Barrier function in reconstructed epidermis and its resemblance to native human skin

Area of Science:

• Dermatology
• Biotechnology
• Materials Science

Background:

• Human skin equivalents are crucial for scientific research and drug screening.
• A key requirement for skin equivalents is mimicking the barrier function of native human skin.

Purpose of the Study:

• To assess the barrier function of in vitro reconstructed human epidermis.
• To compare the stratum corneum lipid organization in reconstructed versus native epidermis.

Main Methods:

• Reconstruction of human epidermis on de-epidermized dermis.
• Analysis of lamellar body formation and extrusion.
• Small-angle X-ray diffraction to study lipid lamellar phases.
• Lipid composition analysis of the stratum corneum.

Main Results:

• In vitro reconstructed epidermis demonstrated extensive lamellar body production and extrusion, forming broad lamellar structures.
• Well-ordered lipid lamellar phases were detected, with the long periodicity phase present in both native and reconstructed epidermis.
• The short periodicity lamellar phase was absent in reconstructed epidermis, and SC lipids primarily formed a hexagonal sublattice.
• All stratum corneum lipids were synthesized in vitro, but differences in fatty acid content and profile were observed.

Conclusions:

• Reconstructed human epidermis exhibits similarities to native skin in barrier formation processes.
• Differences in lipid organization, particularly fatty acid profiles, highlight areas for improvement in in vitro culture conditions.
• Further optimization is necessary to achieve stratum barrier properties comparable to native skin in reconstructed models.