Kinematics of migration of individual fibroblasts in Vitro: Faster in a group, but more target-oriented alone

During repair of localized damage in a monolayer of cells, migrating NIH3T3 fibroblasts exhibit certain kinematic traits that are influenced directly by factors in their environment such as temperature, pH, and particularly the numbers and distributions of neighboring cells. The present study measures the velocity and direction of individual fibroblasts cultured in a monolayer during migration into a damaged region. Specifically, a parameter termed "percent ideal walk" was defined for evaluating the efficiency of the migrating cells, which were divided into two distinct groups based on migration behavior, namely those migrating alone or with up to four cells and those migrating in a large group (more than six cells). The results show significantly lower velocities for cells that migrated alone or in a group of up to four cells, compared to the velocity of the cells that migrated in a group of more than seven cells (p < 0.05). Interestingly, cells that migrated alone or in small groups showed a trend of more efficient directional migration, which was on the edge of statistical significance (p = 0.056). This may be attributed to the abundance of mechanical and chemical stimuli that migrating cells generate and sense in a larger group.