Peer-Reviewed Journal Details
Mandatory Fields
James Jenkins, Sergey M. Borisov, Dmitri B. Papkovsky, and Ruslan I. Dmitriev
Analytical Chemistry
Sulforhodamine Nanothermometer for Multiparametric Fluorescence Lifetime Imaging Microscopy
Optional Fields
Live cells function within narrow limits of physiological temperature (T) and O2 and metabolite concentrations. We have designed a cell-permeable T-sensitive fluorescence lifetime-based nanoprobe based on lipophilic sulforhodamine, which stains 2D and 3D cell models, shows cytoplasmic localization, and has a robust response to T (∼0.037 ns/K). Subsequently, we evaluated the probe and fluorescence lifetime imaging microscopy (FLIM) technique for combined imaging of T and O2 gradients in metabolically active cells. We found that in adherent 2D culture of HCT116 cells intracellular T and O2 are close to ambient values. However, in 3D spheroid structures having size >200 μm, T and O2 gradients become pronounced. These microgradients can be enhanced by treatment with mitochondrial uncouplers or dissipated by drug-induced disaggregation of the spheroids. Thus, we demonstrate the existence of local microgradients of T in 3D cell models and utility of combined imaging of O2 and T.
Grant Details
Science Foundation Ireland