Microfluidic channel optimization to improve hydrodynamic dissociation of cell aggregates and tissue

Abstract

Maximizing the speed and efficiency at which single cells can be liberated from tissues would dramatically advance cell-based diagnostics and therapies. Conventional methods involve numerous manual processing steps and long enzymatic digestion times, yet are still inefficient. In previous work, we developed a microfluidic device with a network of branching channels to improve the dissociation of cell aggregates into single cells. However, this device was not tested on tissue specimens, and further development was limited by high cost and low feature resolution. In this work, we utilized a single layer, laser micro-machined polyimide film as a rapid prototyping tool to optimize the design of our microfluidic channels to maximize dissociation efficiency. This resulted in a new design with smaller dimensions and a shark fin geometry, which increased recovery of single cells from cancer cell aggregates. We then tested device performance on mouse kidney tissue, and found that optimal results were obtained using two microfluidic devices in series, the larger original design followed by the new shark fin design as a final polishing step. We envision our microfluidic dissociation devices being used in research and clinical settings to generate single cells from various tissue specimens for diagnostic and therapeutic applications.

Novel microfluidic platform accelerates processing of tissue into single cells for molecular analysis and primary culture models

“…At 10 mL/min, single cells increased by ~ 20% after 30 s of recirculation, with no change in viability, which is similar to previous work using a syringe pump. 53 Longer recirculation times enhanced single cell numbers but decreased viability. Thus, we selected to evaluate short recirculation times at 10 mL/min using minced kidney that had been processed using the digestion device for 15 min.…”

“…[49][50][51] We developed a micro uidic device that speci cally focused on breaking down cellular aggregates into single cells. 52,53 This dissociation device contained a network of branching channels that progressively decreased in size down to ~ 100 µm, and contained repeated expansions and constrictions to break down aggregates using shear forces. We then developed a device for on-chip tissue digestion using the combination of shear forces and proteolytic enzymes.…”

Microfluidic technologies to engineer mesenchymal stem cell aggregates—applications and benefits

“…Three-dimensional cell culture approaches can be classified as scaffold-based and scaffold-free strategies. In general, scaffold-free cell delivery can be divided into three basic methods which are single-cell delivery (Mao et al, 2017;Kamperman et al, 2017a;Lienemann et al, 2017;Qiu et al, 2018;Carvalho et al, 2015;Mei et al, 2019), cell sheet engineering, and microtissue technology (Kelm and Fussenegger, 2010). Microtissues are cell aggregates with a spheroidal shape and diameters between 100 and 500 μm.…”

Hydrodynamic Red Blood Cells Deformation by Quantitative Phase Microscopy and Zernike Polynomials

“…Many reasons exist for microfluidics development such as more precise fabrication processes or the possibility, in biology, to achieve single-cell analysis [2,3]. Hydrodynamic forces are fundamental components in the microfluidics environment and they have been exploited for many purposes as dissociation of cell aggregates [4] or cell sorting [5] besides industrial applications concerning liquid-liquid emulsions [6].…”