Multifunctional poly(quaternary ammonium)/Fe3O4 composite nanogels for integration of antibacterial and degradable magnetic redox-responsive properties

Multifunctional cationic poly(2-(dimethylamino)-ethyl methacrylate)/Fe 3 O 4 composite nanogels (PQDMAEMA/Fe 3 O 4 CNGs) with degradable, magnetic, redox-responsive, and antibacterial properties were tailored through activators generated by electron transfer atom transfer radical polymerization in inverse miniemulsion systems. The as-prepared PQDMAEMA/Fe 3 O 4 CNGs not only inherited good superparamagnetism of Fe 3 O 4 nanoparticles but also displayed a marked redox-responsiveness (using a disulfide-containing cross-linker) and a reversible pH-dependent loading and release behavior of a model protein (bovine serum albumin). Most importantly, the PQDMAEMA/Fe 3 O 4 CNGs exhibited potent broad-spectrum antimicrobial activity towards Escherichia coli, Staphylococcus aureus, and Canidia albicans . The results reveal that the multifunctional PQDMAEMA/Fe 3 O 4 CNGs have essential promise in tackling bacterial infection and stimuli-responsive applications such as protein adsorption and separation.