Skin regeneration for giant pigmented nevus using autologous cultured dermal substitutes and epidermis separated from nevus skin.

We have developed a modality of treatment of giant pigmented nevus of intradermal type. This method involves application of autologous cultured dermal substitute (CDS), followed by grafting of epidermis separated from the patient's nevus skin. To prepare the wound bed, autologous CDS was applied onto a full-thickness skin defect after complete excision of the nevus. The excised nevus skin was preserved for 1 week, after which the epidermis was separated from the nevus skin by enzymatic treatment with dispase. The epidermis thus obtained was grafted onto the resulting wound bed. This procedure was used to treat a giant pigmented nevus on a 7-year-old patient. The grafted region was soft with good tone 1 year after epidermis grafting. These results indicate that the present method can achieve complete excision of giant nevus, with esthetically acceptable results, although it requires careful monitoring for a long time.

Clinical evaluation of allogeneic cultured dermal substitutes for intractable skin ulcers after tumor resection.

Clinical research on allogeneic cultured dermal substitute (CDS), which was newly developed at the R&D Center for Artificial Skin of Kitasato University, has been carried out in medical centers across Japan with the support of the Millennium Project of the Ministry of Health, Labor and Welfare of Japan. Allogeneic CDS was prepared by cultivation of fibroblasts on a two-layered spongy matrix of hyaluronic acid and atelo-collagen. This paper reports the clinical results of application of allogeneic CDS in 12 patients with full-thickness skin defects after surgical resection of skin tumors. In 9 of 10 patients, healthy granulation tissue developed immediately, allowing us to perform split-thickness skin grafts at an early stage. In two cases, allogeneic CDS was used to cover an expanded mesh skin graft that had been applied to treat a large ulcer, and rapid epithelization was observed. No patient developed local infection nor local tumor recurrence after treatment with CDS. The spongy matrix itself as well as the vascular endothelial growth factor (VEGF) released by the allogeneic CDS seemed to be beneficial for the treatment of intractable skin ulcers. Allogeneic CDS functions as an excellent biological dressing, and could dramatically change the treatment of intractable skin ulcers.

Treatment of full-thickness skin defect with concomitant grafting of 6-fold extended mesh auto-skin and allogeneic cultured dermal substitute.

The aim of this clinical study was to evaluate an allogeneic cultured dermal substitute (CDS) as a biological dressing for highly extended mesh auto-skin grafting. The subjects were five patients with extensive deep burn wounds. Allogeneic CDS was prepared by seeding fibroblasts on a spongy matrix of hyaluronic acid and atelo-collagen. Six-fold extended auto-skin graft was applied to the debrided wound, on which allogeneic CDS was placed. A conventional ointment-gauze dressing was used to protect the CDS. The CDS was applied repeatedly at intervals of 5-7 days. In all cases, the wounds were closed by successful take of mesh auto-skin graft and prompt epithelization from the grafted skin. The skin on the grafted area had a cicatrix appearance, but was soft and thin, maintaining good quality. The application of 6-fold extended auto-skin graft in conjunction with allogeneic CDS is an effective method for treatment of extensive severe burn wounds.