Acta of Bioengineering and Biomechanics Original paper Vol. 13, No. 2, 2011 Determination of the mechanical properties of the skin of pig foetuses with respect to its structure MAŁGORZATA ŻAK 1 , PIOTR KUROPKA 2 , MAGDALENA KOBIELARZ 1 , AGNIESZKA DUDEK 2 , KATARZYNA KALETA-KURATEWICZ 2 , SYLWIA SZOTEK 1 * 1 Division of Biomedical Engineering and Experimental Mechanics, Faculty of Mechanical Engineering, Wrocław University of Technology, Poland. 2 Department of Animal Physiology and Biostructure, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Poland. Skin is an important barrier protecting the organism against external environmental factors. Determination of its mechanical charac- teristics as regards its structure has significant scientific and application value. In this work, uniaxial tensile tests were conducted to determine the basic mechanical parameters of skin with respect to its structure. The subject of the study were skin samples taken from domestic pig foetuses. They were excised from different parts of body, in the direction parallel to the long axis of the body. Regardless of the sampling site, the tests revealed no significant differences in the values of the maximum tensile strength (2.08 ± 0.25 MPa) and the conventional Young’s modulus (5.87 ± 1.52 MPa). The mechanical and structural tests confirmed that regardless of the sampling region the skin of domestic pig foetuses may constitute a human skin substitute model. Key words: skin, uniaxial tensile test, mechanical properties, histology, animal specimens 1. Introduction The skin, being a multilayer material, is adapted to a number of functions important for the body, ensur- ing its proper operation. We can distinguish three main layers in the histological structure of the skin: epidermis, dermis, and hypodermis [18], [22]. In the case of individual regions of the body, the integu- mentary system (epidermis and dermis) undergoes modifications during its development to adapt to the performance of specific functions, depending on the local specific load conditions. In terms of mechanical properties, the most important role is played by the dermis layer [20], [21]. The physicochemical proper- ties of individual structural elements of skin are af- fected by a number of biological factors: an individ- ual’s genotype, diet, and physiological status, including the level of hormones, vitamins, micro- and macronu- trients [6], [26]. So far, mechanical properties have been studied on animal models (including mice, rats, sheep, and do- mestic pigs) because this ensures high homogeneity of the material. This stems from a uniform way of feed- ing, similar impact of external factors, and the same age of the animals forming the research group [2], [8], [22], [23], [24], [29]. The aim of this study was to determine the basic mechanical properties of the skin of domestic pig foetuses, sampled in a direction par- allel to the long axis of the body from different re- gions of the body (nuchal region, dorsal region, lateral abdominal region, cranial abdominal region, and tho- racic limb region), with respect to its structure. The analysis of an up-to-date knowledge suggests that mature porcine skin shows the greatest similarity to human skin both in terms of structure and mechanical ______________________________ * Corresponding author: Sylwia Szotek, Division of Biomedical Engineering and Experimental Mechanics, Wrocław University of Technology, ul. Łukasiewicza 7/9, 50-371 Wrocław, Poland. E-mail: sylwia.szotek@pwr.wroc.pl Received: March 1st, 2011 Accepted for publication: May 5th, 2011