Problems of Red Blood Cell Aggregation and Deformation Assessed by Laser Tweezers, Diffuse Light Scattering and Laser Diffractometry

Abstract

This study aims to highlight the problems with implementing optical techniques (laser tweezers, diffuse light scattering and laser diffractometry) in clinical hemorheological practice. We provide the feasibility of these techniques to assess microrheological effects of various molecular mechanisms affecting RBC aggregation and deformability. In particular, we show that they allow assessment of changes in RBC aggregation in whole blood samples both on the level of single cells and on the level of large ensembles of cells. Application of these methods allows for studying the mechanisms of RBC aggregation because they are sensitive to changes in the medium which surrounds the RBC (i.e., blood plasma, serum or model solutions of blood plasma proteins) and to changes in the cellular properties of RBCs (i.e., effects on the cell membrane due to glycoprotein inhibition).

The Impact of COVID-19 on Cellular Factors Influencing Red Blood Cell Aggregation Examined in Dextran: Possible Causes and Consequences

“…The increased compactness of the aggregates indicates their greater stability, which may decrease the likelihood of disaggregation of these aggregates due to shear stress. In healthy subjects, the shear stress in the circulatory system is sufficient to separate the aggregate into individual erythrocytes [11,16,33]. Whereas, in COVID-19 patients, denser, more stable aggregates may not disaggregate under these conditions.…”

Thermography of Whole Blood during Laser Heating through Bare Fiber

“…These processes determine the increase in light transmission [18]. Recent studies [19] showed that aggregation leads to an increase in forward-scattered light intensity and decrease in back-scattered light intensity. Such changes in the scattering pattern indicate an increase in the anisotropy factor g. As a consequence, the effective absorption coefficient eff decreases.…”

“…3) can be associated with the physicochemical processes occurring during blood calorimetry. For a more accurate specification of the processes, the data of calorimetric measurements should be analyzed in combination with data on changes in the optical properties of blood under traditional [18], laser [14,15] heating and low shear stress [19]. At stage 1 of heating, the transition of erythrocytes from a discshaped biconcave shape to a spherical one occurs, protein denaturation, cell aggregation and rupture of cell membranes [14,15,17,18].…”

Advances in Microfluidics for Single Red Blood Cell Analysis

“…The method proved that mechanical vibration of the sample promoted RBC agglutination and redistribution through the sample volume [116]. Semenov et al assessed RBC aggregation and deformation by laser tweezers, diffuse light scattering, and laser diffractometry demonstrating the benefits of the optical methods for studying RBC aggregation deformability [117] while Trejo-Soto et al studied microfluidics methods of assessing blood rheology in microcirculation [118].…”