Skin Equivalent Models: Protocols for In Vitro Reconstruction for Dermal Toxicity Evaluation

This chapter presents the protocols for developing of skin equivalents (SE) and reconstructed human epidermis (RHE) models for dermal toxicity evaluation as an alternative method to animal use in research. It provides a detailed protocol for the in vitro reconstruction of human skin from primary keratinocytes, melanocytes, and fibroblasts obtained from foreskin biopsies, including the procedures for reconstruction of a stratified epidermis on a polyester membrane. SE and RHE developed through these methods have been proven suitable not only for dermal toxicity studies, but also for investigating of pathological conditions in the skin, such as diabetes and invasion of melanoma.

The Use of Reconstructed Human Epidermis EPISKIN™ in the Assessment of Local Tolerance of Cosmetics and Chemicals

Models of reconstructed human skin provide useful tools for both basic research and evaluation of the safety and efficacy of dermato-cosmetological products. They can provide alternative models to replace human and animal experiments. However, their use requires confidence in their reproducibility and similarity of the results obtained as compared to in vivo experiments. Their morphology, architecture and properties must be as close as possible to human skin. The present paper reviews the results obtained on the EPISKIN™ model through characterisation of the model, reproducibility studies and multicentre studies or (pre)validations.

Development and Characterization of an Engraftable Tissue-Cultured Skin Autograft: Alternative Treatment for Severe Electrical Injuries

BACKGROUND/AIMS

Optimizing the treatment regimens of extensive or nonhealing defects is a constant challenge. Tissue-cultured skin autografts may be an alternative to mesh grafts and keratinocyte suspensions that are applied during surgical defect coverage.

METHODS

Autologous epidermal and dermal cells were isolated, in vitro expanded and seeded on collagen-elastin scaffolds. The developed autograft was immunohistochemically and electron microscopically characterized. Subsequently, it was transplanted onto lesions of a severely burned patient.

RESULTS

Comparability of the skin equivalent to healthy human skin could be shown due to the epidermal strata, differentiation, proliferation markers and development of characteristics of a functional basal lamina. Approximately 2 weeks after skin equivalent transplantation the emerging new skin correlated closely to the adjacent normal skin.

CONCLUSION

The present study demonstrates the comparability of the developed organotypic skin equivalent to healthy human skin and its versatility for clinical applications.

Clinical application of a tissue-cultured skin autograft: an alternative for the treatment of non-healing or slowly healing wounds?

BACKGROUND

The treatment regime of non-healing or slowly healing wounds is constantly improving. One aspect is surgical defect coverage whereby mesh grafts and keratinocyte suspension are applied.

OBJECTIVE

Tissue-cultured skin autografts may be an alternative for the treatment of full-thickness wounds and wounds that cover large areas of the body surface.

METHODS

Autologous epidermal and dermal cells were isolated, expanded in vitro and seeded on collagen-elastin scaffolds. The developed autograft was immunohistochemically characterized and subsequently transplanted onto a facial chronic ulceration of a 71-year-old patient with vulnerable atrophic skin.

RESULTS

Characterization of the skin equivalent revealed comparability to healthy human skin due to the epidermal strata, differentiation and proliferation markers. Within 138 days, the skin structure at the transplantation site closely correlated with the adjacent undisturbed skin.

CONCLUSION

The present study demonstrates the comparability of the developed organotypic skin equivalent to healthy human skin and the versatility for clinical applications.