Ultrafast Bio- and Nanophotonics Group, INL - International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal.
Nanoscale. 2020 Nov 5;12(42):21647-21656. doi: 10.1039/c9nr10370h.
Temperature is a key parameter for optimal cellular function and growth. Temperature perturbation may directly lead to cell death. This can be used in cancer therapies to kill cells in tumors, a therapeutic approach called hyperthermia. To avoid overheating of tumors that may damage healthy tissues, a knowledge of the intracellular temperature reached during the hyperthermia treatment of cancer cells is relevant. Recently, several luminescent intracellular nanothermometers have been proposed; however an application to sense temperature during a hyperthermia treatment is lacking. Here we present a technique to measure intracellular temperature changes in in vitro cancer cell models. For this purpose, we study for the first time the temperature dependence of the green fluorescent protein (GFP)'s fluorescence lifetime parameter. We find the fluorescence lifetime of GFP can be used for nanothermosensing. We use GFP in a bound form to actin filaments as an intracellular thermal reporter. Furthermore, we assess intracellular temperature during in vitro magnetothermal therapy on live HeLa cells incubated with polyacrylic acid-coated iron oxide nanoparticles. Compared to other thermosensitive materials and formulations reported so far, the GFP nanothermosensor is easily expressed via transfection and various GFP variants are commercially available. We foresee that the nanothermometer developed might find widespread applications in cancer therapy research and development.
温度是细胞最佳功能和生长的关键参数。温度干扰可能直接导致细胞死亡。这可以用于癌症治疗以杀死肿瘤中的细胞，这是一种称为热疗的治疗方法。为了避免肿瘤过热可能损害健康组织，可以了解在癌细胞的热疗过程中达到的细胞内温度。最近，已经提出了几种发光的细胞内纳米温度计；然而，缺乏用于在热疗过程中感测温度的应用。在这里，我们提出了一种在体外癌细胞模型中测量细胞内温度变化的技术。为此，我们首次研究了绿色荧光蛋白（GFP）荧光寿命参数对温度的依赖性。我们发现 GFP 的荧光寿命可用于纳米热感测。我们将 GFP 以结合形式用于肌动蛋白丝作为细胞内热报告器。此外，我们评估了用聚丙烯酸包覆的氧化铁纳米粒子孵育的活 HeLa 细胞进行体外磁热疗期间的细胞内温度。与迄今为止报道的其他热敏材料和配方相比，GFP 纳米温度计可通过转染轻松表达，并且各种 GFP 变体都可商购。我们预计开发的纳米温度计可能会在癌症治疗的研究和开发中得到广泛应用。
