Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society
-
Keloids, which overgrow the boundaries of the original injury, represent aberrations in the fundamental process of wound healing that include over-abundant cell in-migration, cell proliferation, and inflammation, as well as increased extracellular matrix synthesis and defective remodeling. To understand the key events that result in the formation of these abnormal scars would open new avenues for better understanding of excessive repair, and might provide new therapeutic options. We examined epidermal growth factor receptor (EGFR)-induced cell motility in keloid fibroblasts, as this receptor initiates cell migration during normal wound repair. ⋯ Interestingly, while extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK-MAPK) activation was relatively robust in keloid fibroblasts, the downstream triggering of the motility-associated calpain activity was blunted. This was reflected by high cell-substratum adhesiveness in the keloid fibroblasts. Thus, the blunted migratory response to EGF noted in keloid fibroblasts appears due to limited activation of two important biochemical switches for cell motility.
-
Currently, the use of cultured epithelial autografts as an alternative to split-thickness skin autografts for coverage of full-thickness wounds is limited due to fragility of the sheet and variability in the outcome of healing. This could be circumvented by the transfer of proliferating keratinocytes, instead of differentiated sheets, to the wound bed and the "in vivo" regeneration of epidermis. The aim of this study was to achieve re-epithelialization on experimental full-thickness wounds in the pig using a porous, synthetic carrier seeded with proliferating keratinocytes. ⋯ At day 12 a stratified epidermis and wound closure were established and epithelial cysts were formed by differentiation of epithelial islands. Wounds treated with seeding densities as low as 50,000 cells/cm(2) showed wound closure within 12 days, whereas wounds treated with 10,000 cells/cm(2) or the nonseeded (acellular) carriers did not show complete re-epithelialization before day 17 after treatment. This study showed that porcine keratinocytes, transplanted "upside down" in experimental full-thickness wounds using a synthetic carrier, continued to proliferate and started to differentiate, enabling the formation of a new epidermis in a time frame of 12 days.