Controlling mechanical and swelling properties of alginate hydrogels independently by cross-linker type and cross-linking density

The mechanical properties and swelling degrees of alginate hydrogels was tightly regulated by using different kinds of cross-linking molecules and controlling the cross-linking densities. The chemistry of cross-linking molecules exerted a significant effect on hydrogel swelling. Further, the introduction of hydrophilic cross-linking molecules as a second macromolecule compensated the loss of hydrophilic character of the hydrogel during the cross-linking reaction between hydrophilic groups in the backbone.