Advanced imaging enables greater understanding of wound healing

The imaging equipment was used by a team at Nanyang Technological University, Singapore (NTU Singapore) to observe the motion of cells in synthetic wounds that mimic human skin. Their results are detailed in PNAS.

An essential component of wound healing is re-epithelialisation, a process in which the epithelial cell found on skin moves to form a bridge between the wound and the skin, closing its gap.

Previous studies have found that zig zag wounds healed faster than straight wounds, but little is known about how different wound curvatures (shape) and wound sizes influence healing efficiency, nor about the mechanism of re-epithelialisation.

To investigate, the NTU scientists prepared synthetic wounds with a range of widths (30 micrometres to 100 micrometres) and curvatures (radius of curvature: 30 micrometre, 75 micrometre,150 micrometre and straight line) to learn how cells moved to close wound gaps in different circumstances.

Using particle image velocimetry researchers found that wavy wounds induced more complex collective cell movements, such as a swirly, vortex-like motion. By contrast in a straight wound, cells moved parallel to the wound front, moving in straight lines.

In a statement, lead investigator Professor K Jimmy Hsia said: “Scientists have long known that the way you cut your skin affects how fast it heals. However, not much is known about why this happens, and the factors that could affect the healing speed. Our study contributes new knowledge to the promising field of mechanobiology, which could help surgeons develop better strategies for patients’ wound care.”

The NTU team also observed the healing progress of the synthetic wounds over a period of 64 hours and found that the healing efficiency of wavy gaps – measured by the percentage area covered by the cells over time - is nearly five times faster than straight gaps.

Co-lead investigator, Assistant Professor Huang Changjin at NTU School of Mechanical & Aerospace Engineering, said, “This study has revealed the cellular and molecular mechanisms of gap closure, contributing to the scientific understanding of the underlying principles of the wound-healing process. Clinicians and surgeons can use this knowledge to develop better strategies, such as incision methods, for patients’ wound management care in future.”