Tunable release of silver nanoparticles from temperature-responsive polymer blends

Polymer blends of thermoresponsive poly(N-isopropylacrylamide) and poly(methyl methacrylate) with in situ synthesized silver nanoparticles (AgNPs) are proposed as stimuli-responsive antimicrobial materials. AgNPs were prepared in the semi-dried polymer blends by N-methyl-2-pyrrolidone reduction. Temperature controlled kinetic of silver release was examined for different weight ratios of the polymers. Synthesized AgNPs were characterized by transmission electron microscopy and temperature-dependent releasing was analyzed by ultraviolet-visible and atomic absorption spectroscopies. Temperature-dependent changes of polymer matrices were observed by confocal microscopy and infrared spectroscopy. It was shown that the polymer weight ratio determines both, starting time and kinetic of nanoparticle release. Antibacterial activities of the prepared material were demonstrated on Gram-positive Staphylococcus aureus (S. aureus) and gram-negative Pseudomonas aeruginosa (P. aeruginosa). Quantitative evaluation of antimicrobial efficacy of prepared materials was performed on the base of inhibition zone size. It was shown that prepared materials could serve as effective antibacterial coating with quick antimicrobial response.