Nano Lett. 2022 Aug 10;22(15):6375-6382. doi: 10.1021/acs.nanolett.2c02185. Epub 2022 Jul 25.
Spatiotemporal pH monitoring of single living cells across rigid cell and organelle membranes has been challenging, despite its significance in understanding cellular heterogeneity. Here, we developed a mechanically robust yet tolerably thin nanowire waveguide that enables in situ monitoring of pH dynamics at desired cellular compartments via direct optical communication. By chemically labeling fluorescein at one end of a poly(vinylbenzyl azide) nanowire, we continuously monitored pH variations of different compartments inside a living cell, successfully observing organelle-exclusive pH homeostasis and stimuli-selective pH regulations. Importantly, it was demonstrated for the first time that, during the mammalian cell cycle, the nucleus displays pH homeostasis in interphase but a tidal pH curve in the mitotic phase, implying the existence of independent pH-regulating activities by the nuclear envelope. The rapid and accurate local pH-reporting capability of our nanowire waveguide would be highly valuable for investigating cellular behaviors under diverse biological situations in living cells.
尽管在理解细胞异质性方面具有重要意义，但对刚性细胞膜和细胞器膜内的单个活细胞进行时空 pH 监测一直具有挑战性。在这里，我们开发了一种机械坚固但又足够薄的纳米线波导，通过直接光学通信，可以在所需的细胞区室原位监测 pH 动力学。通过在聚（苯乙烯基叠氮化物）纳米线的一端化学标记荧光素，我们连续监测了活细胞内不同区室的 pH 变化，成功观察到细胞器特有的 pH 动态平衡和刺激选择性 pH 调节。重要的是，首次证明在哺乳动物细胞周期中，核在间期中表现出 pH 动态平衡，但在有丝分裂相中呈现潮汐 pH 曲线，这表明核膜具有独立的 pH 调节活性。我们的纳米线波导具有快速准确的局部 pH 报告能力，对于在活细胞中不同生物条件下研究细胞行为非常有价值。
