Polymer–metal oxide composites of CuO and NiO as antimicrobial agents

To evaluate the antimicrobial potential of polymer-metal oxide composites, the previously developed M8 polymer blend-comprising chitosan, polyethylene glycol, polyvinyl alcohol, and polyvinylpyrrolidone-was modified with copper oxide (CuO) and nickel oxide (NiO) particles, having average sizes of 152.7 ± 4.5 nm and 91.4 ± 4.9 nm, respectively. The resulting composites (M8/CuO and M8/NiO) were tested against Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Salmonella enterica (SE). In previous work, pure M8 exhibited minimum inhibitory concentration (MIC90) values of 12.5% dilution against SA. In the present study, both M8/CuO and M8/NiO displayed MIC50 values of 25% dilution against SE and PA. Against SA, M8/NiO retained higher efficacy (MIC50 = 12.5% dilution) compared with M8/CuO (25% dilution). M8/NiO achieved MIC90 for PA and SE at 25% dilution and 50% dilution, respectively, while M8/CuO reached MIC90 only for SE at 50% dilution. Neither composite attained MIC90 against SA.