Stilgoe Alexander B, Kashchuk Anatolii V, Balanant Marie-Anne, Santangelo Deborah, Nieminen Timo A, Sauret Emilie, Flower Robert, Rubinsztein-Dunlop Halina
School of Mathematics and Physics, The University of Queensland, St. Lucia, Brisbane, QLD, 4072, Australia.
Australian Research Council Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, St. Lucia, QLD, 4072, Australia.
Biomed Opt Express. 2024 Jan 4;15(2):656-671. doi: 10.1364/BOE.504779. eCollection 2024 Feb 1.
Red blood cells (RBCs) undergo a progressive morphological transformation from smooth biconcave discocytes into rounder echinocytes with spicules on their surface during cold storage. The echinocytic morphology impacts RBCs' ability to flow through narrow sections of the circulation and therefore transfusion of RBC units with a high echinocytic content are thought to have a reduced efficiency. We use an optical tweezers-based technique where we directly trap and measure linear stiffness of RBCs under stress without the use of attached spherical probe particles or microfluidic flow to induce shear. We study RBC deformability with over 50 days of storage performing multiple stretches in blood plasma (serum with cold agglutinins removed to eliminate clotting). In particular, we find that discocytes and echinocytes do not show significant changes in linear stiffness in the small strain limit ( change in length) up to day 30 of the storage period, but do find differences between repeated stretches. By day 50 the linear stiffness of discocytes had increased to approximately that measured for echinocytes throughout the entire period of measurements. These changes in stiffness corresponded to recorded morphological changes in the discocytes as they underwent storage lesion. We believe our holographic trapping and direct measurement technique has applications to directly control and quantify forces that stretch other types of cells without the use of attached probes.
在冷藏过程中，红细胞（RBCs）会经历从光滑的双凹圆盘状细胞逐渐转变为表面带有刺状突起的更圆的棘状细胞的形态变化。棘状细胞形态会影响红细胞通过循环系统狭窄部位的能力，因此，棘状细胞含量高的红细胞单位输血效率被认为会降低。我们使用一种基于光镊的技术，在不使用附着的球形探针颗粒或微流体流动来诱导剪切力的情况下，直接捕获并测量红细胞在应力下的线性刚度。我们在血浆（去除冷凝集素以消除凝血的血清）中对储存超过50天的红细胞进行多次拉伸，研究其变形能力。特别是，我们发现圆盘状细胞和棘状细胞在储存期第30天之前的小应变极限（长度变化）下，线性刚度没有显著变化，但在重复拉伸之间确实存在差异。到第50天时，圆盘状细胞的线性刚度在整个测量期间已增加到与棘状细胞测量值大致相当的水平。这些刚度变化与圆盘状细胞在经历储存损伤时记录到的形态变化相对应。我们相信我们的全息捕获和直接测量技术可应用于直接控制和量化拉伸其他类型细胞的力，而无需使用附着的探针。
