In Vitro Cellular Uptake Studies of Self-Assembled Fluorinated Nanoparticles Labelled with Antibodies

Nanoparticles (NPs) functionalized with antibodies (Abs) on their surface are used in a wide range of bioapplications. Whereas the attachment of antibodies to single NPs to trigger the internalization in cells via receptor-mediated endocytosis has been widely studied, the conjugation of antibodies to larger NP assemblies has been much less explored. Taking into account that NP assemblies may be advantageous for some specific applications, the possibility of incorporating targeting ligands is quite important. Herein, we performed the effective conjugation of antibodies onto a fluorescent NP assembly, which consisted of fluorinated Quantum Dots (QD) self-assembled through fluorine–fluorine hydrophobic interactions. Cellular uptake studies by confocal microscopy and flow cytometry revealed that the NP assembly underwent the same uptake procedure as individual NPs; that is, the antibodies retained their targeting ability once attached to the nanoassembly, and the NP assembly preserved its intrinsic properties (i.e., fluorescence in the case of QD nanoassembly).This research was financially supported by the research core of TMU (Grant No: IG-39707) and the Biotechnology Development Council of the Islamic Republic of Iran (Grant No: 950709). Part of this work was funded by the Cluster of Excellence ‘Advanced Imaging of Matter’ of the Deutsche Forschungsgemeinschaft (DFG)-EXC 2056-project ID 390715994

Toward Diffusion Measurements of Colloidal Nanoparticles in Biological Environments by Nuclear Magnetic Resonance

Protein corona formation on the surface of nanoparticles (NPs) is observed in situ by measuring diffusion coefficients of the NPs under the presence of proteins with a F-19 nuclear magnetic resonance (NMR) based methodology. Formation of a protein corona reduces the diffusion coefficient of the NPs, based on an increase in their effective hydrodynamic radii. With this methodology it is demonstrated that the apparent dissociation constant of protein-NP complexes may vary over at least nine orders of magnitude for different types of proteins, in line with the Vroman effect. Using this methodology, the interaction between one type of protein and one type of nanoparticle can be studied quantitatively. Due to the NMR-based detection, this methodology has no interference by absorption/scattering effects, by which optical detection schemes are affected. By using the potential of the NMR chemical shift, the detection of multiple F-19 signals simultaneously opens the possibility to study the diffusion of several NPs at the same time. The F-19 labeling of the NPs has negligible effect on their acute toxicity and moderate effect on NPs uptake by cells.This work was supported by the Cluster of Excellence "Advanced Imaging of Matter" of the Deutsche Forschungsgemeinschaft (DFG) EXC 2056 - project ID 390715994, by the Basque Government (project IT1196-19) and by the Fundacion Biofisica Bizkaia and the Basque Excellence Research Centre (BERC) program of the Basque Government. This work was performed under the Maria de Maeztu Units of Excellence Programme-Grant No. MDM-2017-0720 Ministry of Science, Innovation and Universities. The help of Marta Gallego in the surface tension and TEM measurements is acknowledged. Parts of the ICP-MS measurements were done at the ICP-MS facility of CIC biomaGUNE by Javier Calvo

Fluorine Labeling of Nanoparticles and In Vivo 19F Magnetic Resonance Imaging

Fluorinated nanoparticles have increasing applications, but they are still challenging to prepare, especially in the case of water-soluble fluorinated nanoparticles. Herein, a fluorine labeling strategy is presented that is based on the conjugation of custom-made small fluorinated building blocks, obtained by simple synthetic transformations, with carboxylated gold nanoparticles through a convenient phase-transfer process. The synthesis of four fluorinated building blocks with different chemical shifts in 19F nuclear magnetic resonance and varied functionalities is reported, along with their conjugation onto nanoparticles. Fluorinated nanoparticles of small core size obtained by this conjugation methodology and by direct synthesis presented high transverse relaxation times (T2) ranging from 518 to 1030 ms, and a large number of equivalent fluorine atoms per nanoparticle (340-1260 fluorine atoms), which made them potential candidates for 19F magnetic resonance related applications. Finally, nontargeted fluorinated nanoparticles were probed by performing in vivo 19F magnetic resonance spectroscopy (19F MRS) in mice. Nanoparticles were detected at both 1 and 2 h after being injected. 19F MRI images were also acquired after either intravenous or subcutaneous injection. Their fate was studied by analyzing the gold content in tissues by ICP-MS. Thus, the present work provides a general fluorination strategy for nanoparticles and shows the potential use of small fluorinated nanoparticles in magnetic-resonance-related applicationsThis work was supported in part by grants from the Spanish State Research Agency (MCI/PID2019-107449RB-I00/AEI/10.13039/501100011033, RYC-2017-22412, and SAF2017-84494-C2-R), from the Fundación Biofísica Bizkaia, the Basque Excellence Research Centre (BERC) program, and projects IT1196-19 and Grant KK-2019/bmG19 of the Basque Government. We also thank the UE for funding (Nova MRI, H2020-MSCA-ITN-2018-811382). This work was performed under the Maria de Maeztu Units of Excellence Programme Grant MDM-2017-0720 ministry of Science, Innovation and Universities. The authors thank for technical and human support the Materials and Surfaces Service and the Central Analysis Service of Bizkaia provided by SGIker (UPV/EHU) and European funding (ERDF and ESF) for the XPS, TEM and ICP-AES analyses. The MRI service members of CIC biomaGUNE are also acknowledged for their support of the in vivo experiment

Espacios y destinos turísticos en tiempos de globalización y crisis

2 volúmenesXII Coloquio de Geografía del Turismo, Ocio y Recreación de la Asociación de Geógrafos Españoles. Colmenarejo (Madrid), del 17 al 19 de junio de 2010.Este libro ha sido editado con la colaboración económica del Ministerio de Ciencia e Innovación (ref. CS02010-10416-E)