Synthesis, characterization, and in vivo targeted imaging of amine-functionalized rare-earth up-converting nanophosphors

• Published in: Biomaterials Vol. 30; no. 29; pp. 5592 - 5600
• Main Authors: Xiong, Li-Qin, Chen, Zhi-Gang, Yu, Meng-Xiao, Li, Fu-You, Liu, Chun, Huang, Chun-Hui
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.10.2009
• Subjects: Advanced Basic Science; Amine-functionalized; Amines - chemistry; Contrast Media - chemical synthesis; Dentistry; Emulsions - chemistry; HeLa Cells; Humans; In vivo imaging; Luminescent Measurements - methods; Metals, Rare Earth - chemistry; Microscopy, Fluorescence - methods; Modified hydrothermal microemulsion synthesis; Nanostructures - chemistry; Nanostructures - ultrastructure; Phosphorus; Rare-earth nanophosphors; Up-conversion luminescence; Amine-functionalized; Rare-earth nanophosphors; Up-conversion luminescence; Modified hydrothermal microemulsion synthesis; In vivo imaging
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/j.biomaterials.2009.06.015

Abstract 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) × 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.