Sublethal mechanical shear stress increases the elastic shear modulus of red blood cells but does not change capillary transit velocity.
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Author(s)
McNamee, Antony P
Tansley, Geoff D
Simmonds, Michael J
Year published
2020
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Blood exposure to supraphysiological shear stress within mechanical circulatory support is suspected of reducing red blood cell (RBC) deformability and being primal in the pathogenesis of several secondary complications. No prior works have explored RBC dynamics with the resolution required to determine shear elastic modulus, and/or cell capillary velocity, following exposure to mechanical stresses. Healthy RBCs were exposed to 0,5,50, and 100Pa in a Couette shearing system. For comparison, blood was also exposed to heat treatment - a method that predictably increases RBC rigidity. Shear modulus assessment required aspiration ...
View more >Blood exposure to supraphysiological shear stress within mechanical circulatory support is suspected of reducing red blood cell (RBC) deformability and being primal in the pathogenesis of several secondary complications. No prior works have explored RBC dynamics with the resolution required to determine shear elastic modulus, and/or cell capillary velocity, following exposure to mechanical stresses. Healthy RBCs were exposed to 0,5,50, and 100Pa in a Couette shearing system. For comparison, blood was also exposed to heat treatment - a method that predictably increases RBC rigidity. Shear modulus assessment required aspiration of single RBCs through narrow micropipettes at known suction force. Cell transit velocities were measured within micro-channels in regions of fully-developed flow. Supraphysiological shear stress increased the elastic shear modulus by 39% and 69% following exposure to 50 and 100Pa, respectively. Cell transit velocity, however, did not change following shear, with concurrent decreases in cell volume likely nullifying increased shear modulus-friction interactions. Differences observed were consistent with our internal control (heat treatment), supporting that cell mechanics are significantly impaired following supraphysiological-sublethal shear exposure. Given mechanical circulatory support operates at shear stresses consistent with the present study, it is plausible that these devices induce fundamental impairment to the material properties of RBCs.
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View more >Blood exposure to supraphysiological shear stress within mechanical circulatory support is suspected of reducing red blood cell (RBC) deformability and being primal in the pathogenesis of several secondary complications. No prior works have explored RBC dynamics with the resolution required to determine shear elastic modulus, and/or cell capillary velocity, following exposure to mechanical stresses. Healthy RBCs were exposed to 0,5,50, and 100Pa in a Couette shearing system. For comparison, blood was also exposed to heat treatment - a method that predictably increases RBC rigidity. Shear modulus assessment required aspiration of single RBCs through narrow micropipettes at known suction force. Cell transit velocities were measured within micro-channels in regions of fully-developed flow. Supraphysiological shear stress increased the elastic shear modulus by 39% and 69% following exposure to 50 and 100Pa, respectively. Cell transit velocity, however, did not change following shear, with concurrent decreases in cell volume likely nullifying increased shear modulus-friction interactions. Differences observed were consistent with our internal control (heat treatment), supporting that cell mechanics are significantly impaired following supraphysiological-sublethal shear exposure. Given mechanical circulatory support operates at shear stresses consistent with the present study, it is plausible that these devices induce fundamental impairment to the material properties of RBCs.
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Journal Title
Microcirculation
Copyright Statement
© 2020 Wiley-Liss, Inc. This is the peer reviewed version of the following article: Sublethal mechanical shear stress increases the elastic shear modulus of red blood cells but does not change capillary transit velocity., Microcirculation, 2020, which has been published in final form at https://doi.org/10.1111/micc.12652. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving (http://olabout.wiley.com/WileyCDA/Section/id-828039.html)
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This publication has been entered in Griffith Research Online as an advanced online version.
Subject
Biomedical and clinical sciences
Biological sciences
RBC deformability
haemorheology
mechanobiology
micropipette aspiration
rheology