School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Kolkata, 700032, India.
School of Biological Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Kolkata, 700032, India.
Chembiochem. 2020 Oct 15;21(20):2921-2926. doi: 10.1002/cbic.202000303. Epub 2020 Jun 25.
The intracellular transport of molecules, macromolecules or materials is a key step in probing cellular structure and function, as well as regulating a plethora of physical and chemical events for treating disease. This communication reveals direct cellular uptake of pyridyl-disulfide (Py-Ds)-conjugated nonionic and biocompatible macromolecules with the aid of rapid exchange of the highly reactive Py-Ds groups with exofacial cell-surface thiols. Confocal microscopy and flow cytometry analysis confirmed highly efficient cellular uptake of Py-Ds-appended polymers (>50 % in 15 min) by avoiding lysosome as a consequence of thiol-disulfide exchange in the cell surface. In contrast, a control polymer lacking the Py-Ds group followed caveolae-mediated endocytosis. Other control polymers containing either the pyridine group (but not disulfide) or the disulfide group (but not pyridine) revealed significantly low cellular uptake, and thus essential role of the highly reactive Py-Ds group was established beyond doubt.
分子、生物大分子或材料的细胞内运输是探测细胞结构和功能的关键步骤，也是调节大量物理和化学事件以治疗疾病的关键步骤。本通讯揭示了在快速交换高反应性的 Py-Ds 基团与细胞表面外侧巯基的帮助下，吡啶二硫代（Py-Ds）缀合的非离子和生物相容性大分子的直接细胞摄取。共聚焦显微镜和流式细胞术分析证实，通过细胞表面的硫醇-二硫交换，避免了溶酶体，从而使 Py-Ds 修饰的聚合物具有非常高的细胞摄取效率（15 分钟内超过 50%）。相比之下，缺乏 Py-Ds 基团的对照聚合物则通过小窝蛋白介导的内吞作用进入细胞。其他含有吡啶基团（但不含二硫键）或二硫键基团（但不含吡啶）的对照聚合物的细胞摄取率明显较低，因此，高反应性的 Py-Ds 基团的重要作用毋庸置疑。
