Synthesis and characterization of disulfide-crosslinked alginate hydrogel scaffolds

In this paper, alginate was crosslinked by a condensation reaction of cystamine or cysteine with di-terminated amine groups to form hydrogels containing disulfide bonds. These hydrogels were easily decomposed or disintegrated under physiological reducible conditions by cleavage of disulfide crosslinkage to thiol groups. Porous alginate hydrogel scaffolds were prepared by freeze-drying technique. Results indicated that the pore structure and decomposition properties of the scaffolds were determined by a concentration of alginate solution as well as the amount and types of crosslinker. With surface modification using chitosan, the mechanical properties of the scaffolds were greatly improved. Cytotoxicity evaluation demonstrated that these alginate scaffolds were cytocompatible.