title: Simultaneous synthesis and functionalization of water-soluble up-conversion nanoparticles for in-vitro cell and nude mouse imaging.
abstract: Water-solubility and biocompatibility are prerequisites for rare-earth up-converting nanophosphors applied to biological imaging. In this work, we have developed a facile and one-step synthesis technique, through which water-soluble NaYF(4): Yb(3+), Er(3+) nanoparticles (NPs) with functional groups including 3-mercaptopropionic acid, 6-aminocaproic acid and poly(ethylene glycol)methyl ether on their surface can be directly prepared without any further surface treatment. Some inorganic salts will be selected as starting materials, water and some low toxic organic agents have been used as reaction media, which differs from earlier works. Structural and up-converting fluorescence are characterized by a variety of techniques. Cell uptake and in-vitro imaging of the as-synthesized NPs have been investigated using a multiphoton con-focal laser scanning microscope with a near-infrared excitation source. Internalization of the bare and functionalized NPs in human lung carcinoma A549 and human cervical carcinoma HeLa cells are studied at a nanoparticle loading of 10 µg mL(-1) over an exposure period from 30 min to 24 h. The cytotoxicity of modified NPs in HeLa cells is found to be low. In addition, the feasibility of the NPs in animal imaging has been demonstrated by subcutaneously injecting these NPs into nude mouse. The results indicated that our directly synthesized NPs coated with various functional groups are promising as bio-imaging agents due to their easy uptake, long lasting, low cytotoxicity, emissive in various human carcinoma cell lines and small animals through up-conversion with near-infrared excitation.
authors: Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, PR China.
authors: Zhen-Ling
authors: ZL
authors: Wang
authors: Jianhua
authors: J
authors: Hao
authors: Helen L W
authors: HL
authors: Chan
authors: Ga-Lai
authors: GL
authors: Law
authors: Wing-Tak
authors: WT
authors: Wong
authors: Ka-Leung
authors: KL
authors: Wong
authors: Margaret B
authors: MB
authors: Murphy
authors: T
authors: T
authors: Su
authors: Z H
authors: ZH
authors: Zhang
authors: S Q
authors: SQ
authors: Zeng
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D009374:Neoplasms, Experimental / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012995:Solubility; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water