In vitro skin expansion: Wound healing assessment.

For treatments requiring split-thickness skin grafts, it is preferable to mesh the grafts. This reduces the amount of excised skin and covers more wound area. The mesh technique, however, destroys surface continuity, which results in scarring. Strain-based bioreactors, on the other hand, have successfully expanded split-thickness skin grafts in vitro within a 7-day period, increasing graft coverage. After in vitro expansion, the expanded skin grafts were tested in a porcine full-thickness excisional wound model. Expanded graft take rate was 100%. Volumetric, histologic, and mechanical assessments indicated that expanded grafts were comparable to unexpanded grafts (positive control). While there was considerable variation in expansion (31% to -3.1%), this technique has the potential to enhance the coverage area of skin grafts while reducing or eliminating scarring.