Decellularized Human Umbilical Tissue‐Derived Hydrogels Promote Proliferation and Chondrogenic Differentiation of Mesenchymal Stem Cells

Tissue engineering is a promising approach for the repair and regeneration of cartilagi-nous tissue. Appropriate three‐dimensional scaffolding materials that mimic cartilage are ideal for the repair of chondral defects. The emerging decellularized tissue‐based scaffolds have the potential to provide essential biochemical signals and structural integrity, which mimics the natural tissue environment and directs cellular fate. Umbilical cord‐derived hydrogels function as 3D scaffolding material, which support adherence, proliferation, migration, and differentiation of cells due to their similar biochemical composition to cartilage. Therefore, the present study aimed to establish a protocol for the formulation of a hydrogel from decellularized human umbilical cord (DUC) tissue, and assess its application in the proliferation and differentiation of UC‐MSCs along chondrogenic line-age. The results showed that the umbilical cord was efficiently decellularized. Subsequently, DUC hydrogel was prepared, and in vitro chondral differentiation of MSCs seeded on the scaffold was determined. The developed protocol efficiently removed the cellular and nuclear content while re-taining the extracellular matrix (ECM). DUC tissue, pre‐gel, and hydrogels were evaluated by FTIR spectroscopy, which confirmed the gelation from pre‐gel to hydrogel. SEM analysis revealed the fibril morphology and porosity of the DUC hydrogel. Calcein AM and Alamar blue assays confirmed the MSC survival, attachment, and proliferation in the DUC hydrogels. Following seeding of UC‐MSCs in the hydrogels, they were cultured in stromal or chondrogenic media for 28 days, and the expression of chondrogenic marker genes including TGF‐β1, BMP2, SOX‐9, SIX‐1, GDF‐5, and AGGRECAN was significantly increased (* p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001). Moreover, the hydrogel concentration was found to significantly affect the expression of chondrogenic marker genes. The overall results indicate that the DUC‐hydrogel is compatible with MSCs and supports their chondrogenic differentiation in vitro.