MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Langmuir. 2020 Jun 23;36(24):6811-6818. doi: 10.1021/acs.langmuir.0c01183. Epub 2020 Jun 12.
Methylene blue (MB) is widely used as a photosensitizer in photodynamic therapy applications. However, it is easily reduced by reductases in biological environments, which hampers its further applications. Here, we developed a one-pot method to synthesize MB-encapsulated and poly(vinylpyrrolidone) (PVP)-modified zeolitic imidazolate framework-90 (ZIF-90) nanoparticles (MB@ZIF-90/PVP NPs). The NPs show intact crystalline structure with improved colloidal dispersity and stability both in water and in the medium for cell culture. The size of the enzymes is much larger than the pore size of ZIF-9; thus, the access of reductive enzymes to encapsulated MB is prohibited, resulting in the protection of MB's photodynamic activity. Furthermore, cell experiments confirm that MB@ZIF-90/PVP NPs have lower dark cytotoxity than equivalent free MB but can efficiently induce photodynamic damage to tumor cells even in the presence of reductive enzymes upon light irradiation.
亚甲蓝（MB）广泛用作光动力疗法应用中的光敏剂。然而，它很容易被生物环境中的还原酶还原，这阻碍了它的进一步应用。在这里，我们开发了一种一锅法来合成 MB 包封和聚（聚乙烯吡咯烷酮）（PVP）修饰的沸石咪唑酯骨架-90（ZIF-90）纳米粒子（MB@ZIF-90/PVP NPs）。这些纳米粒子具有完整的晶体结构，在水和细胞培养介质中均表现出改善的胶体分散性和稳定性。酶的尺寸比 ZIF-9 的孔径大得多；因此，还原酶进入包封的 MB 受到限制，从而保护 MB 的光动力活性。此外，细胞实验证实，MB@ZIF-90/PVP NPs 的暗毒性比等效的游离 MB 低，但在光照下即使存在还原酶也能有效地诱导肿瘤细胞发生光动力损伤。
