Fabrication of smart nanocontainers with a mesoporous core and a pH-responsive shell for controlled uptake and releaseElectronic supplementary information (ESI) available: Powder X-Ray diffraction patterns of MSN-OH, MSN-RAFT and MSN-PAA; 1H NMR spectra of MSN-PAA at pH 8.0 and 4.0; SEM image of MSN-PAA. See DOI: 10.1039/b820534e

A facile and versatile method to prepare mesoporous core-shell nanostructures with a reversibly switchable nanoshell is reported. Reversible addition-fragmentation chain transfer (RAFT) functionalities were anchored to the exterior surface of mesoporous silica nanoparticles (MSNs), forming RAFT agent coated MSNs. RAFT polymerization was then conducted to graft a poly(acrylic acid) (PAA) shell onto the exterior surface of MSNs, producing novel smart nanocontainers with a MSN as the container and a pH-responsive PAA nanoshell as a smart nanovalve. The PAA nanovalve can control the access of guest molecules to and from the MSN nanocontainer. This core-shell nanostructure should have potential applications in drug and gene delivery. [ABSTRACT FROM AUTHOR]