Antimicrobial and biological effects of polyaniline/polyvinylpyrrolidone nanocomposites loaded with silver nanospheres/triangles

Two silver-polyaniline/polyvinylpyrrolidone (Ag-PANI/PVP) nanocomposites were prepared using in situ integration of silver nanoparticles (AgNPs) during oxidative aniline polymerization, accelerated by the presence of PVP, which as well minimized the risk of particle agglomeration and macroscopic precipitation. Both nanocomposites have similar silver content (similar to 44 wt% Ag) but different morphological features of AgNPs (spheres/triangles) and polymers (granular/wrinkling pattern). Several spectroscopic, macroscopic, and analytical techniques, microscopy, and surface analysis methods have been used to analyze their physical and chemical properties. Investigation of their antimicrobial potential and possible application as an effective weapon against indicator microbial strains, E. coli, S. aureus, and C. albicans, has shown inhibition of microbial growth by more than 90%, even at low composite concentrations (5 ppm) and short contact time (4 h). A biosafety assessment of Ag-PANI/PVP that comprised testing the genotoxicity and redox modulating activity was performed using human peripheral blood cells as a model system. The obtained results have shown that the investigated Ag-PANI/PVP exhibited significant prooxidant and cytostatic effects (p < 0.05) with no apparent potential to induce DNA damage. Although precautions should be taken to protect human health, the significant antimicrobial efficiency of Ag-PANI/PVP makes it suitable for further studies and applications in non-medical areas, such as wastewater treatment.