An Electromagnetic System for Inducing a Localized Force Gradient in an ECM and Its Influence on HMVEC Sprouting

Abstract

Mechanical properties of the extracellular matrix (ECM) have been observed to influence the behavior of cells. Investigations on such an influence commonly rely on using soluble cues to alter the global intrinsic ECM properties in order to study the subsequent response of cells. This article presents an electromagnetic system for inducing a localized force gradient in an ECM, and reports the experimentally observed effect of such a force gradient on in vitro angiogenic sprouting of human microvascular endothelial cells (HMVECs). This force gradient is realized through the induction of magnetic forces on the superparamagnetic microparticle-embedded ECM ( sECM). Both analytical and statistically meaningful experimental results demonstrate the effectiveness of this approach in influencing the behavior of a targeted HMVEC sprout without affecting that of other sprouts nearby. These results suggest the possibility of selectively controlling the in vitro behavior of cells by the induction of a localized force gradient in the ECM.

Microfluidics in vascular biology research: a critical review for engineers, biologists, and clinicians

“…To overcome this issue, three main approaches have been developed: (1) increasing the ratio of PDMS elastomer to curing agent 118 (2) coating 2D PDMS devices with acrylamide/bisacrylamide gels 119 (3) and embedding streptavidin-coated magnetic beads to modify the stiffness of the ECM upon the application of an external magnetic field. 120 Besides ECM stiffness, heterogeneity of pore diameter, number, and alignment results in differential effects on angiogenesis. To examine the relationship between pore size and migration, Keys et al developed a PDMS microfluidic device containing a series of thin channels (1–3 μm in width) that mimic constraints in cell migration with different physiological pore sizes.…”