Zinc oxide nanoparticle and polymer antimicrobial biomaterial composites

Particulate zinc oxide (ZnO) is a known antibacterial agent. Studies show 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, 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 maintained for 24 or 72 h. Crystal violet staining indicated a reduced presence of biofilm on ZnO nanoparticle and polymer composites compared to pure polymer. Live/dead assays provided images to confirm reduced presence of active bacteria on samples with ZnO nanoparticles. Development of this technology may improve biomaterial effectiveness for applications, such as endotrachial tubes and implanted biomaterials, which are prone to bacterial infection.