Substrate Thickness Modulates Electric Field-induced Ligament Fibroblast Migration

INTRODUCTION The microenvironment has a significant impact on cell phenotypic expression and behaviors. One aspect of the microenvironment is the mechanical properties, which modulates cell migration, cytoskeleton structures, gene expression, and differentiation [1]. More recently, substrate thickness has been shown to change cell spreading area and traction forces [2-3]. In addition to changes in depth, effective modulus of the substrate also changes, with thinner gels approximating stiffer gels [4]. We developed a microfluidic system to precisely vary collagen gel thickness and examine its effect on directed ligament fibroblast migration. Furthermore, as cells reside in a highly organized environment in situ, the fibers of the collagen gel are aligned to investigate the effects of contact guidance on cell migration.