Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd, Houston, TX, 77204-5060, USA.
Department of Chemistry, Vanderbilt University, Nashville, TN, USA.
Sci Rep. 2021 Jan 12;11(1):604. doi: 10.1038/s41598-020-79710-3.
Ektacytometry has been the primary method for evaluating deformability of red blood cells (RBCs) in both research and clinical settings. This study was designed to test the hypothesis that the flow of RBCs through a network of microfluidic capillaries could provide a more sensitive assessment of the progressive impairment of RBC deformability during hypothermic storage than ektacytometry. RBC units (n = 9) were split in half, with one half stored under standard (normoxic) conditions and the other half stored hypoxically, for up to 6 weeks. RBC deformability was measured weekly using two microfluidic devices, an artificial microvascular network (AMVN) and a multiplexed microcapillary network (MMCN), and two commercially available ektacytometers (RheoScan-D and LORRCA). By week 6, the elongation indexes measured with RheoScan-D and LORRCA decreased by 5.8-7.1% (5.4-6.9% for hypoxic storage). Over the same storage duration, the AMVN perfusion rate declined by 27.5% (24.5% for hypoxic) and the MMCN perfusion rate declined by 49.0% (42.4% for hypoxic). Unlike ektacytometry, both AMVN and MMCN measurements showed statistically significant differences between the two conditions after 1 week of storage. RBC morphology deteriorated continuously with the fraction of irreversibly-damaged (spherical) cells increasing significantly faster for normoxic than for hypoxic storage. Consequently, the number of MMCN capillary plugging events and the time MMCN capillaries spent plugged was consistently lower for hypoxic than for normoxic storage. These data suggest that capillary networks are significantly more sensitive to both the overall storage-induced decline of RBC deformability, and to the differences between the two storage conditions, than ektacytometry.
激光衍射法（ektacytometry）一直是评估红细胞（RBC）变形性的主要方法，无论是在研究还是临床环境中。本研究旨在检验一个假设，即 RBC 通过微流控毛细血管网络的流动可以比激光衍射法更敏感地评估低温储存过程中 RBC 变形性的逐渐损伤。将 RBC 单位（n=9）分成两半，一半在标准（常氧）条件下储存，另一半在缺氧条件下储存，最长可达 6 周。每周使用两种微流控设备（人工微血管网络（AMVN）和多路复用微毛细管网络（MMCN））和两种市售的激光衍射仪（RheoScan-D 和 LORRCA）测量 RBC 变形性。到第 6 周，RheoScan-D 和 LORRCA 测量的伸长指数下降了 5.8-7.1%（缺氧储存下降了 5.4-6.9%）。在相同的储存时间内，AMVN 灌注率下降了 27.5%（缺氧下降了 24.5%），MMCN 灌注率下降了 49.0%（缺氧下降了 42.4%）。与激光衍射法不同，在储存 1 周后，两种条件之间的 AMVN 和 MMCN 测量均显示出统计学上的显著差异。RBC 形态不断恶化，不可逆损伤（球形）细胞的比例增加得更快，常氧储存比缺氧储存更快。因此，MMCN 毛细管堵塞事件的数量和 MMCN 毛细管堵塞的时间对于缺氧储存始终低于常氧储存。这些数据表明，毛细血管网络对 RBC 变形性的整体储存诱导下降以及两种储存条件之间的差异都比激光衍射法更敏感。
