Hollow chitosan-silica nanospheres as pH-sensitive targeted delivery carriers in breast cancer therapy

Promising drug nanocarriers consisting of mono-dispersed and pH sensitive chitosan-silica hollow nanospheres (CS-SiO₂ HNPs) suitable for breast cancer therapy are produced and investigated. The SiO₂ HNPs are fabricated using a one-step, one-medium process which obviates the need for post-treatment to remove the templates, additional dissolution, or calcination. Taking advantage of the cross-linking reaction with (3-Glycidyloxypropyl) trimethoxysilane (GTPMS), cationic polysaccharide-chitosan decorates the surface and produces pH sensitive CS-SiO₂ HNPs. The materials enable controlled release of loaded drugs in pericellular and interstitial environments. In particular, the antibody molecule (to ErbB 2) can be conjugated onto the surface of the CS-SiO₂ HNPs thereby allowing the hollow nanospheres to serve as a targeted delivery agent to breast cancer cells. TNF-α are delivered to MCF-7 breast cancer cells under both in vitro and in vivo conditions to suppress the growth of cancerous cells and even kill them with high therapeutic efficacy. Owing to their hollow inner cavity and porous structures, the CS-SiO₂ HNPs are excellent pH-responsive targeted nanocarriers. © 2011 Elsevier Ltd.