Supramolecular proteoglycan aggregate mimics: cyclodextrin-assisted biodegradable polymer assemblies for...

Self-assembled, noncovalent polymeric biodegradable materials mimicking proteoglycan aggregates were synthesized from inclusion complexes of cationic surfactants with γ-cyclodextrin and the natural anionic polymer hyaluronan. The amorphous structure of this ternary system was proven by X-ray diffraction and thermal analysis. Light-scattering measurements showed that there was a competition between hyaluronic acid and the surfactant for the cyclodextrin cavity. These self-assembled supramolecular matrices were loaded with both hydrophilic and lipophilic drug substances for dissolution studies. The release of the entrapped drugs was found to be controlled by cations in the surrounding media and by biodegradation. Slow drug release in an ion-free medium became faster in physiological salt solution in which the macroscopic polymer matrix was disassembled. In contrast, the enzymatic degradation of hyaluronan was hindered in the polymeric matrix. The supramolecular systems consisting of γ-cyclodextrin as a macrocyclic host, a cationic surfactant guest, and hyaluronic acid as the anionic polymer electrostatically cross-linked by the inclusion complex of the first two was found to be a novel drug-delivery system for the controlled release of traditional drugs such as curcumin and ketotifen and proteins such as bovine serum albumin.