Rheological properties and preclinical data of novel hyaluronic acid filler containing epidermal growth factor.

Recently, a novel hyaluronic acid (HA) filler containing the epidermal growth factor (EGF) was developed. The objective of this study was to evaluate the rheological properties, preclinical efficacy and biocompatibility of the EGF-containing HA filler (HA-EGF filler) using a photoaged mouse model. The rheological properties of the new HA-EGF filler were assessed. Twenty-four female hairless mice (SKH1) underwent photoaging induction with 8 weeks of ultraviolet-B irradiation. The mice were randomly divided into four groups and intradermally injected 100 μl of phosphate-buffered saline, HA-EGF filler, HA filler or polynucleotide (PN) into the dorsal region. We examined the effect of fillers on photoaged skin by dermoscopic examination. Furthermore, histological evaluation with immunohistochemical staining was performed to determine the biocompatibility and collagen formation at the 10th week. A real-time quantitative polymerase chain reaction analysis and western blot test assessed the expression of collagen I/III, matrix metalloproteinases (MMPs) and transforming growth factor. The viscosity and elasticity of the HA-EGF filler were lower than those of the HA filler. Histological evaluation revealed no significant differences in the collagen synthesis between the HA-EGF, HA and PN filler groups. No inflammation was observed during the experimental period. The HA-EGF filler induced type I/III collagen production and downregulated the expression of MMP-1, 3 and 9. Our results suggest that the novel HA-EGF filler may be an additional therapeutic option for photoaged skin, which works by inducing collagen synthesis. Based on these preclinical results, further well-controlled clinical studies are required.