Culture‐expanded mesenchymal stromal cells (MSCs) are promising candidates for clinical cell‐based therapies. MSC products are heterogeneous and we therefore investigated whether acoustophoresis, an ultrasound‐based separation technology, could be used for the label‐free enrichment of functionally different MSC populations. Acoustophoresis uses an ultrasonic standing wave field in a microchannel that differentially affects the movement of cells depending on their acoustophysical properties, such as size, density, and compressibility. Human bone marrow (BM) MSCs were generated by standard adherent culture in xeno‐free medium and separated by microchip acoustophoresis. MSCs with up to 20% higher proliferation and 1.7‐fold increased clonogenic potential were enriched in the side outlet of the chip compared to the input sample. These cells were significantly smaller (average diameter 14.5 ± 0.4 μm) compared to the center outlet fraction (average diameter 17.1 ± 0.6 μm) and expressed higher levels of genes related to proliferation and stem cell properties (i.e., Ki‐67 [1.9‐fold], Nanog1 [6.65‐fold], Oct4 [2.9‐fold], and CXCL12 [1.8‐fold], n = 3) in the side outlet compared to input. Fractions of MSCs in G₀/G₁ cell cycle phase were significantly enriched in the side fraction and an up to 2.8‐fold increase of cells in S/G₂/M phases were observed in center fractions compared to side fractions and 1.3‐fold increased compared to the input sample. Acoustophoresis did not compromise MSC phenotype, proliferation, clonogenic capacity, and viability (generally 87–98%), nor did it affect differentiation or immunomodulatory capacities. These results demonstrate that label‐free acoustic separation can enrich functionally different MSC subsets which can potentially be employed to produce better‐defined stromal cell products from cultured MSCs. Hence, acoustophoresis is a potentially promising separation technology to provide improved cell products for research and possible future clinical use. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals LLC. on behalf of International Society for Advancement of Cytometry.

中文翻译：

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声渗法使培养的骨髓基质细胞功能不同亚群的无标记分离成为可能

培养扩增的间充质基质细胞 (MSCs) 是临床细胞疗法的有希望的候选者。MSC 产品是异质的，因此我们研究了声渗法，一种基于超声的分离技术，是否可用于功能不同的 MSC 群体的无标记富集。声波疗法在微通道中使用超声波驻波场，根据细胞的声物理特性（如大小、密度和可压缩性）不同地影响细胞的运动。人骨髓 (BM) MSC 在无异种培养基中通过标准贴壁培养产生，并通过微芯片声泳分离。与输入样品相比，在芯片的侧出口富集了具有高达 20% 的增殖和 1.7 倍增加的克隆形成潜力的 MSC。即， 与输入相比，侧出口的Ki-67 [1.9 倍]、Nanog1 [6.65 倍]、Oct4 [2.9 倍]和CXCL12 [1.8 倍]，n = 3)。G ₀ /G ₁细胞周期阶段的 MSCs部分在侧部分显着富集，S/G ₂细胞增加高达 2.8 倍与侧部分相比，在中心部分观察到 /M 相，与输入样品相比增加了 1.3 倍。声渗法不会影响 MSC 的表型、增殖、克隆能力和活力（通常为 87-98%），也不会影响分化或免疫调节能力。这些结果表明，无标记声学分离可以丰富功能不同的 MSC 亚群，这些亚群有可能用于从培养的 MSC 中生产定义更明确的基质细胞产品。因此，声渗法是一种具有潜在前景的分离技术，可为研究和未来可能的临床应用提供改进的细胞产品。© 2020 作者。由 Wiley Periodicals LLC 出版的Cytometry Part A。代表国际细胞计量学促进会。