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Single-cell suspensions of cultured human keratinocytes in fibrin-glue reconstitute the epidermis.

To overcome common disadvantages of standard cultured epidermal sheet grafts (CEG) we have developed a new technique of transplanting cultured human keratinocytes suspended as single cells in a fibrin-glue matrix (Keratinocyte-fibrin-glue suspension-KFGS). In an athymic mouse model with reproducible standardized full thickness wounds this new technique was compared directly to CEG. Reepithelialization was similar in both groups, but reconstitution of the dermo-epidermal junction zone, as shown by electron microscopy and immunohistochemistry was significantly enhanced by the fibrin-glue suspension technique. The new KFGS technique is earlier available than sheet grafts, is able to transfer actively proliferative single keratinocytes, and simplifies the application.

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PubMedDate not supplied

Paracrine stimulation of keratinocytes in vitro and continuous delivery of epidermal growth factor to wounds in vivo by genetically modified fibroblasts transfected with a novel chimeric construct.

BACKGROUND: Growth factors play an important role in tissue repair. While the effectiveness of growth factor therapy in animal wound healing models and limited human clinical trials has been demonstrated, the ideal method for their administration to the wound remains unclear. Experimental data suggest that the continuous presence in the early stages of wound repair is beneficial. MATERIALS AND METHODS: We have constructed a novel chimeric expression plasmid in which the biologically active portion of the human epidermal growth factor (EGF) gene is fused in-frame to the human granulocyte colony-stimulating factor signal sequence. RESULTS: Clonally selected human fibroblasts transfected with this construct secrete biologically active EGF. After the transplantation of irradiated gene-transfected fibroblasts suspended in fibrin glue to murine full-thickness wounds, EGF can be demonstrated for at least seven days in the wounds, slowly decreasing from initially 470 pg/ml to 140 pg/ml on day 7. No EGF was found in the wound at day 14. CONCLUSIONS: A single application of irradiated EGF genetransfected fibroblasts to wounds can thus continuously deliver the transgene in vivo and could be used to administer drugs to the wound bed during the crucial first seven days of wound-healing.

Amino Acid Sequence↗