In this study, amino-functionalized mesoporous silica (MS) particles were synthesized and loaded with the anticancer drug, 5-Fu. In a post-modification reaction, the pores were gated by an azobenzene derivative to act as an enzyme-responsive drug delivery system. The synthesis and characterization of the MS structure were validated using various instrumental techniques such as XRD, N₂ adsorption/desorption, and FE-SEM and TEM. The loading efficiency and capacity of 5-Fu adsorption onto MS were evaluated; the adsorption isotherm graphs were plotted. The enzyme responsiveness feature of this nanocarrier was tested in the 5-Fu release study. The 5-Fu release from MS and the azo-capped compound was measured, and when sodium dithionite was used as a reducing agent and an azoreductase enzyme mimicker, the controlled release was observed. Finally, the cytotoxicity of 5-Fu loaded and azo-capped MS in normal medium and sodium dithionate-containing medium was evaluated and compared with the cytotoxicity of the free drug.

中文翻译：

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用偶氮守门人修饰的介孔二氧化硅纳米结构用于结肠靶向递送 5-氟尿嘧啶

在这项研究中，合成了氨基功能化的介孔二氧化硅 (MS) 颗粒并负载了抗癌药物 5-Fu。在后修饰反应中，孔由偶氮苯衍生物封闭，作为酶响应药物递送系统。使用各种仪器技术（如 XRD、N _{2 ）验证 MS 结构的合成和表征}吸附/解吸，以及 FE-SEM 和 TEM。评估了 5-Fu 吸附到 MS 上的负载效率和容量；绘制吸附等温线图。这种纳米载体的酶响应特性在 5-Fu 释放研究中进行了测试。测量了 MS 和偶氮封端化合物的 5-Fu 释放，当连二亚硫酸钠用作还原剂和偶氮还原酶模拟物时，观察到受控释放。最后，评估了载有 5-Fu 和偶氮封端的 MS 在正常培养基和含有连二硫酸钠的培养基中的细胞毒性，并与游离药物的细胞毒性进行了比较。