Lymph Node Subcapsular Sinus Microenvironment-On-A-Chip Modeling Shear Flow Relevant to Lymphatic Metastasis and Immune Cell Homing.

A lymph node sinus-on-a-chip adhesion microfluidic platform that recapitulates the hydrodynamic microenvironment of the lymph node subcapsular sinus was engineered. This device was used to interrogate the effects of lymph node remodeling on cellular adhesion in fluid flow relevant to lymphatic metastasis. Wall shear stress levels analytically estimated and modeled after quiescent and diseased/inflamed lymph nodes were experimentally recapitulated using a flow-based microfluidic perfusion system to assess the effects of physiological flow fields on human metastatic cancer cell adhesion.

Computational models of migration modes improve our understanding of metastasis.

Tumor cells migrate through changing microenvironments of diseased and healthy tissue, making their migration particularly challenging to describe. To better understand this process, computational models have been developed for both the ameboid and mesenchymal modes of cell migration. Here, we review various approaches that have been used to account for the physical environment's effect on cell migration in computational models, with a focus on their application to understanding cancer metastasis and the related phenomenon of durotaxis.

Photoconversion and chromatographic microfluidic system reveals differential cellular phenotypes of adhesion velocity versus persistence in shear flow.

An integrated photoconversion and cell sorting parallel-plate chromatography channel enabling the measurement of instantaneous and average velocities of cells mediating adhesion in flow fields was engineered to study the mechanisms underlying adhesion to selectins by metastatic cancer cells. Through the facile enrichment of cells into subfractions of differing adhesive behaviors and a fluorescent velocity probe amenable to off-chip analysis, underlying, causal molecular profiles implicated in differing adhesive phenotypes of metastatic cancer cells could be interrogated. This analytical method revealed selectin-mediated rolling adhesion to be strongly associated with expression of selectin ligands, correlations that vary with ligand type and rolling velocity magnitude.

Analyzing Mechanisms of Metastatic Cancer Cell Adhesive Phenotype Leveraging Preparative Adhesion Chromatography Microfluidic.

An integrated, parallel-plate microfluidic device is engineered to interrogate and fractionate cells based on their adhesivity to a substrate surface functionalized with adhesive ligand in a tightly controlled flow environment to elucidate associated cell-intrinsic pathways. Wall shear stress levels and endothelial presentation of E-selectin are modeled after the inflamed vasculature microenvironment in order to simulate in vitro conditions under which in vivo hematogenous metastasis occurs. Based on elution time from the flow channel, the collection of separate fractions of cells-noninteracting and interacting-at high yields and viabilities enables multiple postperfusion analyses, including flow cytometry, in vivo metastasis modeling, and transcriptomic analysis.

Fluorometric Quantification of Single-Cell Velocities to Investigate Cancer Metastasis.

Hematogenous metastasis is a multistep, selectin-regulated process whose mechanisms remain poorly understood. To investigate this biological pathway of cancer dissemination and better understand circulating cancer cells, we developed a high-throughput methodology that integrates organ-on-chip-like microfluidic and photoconvertible protein technologies. Our approach can ascribe single-cell velocity as a traceable cell property for off-chip analysis of the direct relationships between cell molecular profiles and adhesive phenotypes in the context of physiologically relevant fluid flow.

P-, but not E- or L-, selectin-mediated rolling adhesion persistence in hemodynamic flow diverges between metastatic and leukocytic cells.

The ability of leukocytic cells to engage selectins via rolling adhesion is critical to inflammation, but selectins are also implicated in mediating metastatic dissemination. Using a microfluidic- and flow-based cell adhesion chromatography experimental and analytical technique, we interrogated the cell-subtype differences in engagement and sustainment of rolling adhesion on P-, E-, and L-selectin-functionalized surfaces in physiological flow. Our results indicate that, particularly at low concentrations of P-selectin, metastatic but not leukocytic cells exhibit reduced rolling adhesion persistence, whereas both cell subtypes exhibited reduced persistence on L-selectin and high persistence on E-selectin, differences not revealed by flow cytometry analysis or reflected in the extent or velocity of rolling adhesion.