Porous titanium scaffold surfaces modified with silver loaded gelatin microspheres and their antibacterial behavior

Recent years, porous titanium (PT) attracts much attention because of its growing application as medical implants. However, bacterial infections related to implants remain one of the most common and serious complications. In this study, silver loaded gelatin microspheres (Ag/GMSs) were fabricated and incorporated into porous titanium to get antibacterial implants. Prior to incorporating microspheres, oxide film and micro/nanostructures were formed on porous titanium by micro-arc oxidation (MAO) to improve its activity, and the resulted sample is named MPT. Samples were characterized with scanning electron microscope, energy dispersive X-ray spectroscope, transmission electron microscope, X-ray diffractometer, laser scattering particle analyzer and atomic absorption spectrometer. The results showed that Ag particles were loaded to the gelatin microspheres with average diameter of 4.46 mu m and Ag/GMSs distributed uniformly on the pore walls of PT and MPT. Ag particles were demonstrated not only formed on the surface of gelatin microspheres but also inside them. The silver loaded samples exhibited a high antibacterial ability against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The MPT sample was not only better in supporting osteoblast cell viability and good cell proliferation, but also was beneficial to immobilize the silver loaded microspheres to achieve a stronger antibacterial effect than PT. The MPT sample with silver loaded gelatin microspheres increased the cumulative release period of Ag and reached to more than ten days. The main idea of this study also elicited a new surface functionalization strategy for improving antibacterial ability of porous titanium. (C) 2015 Elsevier B.V. All rights reserved.