Photocrosslinked alginate hydrogels with tunable biodegradation rates and mechanical properties

Photocrosslinked and biodegradable alginate hydrogels were engineered for biomedical applications. Photocrosslinkable alginate macromers were prepared by reacting sodium alginate and 2-aminoethyl methacrylate in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide. Methacrylated alginates were photocrosslinked using ultraviolet light with 0.05% photoinitiator. The swelling behavior, elastic moduli, and degradation rates of photocrosslinked alginate hydrogels were quantified and could be controlled by varying the degree of alginate methacrylation. The methacrylated alginate macromer and photocrosslinked alginate hydrogels exhibited low cytotoxicity when cultured with primary bovine chondrocytes. In addition, chondrocytes encapsulated in these hydrogels remained viable and metabolically active as demonstrated by Live/Dead cell staining and MTS assay. These photocrosslinked alginate hydrogels, with tailorable mechanical properties and degradation rates, may find great utility as therapeutic materials in regenerative medicine and bioactive factor delivery.