Biomimetic RGD-engineered elastin-like extracellular matrix facilitates cutaneous wound healing in C57BL/6 mice by way of promoting the migration of epidermal keratinocytes and dermal fibroblasts

Abstract

Elastin-like proteins (ELPs) modeled after tropoelastin are emerged in the development of biomimetic matrices due to their biocompatibility and the possibility to precisely control their environmental responsiveness and mechanical properties. Integrins which were trans-membrane receptors known to mediate dynamic interactions for cellular movement binds to specific RGD motifs of ECM proteins such as fibronectin, collagen and laminin. To facilitate integrin-related bindings between cell and extra cellular matrix, we biosynthesized a modular Elastin-like proteins (ELPs), represented as TGPG[VGRGD(VGVPG)6]20WPC (RGD-ELP), consisting of elastic (VGVPG)6 structural domains and cell-binding VGRGD motifs. To evaluate the effect of RGD-ELP on tissue regeneration in vivo, we performed wound healing experiment using male C57BL/6 mice. We observed the notably accelerated wound closure in gross observation and promoted wound repair showing decreased area of granulation tissue and enhanced collagen formation by RGD-ELP treatment. Furthermore, RGD-ELP up-regulated the expression of α-smooth muscle actin (α-SMA) in granulation tissue of wounds and the expression level of E-cadherin in the epidermis. In in vitro wound healing assay using fibroblasts and keratinocytes, the migration of cells was significantly promoted on RGD-ELP-coated plates compared with non-coated plates. On the basis of these physiological and pathological changes, we concluded that RGD-ELP facilitates wound healing processes by way of promoting the migration of epidermal keratinocytes and dermal fibroblasts and enhancing the synthesis of collagen fibers and α-SMA. Thus, RGD-ELP is believed to be used as an elastin-like matrix of a therapeutic agent for wound healing.