Department of Pharmaceutical Nanotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.
Center for Nanotechnology in Drug Delivery, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.
Iran J Med Sci. 2021 Nov;46(6):475-486. doi: 10.30476/ijms.2020.86173.1595.
Silibinin (SBN), a major active constituent of milk thistle seeds, exhibits numerous pharmacological activities. However, its oral bioavailability is low due to poor water solubility. This study aimed to develop a new synthetic approach for tuning the pore characteristics of mesoporous silica nanoparticles (MSNs) intended for the oral delivery of SBN. In addition, the effects of the pore diameter of MSNs on the loading capacity and the release profile of SBN were investigated.
The present study was performed at Shiraz University of Medical Sciences, Shiraz, Iran, in 2019. This synthesis method shares the features of the simultaneous free-radical polymerization of methyl methacrylate and the sol-gel reaction of the silica precursor at the n-heptane/water interface. SBN was loaded onto MSNs, the release was determined, and the radical scavenging activities were compared between various pH values using the analysis of variance.
According to the Brunauer-Emmett-Teller protocol, the pore sizes were well-tuned in the range of 2 to 7 nm with a large specific surface area (600-1200 m/g). Dynamic light scattering results showed that different volume ratios of n-heptane/water resulted in different sizes, ranging from 25 to 100 nm. Interestingly, high SBN loading (13% w/w) and the sustained release of the total drug over 12 hours were achieved in the phosphate buffer (pH=6.8). Moreover, the antioxidant activity of SBN was well preserved in acidic gastric pH.
Well-tuned pores of MSNs provided a proper substrate, and thus, enhanced SBN loading and oral dissolution and preserved its antioxidant activity. Nevertheless, further and investigations are needed.
水飞蓟宾（SBN）是奶蓟种子的主要活性成分，具有多种药理活性。然而，由于其水溶性差，其口服生物利用度较低。本研究旨在开发一种新的合成方法，用于调节介孔二氧化硅纳米粒子（MSNs）的孔特征，以用于 SBN 的口服递送。此外，还研究了 MSNs 的孔径对 SBN 的载药量和释放特性的影响。
本研究于 2019 年在伊朗设拉子市 Shiraz 大学进行。该合成方法具有在正庚烷/水界面同时进行甲基丙烯酸甲酯自由基聚合和硅前驱体溶胶-凝胶反应的特点。将 SBN 负载到 MSNs 上，测定释放情况，并通过方差分析比较不同 pH 值下的自由基清除活性。
根据 Brunauer-Emmett-Teller 方案，孔径在 2 至 7nm 范围内得到了很好的调节，比表面积为 600-1200m/g。动态光散射结果表明，不同的正庚烷/水体积比会导致不同的粒径，范围从 25 到 100nm。有趣的是，在磷酸盐缓冲液（pH=6.8）中实现了 13%w/w 的高 SBN 载药量和 12 小时内总药物的持续释放。此外，SBN 的抗氧化活性在酸性胃 pH 值下得到了很好的保存。
MSNs 的调谐孔提供了合适的基质，从而增强了 SBN 的载药量和口服溶解，并保持了其抗氧化活性。然而，还需要进一步的研究。
