Fig. 3.

Schematic image demonstrating the steps to develop a cell-laden alginate hydrogel. a Alginate solution can be mixed with bioactive factors and the desired source of stem cells before crosslinking. b Alginate structure can be crosslinked with the addition of divalent cations such as Ca²⁺. The source of the divalent cation is one of the factors controlling the gelation rate to fabricate different types of alginate hydrogel including microspheres or thin gel layers. c The SEM image (upper panel) shows the homogeneous microporous structure, and the live/dead cell viability assay (lower panel) demonstrates higher biocompatibility of the alginate hydrogels. d The developed cell-laden hydrogel can be easily administered into the defect site