Chitosan hydrogels cross-linked with tris(2-(2-formylphenoxy)ethyl)amine: Swelling and drug delivery.

Tris(2-(2-formylphenoxy)ethyl)amine was designed and synthesized by reaction of salicylaldehyde with tris(2-chloroethyl)amine hydrochloride and evaluated as a new multi-functional cross-linker for preparation of new pH- and thermo-responsive chitosan hydrogels through formation of covalent Schiff-base linkage. The structure and properties of the hydrogels were characterized by FT-IR, H NMR and scanning electron microscopy (SEM). The swelling behavior of prepared hydrogels at different pHs and temperatures was investigated.