Gene expression advances skin reconstruction and wound repair better on silk fibroin-based materials than on collagen-based materials

Abstract

To evaluate silk fibroin sponge (SFS) materials as dressings for wound repair in comparison with collagen material, human epidermal keratinocytes (HEKs) were cultured on silk fibroin materials in the absence of differentiation factors. Higher cell motility, which is known to play an important role during wound repair, was observed on silk fibroin than on collagens. More HEKs on the silk fibroin surface were flatter and elongated, indicating a higher migration stage of HEKs than that shown on the other surface. Quantitative RT-PCR results revealed up-regulated gene expression of HEKs to the differentiation stage related to skin reconstruction. We observed higher gene expression profiles of keratinocyte-specific differentiation markers in HEKs cultured on silk fibroin surfaces than those observed on collagen surfaces. Higher gene expression related with wound healing such as granulin (GLN), which is reported as an important growth factor for wound repair, was found by DNA microarray analysis in HEKs cultured on SFS than oncollagen sponge. Scar-formation-related genes at the wound site were expressed in HEKs on SFS less than on collagen sponge. These gene expression results suggest that silk fibroin-based biomaterials used as a wound dressing can hasten skin reconstruction (epithelialization) and wound repair with formation of less scar tissue during wound healing.