# A microfluidic platform to study sickle blood rheology

> **NIH NIH R01** · UNIVERSITY OF MINNESOTA · 2020 · $524,134

## Abstract

Sickle cell disease (SCD) is a devastating hereditary disorder that affects more than 13 million people
worldwide with health care costs in the U.S. alone exceeding $1 billion per year. The origin of SCD is a mutant
hemoglobin molecule (sickle hemoglobin or HbS) that polymerizes into rigid fibers when deoxygenated. These
fibers cause large changes in blood rheology and can ultimately result in complete occlusion of blood vessels,
tissue infarction, organ damage, and even death. Despite more than 100 years of research, a clear picture of
the vaso-occlusive process remains elusive, and the result is a dearth of treatment options and poor quality of
life for the millions of individuals who suffer from this disease. Low oxygen concentration is the one necessary
condition for morbidity and mortality in sickle disease, but the quantitative relationship between oxygen
concentration and sickle cell blood rheology in physiologic regimes of pressure, vessel size, and hemoglobin
concentration is unknown. Ultimately, clinical progress in sickle cell disease requires that we understand how
low can a patient's tissue oxygen level fall before a vaso-occlusion will occur, how changes in pressure and
vessel dilation modulate the probability of vaso-occlusion at different oxygen concentrations, and how sensitive
vaso-occlusion is to slight changes in hemoglobin concentration. Thus, our Specific Aims in these studies are
to: (1) Determine the quantitative relationship between sickle blood rheology and blood oxygen concentration;
(2) Quantify the effect of vessel size and blood pressure on the relationship between sickle blood rheology and
oxygen concentration; (3) Quantify the effect of sickle hemoglobin concentration on the relationship between
sickle blood rheology and oxygen concentration. Our primary hypothesis is that the relationship between blood
viscosity and oxygen concentration comprises multiple functional regimes, characterized by critical oxygen
thresholds, and that this relationship is sensitive to vessel size, blood pressure, and HbS concentration in vivo.
Because these parameters cannot be controlled in vivo, we will use an in vitro microfluidic platform with oxygen
control to systematically vary these parameters and quantify the effects on sickle blood rheology. The phase
space of sickle blood rheology, such as the oxygen thresholds, may be modulated by treatments such as drugs
that modulate hemoglobin oxygen binding affinity. Thus, the platforms developed here would be ideal for
testing such therapies. The parameters uncovered in these studies may also serve as biomarkers for disease
severity to indicate which patients are most in need of care or when patients are most at risk of complications.
Overall, the results of these studies will be a clearer understanding of how sickle blood rheology depends on
critical physiologic parameters, and this work will produce new platforms and biomarkers for patient monitoring
and for prioritizing experimental t...

## Key facts

- **NIH application ID:** 9988479
- **Project number:** 5R01HL132906-04
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** David Kevin Wood
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $524,134
- **Award type:** 5
- **Project period:** 2017-09-01 → 2021-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9988479

## Citation

> US National Institutes of Health, RePORTER application 9988479, A microfluidic platform to study sickle blood rheology (5R01HL132906-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9988479. Licensed CC0.

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