Glucose-sensitive capsules based on hydrogen-bonded (polyvinylpyrrolidone / phenylboronic -modified alginate) system

Glucose-responsive multilayer capsules have been produced through the layer-by-layer deposition of biodegradable polymers based on hydrogen bonding. The used polymers are alginate derivative and polyvinylpyrolidone (PVPON). Concentration-dependent glucose responsiveness was reached through chemical modification of alginate, selected as polyanion, with phenylboronic acid moieties (known to enable complexes with diols derivative) demonstrated that the alginate derivative self-assembles with the PVPON in accordance with (i) the formation of hydrogen bonding layer-by-layer assembly, and (ii) also evidence an enhancement of the stability versus the pH. We demonstrate that incorporating boronic acid moieties inside a polymer chain allows (i) glucose-responsiveness and (ii) using boronic moieties as hydrogen bond acceptor. This strategy was implemented for the fabrication of smart capsules employing calcium carbonate microparticles as a removable core template. This later enables to consider the loading of two probes. The porosity of the calcium carbonate microparticles template has been used to load the first probe (rhodamine b) and the other one has been loaded through electrostatic interaction with the carboxylate moiety in the alginate (methylene blue hydrate). Insulin has also been loaded as chemical of interest to demonstrate the interest of the present strategy.