In vitro apatite formation and drug loading/release of porous TiO2 microspheres prepared by sol-gel processing with different SiO2 nanoparticle contents.
Bioactive titania (TiO2) microparticles can be used as drug-releasing cement fillers for the chemotherapeutic treatment of metastatic bone tumors. Porous anatase-type TiO2 microspheres around 15 μm in diameter were obtained through a sol-gel process involving a water-in-oil emulsion with 30:70 SiO2/H2O weight ratio and subsequent NaOH solution treatment. The water phase consisted of methanol, titanium tetraisopropoxide, diethanolamine, SiO2 nanoparticles, and H2O, while the oil phase consisted of kerosene, Span 80, and Span 60. The resulting microspheres had a high specific surface area of 111.7 m(2)·g(-1). Apatite with a network-like surface structure formed on the surface of the microspheres within 8 days in simulated body fluid. The good apatite-forming ability of the microspheres is attributed to their porous structure and the negative zeta potential of TiO2. The release of rhodamine B, a model for a hydrophilic drug, was rapid for the first 6 h of soaking, but diffusion-controlled thereafter. The burst release in the first 6h is problematic for clinical applications; nonetheless, the present results highlight the potential of porous TiO2 microspheres as drug-releasing cement fillers able to form apatite.
Graduate School of Biomedical Engineering, Tohoku University, Sendai 980-8579, Japan. Electronic address: m-kawa@ecei.tohoku.ac.jp.
Masakazu
M
Kawashita
School of Engineering, Tohoku University, Sendai 980-8579, Japan.
Yui
Y
Tanaka
School of Engineering, Tohoku University, Sendai 980-8579, Japan.
Shoji
S
Ueno
Graduate School of Biomedical Engineering, Tohoku University, Sendai 980-8579, Japan.
Gengci
G
Liu
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
Zhixia
Z
Li
Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu 808-0196, Japan.
Toshiki
T
Miyazaki
D001031:Apatites / Q000138:chemical synthesis* / Q000737:chemistry; D003102:Colloids / Q000737:chemistry; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D044367:Phase Transition; D016062:Porosity; D012235:Rhodamines / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
D001031:Apatites; D003102:Colloids; D012235:Rhodamines; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium; C029773:rhodamine B
Apatite; Bioactivity; Drug-release; Microsphere; Rhodamine B; TiO(2)