Development and characterization of hybrid hydrogels derived from decellularized human umbilical cord for tissue engineering applications

Decellularized extracellular matrix (ECM) are rich in distinct structural and functional components which help in cell growth and proliferation. ECM of human decellularized umbilical cord (DUC) is rich in collagen, glycosaminoglycans (GAGs), glycoproteins, growth factors, and other bioactive molecules that can affect various cellular functions like cell proliferation, survival, differentiation, and migration. This study presents the development of extracellular matrix (ECM)-based hydrogels, derived from decellularized human umbilical cord (UC) tissue, combined with varying concentrations of chitosan. Human umbilical cord (UC) tissue was decellularized using a newly established decellularization protocol, and its efficacy was confirmed via DNA quantification, gel electrophoresis, histological analyses (H&E, Masson's trichrome, and Alcian blue staining) and by the quantification of collagen and GAGs. The resulting ECM was enzymatically digested, and subsequently, hydrogels were fabricated by adding different concentrations of chitosan (CS) (2 %CS Hydrogel, 2.5 %CS Hydrogel, and 3 %CS Hydrogel) in solubilized ECM solution. FTIR spectroscopy and rheological frequency sweep analysis were performed to study the chemical and mechanical properties of hydrogels. Additionally, swelling and degradation behaviour of hydrogels were explored in PBS and lysozyme solution, respectively. An in vitro cell viability assay was performed on NIH-3T3 mouse fibroblasts, which confirmed that all the hydrogels are biocompatible. Overall, DUC hydrogels and DUC-CS hybrid hydrogels have considerable potential for biomedical engineering, drug delivery, and tissue engineering applications.