Engineered skin substitute (ESS) as a model to study human barrier maturation and injury.

<p>(A) ESS derived from primary human keratinocytes and fibroblasts were grafted onto 14 female NIH-III mice after two weeks in air-liquid interface (ALI) culture. Image was taken two weeks after surgery when bandages were removed. (B) Grafts were allowed to heal for an additional four weeks. (C) Histology of grafted ESS at the junction of the grafted mouse epidermis. Arrowhead indicates grafted human ESS, arrow points to native mouse skin. (D) Tape-stripping was performed on 7 of the mice, with the other 7 as grafted controls. Transepidermal water loss (TEWL) was used as an indicator of barrier integrity. (E) qRT-PCR using long-form <i>TSLP</i> -specific primers of monolayer keratinocytes, ESS at ALI, grafted ESS, and in grafted ESS 3 hours after tape-stripping. Data are normalized to GAPDH and shown as fold change over keratinocytes; error bars = standard deviation. (F) Sonicated ESS DNA run on a 1% agarose gel. Sonication was performed in buffer containing 0, 0.1%, 0.5%, 1%, and 5% SDS. (G) FAIRE workflow for human epidermis. Modifications from the published protocol are shown with red text.