Engineering an Injectable Scaffold with Enhanced ECM Mimicry for Cell Delivery and Tissue Regeneration.

The development of biomimetic scaffolds that emulate the extracellular matrix (ECM) is critical for advancing cell-based therapies and tissue regeneration. This study reports the formulation of CHyCoGel, a novel injectable, ECM-mimetic hydrogel scaffold composed of chitosan, hyaluronic acid, chondroitin sulfate, and an amphiphilic stabilizer. CHyCoGel addresses key limitations of existing scaffolds, offering improved structural uniformity, injectability, and in situ gelation suitable for cell encapsulation and minimally invasive delivery. Primary dermal fibroblasts (PDFs) isolated from neonatal rat skin were grafted into CHyCoGel, which supported high cell viability, well-organized cytoskeletal structures, and modulation of genes involved in tissue remodeling, including α-SMA, fibronectin, Col1A1, and TGF-β. In vivo application of PDF-loaded CHyCoGel significantly enhanced wound healing, epithelialization, and the regeneration of skin appendages. Notably, CHyCoGel promoted angiogenesis by upregulating VEGF and facilitated balanced ECM remodeling through enhanced type I collagen expression with reduced total collagen accumulation. These findings highlight CHyCoGel's potential as a cytocompatible, bioactive scaffold capable of directing reparative cellular behavior and promoting structurally and functionally integrated tissue regeneration, particularly in chronic and complex wound settings.