Evaluation of Epidermal Growth Factor-Incorporating Skin Care Product in Culture Experiment Using Human Fibroblasts

This study aimed to investigate the potential of a skin care product composed of hyaluronic acid (HA) and collagen (Col) sponge containing epidermal growth factor (EGF), vitamin C derivative (VC), glucosylceramide (GC), poly(γ-glutamic acid) (PGA), and argentine (Arg). High-molecular weight HA aqueous solution, hydrolyzed low-molecular weight HA aqueous solution, and heat- denatured Col aqueous solution were mixed, into which each aqueous solution containing EGF, VC, GC, PGA, or Arg were added, followed by freeze-drying to obtain a spongy EGF-incorporating skin care product (EGF-skin care product). In order to evaluate the first efficacy of EGF, fibroblast proliferation was assessed after 6 days of cultivation in the conditioned medium prepared by dissolving EGF-skin care product in a conventional culture medium. The fibroblast densities increased more effectively in conditioned medium with EGF than in control medium without EGF. In order to evaluate the second efficacy of EGF, the amount of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) produced by fibroblasts were assessed in a wound surface model. A fibroblast-incorporating Col gel sheet (cultured dermal substitute: CDS) was elevated to the air- medium interface, onto which a spongy sheet of EGF-skin care product was placed and cultured for 7 days. The condition covered with or without EGF-skin care product is divided into (+) EGF or (-) EGF, respectively. Fibroblasts in the CDS released 3.7 times more VEGF and 25 times more HGF in (+) EGF compared with (-) EGF. In another experiment, an aqueous solution of EGF-skin care product was added onto CDS and cultured for 7 days. Aqueous solutions were prepared and stored at 4°C or 37°C for a different period of 1 day, 2 weeks, and 4 weeks, respectively. Fibroblasts in CDS under different condition released similar amount of VEGF and HGF. This result indicated that the efficacy of EGF was maintained even after preservation at 37°C for 4 weeks. These findings suggest that EGF-skin care product can be used on damaged skin surface by placing its spongy sheet or its solution.