Studying the forces behind skin healing

One of the key stages of wound healing is re-epithelialization, the process in which skin cells migrate to cover an open wound. Improving this process would improve wound healing, decrease recovery time, and enhance patient quality of life.

Spencer et al. studied the physical role of the epidermal growth factor (EGF)-like molecule — known as heparin-binding EGF — in re-epithelialization to improve the process of cell migration.

“HB-EGF stimulates cells into a highly active motile state,” said author Jonah Spencer. “We innately know that motion is the result of forces, but active forces produced by cells and passive forces transmitted over space make the relationship between force and motion unclear.”

The researchers used a theoretical model to separate the active force — which propels the cells forward — from the drag force, building upon previous models to relate forces and motion in collective migration.

“This led to two inferences: The first is that the forces at the edge of the cell layer were elevated in response to HB-EGF, which matched the experimental data,” said author Jacob Notbohm. “The second inference is about the distribution of active, propulsive forces — the theory indicated that propulsive forces were elevated further back into the bulk of the cell layer.”

Validating this with experimental data, the researchers determined that the distribution of forces within a cell layer contributed to migration just as much as the magnitude of the forces.

“Questions we are currently interested in relate to how cells communicate over space to coordinate their forces,” said Spencer. “We are interested in modulating tension to decrease the resisting force, hence increasing motion.”

Source: “HB-EGF enhances collective cell migration via spatial coordination of traction,” by Jonah J. Spencer, Emily Rhine, Pamela K. Kreeger, and Jacob Notbohm, APL Bioengineering (2026). The article can be accessed at https://doi.org/10.1063/5.0326208 .