Percutaneous Collagen Induction (PCI) in rat

The purpose of the present study is to determine the effect of Percutaneous Collagen Induction (PCI) on the epidermis and dermis, including the systemic inflammatory response on gene expression level using microarray analysis. PCI Therapy is an alternative for safely treating wrinkles and scars and smoothening the skin. Therefore animal experiments were performed using 31 male Sprague-Dawley rats (350–375 g), age 4 month, randomly assigned into three groups: group (A) (n=24: needling plus skin care), group (B) (n=6: skincare only, controls after 24 h) and group (C) (n=1: negative control). Rats were anesthetized, shaved, and received a 30% total body surface area (TBSA) scald needling (10min) to induce percutaneous collagen, using a medical needling instrument (Environ® Medical Roll-CITTM, Vivida SA cc, Cape Town, South Africa). After needling surgery, the rats were immediately prepared with high levels of vitamin A cream and vitamin C cream, applied topically after cleaning once per day. The control group (C) rats received no injury, no skin care, no treatment, no anesthesia, and no analgesia. Gene expression analyses were performed 1 h, 24 h, 2, 4, and 8 weeks after PCI surgery. To confirm RNA expression in rat skin, self developed microarrays including genes like cytokines, such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF 2), keratinocyte growth factor (KGF), epidermal growth factor (EGF), and transforming growth factors (TGF ß1, ß2, ß3) were used. Results from 6 microarrays are summarized in this study. The samples originate from different time points after needling surgery mentioned above. Microarrays were hybridized in a loop design with one common reference using a dye swap approach.