Reduced Adhesion of Staphylococcus aureus to ZnO/PVC Nanocomposites: A Novel Method to Combat Bacterial Biofilm Formation on Implanted Medical Devices

Abstract

In hospitals and clinics worldwide, medical device surfaces have become a rapidly growing source of nosocomial infections. Contamination can occur from the presence of just a small number of microorganisms, and almost immediately after adhering to a device surface, bacteria can begin to form a biofilm: a robust, sticky matrix that provides protection against the host immune system and antibiotics. This makes the infection especially difficult to treat, and often necessitates device removal. Adding to the severity of this problem is the spread of bacterial genetic tolerance to antibiotics, in part demonstrated by the recent and significant increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA). ææNanomaterials are beginning to be used for a wide variety of biomedical applications due to their unique surface properties which have the ability to control initial protein adsorption and subsequent cell behavior. This ñnanoroughnessî gives nanomaterials a greater functional surface area than conventional materials, which do not have significant features on the nanoscale. In addition, it is theorized that nanoparticles may also have general mechanisms of toxicity towards bacteria that do not cause problems for mammalian cells. æThe objective of the present in vitro study was to reduce S. aureus density on conventional polyvinyl chloride by embedding the polymer with zinc oxide nanoparticles through a simple and inexpensive procedure. Results demonstrated that this technique significantly decreased bacterial density and biofilm formation without the incorporation of antibiotics, thus providing much promise for use in the manufacture of common implanted medical devices.