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

The 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.