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

Date

9/10/2014

Journal Title

Journal ISSN

Volume Title

Publisher

Clinical Hemorheology and Microcirculation

Abstract

The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0% – 0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further development of biomimetic tools for measuring RBC deformability (e.g. the AMVN) could enable a more functionally relevant testing of RBC mechanical properties.

Description

Keywords

red blood cell deformability, micropore filtration, ektacytometry, artificial microvascular network, microfluidics

Citation

Copyright 2014 Clinical Hemorheology and Microcirculation. This is a post-print version of a published paper that is available at: https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch1719 Recommended citation: Sosa, J. M., N. D. Nielsen, S. M. Vignes, T. G. Chen, and S. S. Shevkoplyas. "The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network." Clinical hemorheology and microcirculation 57, no. 3 (2014): 275-289. DOI: 10.3233/CH-131719 This item has been deposited in accordance with publisher copyright and licensing terms and with the author’s permission.