利用金属-有机框架材料ZIF-8包裹二硫化钼(MoS2)纳米片和阿霉素(DOX)构建一种可通过酸性pH和近红外(NIR)光双触发的肿瘤化学/光热协同治疗体系。首先, 通过水热反应和超声处理制备粒径为~100 nm、厚度为0.3~1.4 nm的MoS2纳米片。然后, 通过一步法将可酸降解的金属-有机框架ZIF-8包裹在所制备的MoS2纳米片上, 并同时装载抗肿瘤药物DOX, 形成装载DOX的ZIF-8包裹MoS2纳米复合物(DOX/MoS2@ZIF-8)。将该纳米复合物应用到肿瘤细胞的化学/光热协同治疗: 当处于酸性条件(例如: 溶酶体中pH大约为5)和NIR激光(780 nm, 2.1 W/cm2)照射的情况下, DOX/MoS2@ZIF-8纳米复合物上包裹的ZIF-8金属-有机框架会发生酸降解, 释放出所包裹的DOX, 细胞质中的DOX可以进入细胞核中诱导细胞凋亡; 同时, MoS2纳米片能够将光能转换为热能, 光致高温同样能诱导细胞凋亡, 因此, 化学/光热协同肿瘤治疗得以实现。细胞存活率试验证明: 该DOX/MoS2@ZIF-8纳米复合物在SMMC-7721细胞上表现出良好的化学/光热协同治疗作用, 能够对肿瘤细胞进行高效地杀伤。

Here, we report a novel metal-organic framework ZIF-8-based nanocomposite with encapsulated molybdenum disulfide(MoS2)nanosheets and doxorubicin(DOX)for pH- and NIR-triggered synergistic chemo/photothermal treatment of cancer cells. First, MoS2 nanosheets, which have uniform size of ~100 nm and topological height of 0.3~1.4 nm, are synthesized by hydrothermal reaction and ultrasonic treatment. Subsequently,an acid-degradable metal-organic framework ZIF-8 is employed to synchronously encapsulate MoS2 nanosheets and anti-cancer drug DOX to obtain DOX loaded ZIF-8 coated MoS2 (DOX/MoS2@ZIF-8)nanocomposites by one-step method. The nanocomposites are used for chemo/photothermal synergistic treatment of cancer cells: under acid conditions (e.g. pH 5.0 in a lysosome)and NIR laser irradiation (780 nm, 2.1 W/cm2), the ZIF-8 of the DOX/MoS2@ZIF-8 nanocomposites can be degraded, resulting in the release of encapsulated DOX, the cytosolic DOX can enter the nucleus to induce apoptosis. Meanwhile, the MoS2 nanosheets can effectively convert NIR laser light energy into heat energy, the photoinduced hyperthermia can also induce apoptosis. Thus, chemo/photothermal synergistic cancer therapy is realized. Cell viability assays show that this DOX/MoS2@ZIF-8 nanocomposites have an excellent chemo/photothermal synergistic treatment effect on SMMC-7721 cells, which can kill the tumor cells efficiently.