Center of Physical Sciences and Technology, Saultekio av. 3, Vilnius, LT-10257, Lithuania.
Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko str. 24, Vilnius, LT-03225, Lithuania.
J Mater Chem B. 2023 May 3;11(17):3919-3928. doi: 10.1039/d3tb00305a.
Intracellular polarity in lipid droplets as well as other organelles may provide useful knowledge about various processes taking place in live cells. Therefore, small fluorophores capable of visualising polarity are undergoing rapid development. In this paper, we report new red-emitting polarity sensitive BODIPY probes that can distinguish between liquid-ordered and liquid-disordered phases and can internalise into lipid droplets of live cells. Our reported probes sense lipid environment not through solvatochromic shift of the fluorescence spectra but through the change in the fluorescence lifetime of their monoexponential decays. This makes them convenient for fluorescence lifetime imaging microscopy. The probes were synthesised by modifying viscosity-sensitive -phenyl BODIPY with electron-donating 2-thienyl moieties at the α- and β-positions, significantly red-shifting absorption and fluorescence spectra of the dyes and improving sensitivity to polarity, while suppressing viscosity dependence. Finally, a novel probe - BP OC TP2 was suitable for sensing polarity in lipid droplets of live MCF-7 human breast cancer cells. We demonstrated that different chemotherapeutics affected lipid droplet polarity differently: cisplatin had no effect on lipid droplet polarity, whereas paclitaxel, depending on its concentration, either decreased or increased lipid droplet polarity.
细胞内脂滴和其他细胞器的极性可为研究活细胞内发生的各种过程提供有用的信息。因此，能够可视化极性的小分子荧光染料正在快速发展。本文报道了新的红色发射型对极性敏感的 BODIPY 探针，它们能够区分有序相和无序相，并能内化到活细胞的脂滴中。我们报道的探针通过单指数衰减荧光寿命的变化而不是荧光光谱的溶剂化变色来感知脂质环境，这使得它们便于荧光寿命成像显微镜使用。这些探针是通过在 - 苯基 BODIPY 的α-和β-位上修饰给电子 2-噻吩基来合成的，这显著红移了染料的吸收和荧光光谱，并提高了对极性的敏感性，同时抑制了对粘度的依赖性。最后，一种新型探针 - BP OC TP2 适用于检测活 MCF-7 人乳腺癌细胞脂滴的极性。我们证明，不同的化疗药物对脂滴极性的影响不同：顺铂对脂滴极性没有影响，而紫杉醇则取决于其浓度，要么降低要么增加脂滴极性。
