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Disorders in the erythrocyte morphology and structure of their membranes during long-term storage of erythrocyte suspension (30 days at 4°C) were studied by atomic force microscopy. The morphology and nanostructure of erythrocyte membranes, biochemical parameters, ion exchange parameters, and hemoglobin spectra were recorded. The transformation of erythrocyte morphology and destruction of their membranes were observed throughout the storage period. Irreversible forms of spheroechinocytes and their fragments formed by the end of storage. The concentrations of potassium ions and lactate in solution of the blood preservatiive increased, while pH value decreased. Hemolysis detected by the erythrocyte "leakage" effect was observed starting from days 16-23 of storage.

Zinc-induced injuries to red blood cell membrane nanostructures at different zinc concentrations were studied by atomic force microscopy. In order to distinguish the intrinsic characteristics of membrane nanostructures, the membrane surfaces were represented by three orders using 3D Fourier transform. Increasing the concentrations of zinc ions modified the pattern of induced injuries: their depths and diameters and their number on the membrane surface test area increased. The injuries and their distribution for each order of membrane surface were analyzed. Albumin restored membrane nanosurface.

The authors studied changes in erythrocyte membrane nanostructure using a rodent model of hemorrhagic hypotension and resuscitation. Both macro- and microstructural elements were examined using atomic force microscopy. Membrane "roughness" was characterized using spatial Fourier transformation and was stratified according to the periodicity of the membrane. Acute hemorrhage resulted in an increase in the diameter and height of erythrocytes, which returned to baseline levels by the end of the hemorrhagic hypotensive period. The effect of hypotension on the erythrocyte surface was nonuniform. In those regions where damage was considerable, the rate of restoration of the membrane microstructure to baseline levels was prolonged. The less damaged surfaces were restored more rapidly to control values after reperfusion. More detailed use of atomic force microscopy in the definition of the erythrocyte membrane microstructure may further define the mechanisms of cellular functional restoration after hemorrhage.

Purpose: After the influence of different actions on the blood, the erythrocytes may change their macrostructure. At the same time, the microstructure of cell membrane will be changed as well. This study provides the results of comparison of red blood cell membrane microstructure after they have been affected by different factors., Materials and Methods: Images and spatial profiles of the cell surface were obtained by atomic force microscope. It was proposed to use spatial Fourier transform to decompose the initial complex profile into series of simple ones. This made it possible to compare surface parameters after exposure of red blood cells to different external actions., Results: Quantitative differences between membrane profile harmonic composition parameters (amplitude and spatial period) after physical impact (impulse electrical field, osmotic swelling) and after chemical impact (the fixing fluid glutaraldehyde and the drug Esmeron) were experimentally confirmed., Conclusions: Such experimental and theoretical approach may lay down the foundations of mechanisms of different factors' effect on red blood cells both in research and in clinics., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Atomic force microscopy was used for examination of the surface of human erythrocyte membrane after calibrated electroporation and application of pharmacological agents. Three-order surface inhomogeneities were revealed with various spectral windows of Fourier transform to elaborate the quantitative criteria to assess the state of membrane surface. The size of structural alterations induced in the membranes by electroporation was 100-300 nm, which is comparable to the size of membrane matrix.

We studied the effects of high-voltage single, double unipolar, and double bipolar electric pulses of exponential or sine shape on erythrocyte membranes. Either single or double (mono- or bipolar) pulses were used. All pulses electroporated the membranes, and the electroporation threshold did not depend on the pulse shape. Two successive pulses decreased erythrocyte number in a nonadditive way. Similar to defibrillation of the whole heart, the effect of two bipolar pulses on erythrocytes was more pronounced than the effect of two unipolar pulses.