The use of PEGT/PBT as a dermal scaffold for skin tissue engineering.

Human skin equivalents (HSEs) were engineered using biodegradable-segmented copolymer PEGT/PBT as a dermal scaffold. As control groups, fibroblast-populated de-epidermized dermis, collagen, fibrin and hybrid PEGT/PBT-collagen matrices were used. Two different approaches were used to generate full-thickness HSE. In the 1-step approach, keratinocytes were seeded onto the fibroblast-populated scaffolds and cultured at the air-liquid (A/L) interface. In the 2-step approach, fully differentiated epidermal sheets were transferred onto fibroblast-populated scaffolds and cultured at the A/L. In a 1-step procedure, keratinocytes migrated into the porous PEGT/PBT scaffold. This was prevented by incorporating fibroblast-populated collagen into the pores of the PEGT/PBT matrix or using the 2-step procedure. Under all experimental conditions, fully differentiated stratified epidermis and basement membrane was formed. Differences in K6, K16, K17, collagen type VII, laminin 5 and nidogen staining were observed. In HSE generated with PEGT/PBT, the expression of these keratins was higher, and the deposition of collagen type VII, laminin 5 and nidogen at the epidermal/matrix junction was retarded compared to control HSEs. Our results illustrate that the copolymer PEGT/PBT is a suitable scaffold for the 2-step procedure, whereas the incorporation of fibroblast-populated collagen or fibrin into the pores of the scaffold is required for the 1-step procedure.