The mechanical properties of stored red blood cells measured by a convenient microfluidic approach combining with mathematic model

Abstract

The mechanical properties of red blood cells (RBCs) are critical to the rheological and hemodynamic behavior of blood. Although measurements of the mechanical properties of RBCs have been studied for many years, the existing methods, such as ektacytometry, micropipette aspiration, and microfluidic approaches, still have limitations. Mechanical changes to RBCs during storage play an important role in transfusions, and so need to be evaluated pre-transfusion, which demands a convenient and rapid detection method. We present a microfluidic approach that focuses on the mechanical properties of single cell under physiological shear flow and does not require any high-end equipment, like a high-speed camera. Using this method, the images of stretched RBCs under physical shear can be obtained. The subsequent analysis, combined with mathematic models, gives the deformability distribution, the morphology distribution, the normalized curvature, and the Young's modulus (E) of the stored RBCs. The deformability index and the morphology distribution show that the deformability of RBCs decreases significantly with storage time. The normalized curvature, which is defined as the curvature of the cell tail during stretching in flow, suggests that the surface charge of the stored RBCs decreases significantly. According to the mathematic model, which derives from the relation between shear stress and the adherent cells' extension ratio, the Young's moduli of the stored RBCs are also calculated and show significant increase with storage. Therefore, the present method is capable of representing the mechanical properties and can distinguish the mechanical changes of the RBCs during storage. The advantages of this method are the small sample needed, high-throughput, and easy-use, which make it promising for the quality monitoring of RBCs. V C 2016 AIP Publishing LLC.

Modelling of Red Blood Cell Morphological and Deformability Changes during In-Vitro Storage

“…Therefore, it is important to measure the quality of each RBC unit prior to use, and the RBC deformability is a key indicator of RBC quality and post-transfusion viability [8,[24][25][26]. RBC deformability is primarily influenced by mechanical and geometrical factors of the cell such as cell surface area and volume, elasticity and viscosity of the cell membrane, and volume and viscosity of the cytosol [27][28][29][30][31][32][33]. Therefore, the changes in the cell membrane structure and its mechanical properties adversely affect the cell deformability, and less deformable RBCs can obstruct capillaries and require significantly higher transit time to navigate through the microvasculature leading to decreased levels of oxygen delivery to organs [34][35][36].…”

“…Therefore, the RBC deformability is a potential measure of cell viability subjected to morphological, structural and functional changes, and provide valuable insights into the physiology, cell biology and biorheology under pathophysiological conditions. Different techniques have been used to investigate RBC deformability, and descriptions of these techniques can be found in [17,25,29,33,42,43,47,[57][58][59][60][61][62][63][64][65][66][67][68][69][70]. Optical tweezers is one such technique and provides a highly sensitive assessment of the cell deformability at the single cell level.…”

Advances in Microfluidics for Single Red Blood Cell Analysis

“…Mathematical models of deformable RBC with Discrete Element Methods have also been taken into account, along with the lattice Boltzmann models of immersed boundaries [172,173]. Other relevant studies include the assessment of shear dependencies in RBC adhesion [174], analysis of the changes in RBC stiffness [175], mechanical characterization of stored RBCs via mathematical models [176], donor-dependent aging curves based on microfluidic RBC models [177], effects of channel geometry in RBC sorting [178], and the assessment of RBC deformity using iron-dextran tests [179].…”

The P 50 value detected by the oxygenation-dissociation analyser and blood gas analyser

“…Blood collection and storage were performed as previously described by Wang et al [31]. Briefly, blood was withdrawn via the carotid artery and mixed with CPDA-1 to yield a final concentration of 14% CPDA-1.…”