Fan Xin, Domszy Roman C, Hu Naiping, Yang Arthur J, Yang Jeff, David Allan E
Department of Chemical Engineering, Auburn University, Auburn, AL.
Industrial Science & Technology Network, Inc., Lancaster, PA.
J Solgel Sci Technol. 2019;91(1):11-20. doi: 10.1007/s10971-019-04995-4. Epub 2019 May 2.
Composite silica-alginate nanoparticles were prepared via silica sol-gel technique using a water-in-oil microemulsion system. In our system, cyclohexane served as the bulk oil phase into which aqueous solutions of sodium alginate were dispersed as droplets that confined nanoparticle formation after addition of tetraethylorthosilicate (TEOS). Our studies showed that much of the particle growth is completed within the first 24 hours and reaction times up to 120 hours only resulted in an additional 5% increase in particle diameter. Average particle size was found to decrease with increasing water-to-surfactant molar ratio () and with increasing cocentration of alginate in the aqueous phase. The potential for drug loading during particle formation was demonstrated using rhodamine B as a model drug. release studies showed that particles incubated in pH 2.5 phosphate buffer released only about 7% of the drug load in 27 days, while 42% was released in pH 7.5 phosphate buffer over the same period. Analysis of the release profile suggested that rhodamine B was homogeneously distributed throughout the particle and that the drug diffusivity was 40-fold greater in pH 7.5 buffer compared to that at pH 2.5. These results suggest that silica-alginate nanoparticles could be used as a pH-responsive drug carrier for controlled drug release.
采用油包水微乳液体系，通过硅溶胶-凝胶技术制备了复合二氧化硅-海藻酸钠纳米颗粒。在我们的体系中，环己烷作为主体油相，海藻酸钠水溶液以液滴形式分散在其中，在加入正硅酸四乙酯（TEOS）后，这些液滴限制了纳米颗粒的形成。我们的研究表明，大部分颗粒生长在最初24小时内完成，反应时间延长至120小时只会使颗粒直径额外增加5%。发现平均粒径随着水与表面活性剂摩尔比（）的增加以及水相中海藻酸钠浓度的增加而减小。以罗丹明B作为模型药物，证明了在颗粒形成过程中载药的可能性。释放研究表明，在pH 2.5磷酸盐缓冲液中孵育的颗粒在27天内仅释放了约7%的载药量，而在相同时间内，在pH 7.5磷酸盐缓冲液中释放了42%。对释放曲线的分析表明，罗丹明B均匀分布在整个颗粒中，并且与pH 2.5时相比，药物在pH 7.5缓冲液中的扩散率高40倍。这些结果表明，二氧化硅-海藻酸钠纳米颗粒可作为pH响应性药物载体用于药物控释。
