Angelopoulou A, Efthimiadou E K, Boukos N, Kordas G
Laboratory for Sol-Gel, Advanced Materials, Physicochemical Processes, Nanotechnology & Microsystems, NCSR "Demokritos", 153 10 Ag. Paraskevi Attikis, Greece; Department of Materials Science, School of Natural Sciences, University of Patras, 26 500 Patras, Greece.
Laboratory for Sol-Gel, Advanced Materials, Physicochemical Processes, Nanotechnology & Microsystems, NCSR "Demokritos", 153 10 Ag. Paraskevi Attikis, Greece.
Colloids Surf B Biointerfaces. 2014 May 1;117:322-9. doi: 10.1016/j.colsurfb.2014.02.047. Epub 2014 Mar 12.
In this work, hybrid microspheres were prepared in a two-step process combining the emulsifier free-emulsion polymerization and the sol-gel coating method. In the first step, polystyrene (St) and poly(methyl methacrylate) (PMMA) microspheres were prepared as sacrificial template and in the second step a silanol shell was fabricated. The functionalized surface of the hybrid microspheres by silane analogs (APTES, TEOS) resulted in enhanced effects. The hollow microspheres were resulted either in an additional step by template dissolution and/or during the coating process. The microspheres' surface interactions and the size distribution were optimized by treatment in simulated body fluids, which resulted in the in vitro prediction of bioactivity. The bioassay test indicated that the induced hydroxyapatite resembled in structure to naturally occurring bone apatite. The drug doxorubicin (DOX) was used as a model entity for the evaluation of drug loading and release. The drug release study was performed in two different pH conditions, at acidic (pH=4.5) close to cancer cell environment and at slightly basic pH (pH=7.4) resembling the orthopedic environment. The results of the present study indicated promising hybrid microspheres for the potential application as drug delivery vehicles, for dual orthopedic functionalities in bone defects, bone inflammation, bone cancer and bone repair.
在本研究中，通过结合无乳化剂乳液聚合和溶胶 - 凝胶包覆法的两步法制备了杂化微球。第一步，制备聚苯乙烯（St）和聚甲基丙烯酸甲酯（PMMA）微球作为牺牲模板，第二步，制备硅醇壳层。硅烷类似物（APTES、TEOS）对杂化微球表面进行功能化处理，增强了效果。中空微球可通过模板溶解的额外步骤和/或在包覆过程中获得。通过在模拟体液中处理优化了微球的表面相互作用和尺寸分布，从而实现了生物活性的体外预测。生物测定试验表明，诱导生成的羟基磷灰石在结构上与天然骨磷灰石相似。使用阿霉素（DOX）作为模型实体来评估药物负载和释放。药物释放研究在两种不同的pH条件下进行，一种是接近癌细胞环境的酸性条件（pH = 4.5），另一种是类似于骨科环境的弱碱性pH条件（pH = 7.4）。本研究结果表明，这种杂化微球有望作为药物递送载体，用于骨缺损、骨炎症、骨癌和骨修复等方面的双重骨科功能应用。
