In this proposal, we report novel syringe-injectable bioadhesive hydrogels with inherent antibacterial properties prepared from mixing oxidized starch (OS) and water soluble chitosan (WSC). Both starting materials are produced from natural sources. Starch can be obtained from grain food-stuffs, e.g., rice, potato, corn, which then is oxidized to introduce aldehyde groups on the backbone; whereas WSC can be produced from chitin, which is isolated fromthe exoskeleton of crustaceans, e.g., crab shells, lobsters, shrimp. In bioadhesive preparation, two components are dissolved separately in water and injected into surgical site by using a barrel dual syringe.
The bioadhesive hydrogel is formed through crosslink reaction of aldehyde groups of OS and amine groups of WSC to form imine linkages (Schiff’s bases). By the same mechanism, the bioadhesive hydrogel binds to extracellular matrix (ECM) via imine linkages between aldehyde groups of OS and amine groups of amino acids in ECM at surgical site. The bioadhesives are expected to have good biocompatibility thanks to its highly biocompatible components. The presence of chitosan, a natural antibacterial agent, can provide antibacterial properties for bioadhesives. Moreover, bioadhesives are fabricated in water, which is suitable for internal-body uses.