Fabrication, biomolecular binding, in vitro drug release behavior of sugar-installed nanoparticles from star poly(ε-caprolactone)/glycopolymer biohybrid with a dendrimer core

Star poly(amido amine)-b-poly(epsilon-caprolactone)-b-poly(D-gluconamidoethyl methacrylate) (PAMAM-PCL-PGAMA) block copolymers with a dendrimer core were synthesized from the ring-opening polymerization of epsilon-caprolactone using a hydroxyl-terminated dendrimer poly(amido amine) initiator followed by the direct atom transfer radical polymerization of unprotected glycomonomer. The self-assembly and the biomolecular binding of PAMAM-PCL-PGAMA with Concanavalin A (Con A) were investigated by NMR, UV-vis, dynamic light scattering, and transmission electron microscopy, respectively. Multivalent sugar-installed vesicles and large compound aggregates were self-assembled from these dendritic copolymers in aqueous solution, demonstrating thermodynamically more stable than those self-assembled from linear counterpart. Moreover, these copolymers presented specific biomolecular binding with Con A lectin compared with bovine serum albumin, while both the lower mobility and the higher spatial hindrance within dendritic copolymers, to some extent, limited the clustering between sugar and Con A. Furthermore, these star copolymer nanoparticles showed a higher drug-loading efficiency and less burst release compared with linear counterpart. This work provides a method not only for the synthesis of star PCL/glycopolymer biohybrid with a dendrimer core but also for the fabrication of sugar-installed nanoparticles with tunable clustering ability, good drug-loading efficiency, and controlled drug-release profile useful for targeted drug delivery system. (C) 2009 Elsevier Ltd. All rights reserved.