A biodegradable starch hydrogel synthesized via thiol-ene click chemistry

The biodegradable polysaccharide hydrogels have attracted much attention due to its biocompatible and non-toxicity. Herein, we report a starch hydrogel synthesized via thiol-ene click reaction between thiol starch (St-SH) and allyl starch (AS). The swelling behaviors, rheological experiment and biodegradable properties of the obtained hydrogel were investigated in details. The chemical structure of functioned starch was confirmed by 1H-NMR and 13C-NMR. Moreover, the rheological experiment indicated that starch hydrogel possessed high mechanical strength, and its modulus could be manipulated by the thiol-ene molar ratio. Biodegradation tests revealed that the hydrogel could be biodegradable rapidly in the presence of α-amylase. The biodegradation rate could be controlled by the thiol-ene molar ratio or the concentration of α-amylase. Degradation kinetics from the hydrogel suggested that the degradation/erosion of starch hydrogel come from a combination of both the surface erosion and diffusion mechanisms.