Characterization of a New Full-Thickness In Vitro Skin Model.

Since 30 years, bioengineering allowed to reconstruct human tissues using normal human cells. Skin is one of the first organ to be reconstructed thanks to the development of specific cell culture media and supports favoring the culture of human skin cells, such as fibroblasts, keratinocytes, or melanocytes. Skin models have evolved from epidermis to complex models including a dermis. The purpose of the present study was to design a reconstructed full-thickness (FT) skin suitable to perform in vitro testing of both molecules and plant extracts. First, we reconstructed epidermis with normal human keratinocytes displaying the expected multilayered morphology and expressing specific epidermal proteins (e-cadherin, claudin-1, p63, Ki67, Keratin 10, filaggrin, and loricrin). Then, a dermal equivalent was developed using a collagen matrix allowing the growth of fibroblasts. The functionality of the dermis was demonstrated by the measurement of skin parameters such as rigidity or elasticity with Ballistometer® and other parameters such as the contraction over time and the expression of dermal proteins. The combination of these two compartments (dermis and epidermis) allowed to reconstruct an FT model. This study model allowed to study the communication between compartments and with the establishment of a dermoepidermal junction showing the expression of specific proteins (collagen XVII, laminin, and collagen IV). Impact statement The objective of our research project was to design a three-dimensional human full-thickness (FT) skin suitable to perform in vitro testing of molecules and plant ingredients. The combination of these two reconstructed compartments (dermis and epidermis) allowed to reconstruct an FT model. This study model allowed to study the communication between compartments and with the establishment of a dermoepidermal junction showing the expression of specific proteins (collagen XVII, laminin, and collagen IV). This in vitro model can be use by cosmetic and pharmaceutical industries to study the effect of chemical or natural compounds on the skin.