Application Of FB/H₂O₂/Hb Hydrogel Loaded With Adipose-Derived Stem Cells In Repairing Articular Focal Cartilage Defects

The self-healing ability of articular cartilage is poor,and cartilage regeneration faces great challenges.With the continuous advancement of cartilage tissue engineering research,in situ injectable hydrogels are of great significance for the repair of focal cartilage defects.Hydrogel is a porous three-dimensional polymer network with high water content.It has certain mechanical properties and degradation properties.It is similar in structure to extracellular matrix and is suitable for cell culture and tissue filling.It has been widely used in cartilage regeneration medicine.However,clinical translation of most hydrogels is limited due to issues of material origin,mechanical strength,biodegradation,and biotoxicity.Therefore,we developed a novel FB/H₂O₂/Hb hydrogel based on fibrinogen（FB）and hemoglobin（Hb）,which can be extracted from blood,and hydrogen peroxide（H₂O₂）,which is widely used in clinic,and Hb mimics peroxide.Enzymes that trigger redox reactions with H₂O₂ to achieve rapid cross-linking of FBs.This FB/H₂O₂/Hb hydrogel can be rapidly gelled in situ with tunable mechanical strength,excellent biocompatibility and biodegradability.The FB/H₂O₂/Hb hydrogel provides a favorable 3D microenvironment for the proliferation and chondrogenic differentiation of adipose stem cells（ADSCs）,and acts as a carrier to fully exert the immunomodulatory effect of ADSCs.In a rabbit model of focal cartilage defect,FB/H₂O₂/Hb hydrogel-loaded ADSCs can regenerate cartilage tissue.We believe that FB/H₂O₂/Hb hydrogel is a safe,efficient and clinically translational biomaterial for in situ regeneration of focal cartilage defects...