SEM analysis of HSE. (A, B) SEM images of dermal compartment of HSE showed ECM with a typical interwoven network morphology and architecture with embedded dermal fibroblasts lying along dense matrix of collagen fibers. (C, D, E, F) Epidermal layers of skin were increasingly flattened as they move to the surface to form SC. The inner layers of keratinocytes (C) were continuous with less flattened morphology. Keratinocytes of the individual layers are marked with yellow asterisk; N = 2, n = 3.