Red blood cell-deformability measurement: Review of techniques

Abstract

Cell-deformability characterization involves general measurement of highly complex relationships between cell biology and physical forces to which the cell is subjected. The review takes account of the modern technical solutions simulating the action of the force applied to the red blood cell in macro-and microcirculation. Diffraction ektacytometers and rheoscopes measure the mean deformability value for the total red blood cell population investigated and the deformation distribution index of individual cells, respectively. Deformation assays of a whole single cell are possible by means of optical tweezers. The single cell-measuring setups for micropipette aspiration and atomic force microscopy allow conducting a selective investigation of deformation parameters (e.g., cytoplasm viscosity, viscoelastic membrane properties). The distinction between instrument sensitivity to various RBC-rheological features as well as the influence of temperature on measurement are discussed. The reports quoted confront fascinating possibilities of the techniques with their medical applications since the RBC-deformability has the key position in the etiology of a wide range of conditions.

The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network

“…17 Pa) it primarily reflects so-called “maximal deformability”, which is determined by the RBC geometrical parameters (i.e., the cell surface area to volume ratio). [22, 36] The measurement of RBC deformability using ektacytometry is confounded by several important factors, including: (a) the viscosity of the PVP solution is about 30-times larger than that of plasma, which is not physiological and thus completely changes the mechanical response of RBCs to shear (i.e. RBCs subjected to shear in plasma flip, not elongate), and (b) the hematocrit of RBC suspension tested is extremely low (<0.5%) and thus ektacytometry cannot account for RBC deformations due to cellular collisions (which are abundant in real blood flow).…”

“…[45, 46] In this sense, the measurement of AMVN perfusion rate provides a more realistic assessment of RBC rheology and (because the AMVN evaluates RBC mechanical properties directly in terms of microvascular perfusion) the results of this assessment should be easier to interpret clinically and may have more significant diagnostic implications. [22]…”

“…[22] The two techniques most frequently utilized in the vast majority of research performed to date in this area (and perhaps most accessible in the clinical settings) are the micro-pore filtration assay[23-30] and ektacytometry. [31-43] In this paper, we directly compare the measurements of RBC deformability performed using these two methodologies with the ability of RBCs to perfuse an artificial microvascular network (AMVN), a microfluidic device developed in our laboratory for modeling the dynamics of blood flow and traffic of circulating cells in the microvasculature.…”

Quantitative biomechanics of healthy and diseased human red blood cells using dielectrophoresis in a microfluidic system

“…Key methods include micropipette aspiration [10, 11], atomic force microscopy [12, 13], optical tweezers [14-16], diffraction phase microscopy [17-19], and magnetic twisting cytometry [20]. Although these techniques have varying levels of force and displacement resolutions for probing cellular and subcellular components in living cells, they often suffer from low throughput, cumbersome experimental set-up and data interpretation, limited portability, and/or applicability only to specific testing and geometry conditions [3-5, 21]. Microfluidic platforms for assessing cell biorheology, on the other hand, offer the means to probe large cell populations in high throughput [22-25], but are often limited in their flexibility to quantitatively determine specific cell mechanical properties using label-free methods(i.e., methods without using any biochemical or immunological tagging techniques).…”

Analysis of the Magnetic Field Influence on the Rheological Properties of Healthy Persons Blood

“…Additional information about erythrocytes properties, similar to that from direct measurements of red cells aggregability and deformability [7, 8, 10, 11], can be achieved indirectly from a mathematical analysis of the flow curve with the use of rheological models [7, 12]. In this work we use the Quemada model [13, 14].…”