Glutathione-Sensitive Silicon Nanowire Arrays for Gene Transfection.

Ingenious surface modification strategies and special topological morphologies endow the biomaterial interface with excellent ability to regulate the cell fate. In this work, a gene delivery platform based on glutathione-sensitive silicon nanowire arrays (SiNWAs) is developed, exhibiting good transfection efficiency of several cell types. Briefly, the surface of SiNWAs is grafted of PEI, a branched cationic polymer cross-linked by disulfide bonds (SN-PEI). When the cells adhere to the platform surface, silicon nanowires penetrate into the cells and the high concentration of reduced glutathione (GSH) in cytoplasm breaks the disulfide bonds (S-S) in PEI The plasmid DNA preloaded on the cationic polymers is successfully delivered to the nuclei through the nonlysosomal pathway. Cells harvested from the SN-PEI show high retention of viability and the platform surface can be reused though S-S replacement for at least three times. In general, our platform is a creative combination of intracellular responsive strategy and surface morphology, which has great potential for auxiliary use in ex vivo cell-based therapies and various biomedical applications.