Dynamic cell photo-manipulation technology for the molecular and mechanical regulation analyses of collective cell migration

Collective cell migration is an essential biological process. Migration behaviors of multiple cellular units depend on the mechanical and chemical properties of their scaffolds and the geometry of the cells. However, the mechanisms by which these properties synergistically regulate the collective cell characteristics remain unknown. A robust method is required to analyze collective cell migration. Therefore, in this study, we developed a new method for collective cell migration analysis using defined chemical, mechanical, and geometrical properties. Our method is based on a poly(acrylic acid) hydrogel, whose surface is functionalized with photocleavable poly(ethylene glycol) and a cell-adhesive peptide. By controlling the UV irradiation of the photoactivatable hydrogel, we created geometrically controlled cellular clusters and induced collective migration. Furthermore, chemical and mechanical cues exposed to cell clusters were manipulated depending on the surface density of the cell-adhesive peptide and crosslinking density of the hydrogel. As a proof of concept, we also demonstrated that the collective migration of epithelial cells was synergistically regulated by the chemical and mechanical properties of the scaffold. Our results suggest the new photoactivatable substrate as a promising tool for advanced molecular and mechanobiological analyses of collective cell migration.