1. Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2‐3‐10, Kanda‐surugadai, Chiyoda‐ku, Tokyo 101‐0062, Japan;2. Global Center of Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, Tokyo, Japan. Fax +81‐3‐5280‐8067
Abstract:
Highly branched cyclic dextrin derivatives (CH‐CDex) that are partly substituted with cholesterol groups have been synthesized. The CH‐CDex forms monodisperse and stable nanogels with a hydrodynamic radii of ≈10 nm by the self‐assembly of 4–6 CH‐CDex macromolecules in water. The CH‐CDex nanogels spontaneously trap 10–16 molecules of fluorescein isothiocyanate‐labeled insulin (FITC‐Ins). The complex shows high colloidal stability: no dissociation of trapped insulin is observed after at least 1 month in phosphate buffer (0.1 M , pH 8.0). In the presence of bovine serum albumin (BSA, 50 mg · mL?1), which is a model blood system, the FITC‐Ins trapped in the nanogels is continuously released (≈20% at 12 h) without burst release. The high‐density nanogel structure derived from the highly branched CDex significantly affects the stability of the nanogel–protein complex.
