Preparation of polyaspartamide-based adhesive hydrogels via Schiff base reaction with aldehyde-functionalized dextran

Tissue adhesives have become vital candidates for the treatment of injuries, working as hemostatic agents for wound-healing and tissue-sealing. The most accessible commercial adhesives are based on cyanoacrylate and fibrin glue; however, they suffer from drawbacks such as cytotoxicity and poor adhesive strength, which limit their bioapplications. Therefore, the development of an adhesive system that improves tissue repair and closure while exhibiting low cytotoxicity is an important but challenging task. Herein, to overcome the limitations of commercial adhesives, we fabricated biocompatible hydrogels based on amino-functionalized polyaspartamide crosslinked with naturally occurring dextran aldehyde via Schiff base chemistry and investigated their adhesive properties. The crosslink density is affected by the ratio between the amine and aldehyde functional groups of each polymer, as well as by the polymer concentrations. We evaluated the adhesive characteristics of the hydrogels using rheometer and lap shear tests. The polyaspartamide-based adhesive hydrogels showed good mechanical strength and self-healing properties and higher adhesive properties than fibrin glue, demonstrating their potential for tissue adhesion applications.