Electrically-Controlled Penicillin/Streptomycin Release from Nanostructured Polypyrrole Coated on Titanium for Orthopedic Implants

Abstract

Implant infection leading to revision surgery can be avoided by incorporating controllable antibiotic release from titanium (Ti) implant surfaces. In this study, penicillin/streptomycin (P/S) and dexamethasone (Dex) were successfully immobilized via electropolymerization within polypyrrole membranes coated on the surface of Ti, which is widely used in orthopedic applications. In vitro results showed that greater numbers of osteoblasts adhered on these polymer-coated substrates than on currently-used unmodified Ti. X-ray photoelectron spectroscopy was used to monitor and compare the reaction effectiveness and the yield of electropolymerization. Polypyrrole membranes conjugated with P/S and Dex, and then coated with PLGA, all possessed nanometer scale roughness, as analyzed by atomic force microscopy. In summary, this study demonstrated that drugs incorporated within electroactive polypyrrole membranes, whose release was controlled by applying voltages, supported osteoblast adhesion and could potentially fight bacterial infection.