Crosslinking of gelatin Schiff base hydrogels with different structural dialdehyde polysaccharides as novel crosslinkers: Characterization and performance comparison.

Few studies have been conducted on the relationship between the crosslinking ability of dialdehyde polysaccharides (DPs) with different structures and the structure and properties of hydrogels. Herein, the effects of dialdehyde sodium alginate (DSA), dialdehyde guar gum (DGG), and dialdehyde dextran (DDE) as crosslinking agents for gelatin (GE)-based hydrogels were comparatively studied. First, the structure and aldehyde content of DPs were evaluated. Subsequently, the structure, crosslinking degree, and physicochemical properties of GE/DP hydrogels were characterized. Compared with pure GE hydrogels, GE/DP hydrogels had higher thermal stability and mechanical properties. Moreover, the aldehyde content of DPs was ordered as follows: DSA < DGG < DDE. The higher crosslinking degree of the hydrogels formed by DPs with a higher aldehyde content resulted in smaller hydrogel pores, higher mechanical strength, and a lower equilibrium swelling rate. These observations provide a theoretical basis for selecting crosslinking candidates for hydrogel-specific applications. [Display omitted] • Dialdehyde polysaccharides (DPs) are novel green crosslinking agents. • Gelatin/DP hydrogels were crosslinked via the Schiff base reaction. • Aldehyde content of DP was regulated by varying the structure of polysaccharide. • Degree of hydrogels crosslinking depended on the aldehyde content of the DPs. • The hydrogels exhibited excellent mechanical, rheological, and swelling properties. [ABSTRACT FROM AUTHOR]