Functionalized microgels with acid-cleavable hydrophobic pendant moiety for controlled drug release

Abstract

Thermosensitive microgels with acid cleavable pendant t -butoxycarbonyl (Boc) groups were prepared through precipitation copolymerization of N -isopropylacrylamide (NIPAAm) and N -( N -Boc-ethylenediamine) methacryloylglycylglycylamide (BEMAGG) with pendent Boc group. The physicochemical characteristics and the drug release behavior from the microgels were greatly influenced by the structural changes upon the removal of Boc groups in acid condition. The size, zeta potentials and the cloud point gradually increased with the acid-triggered removal of the pendant Boc groups from the microgels, which resulted in a much faster drug release of doxorubicin hydrochloride from these microgels in acid condition. These results indicated the great potentials of these functional microgels in the drug delivery systems.