Understanding heat dissipation processes at nanoscale during cellular thermogenesis is essential to clarify the relationships between the heat and biological processes in cells and organisms. A key parameter determining the heat flux inside a cell is the local thermal conductivity, a factor poorly investigated both experimentally and theoretically. Here, using a nanoheater/nanothermometer hybrid made of a polydopamine encapsulating a fluorescent nanodiamond, we measured the intracellular thermal conductivities of HeLa and MCF-7 cells with a spatial resolution of about 200 nm. The mean values determined in these two cell lines are both 0.11 ± 0.04 W m⁻¹ K⁻¹, which is significantly smaller than that of water. Bayesian analysis of the data suggests there is a variation of the thermal conductivity within a cell. These results make the biological impact of transient temperature spikes in a cell much more feasible, and suggest that cells may use heat flux for short-distance thermal signaling.

了解细胞生热过程中纳米级的散热过程对于阐明细胞和生物体中热量与生物过程之间的关系至关重要。决定细胞内热通量的一个关键参数是局部热导率，这是一个在实验和理论上都很少研究的因素。在这里，我们使用由封装荧光纳米金刚石的聚多巴胺制成的纳米加热器/纳米温度计混合物，以大约 200 nm 的空间分辨率测量了 HeLa 和 MCF-7 细胞的细胞内热导率。在这两个细胞系中测定的平均值均为 0.11 ± 0.04 W m ^-1 K ^-1, 明显小于水。数据的贝叶斯分析表明，细胞内的热导率存在变化。这些结果使细胞中瞬时温度峰值的生物学影响更加可行，并表明细胞可以使用热通量进行短距离热信号。