Measurements of Mechanical Properties of Human Red Blood Cells

Author(s):  
Choongbae Park ◽  
Steven T. Wereley ◽  
Osvaldo H. Campanella ◽  
David E. Nivens ◽  
Kenneth M. Little ◽  
...  

We developed a novel method to measure the rheological properties of single red blood cells (RBC) using the atomic force microscope (AFM). A spherical bead at the AFM cantilever tip compressed and relaxed the RBC. The force and displacement were converted into effective stress and strain. The impulse viscoelastic technique was used to compute the effective storage (E') and loss (E") moduli and phase lag (δ). Unfixed and fixed red blood cells were tested. Both cells were on glass coated with poly-l-lysine and then kept in phosphate buffered saline (PBS) until the experiment was finished. Measurements were done with height change and force up to 451nm and 64nN. The cells were found to be quite elastic, with phase lag on the order of 10-2 to 10-1 rad. Stepped changes in oscillation rate from 0.5Hz to 2.5Hz did not result in significant change in the measured results. To improve accuracy, we also design a bimaterial cantilever which consists of a gold layer on silicon with controlled thermal stresses such that the cantilever is curved. The curvature allows the root to fits the angle of the AFM head and the tip to be parallel to the substrate so that the RBC is squeezed between two parallel surfaces.

2020 ◽  
Vol 16 (3) ◽  
pp. 4-13 ◽  
Author(s):  
V. V. Moroz ◽  
A. M. Chernysh ◽  
Elena K. Kozlova

This paper highlights published hypotheses on the possibility of coronavirus SARS-CoV-2 entry into the bloodstream, its interaction with vascular endothelium, red blood cells, hemoglobin and its fragments. As a result of such interaction, iron ions may be released into the bloodstream and, subsequently, a cytokine storm may occur. In this context, it is important to find a cytoprotective agent capable of blocking such processes. The perfluorocarbon emulsion could be a candidate for this role.The aim of the paper is to show the feasibility of biophysical methods to study the molecular mechanisms of action of SARS-CoV-2 on human red blood cells and hemoglobin as well as the restorative and cytoprotective effect of the perfluorocarbon emulsion during Fe2+ oxidation in heme.Materials and methods. High resolution spectroscopy, atomic force microscopy, atomic force spectroscopy, electroporation were used. Blood was exposed to oxidizing agents of different nature. Perfluorocarbon emulsion was added in various concentrations and its effect at various incubation times was studied. Concentration of hemoglobin derivatives was calculated considering multicollinearity, and statistical analysis of the results was performed.Results. The perfluorocarbon emulsion was shown to have an effective restorative and cytoprotective action in iron ion oxidation in the heme: Fe3+ was restored to Fe2+. The degree of MetHb reduction to HbO2 and Hb depended on the concentration of the oxidizing agent and incubation time. We observed a change in MetHb content from 80-90% to 5-12%. The perfluorocarbon emulsion in clinical concentrations helped eliminate local membrane defects and restored normal erythrocyte morphology.Conclusion. In the light of the studied hypotheses, the use of perfluorocarbon emulsion can become an effective method for blocking the consequences of coronavirus effect on the blood cells and restoring a normal gas exchange.


2019 ◽  
Vol 7 (6) ◽  
pp. 2545-2551 ◽  
Author(s):  
Katerina E. Aifantis ◽  
Sanjiv Shrivastava ◽  
Sygkliti-Henrietta Pelidou ◽  
Alfonso H. W. Ngan ◽  
Stavros I. Baloyannis

Atomic force microscopy indentation was employed to illustrate that pentoxifylline reduces the elastic modulus of red blood cells (from healthy human subjects), increasing hence their flexibility.


The Analyst ◽  
2010 ◽  
Vol 135 (3) ◽  
pp. 525 ◽  
Author(s):  
Mehdi Asghari-Khiavi ◽  
Bayden R. Wood ◽  
Adam Mechler ◽  
Keith R. Bambery ◽  
Donna W. Buckingham ◽  
...  

2021 ◽  
Vol 23 (1) ◽  
pp. 227
Author(s):  
Velichka Strijkova-Kenderova ◽  
Svetla Todinova ◽  
Tonya Andreeva ◽  
Desislava Bogdanova ◽  
Ariana Langari ◽  
...  

Human red blood cells (RBCs) are unique cells with the remarkable ability to deform, which is crucial for their oxygen transport function, and which can be significantly altered under pathophysiological conditions. Here we performed ultrastructural analysis of RBCs as a peripheral cell model, looking for specific signatures of the neurodegenerative pathologies (NDDs)—Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and Alzheimer’s disease (AD), utilizing atomic force (AFM) and conventional optical (OM) microscopy. We found significant differences in the morphology and stiffness of RBCs isolated from patients with the selected NDDs and those from healthy individuals. Neurodegenerative pathologies' RBCs are characterized by a reduced abundance of biconcave discoid shape, lower surface roughness and a higher Young’s modulus, compared to healthy cells. Although reduced, the biconcave is still the predominant shape in ALS and AD cells, while the morphology of PD is dominated by crenate cells. The features of RBCs underwent a marked aging-induced transformation, which followed different aging pathways for NDDs and normal healthy states. It was found that the diameter, height and volume of the different cell shape types have different values for NDDs and healthy cells. Common and specific morphological signatures of the NDDs were identified.


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