Comparative evaluation of re-epithelialization promoted by fresh or cryopreserved cultured dermal substitute

Allogeneic cultured dermal substitute (CDS) was prepared by plating cultured fibroblasts on a two-layered spongy matrix of hyaluronic acid and atelocollagen, followed by culturing for 1 week. The resulting fresh CDS was then cryopreserved in a freezer at -152 degrees C in accordance with conventional procedures. Fresh CDS was rinsed thoroughly with lactated Ringer's solution to remove fetal bovine serum (FBS) and was then used in the clinical study, whereas cryopreserved CDS was thawed and then rinsed with lactated Ringer's solution to remove cryoprotectant and FBS. The present study was designed to compare the efficacy of fresh and cryopreserved CDS in promoting reepithelialization at donor sites leaving behind split-thickness skin autografts. Fourteen donor sites were used for this comparative study. There were no differences in the period of complete re-epithelialization between the fresh and cryopreserved CDS. The results of this comparative study thus suggest that cryopreserved CDS is able to maintain the same level of potency to promote re-epithelialization as fresh CDS. This indicates that, although the release of growth factors is suppressed to some extent during the course of cryopreserving, thawing, and rinsing procedures, it is still sufficient to promote re-epithelialization.