Published online by Cambridge University Press: 25 March 2011
Particulate zinc oxide (ZnO) is a known antibacterial agent. Studies have shown that reducing the size of ZnO particles to nanoscale dimensions further enhances their antibacterial properties. Polymers, like all biomaterials, run the risk of harboring bacteria which may produce an antibiotic-resistant biofilm. The addition of ZnO nanoparticles, to form a composite material, may reduce undesirable bacteria activity. The purpose of the present in vitro study was to investigate the antibacterial properties of ZnO nanoparticles when incorporated into a polymer biomaterial. Staphylococcus aureus were seeded at a known cell density onto coverslips coated in a film of polyvinyl chloride (PVC) with varying concentrations of ZnO nanoparticles. Samples were cultured for 24 or 72 h. Methods of analysis, including optical density readings and crystal violet staining, indicated a reduced presence of biofilm on ZnO nanoparticle and polymer composites compared to polymer control. Live/dead assays provided images to confirm reduced presence of active bacteria on samples with zinc oxide nanoparticles. Development of this technology may improve biomaterial effectiveness for applications, such as endotracheal tubes and implanted biomaterials, which are prone to bacterial infection.