Controlling the Degradation of an Oxidized Dextran-based Hydrogel Independent of the Mechanical Properties

The objective of this study is to control and elucidate the mechanism of molecular degradation in a polysaccharide hydrogel. Glycidyl methacrylate (GMA) immobilized dextran (Dex-GMA) was oxidized by periodate to introduce aldehyde groups (oxidized Dex-GMA). The hydrogel was formed by the addition of dithiothreitol to the oxidized Dex-GMA solution through thiol Michael addition with the preservation of the aldehyde group for degradation points. It was experimentally determined that the degradation of this hydrogel can be controlled by the addition of amino groups and the speed of degradation can be controlled independently of mechanical properties because crosslinking and degradation points are different. In addition, the molecular mechanism of the crosslinking between the thiol and aldehyde groups was found to control the degradation of dextran derivatives. It is expected that these results will be beneficial in the design of polymer materials in which the speed of degradation can be precisely controlled. In addition, the cytotoxicity of oxidized Dex-GMA was approximately 3000 times lower than that of glutaraldehyde. The low cytotoxicity of the aldehyde in oxidized Dex-GMA was the likely reason for the harmless functionalized polysaccharide material. Possible future clinical applications include cell scaffolds in regenerative medicine and carriers for drug delivery systems.