Carbamohydrazonothioate-based polymer-magnetic nanohybrids: Fabrication, characterization and bactericidal properties

Abstract

Herein is presented fabrication of new efficient antibacterial polymer/gold/magnetic nanohybrids. These nanohybrids consist of a superparamagnetic nanoparticle core, which ensures their facile separation, purification and recyclability, and polymeric coating which exhibits bactericidal activity. They were prepared in an efficient four-step synthetic route involving the following: (1) magnetic nanoparticles fabrication by co-precipitation of Fe2+ and Fe3+ in the presence of ammonia solution; (2) gold shell formation; (3) immobilization of RAFT/MADIX (reversible addition-fragmentation transfer/macromolecular design via the interchange of xanthates) initiating agent on the surface of nanoparticles; and (4) surface-initiated RAFT/MADIX polymerizations of bactericidal monomers. Physicochemical properties of bare and functionalized magnetic nanoparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), magnetization measurements, transmission and scanning electron microscopies (TEM and SEM). Hemolytic and antibacterial activity of the obtained materials (monomers and polymer/gold/magnetic nanohybrids) against human red blood cells and Pseudomonas aeruginosa was determined. It was demonstrated that the tested agents do not affect red blood cells membrane permeability at the concentration range of 1–100 μg/ml. Simultaneously, at this concentration, they effectively kill and restrict metabolic activity of planktonic P. aeruginosa as well as prevent its biofilm formation. Keywords: Magnetic nanoparticles, Polymer shell, RAFT/MADIX polymerization, Bactericidal properties