title: Dual-modal upconversion fluorescent/X-ray imaging using ligand-free hexagonal phase NaLuF4:Gd/Yb/Er nanorods for blood vessel visualization.
abstract: Visualization of blood vessel of lung can improve the detection of the lung and pulmonary vascular diseases. However, research on visualization of blood vessel of lung using the new generation upconversion nanoprobes is still scarce. Herein, high quality hexagonal phase NaLuF4:Gd/Yb/Er nanorods were synthesized by a simple hydrothermal method through doping Gd(3+). Doping Gd can not only promote the phase transformation from cubic to hexagonal and the shape evolution from microtube to rod-like, but also provide an additional magnetic properties for biomedical application. The as-prepared nanorods were further converted to water solubility by treating with HCl for eliminating the capped oleic acid. The ligand-free nanorods were successfully used for high-contrast upconversion fluorescent bioimaging of HeLa cells. Moreover, the in vivo synergistic upconversion fluorescent and X-ray imaging of nude mice were demonstrated by subcutaneously and intravenously administrated the ligand-free nanorods. The X-ray signals were matched well with the upconversion signal, indicating the successfully synergistic bioimaging. The ex-vivo X-ray and upconversion fluorescent imaging of various organs revealed that the nanorods were mainly accumulated in liver and lung. More importantly, the blood vessel of the lung can be readily visualized when these ligand-free nanorods are intravenously injected. Apart from the synergistic X-ray and upconversion bioimaging, the ligand-free nanorods can also possess excellent paramagnetic property for potential magnetic resonance imaging contrast agent. Our results have demonstrated the enhanced visualization of blood vessel of lung performed by dual-modal bioimaging of X-ray and upconversion fluorescence, revealing the great promise of these nanoprobes in angiography imaging. Such a new technique enables the integration of the two bioimaging techniques by combining their collective strengths and minimizing their shortcomings.
authors.affiliation: College of Physics and Information Science and Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of the Ministry of Education, Hunan Normal University, Changsha, Hunan, China. Electronic address: songjunz@hunnu.edu.cn.
authors.forename: Songjun
authors.initials: S
authors.lastname: Zeng
authors.affiliation: Faculty of Materials, Optoelectronics and Physics, Key Laboratory of Low-dimensional Materials and Application Technology (Ministry of Education), Xiangtan University, Xiangtan 411105, People's Republic of China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong.
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.affiliation: Faculty of Materials, Optoelectronics and Physics, Key Laboratory of Low-dimensional Materials and Application Technology (Ministry of Education), Xiangtan University, Xiangtan 411105, People's Republic of China.
authors.forename: Zhigao
authors.initials: Z
authors.lastname: Yi
authors.affiliation: Faculty of Materials, Optoelectronics and Physics, Key Laboratory of Low-dimensional Materials and Application Technology (Ministry of Education), Xiangtan University, Xiangtan 411105, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Rao
authors.affiliation: College of Physics and Information Science and Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of the Ministry of Education, Hunan Normal University, Changsha, Hunan, China.
authors.forename: Hongrong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong. Electronic address: jh.hao@polyu.edu.hk.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Hao
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000033:anatomy & histology*; D003952:Diagnostic Imaging / Q000379:methods*; D004871:Erbium; D005453:Fluorescence; D005459:Fluorides; D005682:Gadolinium; D006367:HeLa Cells; D006801:Humans; D007275:Injections, Intravenous; D008024:Ligands; D008168:Lung / Q000098:blood supply; D008187:Lutetium; D060328:Magnetic Phenomena; D051379:Mice; D008819:Mice, Nude; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D061848:Optical Imaging / Q000379:methods*; D009928:Organ Specificity; D010316:Particle Size; D014965:X-Rays; D015018:Ytterbium
chemical_list: D008024:Ligands; D008187:Lutetium; D004871:Erbium; D005682:Gadolinium; D015018:Ytterbium; D005459:Fluorides
keywords: Enhanced visualization of blood vessel; Multi-modal nanoprobes; Synergistic X-ray and upconversion fluorescent bioimaging; Upconversion nanorods