叶酸功能化介孔碳纳米球负载阿霉素的细胞靶向传递及可控释放

Folate Functionalized Mesoporous Carbon Nanospheres as Nanocarrier for Targetted Delivery and Controlled Release of Doxorubicin to HeLa Cells

以粒径90 nm的介孔碳纳米球作为靶向传药载体,采用酸化处理改进了材料表面的亲疏水性及在溶液中的分散性,通过壳寡糖功能化,并利用EDC-NHS将叶酸修饰到介孔碳纳米球表面.通过共聚焦激光扫描显微镜及流式细胞仪对实验体系的系统研究,结果表明基于叶酸功能化的介孔碳纳米球能够有效提高负载药物对于HeLa细胞的跨膜转运效率,叶酸阳性表达的HeLa细胞对于叶酸修饰的介孔碳纳米小球的吞噬效率明显高于叶酸阴性表达的MCF-7细胞.对HeLa细胞毒性的定量分析表明叶酸的靶向作用在提高介孔碳纳米球内吞效率的同时,进一步提高了阿霉素对于HeLa细胞的毒性.

Ordered mesoporous carbon is a kind of novel carrier for intracellular drug release. There are few reports on the use of mesoporous carbon nanospheres （MCNs） as the transmembrane deliverer in human cancer cells; on the other hand, the particle size of MCNs synthesized by hard templates is usually larger than 100 nm. It is accepted that the optimal size of a transmemhrane delivery vehicle should be less than 100 nm in diameter and the surface should be hydrophilic to circumvent clearance by macrophages, to maximize circulation times and targeting ability. In this work, MCNs with a diameter of ca. 90 nm have been developed as a targeted drug delivery system of an anticancer drug, doxorubicin （DOX）. The small MCNs were synthesized using triblock copolymer Pluronic F127 as a template. The MCNs were first treated by acid to improve its dispersion property in an aqueous solution, and then modified by folic acid through EDC-NHS. The structure of the MCNs was well characterized by transmission electron microscopy, small-angle X-ray scattering, nitrogen adsorption/desorption and dynamic light scattering, pH-dependent drug release is successfully achieved due to the supramolecular 7t-n stacking between DOX and the carbonaceous structures. By effective passive and active targeting, MCNs can be readily internalized into HeLa cells, where the carried DOX can be efficiently released in the acidic microenvironment of the tumors for further therapy. The results from confocal laser scanning microscope and flow cytometry demonstrated that the cellular uptake efficiency of MCNs toward HeLa cells was increased through the functionalization with folic acid, and the folate modified MCNs show much higher endocytosis properties toward HeLa cells （folate receptor positive） than toward MCF-7 cells （folate receptor negative）. The cytotoxicities toward HeLa cells were studied by MTT method, which indicated that the cytotoxicities of DOX loaded mesoporous carbon nanoparticles was also enhanced due to the introduction of folio acid and targeted delivery, while the cytotoxicities of MCNs show very good biocompatibility toward both HeLa and KB cells.