Polycation-functionalized gold nanodots with tunable near-infrared fluorescence for simultaneous gene delivery and cell imaging
near-infrared fluorescent material, Au nanodot, tunable fluorescence, gene delivery, bioimaging
ABSTRACT Near-infrared (NIR) fluorescent metal nanodots may have significant advantages in biological detection and bioimaging. Herein, we introduce tunable near-infrared fluorescent gold nanodots (AuNDs) protected by branched polyethylenimine (PEI) modified by surface segmental attachment of sulfhydryl groups (PEI-SH), abbreviated as PEI-SH-AuNDs, for simultaneous gene delivery and cell imaging. The modified PEI endows the resultant PEI-SH-AuNDs with the following excellent advantages. Sulfhydryl groups of PEI-SH anchor to the surface of AuNDs, and such polycations with amine groups give PEI-SH-AuNDs remarkable stability. The cationic polymer PEI-SH with positive charges enables PEI-SH-AuNDs to perform gene delivery, and the gene transfection efficiency can reach 22.8%. Moreover, the fluorescence of PEI-SH-AuNDs is tunable from visible red light (wavelength 609 nm) to NIR light (wavelength 811 nm) via an increase in the size of AuNDs. PEI-SH-AuNDs yielded gene transfection efficiency similar to that of commercial PEI, but showed much lower cytotoxicity and much greater red-shift fluorescence. With excellent photoluminescent properties, such multifunctional fluorescent PEI-SH-AuNDs hold promise in applications to bioimaging and as ideal fluorescent probes for tracking gene transfection behavior.
Tsinghua University Press
Yuanqing Sun,Dandan Wang,Yueqi Zhao,Tianxin Zhao,Hongchen Sun,Xiangwei Li,Chuanxi Wang,Bai Yang,Quan Lin, Polycation-functionalized gold nanodots with tunable near-infrared fluorescence for simultaneous gene delivery and cell imaging. NanoRes.2018, 11(5): 2392–2404