Red blood cell (RBC) suspensions in confined microflows: Pressure-flow relationship. (October 2017)

• Record Type: Journal Article
• Authors: Stauber, Hagit; Waisman, Dan; Korin, Netanel; Sznitman, Josué
• Is Part Of: Medical engineering & physics. Volume 48(2017)
• Page Start: 49
• Page End: 54
• Publication Date: 2017-10
• Subjects: In vitro models -- Microfluidics -- Red blood cells (RBCs) -- Hydrodynamic resistance -- Suspensions -- Pressure-flow measurements; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2017.08.006
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: Influence of buffer on RBC suspensions under confinement is studied in microdevices. Hydrodynamic resistance is extracted from experimental pressure-flow relationships. Select more purposefully suspensions for microfluidic assays of RBC dynamics. Abstract: Microfluidic-based assays have become increasingly popular to explore microcirculation in vitro . In these experiments, blood is resuspended to a desired haematocrit level in a buffer solution, where frequent choices for preparing RBC suspensions comprise notably Dextran and physiological buffer. Yet, the rational for selecting one buffer versus another is often ill-defined and lacks detailed quantification, including ensuing changes in RBC flow characteristics. Here, we revisit RBC suspensions in microflows and attempt to quantify systematically some of the differences emanating between buffers. We measure bulk flow rate (Q) of RBC suspensions, using PBS- and Dextran-40, as a function of the applied pressure drop (ΔP) for two hematocrits (∼0% and 23%). Two distinct microfluidic designs of varying dimensions are employed: a straight channel larger than and a network array similar to the size of individual RBCs. Using the resulting pressure-flow curves, we extract the equivalent hydrodynamic resistances and estimate the relative viscosities. These efforts are a first step in rigorously quantifying the influence of the 'background' buffer on RBC flows within microfluidic devices and thereby underline the importance of purposefully selecting buffer suspensions for microfluidic in vitro assays.