Fabrication of cleavable covalently crosslinked colloidosomes

In this study, cleavable microcapsules were obtained using self-assembly and crosslinking of magnetic nanoparticles at the oil-water interface. To achieve this, iron oxide nanoparticles coated with oleic acid were synthesized and they were coated with three different linkers including azide and alkyne parts, one of which contained a disulfide bond linkage. Since disulfide bonds can be degraded with thiol compounds, they render these microcapsules cleavable. A water in toluene emulsion system including both nanoparticles and Cu(I) catalyst was prepared. By shaking the emulsion, microcapsules were fabricated via Cu(I) catalyzed Huisgen reaction involving cycloaddition of azides and alkynes. Thus, stable microcapsules made through covalent crosslinking of coated iron oxide nanoparticles were obtained. These microcapsules were characterized using microscope and SEM images. Also, FITC labeled dextran was encapsulated within these microcapsules and their release in the presence of dithiothreitol was demonstrated using fluorescence microscopy.