Animal models have been useful in the study of specific mechanisms affecting human skin. Such is the case with ageing and the micromechanical changes determining wrinkles in UV- irradiated mice. These models enabled us to understand that ageing encompasses many peculiar mechanical responses which cannot be explained by homogeneous deformation of the skin. Moreover, a major aspect to consider is that ageing processes differ among species and direct inferences are rarely possible. This project aimed to compare age-induced changes in skin properties by studying two Wistar rat groups of different ages – young adult rats (n=7, 20–24 week-old) and old adult rats (n=5, 48–72 week-old). Non-invasive measuring approaches involving transepidermal water loss (TEWL), superficial hydration (MoistureMeter), and biomechanics (Reviscometer, and Cutometer by MPA80) were taken in the animal dorsum (neck, bottom) over a period of five days, allowing statistical comparisons between groups. Results revealed no significant differences for TEWL, firmness or viscoelasticity between the two groups. However, a significant hydration decrease, of nearly 40%, was noted in the old adult rats group. These results, although preliminary, if translatable to humans could be useful to address age-related changes in processes such as healing, or patch dressing efficacy/safety where hydration is a critical determinant. Their potential use for the prediction of efficacy and or safety of topically applied products for the elderly as compared to young adults may warrant further investigation.
