目的：制备一种精氨酸-甘氨酸-天冬氨酸环肽（cRGD）修饰、Zn2+掺杂并负载双硫仑（DSF）的树枝状介孔硅纳米颗粒，初步研究其对结直肠癌CT26细胞的靶向杀伤作用。方法：采用水热合成法将Zn2+锚定在树枝状介孔硅纳米颗粒的骨架中，再将DSF 负载在介孔孔道中，偶联靶向配体cRGD 到纳米颗粒的表面，得到具有靶向功能的纳米颗粒DSF@Zn-DMSN-cRGD。采用透射电镜（TEM）检测DSF@Zn-DMSN-cRGD 的表面形貌，通过能谱面扫得到元素映射图验证其中的元素分布，通过激光粒度仪检测其粒径与电位变化，使用红外光谱仪检测表面主要化学键。通过TEM观察载体Zn-DMSN 在pH6.5和pH7.4的模拟体液中共培养后的形态，采用细胞摄取实验检测cRGD 修饰的Zn-DMSN 靶向CT26 细胞的能力，采用CCK-8法、Calcein-AM/PI 染色法和流式细胞术检测DSF@Zn-DMSN-cRGD 对CT26 细胞的杀伤能力及对细胞凋亡的影响。结果：TEM 观察表明DSF@Zn-DMSN-cRGD 表面具有多孔径，元素映射结果显示Zn元素和DSF成功负载在纳米颗粒表面，红外光谱仪检测结果表明cRGD成功偶联在DSF@Zn-DMSN 介孔硅复合载体的表面，电位粒径结果显示粒径较未偶联cRGD 前稍大，电位明显增加（P<0.000 1），TEM观察发现Zn-DMSN 在微酸性环境中其骨架崩解明显增多，细胞摄取实验结果表明经cRGD修饰后的Zn-DMSN 被CT26 细胞内吞的效率显著增加（P<0.05）。CCK-8法、Calcein-AM/PI 染色法和流式细胞术检测结果说明DSF@Zn-DMSN-cRGD 能够高效杀伤CT26细胞（均P<0.000 1）并诱导细胞发生凋亡（均P<0.000 1），而对正常地肠上皮细胞NCM460 无明显损伤。结论：成功合成了一种掺杂锌、负载DSF并偶联cRGD的纳米颗粒DSF@Zn-DMSN-cRGD，其载体Zn-DMSN骨架具有良好的pH降解性，其中的cRGD能促进纳米颗粒被CT26 细胞靶向内吞；在体外实验中，Zn-DMSN-cRGD 能够对结直肠癌CT26 细胞产生强烈的靶向细胞毒性。

Objective: To construct a cyclic arginine-glycine-aspartate (cRGD)-modified, Zn2+-doped and disulfiram-loaded dendritic mesoporous silicon nanoparticles and to preliminarily investigate its targeting and killing effects against colorectal cancer CT26 cells.Methods: Firstly, Zn2+ was anchored in the skeleton of dendritic mesoporous silicon nanoparticles by hydrothermal synthesis method,then disulfiram was loaded into the pores, and the targeting ligand cRGD was coupled to the surface of the nanoparticles to obtain functional nanoparticles DSF@Zn-DMSN-cRGD. After that, transmission electron microscopy (TEM) was used to detect the surface morphology of DSF@Zn-DMSN-cRGD, and energy spectrum scanning was further used to obtain element mapping images to verify element distribution. Laser particle size analyzer was used to detect the changes of particle size and zeta potential, and infrared spectrometer was used to detect the major chemical bonds on the surface. The morphology of carrier Zn-DMSN after being co-cultured in simulated body fluid solution (pH6.5 and pH7.4) was observed by transmission electron microscopy. Cell uptake assay was used to detect the ability of cRGD-modified Zn-DMSN to target CT26 cells. CCK-8 assay, Calcein-AM/PI staining and flow cytometry were used to detected the killing ability of DSF@Zn-DMSN-cRGD against CT26 cells and its influence on the apoptosis of CT26 cells.Results: The TEM image displayed that the surface of DSF@Zn-DMSN-cRGD was a multi-aperture structure. Element mapping images showed Zn and DSF were successfully loaded on the surface of nanoparticles. The results of infrared spectroscopy showed that cRGD was successfully coupled on the surface of DSF@Zn-DMSN. The particle size slightly increased after coupling cRGD, while the zeta potential obviously increased (P<0.000 1). The images of TEM showed that Zn-DMSN disintegrated faster in pH6.5 solution than in pH7.4 solution. The results of cell uptake experiments showed that the efficiency of CT26 cells uptaking cRGD-modified Zn-DMSN was enhanced prominently (P<0.05). After DSF@Zn-DMSN-cRGD treatment, the results of CCK-8 assay, Calcein-AM/PI staining,and flow cytometry showed that DSF@Zn-DMSN-cRGD could efficiently kill CT26 cells (all P<0.000 1) and induce apoptosis (all P<0.000 1); there was no significant damage to normal colon epithelial cells. Conclusion: DSF@Zn-DMSN-cRGD has been successfully synthesized, and its core skeleton of carrier Zn-DMSN respondes well to pH degradation. In vitro, DSF@Zn-DMSN-cRGD shows substantial targeted toxicity against colorectal cancer cell line CT26, among them, cRGD promotes the targeted endocytosis of nanoparticles by CT26 cells.

国家自然科学基金项目（No. 32271384）