Degradable multilayer films and hollow capsules via a 'Click' strategy

Degradable polymeric multilayer films and microcapsules are fabricated by 'click' chemistry using dextran modified with azide and alkyne moieties. Alternating layers of dextran modified with azide and alkyne groups, respectively, are covalently bonded by virtue of the 1,3-dipolar cycloaddition reaction, known as click chemistry, which leads to the formation of stable triazole cross-links between the successive layers. The dextran is modified in such a way that the azide and alkyne moieties are connected to the dextran backbone by a hydrolyzable carbonate ester. Therefore, the obtained multilayered structures can be degraded by simple hydrolysis. This type of multilayer avoids the use of polyelectrolytes, which are potentially cytotoxic, and could, therefore, be interesting for the fields of drug delivery and tissue engineering.