Zhou Haiou, Shi Tiejun, Zhou Xun
a School of Chemical Engineering of Hefei University of Technology , Hefei 230009 , P.R. China.
J Biomater Sci Polym Ed. 2014;25(7):641-56. doi: 10.1080/09205063.2014.890919. Epub 2014 Mar 6.
In this paper, with W/O Pickering emulsion stabilized by modified SiO(2) nanoparticles as template, PVA/SiO(2) composite microspheres with PVA hydrogel cores and shells of SiO(2) nanoparticles are successfully fabricated through freezing/thawing method. The final structure and constituents of the products are investigated through SEM, FTIR, and TGA. The PVA/SiO(2) composite microspheres obtained are applied as a drug carrier to study their controlled release behaviors and methylene blue is used as a model drug. The effect of PVA concentration, SiO(2) nanoparticle concentration, and freezing/thawing cycles on the morphology of products and release behaviors is studied. All release curves are, respectively, fitted by Monoexponential equation, Higuchi equation, Weibull equation, and Hixson-Crowell equation. Weibull equation is found to give the best fit to the release process. The fitted results prove that the drug release from the PVA/SiO(2) composite microspheres follows Fick diffusion.
本文以改性SiO₂纳米粒子稳定的W/O Pickering乳液为模板，通过冻融法成功制备了具有PVA水凝胶核和SiO₂纳米粒子壳的PVA/SiO₂复合微球。通过扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）和热重分析（TGA）对产物的最终结构和成分进行了研究。将所得的PVA/SiO₂复合微球用作药物载体，研究其控释行为，并以亚甲基蓝作为模型药物。研究了PVA浓度、SiO₂纳米粒子浓度和冻融循环对产物形态和释放行为的影响。所有释放曲线分别用单指数方程、Higuchi方程、Weibull方程和Hixson-Crowell方程进行拟合。发现Weibull方程对释放过程的拟合效果最佳。拟合结果证明，PVA/SiO₂复合微球中的药物释放遵循菲克扩散。
