The effects of coating culture dishes with collagen on fibroblast cell shape and swirling pattern formation

TL;DR

This study examines how collagen coating on culture dishes influences fibroblast cell shape and swirling pattern formation, revealing that coating affects cell shape and pattern coherence but not cell motility.

Contribution

It provides new insights into how collagen coating alters fibroblast morphology and pattern coherence, supported by experimental results and a mathematical model.

Findings

Collagen coating makes fibroblasts rounder and shorter in perimeter.

Coating reduces the coherence length of swirling patterns.

Motility of fibroblasts remains unaffected by coating.

Abstract

Motile human-skin fibroblasts form macroscopic swirling patterns when grown to confluence on a culture dish. In this paper, we investigate the effect of coating the culture-dish surface with collagen on the resulting pattern, using human-skin fibroblast NB1RGB cells as the model system. The presence of the collagen coating is expected to enhance the adherence of the fibroblasts to the dish surface, and thereby also enhance the traction that the fibroblasts have as they move. We find that, contrary to our initial expectation, the coating does not significantly affect the motility of the fibroblasts. Their eventual number density at confluence is also unaffected. However, the coherence length of cell orientation in the swirling pattern is diminished. We also find that the fibroblasts cultured in a collagen-coated dish are rounder in shape and shorter in perimeter, compared to those cultured in an uncoated dish. We hypothesize that the rounder cell-shape which weakens the cell-cell nematic contact interaction is responsible for the change in coherence length. A simple mathematical model of the migrating fibroblasts is constructed, which demonstrates that constant motility with weaker nematic interaction strength does indeed lead to the shortening of the coherence length.