The cell membrane is an important regulator for the cytotoxicity of chemotherapeutic agents. However, the biochemical and biophysical effects that occur in the membrane under the action of chemotherapy drugs are not fully described. In the present study, changes in the microviscosity of membranes of living HeLa-Kyoto tumor cells were studied during chemotherapy with paclitaxel, a widely used antimicrotubule agent. To visualize the microviscosity of the membranes, fluorescence lifetime imaging microscopy (FLIM) with a BODIPY 2 fluorescent molecular rotor was used. The lipid profile of the membranes was assessed using time-of-flight secondary ion mass spectrometry ToF-SIMS. A significant, steady-state decrease in the microviscosity of membranes, both in cell monolayers and in tumor spheroids, was revealed after the treatment. Mass spectrometry showed an increase in the unsaturated fatty acid content in treated cell membranes, which may explain, at least partially, their low microviscosity. These results indicate the involvement of membrane microviscosity in the response of tumor cells to paclitaxel treatment.
A decrease in the regenerative potential of the liver during the development of non-alcoholic fatty liver disease (NAFLD), which is observed in the vast majority of patients with diabetes mellitus type 1, significantly increases the risk of postoperative liver failure. In this regard, it is necessary to develop new approaches for the rapid intraoperative assessment of the condition of liver tissue in the presence of concomitant liver pathology. A modern label-free approach based on multiphoton microscopy, second harmonic generation (SHG), and fluorescence lifetime imaging microscopy (FLIM) allow for the evaluation of the structure of liver tissue as well as the assessment of the metabolic state of hepatocytes, even at the cellular level. We obtained optical criteria and identified specific changes in the metabolic state of hepatocytes for a reduced liver regenerative potential in the presence of induced diabetes mellitus type 1. The obtained criteria will expand the possibilities for the express assessment of the structural and functional state of liver tissue in clinical practice.