A mathematical study published in Physical Review Letters has revealed the underlying mechanisms of wound healing from a completely new mechanical perspective. An original model developed by a team from the University of Bristol shows that "volume forces" within the tissue surrounding the wound are key to regulating the closure process, a discovery that corrects a blind spot in traditional theories.

For a long time, academic research on wound healing has mainly focused on the process of "reepithelialization," that is, the migration and spreading of skin cells to rebuild the protective barrier. However, Henry Andraloitz, who led this study, pointed out that previous models generally ignored the mechanical effects generated by the tissues surrounding the wound. "It's like focusing only on the 'cloth' covering the wound, without considering how much force is involved in pulling the edges of that 'cloth.'"

To complete this picture, the team focused on the epithelial tissue of fruit fly wings—where cells exhibit remarkable head-to-tail symmetry and are highly ordered along their long axis. Using deep learning tools, they analyzed thousands of cells, abstracting this tissue into a special fluid composed of slender "cell-like particles," and then constructed a mathematical model that could quantify internal tension.

The new model makes a clear prediction: wound healing is significantly accelerated when surrounding tissue actively contracts inward; conversely, closure is delayed if tissue tends to expand outward. More importantly, these "volume forces" change the geometry of the wound—a wound that was originally inclined to be circular will be stretched or compressed during the healing process, eventually aligning with the natural orientation of the surrounding tissue.

“The experimental data fully confirms this prediction,” Andraloitz said. “The shape of the wound changes directionally with the orientation of the tissue itself, which was difficult to explain in previous models.”

Co-author of the paper, Professor of Theoretical Physics Tanimora Liverpool, added that the study also found that the arrangement of cells around a wound may temporarily become disordered locally, but these tiny irregularities disappear naturally as healing is complete, and the tissue returns to its original ordered structure. "This shows that healing is not just about covering the gap, but also about the reconstruction of mechanical order."

The team emphasized that this work benefited from a deep integration of experimental observation and theoretical modeling. Without precise quantification of cell arrangement patterns, the mechanism of action of this overall tissue force could not be deduced. This research not only provides a new theoretical framework for understanding wound repair but also offers potential mechanical targets for future interventions in chronic wounds and improvement of healing quality.

source:

University of Bristol