title: Luminescence Enhanced Eu(3+)/Gd(3+) Co-Doped Hydroxyapatite Nanocrystals as Imaging Agents In Vitro and In Vivo.
abstract: Biocompatible, biodegradable, and luminescent nano material can be used as an alternative bioimaging agent for early cancer diagnosis, which is crucial to achieve successful treatment. Hydroxyapatite (HAP) nanocyrstals have good biocompatibility and biodegradability, and can be used as an excellent host for luminescent rare earth elements. In this study, based on the energy transfer from Gd(3+) to Eu(3+), the luminescence enhanced imaging agent of Eu/Gd codoping HAP (HAP:Eu/Gd) nanocrystals are obtained via coprecipitation with plate-like shape and no change in crystal phase composition. The luminescence can be much elevated (up to about 120%) with a nonlinear increase versus Gd doping content, which is due to the energy transfer ((6)PJ of Gd(3+) → (5)HJ of Eu(3+)) under 273 nm and the possible combination effect of the cooperative upconversion and the successive energy transfer under 394 nm, respectively. Results demonstrate that the biocompatible HAP:Eu/Gd nanocrystals can successfully perform cell labeling and in vivo imaging. The intracellular HAP:Eu/Gd nanocrystals display good biodegradability with a cumulative degradation of about 65% after 72 h. This biocompatible, biodegradable, and luminescence enhanced HAP:Eu/Gd nanocrystal has the potential to act as a fluorescent imaging agent in vitro and in vivo.
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Wangmei
authors.initials: W
authors.lastname: He
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Faculty of Applied Sciences, Sabaragamuwa University of Sri Lanka , 70140 Belihuloya, Sri Lanka.
authors.forename: Thalagalage Shalika Harshani
authors.initials: TS
authors.lastname: Perera
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Gan
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Han
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Shipu
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, P. R. China.|Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology , Wuhan 430070, P. R. China.
authors.forename: Honglian
authors.initials: H
authors.lastname: Dai
mesh_terms: D002470:Cell Survival; D017886:Durapatite; D005063:Europium; D005682:Gadolinium; D006801:Humans; D049449:Luminescence; D053768:Metal Nanoparticles
chemical_list: D005063:Europium; D017886:Durapatite; D005682:Gadolinium
keywords: Eu/Gd codoping; hydroxyapatite; imaging; intracellular degradation; luminescence enhancement; nanocrystals; tissue distribution