Frozen Human Epidermal Allogeneic Cultures Promote Rapid Healing of Facial Dermabrasion Wounds

BACKGROUND: Clinical studies have shown that cultured human epidermal allogenic sheets promote faster reepithelization of skin donor sites and deep partial-thickness wounds. OBJECTIVE: We describe the results of a controlled, clinical study of facial dermabrasion sites treated with a single application of frozen cultured human allogenic epidermal sheets that were thawed for 5-10 minutes at room temperature before application. METHODS: Ten patients with scars from acne or of other etiology underwent facial dermabrasion. One side of the face was treated with the frozen and thawed cultures, the other side was treated with standard dry dressing. RESULTS: The epidermal cultures promoted faster reepithelization of the wounds, with complete reepithelization in an average time of 4.6 days, whereas controls healed in an average of 7. 9 days. The reduction in healing time was 42% (P = 4.82 x 10(-7)). Pain was reduced in sites treated with the thawed cultures. CONCLUSION: Epidermal allogenic cultures, preserved by freezing, promoted significantly faster reepithelization and reduced pain intensity of dermabraded facial wounds, suggesting that they could be used routinely to improve the recovery from dermabrasion.     

Controlled clinical study of deep partial-thickness burns treated with frozen cultured human allogeneic epidermal sheets

Numerous studies, many uncontrolled, have suggested that the application of freshly prepared human allogeneic epidermal cultures promotes faster re-epithelialization of skin donor sites and deep partial-thickness burns. We describe the results of a study of deep partial-thickness burns treated with such cultures preserved in the frozen state. The study was controlled, side-by-side comparative, and randomized. Nine patients with deep partial-thickness burns and 2 patients with superficial partial-thickness burns were treated with the frozen cultures, with the use of adjacent wounds covered with petrolatum-coated gauze (Jelonet, Smith & Nephew Inc, Largo, Fla) as control wounds. The results showed that for the 2 superficial partial-thickness burns, the frozen cultures reduced healing time by 44%. For 5 of the patients with deep partial-thickness burns, the wounds treated with frozen cultures healed in a mean time of 5.6 days, whereas the control wounds healed in 12.2 days. More importantly, for the 4 other patients with deep partial-thickness burns, the wounds treated with the frozen cultures underwent complete re-epithelialization in a mean time of 4.2 days, but the control wounds were partially or mostly unhealed at up to 14 days. The results show that the frozen cultures not only accelerate the re-epithelialization of deep and superficial partial-thickness burns but also make it possible to heal such wounds that otherwise would not heal.     

Use of cultured human epidermal keratinocytes for allografting burns and conditions for temporary banking of the cultured allografts

Five children who suffered burns clinically regarded as full skin thickness loss were grafted with cultured allogeneic skin from newborn prepuce. The wounds had remained open and infected without healing for about 20 days before the patients were received in the burn unit. To avoid losing surviving deep epidermal cells the wounds were débrided but not deeply excised and, a few days before allografting, they were washed with isodine solution and sterile water, and treated with silvadene cream application. All children received 76 cultured allografts of about 60 cm2 each. After allografting, the wounds were epithelized in 7-10 days and the allogeneic grafted skin began desquamation suggesting that the allograft did not 'take' permanently but was replaced by the newly formed skin. On the other hand, since allografting is an adequate therapy to provide early temporary coverage in extensively burned patients, we developed conditions for banking cultured skin to make it available for immediate use. The conditions described allow banking of the cultured grafts for 15-20 days with retention of clonal growth ability similar to that of unstored epithelia. The results show that cultured epidermal cells obtained from human newborn foreskin, when used as allografts for coverage of full skin or deep partial skin thickness burns, allow rapid epithelization of the burn wounds.     

Human keratinocyte cultures (HaCaT) can be infected by DENV,triggering innate immune responses that include IFNλ and LL37

The skin is the first anatomical region that dengue virus (DENV) encounters during the natural infection. Although the role of some skin resident cells like dendritic cells and fibroblasts has been demonstrated to be crucial to elucidate the role of resident cells and molecules participating during the early events of the innate immune response, the participation of keratinocytes during DENV infection has not been fully elucidated. In this paper we aimed to evaluate the use of the HaCaT cell line as a model to study the immune responses of skin keratinocytes to DENV infection. We demonstrated productive DENV-2 infection of HaCaT cells and their capability to establish an antiviral response through production of type I and type III interferons (IFN-β and IFN-λ). The production of these cytokines by HaCaT cells correlated with upregulation of IFN-inducible transmembrane protein-3 (IFITM3) and viperin in bystander, uninfected cells. We also observed an increase in secretion of IL-6 and IL-8. Skin keratinocytes are known to secrete antimicrobial peptides (AMPs) during viral infections. In our model, DENV-2 infected HaCaT cells upregulate the production of cytoplasmic LL-37. We evaluated the dual role of LL-37, HBD2, and HBD3 antiviral activity and immunoregulation during DENV-2 infection of HaCaT cells and found that LL-37 significantly reduced DENV-2 replication. This indicates that the HaCaT cell line can be used as a model for studying the innate response of keratinocytes to DENV infection. Our results also suggest that skin keratinocytes play an important role in the skin microenvironment after DENV infection by secreting molecules like type I and type III IFNs, pro-inflammatory molecules, and LL-37, which may contribute to the protection against arboviral infections.