Significance: Despite the importance of the cell membrane in regulation of drug activity, the influence of drug treatments on its physical properties is still poorly understood. The combination of fluorescence lifetime imaging microscopy (FLIM) with specific viscosity-sensitive fluorescent molecular rotors allows the quantification of membrane viscosity with high spatiotemporal resolution, down to the individual cell organelles. Aim: The aim of our work was to analyze microviscosity of the plasma membrane of living cancer cells during chemotherapy with cisplatin using FLIM and correlate the observed changes with lipid composition and cell’s response to treatment. Approach: FLIM together with viscosity-sensitive boron dipyrromethene-based fluorescent molecular rotor was used to map the fluidity of the cell’s membrane. Chemical analysis of membrane lipid composition was performed with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Results: We detected a significant steady increase in membrane viscosity in viable cancer cells, both in cell monolayers and tumor spheroids, upon prolonged treatment with cisplatin, as well as in cisplatin-adapted cell line. ToF-SIMS revealed correlative changes in lipid profile of cisplatin-treated cells. Conclusions: These results suggest an involvement of membrane viscosity in the cell adaptation to the drug and in the acquisition of drug resistance.

中文翻译：

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使用分子转子和荧光寿命成像显微镜绘制癌细胞中顺铂诱导的粘度变化

意义：尽管细胞膜在药物活性调节中很重要，但药物治疗对其物理性质的影响仍然知之甚少。荧光寿命成像显微镜 (FLIM) 与特定的粘度敏感荧光分子转子相结合，可以以高时空分辨率量化膜粘度，直至单个细胞器。目的：我们工作的目的是使用 FLIM 分析顺铂化疗期间活癌细胞质膜的微粘度，并将观察到的变化与脂质成分和细胞对治疗的反应相关联。方法：FLIM 与粘度敏感的基于硼二吡咯亚甲基的荧光分子转子一起用于绘制细胞膜的流动性。使用飞行时间二次离子质谱（ToF-SIMS）对膜脂成分进行化学分析。结果：我们检测到，经过顺铂长期治疗后，活癌细胞（单层细胞和肿瘤球体）以及适应顺铂的细胞系的膜粘度显着稳定增加。ToF-SIMS 揭示了顺铂处理的细胞脂质谱的相关变化。结论：这些结果表明膜粘度参与细胞对药物的适应和耐药性的获得。