Structural Configuration of Blood Cell Membranes Determines Their Nonlinear Deformation Properties

Abstract

The ability of neutrophils and red blood cells (RBCs) to undergo significant deformations is a key to their normal functioning. Disruptions of these processes can lead to pathologies. This work studied the influence of structural configuration rearrangements of membranes after exposure to external factors on the ability of native membranes of neutrophils and RBCs to undergo deep deformation. The rearrangement of the structural configuration of neutrophil and RBC membranes under the influence of cytological fixatives caused nonlinear deformation phenomena. There were an increase in Young’s modulus, a decrease in the depth of homogeneous bending, and a change in the distance between cytoskeletal junctions. Based on the results of the analysis of experimental data, a mathematical model was proposed that describes the process of deep bending of RBСs and neutrophil membranes.

AFM methods for studying the morphology and micromechanical properties of the membrane of human buccal epithelium cell

“…Following the authors of ref. 10,18 , the coefficient of elasticity of the cell membrane was significantly higher than the coefficient of elasticity of the cantilever beam. Differences are also visible in the near-surface area of action of adhesive forces.…”

“…All this points to the complex mechanical organization of the cell membrane, which manifests itself only with its active stimulation with large force effect. In this regard, the authors of 10 showed that the mechanical action on the membranes of human erythrocytes and neutrophils with a force of up to 125 nN is accompanied by nonlinear effects of elastic deformation–a significant increase in the values of the Hooke’s coefficient K and Young’s modulus E with a decrease in the zone of uniform bending of the membrane. It should be noted that the authors of 10 divided the process of elastic deformation of membranes into three stages characterized by three deformation zones.…”

“…It is one of the important organelles that determines the shape of the cell, ensures its integrity, controls its interaction with external objects, regulates the metabolism and energy exchange between the cell and the environment. At the same time, the integrity of the membrane is determined not only by the integrity of its geometric shape, but also by the unity (relationship) of its various functional characteristics, in particular, the relationship of chemical 6 , physicochemical 7 , physiological 8,9 , as well as physical 10,11 excitation mechanisms. The latter largely determine the mechanical properties of living cells.…”

“…Probe microscopy methods can be considered as one of the most convenient tools for cell biology, providing the study of eukaryotic cells membranes with submicron and nanometer resolution 5,7,[10][11][12][13][14][15][16][17] . Probe research methods, in particular, atomic force microscopy (AFM), with a fairly wide range of functional and spatial resolutions, allow not only qualitative but also quantitative levels of comprehensive study of morphological and physical characteristics (in particular, micro-and nanomechanical) of living biological objects under normal conditions (normal atmospheric pressure and temperature) in air 5 and in liquid media 12 .…”