Transient Plasmonic Photothermal Imaging Deciphers Dynamic Thermal Transfer during the Cell Cycle

A stable thermodynamic environment is a key prerequisite for the orderly conduct of metabolic activities within cells. For cell division, a common but important life-sustaining process the balance between heat generation and dissipation is especially important. Here, we measure the thermal conductivity within single cells and reveal dynamic thermal regulation during the entire cell cycle by using transient plasmonic photothermal microscopy with the help of fluorescence-image-based cell cycle analysis. We find that the thermal conductivities within cells are highly heterogeneously distributed, and some sites in the perinuclear region have relatively low values (as low as 0.035 W·m^-1·K^-1). During different stages of the cell cycle, the thermal conductivity of the cell is dynamically adjusted (with a fluctuation of 0.063 W·m^-1·K^-1) with the level of energy metabolism to maintain thermodynamic robustness. We further perform metabolomic analysis during the cell cycle using single-cell mass spectrometry and extract relevant metabolite pathways. These results provide important insights into how cells adapt and regulate their internal heat balance to ensure the robustness of thermal adaptability.