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Atomic Force Microscopic Observation of Mechanically Traumatized Erythrocytes
Author(s) -
Ohta Yuji,
Okamoto Hiroshi,
Kanno Masahiro,
Okuda Tomoko
Publication year - 2002
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1046/j.1525-1594.2002.06702.x
Subject(s) - surface roughness , membrane , biophysics , hemoglobin , atomic force microscopy , chemistry , shear stress , surface finish , lactic dehydrogenase , erythrocyte deformability , nanotechnology , nanometre , cell membrane , shear force , shear (geology) , red blood cell , materials science , composite material , biochemistry , enzyme , biology
Abstract: Erythrocytes are damaged or stimulated mechanically by artificial organs assisting in circulation. For several decades, a large number of research studies have been conducted to investigate the traumatizing phenomena due to nonphysiological flow conditions. These phenomena are thought to be the physical interaction between the cell membrane and the various fluidic conditions. To elucidate or evaluate the phenomena, however, chemical components emerging into the circulating solution, such as liberated hemoglobin or lactic dehydrogenase (LDH), have been measured as a main parameter. Naturally, the physical reaction caused on the membrane itself cannot be detailed by these parameters because they are the secondary products resulting from the mechanical membrane rupture. The aim of this study is to understand the traumatizing mechanism directly from a microbiological viewpoint. As a first step, we visualized the surface of sheep erythrocytes loaded with shear stress and measured erythrocyte surface roughness by atomic force microscopy (AFM) on a nanometer scale (10 −9 m). The constant shear rate was set at 1,800 (1/s), and the exposure time was set at 0.5, 1, and 2 h. We also measured the liberated hemoglobin concentration. As a result, it was found that the fine structure on the cell surface was changed drastically by the stress. It was also found that the surface roughness value increased with the exposure time, and correlated to the hemoglobin concentration. The visualization and the measurement of surface roughness of traumatized erythrocytes by AFM were thought to offer a new parameter for both hemolytic and subhemolytic studies.