+49 30 838 53555
Human skin is the gold standard for in-vitro skin experiments. Unfortunately, the availability of human skin for research is limited, so alternatives are required. Because of its similar structure, porcine skin has been used frequently as a model of human skin for in vitro studies. Human skin used in dermatological research, is usually abdominal or chest skin obtained from plastic surgery. However, pig skin can be sampled from many locations, even though there are structural variations between different regions (Turner et al,2015). The aim of this study is to identify a region of the body to obtain porcine skin that can be used as the best possible model for human abdominal skin.
MATERIALS AND METHODS
Samples of German Landrace pig skin (10–11 weeks old, n = 8; female = 4, male = 4) were collected from immediately caudal to the ear, lumbar flank, mid-back and the caudal abdomen. Human abdominal skin samples were excised during plastic surgery (n = 3). The skin samples were processed using routine techniques for analysis by light microscopy (LM). Qualitative assessment of the morphology was carried out. Quantitative assessments included counting the number of cell layers in each stratum. Statistical analysis was performed to compare quantitative parameters of each pig skin region to human abdominal skin using a linear mixed model method. A P value of less than 0.05 was considered statistically significant and tests were performed using SPSS version 24 (IBM Deutschland GmbH, Ehningen).
Histologically, morphologic features of all regions of porcine skin studied were similar to human abdominal skin. The overall appearance of the pig epidermis, notably behind the ear and from the flank, was gently folded, similar to that seen in the human skin samples. Elsewhere, the pig samples of the back had a flattened appearance, and those of the caudal abdomen were greatly folded.
The number of layers within the stratum spinosum of porcine skin ranged from 6.94 ± 0.39 to 7.63 ± 0.38 layers, he human abdominal skin had 4.00 ± 0.58 layers. All sampled regions of porcine skin showed significantly more layers of s. spinosum when compared to the human skin. However, there was no significant difference of numbers of cell layers in s. granulosum and s. corneum from pig and human skin. The stratum granulosum of pig skin from all regions showed only 1–2 layers and human skin showed only 1 layer. In the pig, the number of cell layers in the s. corneum ranged from 9.44 ± 0.54 to 15.63 ± 1.44 layers. In the human skin samples, there were 13.33 ± 0.88 layers.
While the morphological studies found a remarkable similarity between the pig skin samples and the human abdominal skin, the statistical analysis revealed specific differences: significantly more layers in the stratum spinosum in all pig samples. Interestingly, the comparison between the pig samples showed no differences. From the results of this study, we can conclude that the German Landrace skin from all regions could potentially be used as a substitute for human skin.