A Novel Way of Measuring Cell Interaction Strength

OBJECTIVE To measure cell binding strength in shear using a flow chamber BACKGROUND The current technology for measuring cell binding strength is limited. Typically, when measuring the binding strength of cells in vitro, an operator manually increases the flow to increase the shear stress the cells are subjected to until the cell interaction is disrupted. This method is imperfect as it introduces time as a confounding variable. We propose a novel method using a shear gradient to eliminate time as an independent variable. METHODS We designed a wedge shaped flow chamber that can vary the shear rate by a factor of 4 on endothelial cells grown in a cell culture dish. We then placed bone marrow derived mononuclear cells on the layer of cultured endothelial cells and allowed them to bind. Saline was pumped over the cells at a constant flow rate. A series of images were acquired along a line bisecting the chamber to quantify the cells binding as a function of shear stress. Shear stress was precisely quantified as a function of position using a finite element model of the chamber. FUTURE WORK We plan on using this chamber to measure binding strength of several cell interactions under a variety of conditions.