Self-rupturing and hollow microcapsules prepared from bio-polyelectrolyte-coated microgels

This paper reports on microcapsules obtained by layer-by-layer deposition of bio-polyelectrolyte multilayers at the surface of biodegradable dextran microgels. The behavior of the layer-by-layer coating upon degradation of the microgel core strongly depends on the bio-polyclectrolytes used. Two types of microcapsules, "self-rupturing" microcapsules and "hollow" microcapsules, are presented. Self-rupturing microcapsules are obtained when the swelling pressure of the degrading microgel core is strong enough to rupture the surrounding bio-polyelectrolyte membrane. Self-rupturing microcapsules could be of interest as a pulsed drug delivery system. Hollow microcapsules are obtained after applying multiple layers of bio-polyelectrolyte that can withstand the swelling pressure of the degrading microgel core. Biomacromolecules (such as albumin and dextran) spontaneously accumulate in the hollow microcapsules prepared from dex-HEMA microgels, which could be of interest for drug-encapsulation purposes.