Synthesis, characterization, and in vivo targeted imaging of amine-functionalized rare-earth up-converting nanophosphors.
Rare-earth up-converting nanophosphors (UCNPs) have great potential to become a new generation of biological luminescent labels, but their use has been limited by difficulties in obtaining water-soluble UCNPs bearing appropriate functional groups. To address this problem, we report herein a simple and efficient procedure for the preparation of amine-functionalized UCNPs by a modified hydrothermal microemulsion route assisted with 6-aminohexanoic acid. The amine content of the resultant UCNPs has been determined to be (9.5+/-0.8) x 10(-5) mol/g, which not only confers excellent dispersibility in aqueous solution, but also allows further conjugation with targeted molecules such as folic acid (FA) as a ligand. By means of the laser scanning up-conversion luminescence microscopy (LSUCLM) and the in vivo up-conversion luminescence (UCL) imaging under excitation at the CW infrared laser at 980 nm, FA-coupled UCNPs have been demonstrated to be effective in targeting folate-receptor overexpressing HeLa cells in vitro and HeLa tumor in vivo and ex vivo. These results indicated that our UCNPs could be used as whole-body targeted UCL imaging agents.
Xiong
Li-Qin
LQ
Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China.
Chen
Zhi-Gang
ZG
Yu
Meng-Xiao
MX
Li
Fu-You
FY
Liu
Chun
C
Huang
Chun-Hui
CH
D000588:Amines / Q000737:chemistry; D003287:Contrast Media / Q000138:chemical synthesis*; D004655:Emulsions / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods*; D008674:Metals, Rare Earth / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010758:Phosphorus
D000588:Amines; D003287:Contrast Media; D004655:Emulsions; D008674:Metals, Rare Earth; D010758:Phosphorus