In vitro assessment of antibacterial properties and cytotoxicity of Al ₂ O ₃ –Ag nanopowders

AbstractThe present paper describes an in vitro assessment of the antibacterial properties and cytotoxic activity on mammalian cells of silver nanoparticles incorporated into an aluminium nano-oxide substrate produced by the thermal decomposition–reduction method. The Al2O3–Ag nanopowders show good bactericidal and fungicidal properties. An Al2O3–Ag (12·55 wt-%) specimen at the concentration of 50 mg mL−1 reduced considerably the populations of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Bacillus subtilis species, whereas the same nanopowder in a concentration of 90 mg mL−1 inhibited significantly the growth of P. aeruginosa, E. coli, S. aureus and Candida albicans and also significantly limited the number of B. subtilis. The Al2O3–Ag nanoparticles also showed no cytotoxic effects on the three selected cell lines, i.e. L929, BJ and HeLa, and the cells remained >75% viability, as measured by MTT assay, and >102% viability, obtained by EZ4U assay, relative to control at concentration as high as 200 μg mL−1.