title: Transport of NaYF4:Er3+, Yb3+ up-converting nanoparticles into HeLa cells.
abstract: An effective, simple and practically useful method to incorporate fluorescent nanoparticles inside live biological cells was developed. The internalization time and concentration dependence of a frequently used liposomal transfection factor (Lipofectamine 2000) was studied. A user friendly, one-step technique to obtain water and organic solvent soluble Er(3+) and Yb(3+) doped NaYF4 nanoparticles coated with polyvinylpyrrolidone was obtained. Structural analysis of the nanoparticles confirmed the formation of nanocrystals of the desired sizes and spectral properties. The internalization of NaYF4 nanoparticles in HeLa cervical cancer cells was determined at different nanoparticle concentrations and for incubation periods from 3 to 24 h. The images revealed a redistribution of nanoparticles inside the cell, which increases with incubation time and concentration levels, and depends on the presence of the transfection factor. The study identifies, for the first time, factors responsible for an effective endocytosis of the up-converting nanoparticles to HeLa cells. Thus, the method could be applied to investigate a wide range of future 'smart' theranostic agents. Nanoparticles incorporated into the liposomes appear to be very promising fluorescent probes for imaging real-time cellular dynamics.
authors.affiliation: Institute of Physics, Polish Academy of Sciences, aleja Lotników 32/46, 02-668 Warsaw, Poland. sikorab@ifpan.edu.pl
authors.forename: Bożena
authors.initials: B
authors.lastname: Sikora
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Fronc
authors.forename: Izabela
authors.initials: I
authors.lastname: Kamińska
authors.forename: Kamil
authors.initials: K
authors.lastname: Koper
authors.forename: Sebastian
authors.initials: S
authors.lastname: Szewczyk
authors.forename: Bohdan
authors.initials: B
authors.lastname: Paterczyk
authors.forename: Tomasz
authors.initials: T
authors.lastname: Wojciechowski
authors.forename: Kamil
authors.initials: K
authors.lastname: Sobczak
authors.forename: Roman
authors.initials: R
authors.lastname: Minikayev
authors.forename: Wojciech
authors.initials: W
authors.lastname: Paszkowicz
authors.forename: Piotr
authors.initials: P
authors.lastname: Stępień
authors.forename: Danek
authors.initials: D
authors.lastname: Elbaum
mesh_terms: D004705:Endocytosis; D004871:Erbium / Q000378:metabolism*; D005459:Fluorides / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D049449:Luminescence; D018613:Microscopy, Confocal; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling; D014961:X-Ray Diffraction; D015018:Ytterbium / Q000378:metabolism*; D015019:Yttrium / Q000378:metabolism*
chemical_list: C525362:sodium yttriumtetrafluoride; D015019:Yttrium; D004871:Erbium; D015018:Ytterbium; D005459:Fluorides