Department of Physics and Astronomy, University of Turku, Turku, Finland.
Eur J Pharm Biopharm. 2010 Mar;74(3):483-94. doi: 10.1016/j.ejpb.2009.12.006. Epub 2009 Dec 16.
Cytotoxicity of ordered mesoporous silica MCM-41 and SBA-15 microparticles (fractions between 1 and 160 microm) was determined in vitro on undifferentiated human colon carcinoma (Caco-2) cell line, considering the feasibility of using these silica-based materials in oral drug formulations. The cellular endpoints employed for assessing the effects of the MCM-41 and SBA-15 microparticles on Caco-2 were: (1) cell membrane integrity by monitoring live-cell protease activity (AFC) and by employing the flow cytometry method; (2) metabolic activity by monitoring total ATP content via luminescence assay; (3) activity of apoptotic effectors by caspase-3/7 activity assay. The generation of reactive oxygen species (ROS) was also followed, specifically the hydrogen peroxide (H(2)O(2)) and the superoxide radical (O(2)(-)). MCM-41 and SBA-15 microparticles caused cytotoxic effects on the Caco-2 cells, at most tested concentrations (0.2-14 mg/ml) and incubation times (3 and 24h). The effects on the cells included weakened cell membrane integrity, diminished cell metabolism and increased apoptotic signalling. The root cause for the cytotoxicity was heightened production of reactive oxygen species (ROS), especially the formation of the superoxide radical O(2)(-) already after 3h incubation with threshold dose 1mg/ml, apparently overwhelming the antioxidant defences and causing mitochondrial dysfunction, hence increasing the apoptotic signalling.
有序介孔硅材料 MCM-41 和 SBA-15 微球（粒径 1 至 160μm）的细胞毒性，通过体外实验在未分化的人结肠癌细胞系（Caco-2）上进行了评估，因为这些基于硅的材料可能会被用于口服药物制剂。采用活细胞蛋白酶活性（AFC）监测和流式细胞术方法来评估 MCM-41 和 SBA-15 微球对 Caco-2 的细胞膜完整性的影响；通过发光测定法监测总 ATP 含量来评估代谢活性；通过 caspase-3/7 活性测定法来评估凋亡效应子的活性。还跟踪了活性氧（ROS）的产生，特别是过氧化氢（H2O2）和超氧自由基（O2(-)）。MCM-41 和 SBA-15 微球在最多测试浓度（0.2-14mg/ml）和孵育时间（3 和 24h）下对 Caco-2 细胞产生了细胞毒性作用。这些作用包括削弱细胞膜完整性、降低细胞代谢和增加凋亡信号。细胞毒性的根本原因是活性氧（ROS）的产生增加，尤其是超氧自由基 O2(-)的形成，在 3h 孵育时就达到了 1mg/ml 的阈剂量，这显然超过了抗氧化防御能力，并导致线粒体功能障碍，从而增加了凋亡信号。
