Electrochemical Deposition of Vancomycin∕Chitosan Composite on Ti Alloy

Abstract

In order to reduce or prevent the probability of osteomyelitis, a novel method of vancomycin/chitosan composite coating on the Ti alloy implant has been carried out in the vancomycin/chitosan mixed aqueous solution by the electrochemical deposition. Though the deposition of vancomycin could not be carried out independently, it has been codeposited with chitosan by the hydrogen bonds between them. The coatings resulting from the deprotonation of chitosan by electrochemical reactions, were characterized by x-ray diffraction (XRD) for crystal phase, transmission electron microscopy (TEM) for microstructure, field emission scanning electron microscopy (FESEM) for the morphological observation, Fourier transform infrared (FTIR) spectroscopy for the specified chemical bonds, and ultravioletvisible (UVVis) spectroscopy for the loading and releasing of vancomycin. It was found that the as-received chitosan powder was form II, the as-deposited film was the mixture of form I and form II, and form I became the major after immersed phosphate buffer solution (PBS). The chitosan film was composed of 2.0 nm diameter fibers which aligned in the direction of fiber axis, and further reduced to 1.6 nm by adding vancomycin due to the lowered pH. The vancomycin loading in the composite coating could be tuned from 150 to 550 gcm 2+ by the deposition time and potential. From antibacterial assay, no bacteria colonies were found in tubes containing the vancomycin/chitosan composite coating. In other words, the vancomycin was not denaturalized during the electrochemical deposition. © 2011 The Electrochemical Society.