Nano-rheological biomarkers for early and improved follow-up of pathologies associated to RBC deformability alteration

A method to detect in a test blood sample whether the red blood cells (RBCs) contained in the test blood sample present an alteration of their deformability, said method comprising the steps of:

• a) mixing the test blood sample containing RBCs with a molecular rotor (MR) able to penetrate RBCs through their cell membranes to form a mixed test blood sample;
• a′) mixing a control blood sample known for exhibiting non alteration of RBC's deformability with a molecular rotor (MR) able to penetrate RBCs through their cell membranes to form a mixed control blood sample;
• a″) emitting an excitation light at 1) the mixed test blood sample to generate a test fluorescence signal and 2) the mixed control blood sample to generate a control fluorescence signal;
• b) quantifying a level of the test fluorescence signal emitted by the molecular rotor in the mixed test blood sample and a level of the control fluorescence signal emitted by the molecular rotor in the mixed control blood sample and/or analysing a distribution of fluorescence level in RBCs among cells in the mixed test blood sample and in the mixed control blood sample;
• and
• c) comparing the quantified test fluorescence signal and the quantified control fluorescence signal and/or the distribution of fluorescence level in RBCs obtained in step b) for the mixed test blood sample with the distribution of fluorescence level in RBCs obtained for the mixed control blood sample, wherein an increase in the test fluorescence signal and/or a modification of the distribution of fluorescence level in RBCs for the mixed test blood sample compared to the control fluorescence signal and/or the distribution of fluorescence level in RBCs of the mixed control blood sample defines an alteration of the RBCs deformability present in the test blood sample, and wherein said molecular rotor (MR) is trans-4-[4-(Dimethylamino) styril]-1-methylpyridinium (tDASMP).