Inclusion complexes of γ-cyclodextrin and carboxyl-modified γ-cyclodextrin with C₆₀: synthesis, characterization and controlled release application via microgels

摘要

Carboxyl modified γ-cyclodextrin (CDSA) with a substitution degree of about 9.5 was prepared by the esterification of γ-cyclodextrin (CD) with succinic anhydride in pyridine at 90 °C. The chemical composition and the structure of CDSA were characterized by FT-IR, MALDI-TOF, X-ray diffraction pattern, potentiometric titration and TGA. Modified and native γ-cyclodextrin associate with fullerene (C₆₀) in DMF-toluene mixture resulting 1:1 CDSA:C₆₀ and CD:C₆₀ inclusion complexes. Aqueous solutions of native cyclodextrin, carboxyl-modified cyclodextrin and their inclusion complexes with C₆₀ were used as microgel solvent (or swelling agent) for controlled release application. The release of solutions was induced by shear stress and demonstrated using rheo-optical set-up.