Acid-degradable core-crosslinked micelles prepared from thermosensitive glycopolymers synthesized via RAFT polymerization

A thermoresponsive block copolymer, namely poly(acryloyl glucosamine)-block-poly(N-isopropylacryamide) (PAGA180-b-PNIPAAM 350) was simultaneously self-assembled and crosslinked in aqueous medium via RAFT polymerization at 60°C to afford core-crosslinked micelles exhibiting a glycopolymer corona and a PNIPAAM stimuli-responsive core. An acid-labile crosslinking agent, 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]- undecane, was employed to generate thermosensitive and acid-degradable core-shell nanoparticles. Stable against degradation at pH = 6 and 8.2, the resulting core crosslinked micelles readily hydrolyzed into well-defined free block copolymers at lower pH (30 min and 12 h respectively at pH = 2 and 4). © 2008 WILEY-VCH Verlag GmbH & Co. KGaA