Fibroblast-Mediated Fiber Realignment in Fibrin Gels

When fibroblasts are added to a fibrin gel, the cells rapidly compact the gel and produce a fiber alignment pattern that depends in part on the cell traction forces, gel geometry, and gel mechanical constraints [1]. Over time the fibrin is digested and replaced with cell synthesized collagen and other extracellular matrix (ECM) proteins that follow the initial alignment pattern of the gel [2]. This remodeling process proceeds in a complex and integrated manner that is influenced by the mechanical environment [3]. In order to better understand fibroblast-fibrin interactions and the remodeling process, we obtained time-lapse images of the development of fiber alignment between clusters of dermal fibroblasts (i.e., explants) in a fibrin gel. The experimental results were then compared to a model that incorporated the effects of traction forces on ECM reorganization.