[Publications]

Abstract

Polyaryletheretherketone (PEEK) has emerged as the material of choice for spinal fusion instrumentation due to its high strength, biocompatibility, and radiolocuency. However, up to 6.7% of all instrumented fusion surgeries result in infection. These infections have greater morbidity and economic burden than their uninfected counterparts. Silver has recently emerged as antimicrobial compound for medical devices, as it has well-established antimicrobial activity and low toxicity. Two pilot studies were conducted to test the hypothesis that 1% loading of silver nanoparticles (<100 nm) in a PEEK matrix would reduce or eliminate bacterial adherence and biofilm formation. S. Aureus was grown in TSB on the surface of both virgin and 1% (w/w%) Ag composite PEEK. Microbial growth was compared first by visually scoring with SEM images at 500X for both bacterial abundance and biofilm formation, and then by direct colony counting after sonication of surface and agar plating of detached bacteria. Qualitative scoring of SEM images shows no significant difference when scoring for bacterial abundance, but higher amounts of clusters of bacteria and biofilm were observed on the virgin PEEK surfaces. Direct colony counting displayed no significant difference between colony count of the virgin and 1% Ag materials at 4hr, 6hr, and 24hrs of incubation. However, our findings are limited to 1% loading, which may be too low to be effective when injection molded, as the molding and compounding process could potentially deposit a lower concentration of Ag on the surface of the polymer.