NIR-to-visible upconversion nanoparticles for fluorescent labeling and targeted delivery of siRNA

• Published in: Nanotechnology Vol. 20; no. 15; p. 155101
• Main Authors: Jiang, Shan, Zhang, Yong, Lim, Kian Meng, Sim, Eugene K W, Ye, Lei
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 15.04.2009
• Subjects: Cell Line, Tumor; Fluorescence; Folic Acid - metabolism; Humans; Microscopy, Confocal; Nanoparticles - chemistry; RNA, Small Interfering - metabolism; Staining and Labeling - methods
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/20/15/155101

Near-infrared (NIR)-to-visible upconversion fluorescent nanoparticles were synthesized and used for imaging and targeted delivery of small interfering RNA (siRNA) to cancer cells. Silica-coated NaYF(4) upconversion nanoparticles (UCNs) co-doped with lanthanide ions (Yb/Er) were synthesized. Folic acid and anti-Her2 antibody conjugated UCNs were used to fluorescently label the folate receptors of HT-29 cells and Her2 receptors of SK-BR-3 cells, respectively. The intracellular uptake of the folic acid and antibody conjugated UCNs was visualized using a confocal fluorescence microscope equipped with an NIR laser. siRNA was attached to anti-Her2 antibody conjugated UCNs and the delivery of these nanoparticles to SK-BR-3 cells was studied. Meanwhile, a luciferase assay was established to confirm the gene silencing effect of siRNA. Upconversion nanoparticles can serve as a fluorescent probe and delivery system for simultaneous imaging and delivery of biological molecules.