Interactions of donor sources and media influence the histo‐morphological quality of full‐thickness skin models

Abstract

Human artificial skin models are increasingly employed as non-animal test platforms for research and medical purposes. However, the overall histopathological quality of such models may vary significantly. Therefore, the effects of manufacturing protocols and donor sources on the quality of skin models built-up from fibroblasts and keratinocytes derived from juvenile foreskins is studied. Histo-morphological parameters such as epidermal thickness, number of epidermal cell layers, dermal thickness, dermo-epidermal adhesion and absence of cellular nuclei in the corneal layer are obtained and scored accordingly. In total, 144 full-thickness skin models derived from 16 different donors, built-up in triplicates using three different culture conditions were successfully generated. In univariate analysis both media and donor age affected the quality of skin models significantly. Both parameters remained statistically significant in multivariate analyses. Performing general linear model analyses we could show that individual medium-donor-interactions influence the quality. These observations suggest that the optimal choice of media may differ from donor to donor and coincides with findings where significant inter-individual variations of growth rates in keratinocytes and fibroblasts have been described. Thus, the consideration of individual medium-donor-interactions may improve the overall quality of human organ models thereby forming a reproducible test platform for sophisticated clinical research.

Evaluation of native and non‐native biomaterials for engineering human skin tissue

“…However, while keratinocytes isolated from neonatal foreskin had a higher rate of proliferation compared to cells isolated from adult skin, the differences in the proliferation of fibroblasts could not be associated with age, gender or anatomical location, but it was rather donor specific. Accordingly, Lange et al showed that optimal culture conditions to generate skin models may differ depending on the cell source 68 . The donor‐to‐donor variability is a key point in the development of tissue engineered models using primary cells for regenerative medicine and fabrication of in vitro models.…”

“…Accordingly, Lange et al showed that optimal culture conditions to generate skin models may differ depending on the cell source. 68 The donor‐to‐donor variability is a key point in the development of tissue engineered models using primary cells for regenerative medicine and fabrication of in vitro models. These observations demonstrate the importance of using a representative cell population for the optimization of biomaterials for tissue engineering.…”

Inflammation-induced tissue damage mimicking GvHD in human skin models as test-platform for immunotherapeutics

“…We employed both a collagen skin model under static conditions and a vascularized skin model under dynamic conditions in a bioreactor system (Groeber et al, 2016a;Rossi et al, 2015;Lange et al, 2016). Pre-stimulated or unstimulated randomly HLA-mismatched lymphocytes injected either directly into the model or into the circulation medium induced a histomorphological pattern typical for GvHD.…”

“…Human full-thickness skin models were generated based on a collagen hydrogel in 24-well inserts (Polycarbonate Membrane Inserts in Multidish 24, Nunc™, Roskilde, Denmark) according to a previously published protocol using the EpiLife ® medium system (Lange et al, 2016). Briefly, 500 µl dermal equivalents were prepared by mixing 5x10 4 fibroblasts per insert with the collagen solution (collagen solution prepared in-house, 4 mg/mL final rat-tail collagen type I concentration).…”

“…Juvenile foreskin biopsies were used to establish the skin models initially as the proliferative capacity of keratinocytes was expected to be higher as shown previously by our group (Lange et al, 2016). Indications for the circumcisions were not available, however all samples underwent a visual inspection before being used in the models so that inflamed or infected tissues could be sorted out.…”