Controlled and sustained drug release performance of calcium sulfate cement porous TiO(2) microsphere composites

BACKGROUND: Calcium sulphate cement (CSC) is widely used as an osteoconductive biomaterial in bone repair and regeneration. PURPOSE: In this study, porous TiO(2) microspheres were added to CSC to achieve a controlled and sustained drug (gentamicin) release. METHODS: Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Brunauer-Emmett-Teller (BET) surface area analysis were conducted to analyse the morphology, phase composition, and surface area of the TiO(2) micro-spheres and composite cements. In addition, the injection time, compressive strength, degradation behaviour, and antibacterial ability of the composite cements were examined during in vitro degradation. Gentamicin release profile was recorded using an ultraviolet spectrophotometer. RESULTS: The results revealed the excellent drug loading ability of the TiO(2) microspheres. The addition of TiO(2) microspheres improved the injectability and compressive strength of the composite cements, the maximum value of which was achieved at a TiO(2) loading of 5 wt.%. When immersed in simulated body fluid (SBF), the composite cements doped with TiO(2) microspheres were observed to release gentamicin in a stable and sustained manner, especially in the latter stages of in vitro degradation. During degradation, CSC doped with TiO(2) microspheres exhibited a typical apatite-like behaviour. Further, antibacterial analysis showed that CSC doped with TiO(2) microspheres exhibited long-term antibiotic activity. CONCLUSION: Thus, as an effective sustained-release formulation material, TiO(2) microspheres show a great potential for application in bone cements.