Developing a gel-col heterogeneous network hydrogel scaffold for tissue-engineered skin with enhanced basement membrane formation

Abstract

Tissue-engineered skin is constructed utilizing biocompatible matrix materials as scaffolds, and incorporating human epidermal keratinocytes (HEKs), dermal fibroblasts (HDFs), and bioactive molecules, addressing clinical issues such as skin graft rejection and donor scarcity. Conventional fabrication methods of tissue-engineered skin typically rely on homogeneous single-network scaffolds, which may not adequately address the distinct requirements of epidermal and dermal cells or the critical formation of the basement membrane, potentially impacting the development and functional integrity of the skin tissue. Cell culture studies employing GelMA hydrogels of varied concentrations have elucidated that epidermal cells exhibit increased viability on scaffolds with higher concentrations (15 %), whereas fibroblasts show increased proliferation within scaffolds of lower concentrations (5 %). Consequently, we have engineered a GelMA-collagen (Gel-Col) hydrogel scaffold with a heterogeneous network of dense and sparse matrices, conducive to the growth of both fibroblasts and epidermal cells. Culturing epidermal cells on this innovative scaffold, coupled with histological section staining, RT-PCR, and Western blot analyses, has demonstrated that the scaffold significantly enhances cellular adhesion and promotes the development of the epidermal basement membrane compared to single-network hydrogels. Mouse wound transplantation experiments have further confirmed the scaffold’s effectiveness in accelerating wound repair, supporting the development of the basement membrane, and enhancing epidermal regeneration. This research provides a reference for constructing tissue-engineered skin that more precisely emulates the intricate architecture and cellular dynamics of natural skin, propelling the advancement of tissue-engineered skin grafts in the clinical treatment of skin injuries.