Porcine ear skin: an <i>in vitro</i> model for human skin

TLDR

Percutaneous penetration studies often rely on animal skin models to approximate human skin properties. This study evaluates porcine ear skin as a substitute for human skin in such investigations. The authors examined shock‑frozen, paraffin‑embedded, and cyanoacrylate‑surface biopsies of porcine ear skin by microscopy to measure skin layer thicknesses and follicular characteristics. The stratum corneum and viable epidermis measured 17–28 µm and 60–85 µm, respectively, with 11–25 hairs per cm² (58–97 µm diameter, 0.96–1.38 mm depth) and infundibular orifices ~200 µm, mirroring human skin and confirming its suitability as a model.

Abstract

Background/purpose: Porcine ear skin is used in studies of percutaneous penetration as a substitute for human skin. The structure of this tissue, including hair follicles, was studied qualitatively and quantitatively in comparison with human skin. Methods: Sections of shock‐frozen biopsies, biopsies embedded in paraffin and cyanoacrylate skin surface biopsies were investigated using microscopy. The thickness of the different skin layers and the follicular characteristics were determined. Results: The thickness of the stratum corneum was 17–28 μm, whereas the viable epidermis was 60–85 μm thick. On 1 cm 2 , 11–25 hairs were detected, showing a diameter of 58–97 μm and a maximal extension depth of 0.96–1.38 mm into the skin. The orifices of the porcine infundibula showed a diameter of approximately 200 μm. Conclusions: The results obtained are similar to those of human skin, indicating the suitability of this porcine tissue as a model for human skin.