenzyl), N,N-diethylamine hydrochloride (briefly named PHEMA-b-PNIPAM-b-PVEAH or ABC) cationic triblock copolymer was synthesized via reversible addition fragmentation transfer (RAFT) polymerization to investigate its antibacterial behavior. Structure of ABC triblock copolymer was explored by means of Fourier Transform Infrared and 1H Nuclear Magnetic Resonance spectroscopies. Furthermore, the antibacterial activity of cationic triblock copolymer was examined on four microorganisms including Bacillus cereus, Staphylococcus aureus, Escherichia coli and Candida albicans. Results and conclusion: Molecular weight of blocks in the copolymer including PHEMA, PHEMA-b-PNIPAM and PHEMA-b-PNIPAM-b-PVEAH was 10950, 17103 and 26165 g mol-1, respectively. Results showed remarkable antibacterial activity so that inhibition diameter of B. cereus and S. aureus were 25, 29, 34 mm and 32, 37, 41 mm, respectively. Low antibacterial activity was detected against E. coli (14, 17 and 21 mm) and the highest antibacterial activity was detected for C. albicans (48, 81 and 98 mm). Acceptable antibacterial and high anti-yeast activity was observed for ABC. Therefore, it could be used in therapeutic purposes and microbial suppression.