Effects of Ascorbic Acid on Keratinocyte and Epidermalization of Skin

BACKGROUND: There are different models of skin substitutes, but no skin substitutes have the characteristics of native skin. It was reported that the incubation of skin substitutes in medium containing ascorbic acid extends cellular viability and promotes formation of an epidermal barrier in vitro. OBJECTIVE: The purpose of this study is to observe the effects of ascorbic acid on the proliferation of keratinocytes and on the reconstruction of epidermis. MATERIALS AND METHODS: Normal human keratinocytes and fibroblasts were isolated and used for culturing living skin equivalent (LSE). RESULTS: When ascorbic acid was added, the expression of p63 and a6 integrin was definitely increased compared to control models. In addition, ascorbic acid increased the proliferation of normal human keratinocytes at a dose dependent manner. Especially, ascorbic acid induced the phosphorylation of ERK and up-regulation of EGF-R CONCLUSION: Results suggest that ascorbic acid is essential in the control of keratinocyte proliferation and basement membrane formation. Ascorbic acid-related keratinocytes proliferation is seemed to be mediated by ERK phosphorylation and EGF-R up-regulation.

The Establishment of a Wound Model Induced by Ultrapulse CO2 Laser / 대한피부과학회지

BACKGROUND: Wound model is important for the development of dressing materials used in dermatologic practice. Most of the wound healing models are not standardized, individualized ones for each special situation. OBJECTIVES: The purpose of our study is to establish a standardized wound model for evaluating the efficiency of wound healing of dressing material and the effect of epidermal growth factor(EGF) on artificially induced wounds. METHODS: Using ultrapulse CO2 laser and rats, we calibrates the most effective level of energy, frequency, and pulse duration for a wound model of upper dermis. Then, we evaluated the effect of various dressing materials such as vaseline gauze, collagen sponge, collagen sponge containing EGF and hydrogel on wound healing. RESULTS: We obtained relatively even and uniformed wound models of upper dermal level with the setting of ultrapulse CO2 laser; continuous mode, 800watt, frequency of 100Hz, and pulse duration of 0.3ms. Wounds applied with collagen sponge containing EGF showed relatively accelerated wound healing, but wounds with hydrogel or collagen sponge only showed delayed healing of wounds CONCLUSION: Ultrapulse CO2 laser could make a wound model of uniform depth level and could be used as a tool for making standardized wound models.