Thermoresponsive chitosan derivative for controlled release of fragrances

Abstract

The amphiphilic thermoresponsive chitosan derivative was synthesized for using as a fragrance controlled release system. The obtained polymer could self-assemble in aqueous media to form polymeric particles with spherical shape. Poly(ethylene glycol), a hydrophilic polymer, was grafted onto chitosan backbone in order to act as thermoresponsive residue in which upon self-assembling became particles’ coronas, whereas perfumery aldehyde (in this case vanillin and citral) was grafted onto the chitosan to inherit hydrophobicity which upon self-assembling became particles’ core. The synthesized thermoresponsive polymer showed aggregation-dissociation behavior, corresponding with temperature trigger, leading to temperature dependence of the fragrance controlled release; significantly release of aldehyde from the particles was observed when the temperature was lower than lower critical solution temperature (LCST) whereas slower release was obvious at the temperature beyond the LCST. The LCST of system could be tuned by adjusting through salt concentration. This delivery system is completely biocompatible, therefore, it can be used in various applications.