Thiolated alginate microparticles exhibiting redox-responsive release

Microparticles composed of calcium ion-crosslinked thiolated alginate chains were prepared by W/O emulsion method and they were made to be reduction-responsive by additionally crosslinking the polysaccharide chains through disulfide bond. The sulfur signals of thiolated alginate chains were found on the EDS spectra of the calcium ion-crosslinked microparticles. The microparticles were oxidized to crosslink the thiolated alginate chains via disulfide bond. The release of payload (blue dextran) loaded in the microparticles was more facilitated as the concentration of dithiothreitol (DTT, a reducing agent) was higher, and the release was more sensitive to DTT concentration as alginate was more thiolated.