Incorporation of magnesium ions into photo-crosslinked alginate hydrogel enhanced cell adhesion ability

Photo-crosslinked alginate hydrogel attracts wide interest in tissue engineering because of its excellent controllability and stability. However, its highly hydrophilic property makes cell adhesion difficult. Plenty of studies have confirmed that magnesium ions (Mg(2+) ) can efficiently improve the attachment of osteoblasts. In this study, for the first time, we fabricated a durable, crosslinked, alginate hydrogel with a dual-crosslinking network. Photo-crosslinked alginate hydrogel was chosen as the basic backbone, and various amounts of Mg(2+) were incorporated into the hydrogel through ionic crosslinking. The results showed that the physicochemical properties of the hydrogels, including surface structure, composition, swelling ratio, ion release and elastic modulus, could be well tuned by controlling the amount of Mg(2+) incorporated. In addition, a certain amount of Mg(2+) significantly improved the attachment and spread of osteoblasts on the hydrogels. These characteristics make Mg(2+) -incorporated photo-crosslinked alginate hydrogel a promising scaffold for bone tissue engineering.