RESUMO
This Communication describes a new light-controlled release system based on molecular recognition of cyclodextrins. Azobenzene (Azo) residue is employed as a photoresponsive guest residue because it can switch the partner from α-cyclodextrin (αCD) to ß-cyclodextrin (ßCD) by irradiation with UV light. Poly(sodium acrylate)s possessing αCD, ßCD, and Azo residues (pAαCD, pAßCD, and pAAzo, respectively) are mixed in aqueous solutions to form aggregates through the formation of inclusion complexes of Azo with αCD and/or ßCD. A chemical cargo, 1-pyrenemethylammonium chloride (PyMA), is contained in the aggregates, and its release behavior is investigated by dialysis experiments under UV irradiation. These data indicate that the amount of PyMA released for the pAαCD/pAßCD/pAAzo ternary mixture is approximately three times as high as those for the pAαCD/pAAzo and pAßCD/pAAzo binary mixtures because of the light-controlled rearrangement of inclusion complexes.
