Chitosan/Gelatin Composite Nonwoven Fabric Scaffold Seeding Minimal Function Unit of Skin for Functional Skin Regeneration

Abstract

The construction of intact functional skin is a challenging field in tissue engineering. Traditional skin tissue engineering, using "seed cells" as a bioactive source for scaffolding materials maybe not efficient enough. Here a new strategy is shown for constructing functional tissue-engineered skin with Minimal Functional Unit of Skin (MFUS) as the source of bioactivity. Chitosan/gelatin non-woven fabric is used as the scaffold. MFUS is derived from autologous skin with full-thickness skin microstructure and complete functional skin unit harvesting. A mathematical model is used to calculate the MFUS Minimal Harvest Diameter and Angle (MHDA). Chitosan/gelatin non-woven fabric (CS+GEL) is porous and absorbable, with an elastic modulus meeting the requirement of skin engineering. It supports layered and 3D growth of MFUS. The degradation rate of chitosan, including filament diameter and density is evaluated in vivo. MFUS-engineered skin could reduce the density of local nerve fibers in the early stage, potentially reducing pain during wound healing, as well as could limit excessive fibroblast cell migration in the later stage, potentially reducing scar formation. This study proposes a new strategy for the clinical treatment of large full-thickness skin defects by constructing intact functional at minimal cost.

Feasibility of repairing skin defects by VEGF165 gene‐modified iPS‐HFSCs seeded on a 3D printed scaffold containing astragalus polysaccharide

“…This provides a new method for constructing skin substitutes with good development prospects and also has very important clinical significance in producing more desirable therapeutic effects for people with difficult wound healing. First, screening for suitable seed cells is considered one of the simplest and most effective methods in tissue‐engineered skin construction, 10 , 11 , 12 and hair follicle stem cells (HFSCs) are present in the ramus of the outer root sheath of the hair follicle, and their specific markers include cytokeratin 19 (CK19), 13 , 14 cell membrane protein CD200, 15 , 16 and integrin β1 (ITGβ1). 17 , 18 HFSCs have the ability of self‐renewal and proliferation in vitro and have the potential to differentiate into hair follicle tissue, connective tissue, neuronal cells, epidermal layer cells and melanocytes, and vascular smooth muscle cells.…”