Figure 4

EDK cells accelerate re-epithelialization of wounded HSEs. (a) Schematic of 3D tissue model of wound re-epithelialization. In step 1, a full-thickness wound is generated by excising a human skin-equivalent (HSE). In step 2, the wounded HSE is placed on a second, contracted collagen gel populated with EDK, H9-MSC, human foreskin fibroblasts (HFF), or constructed without cells. In step 3, keratinocytes (NHK) undergo migration to close the wound gap and restored epithelial integrity. The far right panel is an image of six-well insert containing HSE 96 hours after wounding. (b) Representative morphology of wounded tissues constructed with HFF, EDK, H9-MSC, or without cells 96 hours after wounding (black arrows demarcate the initial wound edges). Bars, 200 μm. (c) EDK showed a rate of wound closure similar to tissues in which HFF were incorporated. The degree of re-epithelialization was significantly lower in H9-MSC and no cells-containing tissues as compared with HFF (t-test: **P < 0.01). (d) Levels of hepatocyte growth factor (HGF) in supernatants of wounded tissues 96 hours after wounding as measured by ELISA. HFF- and EDK-containing tissues produced higher levels of HGF as compared with H9-MSC-containing tissues or tissues constructed without cells. All results are presented as the mean +/- standard deviation of three independent experiments and three technical replicates.