title: Ligand-free gadolinium oxide for in vivo T1-weighted magnetic resonance imaging.
abstract: Gadolinium oxide (Gd2O3), which can be used as a T1-weighted magnetic resonance imaging (MRI) contrast agent, has attracted intense attention in recent years. In this paper, ligand-free monoclinic Gd2O3 nanocrystals of 7.1 nm in diameter are synthesized by a simple and green approach, namely microsecond laser ablation of a gadolinium (Gd) target in deionized water. These nanocrystals obtain high r1 relaxivity of 5.53 s(-1) mM(-1), and their low toxicity was demonstrated by the cell viability of S18 cells and apoptosis in RAW264.7 cells. In vitro and in vivo MR images show these particles to be good T1-weighted MRI contrast agents. Base on the experimental results and theoretical analysis, we suggest that the purity of the Gd2O3 contributes to its high r1 relaxivity value, while the low toxicity is due to its good crystallinity. These findings show that laser ablation in liquid (LAL) is a promising strategy to synthesize ligand-free monoclinic Gd2O3 nanocrystals for use as high efficient T1-weighted MRI contrast agents.
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics & Engineering, Sun Yat-sen University, Guangzhou 510275, PR China.
authors.forename: Ningqi
authors.initials: N
authors.lastname: Luo
authors.forename: Xiumei
authors.initials: X
authors.lastname: Tian
authors.forename: Chuan
authors.initials: C
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Xiao
authors.forename: Wenyong
authors.initials: W
authors.lastname: Hu
authors.forename: Dihu
authors.initials: D
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Li
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002277:Carcinoma; D002460:Cell Line; D003287:Contrast Media / Q000737:chemistry / Q000633:toxicity; D005682:Gadolinium / Q000737:chemistry*; D006801:Humans; D008279:Magnetic Resonance Imaging; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity; D051379:Mice; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging; D011859:Radiography; D014183:Transplantation, Heterologous
chemical_list: D003287:Contrast Media; C030581:gadolinium oxide; D005682:Gadolinium