Smart Core−Shell Nanostructure with a Mesoporous Core and a Stimuli-Responsive Nanoshell Synthesized via Surface Reversible Addition−Fragmentation Chain Transfer Polymerization

A facile and versatile method to prepare mesoporous core−shell nanostructure with a stimuli-responsive nanoshell was reported. Reversible addition−fragmentation chain transfer (RAFT) functionalities were anchored to the mesoporous silica nanoparticle (MSN), and RAFT polymerization of N-isopropylacrylamide (NIPAAm) was subsequently conducted to graft thermo-sensitive PNIPAAm to the exterior surface of the MSN. The nanoshell undergoes reversible switches between solvated, incompact nanoshell and compact nanoshell upon changing the temperature of the solution, which makes this novel core−shell nanostructure highly attractive for controlled release of drugs, DNAs, and proteins.