Highly effective antimicrobial nanocomposites based on hydrogel matrix and silver nanoparticles: long-lasting bactericidal and bacteriostatic effects

ions from the NCs were followed by UV-visible spectroscopy at 300 nm. Biological experiments were based on the plate count method and agar diffusion testing against Pseudomonas aeruginosa. The bacterial death rate using the NCs is higher than when PNIPAM and nanoparticles in solution are used and seems to be related to the large amount of AgNPs contained inside the gels. In all cases, inhibition and diffusion halos were observed upon the exposure of bacterial cultures on agar to NC discs. The presence of both halos confirmed the bactericidal and bacteriostatic effects of the NCs. The reusability (prolonged use) of the materials was demonstrated until the Ag-NP content was exhausted. The NCs with a higher antibacterial capacity are based on a PNIPAM-co-6%APTMAC matrix. It was demonstrated that these NC materials have the capacity to maintain an aseptic/antiseptic zone for 7 to 15 days.