Preparation of polymer-coated mesoporous silica nanoparticles used for cellular imaging by a graft-from'' method

Multi-functional mesoporous silica nanoparticles (MSNs) coated with poly(N-isopropylacrylamide) (PNIPAM) composite nanomaterials have been designed and synthesized by atom transfer radical polymerization (ATRP) on the surface of MSN through the grafting-from'' approach. Such materials not only provide porous cores which can act as suitable reservoirs, but also possess thermosensitive polymer shells which can entrap hydrophilic guest molecules, like FITC, into the cores upon varying the temperature. The materials can easily carry guest molecules into human breast carcinoma cells (MCF-7) and show little cytotoxicity to the cells. It is demonstrated that such MSN@PNIPAM materials can be applied in biological systems for cellular imaging or as biosensors.