Cool, S. | bioRxiv Science

bioRxiv2023

Scalable Mesenchymal Stem Cells Enrichment from Bone Marrow Aspirate using Deterministic Lateral Displacement (DLD) Microfluidics Sorting

The growing interest in regenerative medicine has opened new avenues for novel cell therapies using stem cells. Bone Marrow Aspirate (BMA) is an important source of stromal mesenchymal stem cells (MSCs). Conventional MSC harvesting from BMA relies on archaic centrifugation methods, often leading to poor yield due to osmotic stress, high centrifugation force, convoluted workflow, and long experimental time ([~] 2 - 3 hours). To address these issues, we have developed a scalable microfluidic technology based on Deterministic Lateral Displacement (DLD) for MSC isolation. This passive, label-free cell sorting method capitalizes on the morphological differences between MSCs and blood cells (leukocytes and RBCs) for effective separation using an inverted L-shaped pillar array. To improve throughput, we developed a novel portable multiplexed DLD system that can process 2.5 mL of raw BMA in 20 {+/-} 5 minutes, achieving a 2-fold increase in MSC recovery compared to centrifugation methods. Taken together, we envision the developed DLD platform will enable fast and efficient isolation of MSCs from BMA for effective downstream cell therapy in clinical settings.

bioengineering↗

bioRxiv2020

Raman mapping glucose metabolites during human mesenchymal stem cell adipogenesis

Raman mapping was used to determine the lipid distribution inside human mesenchymal stem cells during induced adipogenesis by monitoring C-H stretching bands of the fats inside the lipid droplets. By incorporating deuterated glucose into the cell culture medium during induction it was possible to distinguish whether or not downstream metabolites, either in lipid droplets or in the cytoplasm, had been formed before or after the adipogenic cascade, because C-D stretching bands are 1/{surd}2 shifted compared to the C-H bands. Thus, metabolites formed after the initiation of the process displayed both C-H and C-D stretching bands and so were forming during induced adipogenesis rather than prior to it. With the ability to distinguish small putative lipid drops formed by the induction of adipogenesis from those pre-formed in the cell, it was possible to analyze spectral changes occurring in the droplets at the earliest stages of adipogenesis. There were two key findings. Firstly, Raman spectra of lipid droplets evolved over time, suggesting that their composition at the early stages was not the same as at the later stages. Secondly, it was apparent that the proportion of unsaturated fats in droplets was higher at early stages than it was at later stages, suggesting that unsaturated fats arrive in the droplets faster than saturated ones.

cell biology↗