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) (PAGA(180)-b-PNIPAAM(350))was simultaneously self-assembled and cross-linked in aqueous medium via RAFT polymerization at 60 degrees 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 crosslinked micelles readily hydrolyzed block copolymers at lower pH (30 min and 12 h respectively pH = 2 and 4).