Controlled gentamicin- strontium release as a dual action bone agent: Combination of the porous titanium scaffold and biodegradable polymers

Abstract

Titanium is considered a promising biomaterial for load bearing implantation in orthopedics. However, its biologically inert behavior makes the surface treatment essential to improve the bioactivity. In this study, a porous titanium scaffold was fabricated using the space holder method and its surface was treated by the direct oxidation method. Strontium containing gelatin micro spheres (SrGMS) were synthesized using the water in oil method and deposited on the surface of the surface treated porous titanium scaffold (Ti-SrGMS). A thin layer of gentamicin containing poly vinyl alcohol (PVA) was deposited on the surface of Ti-SrGMS for two purposes: first, to postpone strontium release and second, to initially release gentamicin. Raman spectroscopy revealed rutile formation due to the thermal oxidation of titanium at 600 °C. Scanning electron microscope observation also indicated that SrGMS particles were deposited uniformly on the surface of the titanium scaffold. Fourier transform infrared (FTIR) spectra showed that strontium ion was loaded in the gelatin micro sphere successfully. In vitro drug release measurement using inductively coupled plasma-mass spectrometer (ICP-MS) also revealed that by using a layer of PVA with different concentrations on SrMGS particles, it would be possible to control the strontium release as it was needed for the surrounding tissue.