Thermodynamic characterization of RBCs highlights correlations between different hemoglobin types and Band 3 interactions

Erythrocytes during their life in the bloodstream are subjected to continuous alterations also related to age, which alter their structure and some functional properties. Some types of erythrocytes such as fetal and sickle possesses particular characteristics both functional and structural that characterize their life. In this paper a thermodynamic characterization of fetal and sickle erythrocytes comparing to normal adults is performed. After an introduction of the Kluitenberg's non equilibrium thermodynamic theory with internal variables, the state and phenomenological coefficients are determined. The interpretation of these physical parameters and the entropy production measure highlighted interesting differences between the erythrocytes tested. This characterization accompanied by biochemical investigations on the functionality of the anion exchange led to focus to hemoglobin as the main promoter of structural and functional variations affecting the deformability of the erythrocytes. In details, fetal and sickle erythrocytes showed lower deformability and greater fragility compared to normal cells. These biophysical-thermodynamic investigations open up new perspectives for the study of blood and its characteristics that can be exploited to improve blood conservation methods through careful monitoring of blood quality control.