Hollow mesoporous silica nanoparticles conjugated with pH-sensitive amphiphilic diblock polymer for controlled drug release

A pH-sensitive amphiphilic diblock polymer (poly(PDM-b-PEGMA)) was grafted from the surface of hollow mesoporous silica nanoparticles (HMS) via atom transfer radical polymerization (ATRP). The morphology of the obtained core-shell nanocomposites, HMS@poly(PDM-b-PEGMA), was determined by transmission electron microscopy (TEM) and scanning electron microscope (SEM). The nanocomposites could be used as drug carriers due to the excellent biocompatibility with a high drug loading efficiency as 80%. Furthermore, less than 10 wt.% of DOX was released from the nanocomposites in neutral condition. When the solution is adjusted to acidic, more than 80 wt.% of DOX was released. In addition, in vitro experiments with human hepatoma 7402 cells and L02 lung cancer cells demonstrated that the nanocomposites could be internalized by both kinds of cells effectively but only release drug in cancer cells. (C) 2011 Elsevier Inc. All rights reserved.