Development of a Novel Zinc Oxide/Polyvinyl Chloride Nanocomposite Material for Medical Implant Applications

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Development of a Novel Zinc Oxide/Polyvinyl Chloride Nanocomposite Material for Medical Implant Applications Benjamin M. Geilich1 and Thomas J. Webster2,3 1 Program in Bioengineering and, 2Department of Chemical Engineering, Northeastern University, Boston, MA 02115 3 Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia ABSTRACT In hospitals and clinics worldwide, medical device surfaces have become a rapidly growing source of nosocomial infections. Almost immediately after adhering to a device surface, bacteria can begin to form a biofilm, which 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). Nanomaterials 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 “nanoroughness” 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. The objective of the present in vitro study was to develop a nanocomposite material by embedding conventional polyvinyl chloride (PVC) with zinc oxide nanoparticles through a simple and inexpensive procedure. The effect of different nanoparticle sizes and %wts were investigated. Results demonstrated that this technique significantly decreased S. aureus density and biofilm formation without the incorporation of antibiotics or other pharmaceuticals, as well as increased the adhesion of human fibroblast cells. Thus, this material could have much promise for use in the manufacture of common implanted medical devices. INTRODUCTION Medical device surfaces are especially prone to bacterial infections since they are commonly composed of materials that do nothing to inhibit the growth of bacteria.1 Contamination can occur from the presence of just a small number of microorganisms due to surgical procedure, improper sterilization, and, more commonly, the simple migration of bacteria from the skin into the body after an operation.2 Almost immediately after attaching to a device surface, bacteria begin to secrete and collect proteins, polysaccharides, and DNA in order to form a complex aggregate of cells, known as a biofilm.3 This protected state guards the bacteria against antibiotics and the host immune system, making the infection especially difficult to treat and often necessitating device removal.4 The scope of this important clinical problem is vast and widespread. Specifically, around 2 million patients contract nosocomial infections per year in the US alone, and around half of these are dev