Injectable enzyme-catalyzed crosslinking hydrogels as BMSCs-laden tunable scaffold for osteogenic differentiation

Bone defects caused by trauma or tumor are a significant challenge in clinical practice. Hydrogel-based tissue engineering has been considered an effective strategy. This study successfully formed a series of injectable hydrogels by enzyme-catalyzed crosslinking hyaluronic acid-tyramine (HA-TA) and sodium alginate-tyramine (ALG-TA) under physiological conditions in the presence of both horseradish peroxidase and hydrogen peroxide. The morphology, mechanical properties, swelling properties, and biodegradation properties of hydrogels were investigated. The results showed that the mechanical properties, swelling properties and biodegradation of HA/ALG hydrogels varied with the precursor solution concentration. Furthermore, the proliferation and osteogenic differentiation of BMSCs within the HA/ALG hydrogels were evaluated in vitro. The results illustrated that the hydrogels could offer an excellent microenvironment for BMSCs growth and promote osteogenic differentiation. Therefore, the injectable hydrogels can be used as an effective 3 D scaffold for bone repair and regeneration.