Antibacterial, antibiofilm and cytotoxic activities of biogenic polyvinyl alcohol-silver and chitosan-silver nanocomposites

Using biogenically synthesized silver nanoparticles (AgNPs) by Enterobacter cloacae Ism 26 (KP988024); Polyvinyl Alcohol-Silver (PVA-Ag) and Chitosan-Silver (CS-Ag) nanocomposites were prepared by augmentation. Thermal stability, AgNPs distribution and concentration within nanocomposites were characterized using thermogravimetric analysis (TGA), scanning electron microscope/energy dispersive x-ray (SEM/EDX) and atomic absorption spectroscopy (AAS). Nanocomposites films showed higher thermal stability than pure polymers, different AgNPs concentrations with homogenous distribution. Antibacterial, antibiofilm and cytotoxic activities of nanocomposites films were studied against Multi Drug Resistant (MDR) bacteria including Staphylococcus epidermidis (S.e), Staphylococcus aureus (S.a), Escherichia coli (E.c) and Klebsiella pneumoniae (K.p). PVA-Ag nanocomposite showed larger zones of inhibitions and higher antibiofilm activities than CS-Ag nanocomposite against both Gram-positive and Gram-negative bacteria. AgNPs solution, PVA-Ag and CS-Ag nanocomposites showed low cytotoxic activities against Huh-7 liver cells and IC50 values of 263.20 mu g ml(-1), 1185.07 mu g ml(-1) and 119.85 mu g ml(-1), respectively. PVA-Ag and CS-Ag nanocomposites films showed enhanced thermal stability and biological properties that qualify them for different biomedical applications.