Lipid droplets (LDs) have emerged as a hot target for cancer therapeutics in recent years owing to findings that have shown them to be key organelles involved in maintaining cellular stability and regulating inter-organelle communication through molecular trafficking. LDs emerge from the endoplasmic reticulum (ER) as a form of cellular homeostasis control. We herein report the study of a library of asymmetric squaraines as superior fluorescence probes to track and image LDs in their native state and environment within cancer cells. The probes are highly selective towards LDs and displayed prominent bright fluorescence with just 1 μM probe concentration. They also possess bimodal LD and ER staining capability via the simple diffusion of small lipophilic molecules. The probes almost instantly stained LDs, while the ER staining rate is dependent on the probe's lipophilicity and the incubation duration. These “on-demand” organelle-selective probes are highly desirable tools for revealing the role of LDs in governing many cellular processes, especially in malignant cells.

中文翻译：

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用于脂滴双峰染色和活细胞内质网成像的方酸探针

近年来，脂滴 (LDs) 已成为癌症治疗的热门靶点，因为研究结果表明它们是参与维持细胞稳定性和通过分子运输调节细胞器间通讯的关键细胞器。LDs 从内质网 (ER) 中出现，作为细胞稳态控制的一种形式。我们在此报告了对不对称方酸库作为高级荧光探针的研究，以跟踪和成像癌细胞内天然状态和环境中的 LD。探针对 LD 具有高度选择性，并显示出显着的明亮荧光，探针浓度仅为 1 μM。它们还具有双峰 LD 和 ER 染色能力，通过小亲脂分子的简单扩散。探针几乎立即染色 LD，而 ER 染色率取决于探针的亲脂性和孵育持续时间。这些“按需”的细胞器选择性探针是非常理想的工具，可以揭示 LD 在控制许多细胞过程中的作用，尤其是在恶性细胞中。