Thin films of oriented collagen fibrils for cell motility studies

Collagen films with oriented fibrils mimic tissues that have been remodeled by fibroblasts, which naturally tend to orient collagen fibrils in vivo. We have prepared thin films of ordered fibrils of collagen I, a major component of the extracellular matrix. The films were prepared by modifying a technique previously used to produce collagen I films for studies of cell morphology and intracellular signaling. By modifying the drying step, we were able to produce thin monolayers of collagen fibrils with consistent orientations over macroscopic (>100 microm) distances. We quantified the degree of orientation of the collagen fibrils using Fourier analysis of optical microscopy images. We also conducted experiments with vascular endothelial cells, and found that cell orientation and migration are well-correlated with fibril orientation. Using polarized cells, we showed oriented thin collagen film induces natural migration along the fibrils without using any sort of attractor. Taken together, these results demonstrate additional functionality and physiological relevance for a class of films being successfully applied in a variety of cell biology experiments.