Multifunctional Gene Carriers Labeled by Perylene Diimide Derivative as Fluorescent Probe for Tracking Gene Delivery

Multifunctional carriers with both gene transfection property and fluorescent tracking function have attracted significant attention in recent years. Herein, a kind of perylene diimide derivative (PDI-C10C8) is conjugated onto the polyethylenimine-g-poly(lactide-co-glycolide)-g-polyethylenimine (PLGA-PEI) polymer to obtain fluorescent multifunctional polymer and micelles (abbreviated as MP). Then, the REDV-G-TAT-G-NLS (TP-G) peptide sequence is grafted onto this MP to obtain multifunctional micelles labeled by perylene diimide derivative (MP-TP-G). These micelles exhibit enhanced photobleaching stability compared with the reference Cy5-labeled micelles, and the fluorescent images of cellular uptake show bright red emission without any background noise. Confocal laser scanning microscope (CLSM) experiments show that gene complexes can deliver gene into nucleus. MP-TP-G carriers do not enter into the cell nucleus, which proves that the nuclear localization signal sequence may not exert its nucleus accumulation ability via conjugating to the amphiphilic polymers. The high transfection efficiency and the enhanced photobleaching stability, combined with the ability to monitor the detailed process of cellular uptake and gene delivery, make these multifunctional micelles have great potential application for endothelialization of artificial blood vessels and gene delivery process study.