Enrichment using antibody‐coated microfluidic chambers in shear flow: Model mixtures of human lymphocytes

Abstract

Isolation of phenotypically-pure cell subpopulations from heterogeneous cell mixtures such as blood is a difficult yet fundamentally important task. Current techniques such as fluorescent activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) require pre-incubation with antibodies which lead to processing times of at least 15-60 min. In this study, we explored the use of antibody-coated microfluidic chambers to negative deplete undesired cell types, thus obtaining an enriched cell subpopulation at the outlet. We used human lymphocyte cell lines, MOLT-3 and Raji, as a model system to examine the dynamic cell binding behavior on antibody coated surfaces under shear flow. Shear stress ranging between 0.75 and 1.0 dyn/cm2 was found to provide most efficient separation. Cell adhesion was shown to follow pseudo-first order kinetics, and an anti-CD19 coated (Raji-depletion) device with approximately 2.6 min residence time was demonstrated to produce 100% pure MOLT-3 cells from 50-50 MOLT-3/Raji mixture. We have developed a mathematical model of the separation device based on the experimentally determined kinetic parameters that can be extended to design future separation modules for other cell mixtures. We conclude that we can design microfluidic devices that exploits the kinetics of dynamic cell adhesion to antibody coated surfaces to provide enriched cell subpopulations within minutes of total processing time.

Immunocapture of prostate cancer cells by use of anti-PSMA antibodies in microdevices

“…Deviations from the analytical solution result from experimentally implemented inlets, outlets, and impenetrable boundaries. Using flow through this device, each experimental run characterizes cell adhesion over a wide range of shear stresses, corresponding to those experienced within microfluidic immunocapture devices (Murthy, Sin et al 2004; Sin, Murthy et al 2005; Gleghorn, Pratt et al 2010). …”

Strategies to develop endogenous stem cell-recruiting bioactive materials for tissue repair and regeneration

“…Antibody coating of biomaterial surfaces has emerged as a promising strategy for promoting recruitment of stem cells to scaffolds or biomedical implants [51, 52]. Antibodies can be immobilized onto the surfaces of scaffolds by chemical or physical interactions and the choice of a particular approach depends on the original properties of the material.…”

Label-free, microfluidic separation and enrichment of human breast cancer cells by adhesion difference

“…7 These cell sorting systems have been miniaturized to microfluidic devices, demonstrating the possibility of being integrated into lab-on-a-chip devices. 8,9 In contrast, label-free methods typically utilize differences in physical properties such as cell size, 10 density, 11 cell adhesion, [12][13][14][15] and dielectric properties. [16][17][18] One potential drawback in label-free methods is that the physical difference is not high enough for efficient separation in many cases, which limits the widespread use of the label-free methods.…”