Development of novel wound dressing composed of hyaluronic acid and collagen sponge containing epidermal growth factor and vitamin C derivative

This study was designed to investigate the potential of a wound dressing composed of hyaluronic acid (HA) and collagen (Col) spongy sheet containing epidermal growth factor (EGF) and vitamin C derivative (VC). High-molecular-weight HA aqueous solution, hydrolyzed low-molecular-weight HA aqueous solution and heat-denatured Col aqueous solution were mixed, followed by freeze-drying to obtain a spongy sheet. Cross-linkage between Col molecules was induced by UV irradiation of the spongy sheet (C-wound dressing). In a similar manner, three types of spongy sheet containing EGF (EGF-wound dressing), containing VC (VC-wound dressing) or containing EGF and VC (EGF·VC-wound dressing) were prepared by freeze-drying the mixed solution containing the specified components. Cytokine production by fibroblasts was assessed in a wound surface model using a fibroblast-incorporating Col gel sheet (cultured dermal substitute; CDS). CDS was elevated to the air–medium interface, onto which each wound dressing was placed and cultured for 7 days. Fibroblasts in CDS covered with EGF-wound dressing released 3.6 times more VEGF and 3.0 times more HGF, as compared with the C-wound dressing. Fibroblasts in CDS covered with EGF·VC-wound dressing released 4.2 times more VEGF and 6.0 times more HGF, as compared with the C-wound dressing. The efficacy of these wound dressings was evaluated in animal tests using diabetic mice. Each wound dressing was applied to a full-thickness skin defect on the dorsal area measuring 1.5 × 2.0 cm. After 1 week of application, wound conditions were evaluated histologically. The EGF·VC-wound dressing more effectively promoted granulation tissue formation associated with angiogenesis, as compared with other wound dressings.