@article {RADCHENKO2016280,
	title = {Labeling and preliminary in vivo assessment of niobium-labeled radioactive species: A proof-of-concept study},
	journal = {Nuclear Medicine and Biology},
	volume = {43},
	number = {5},
	year = {2016},
	pages = {280 - 287},
	abstract = {The application of radionuclide-labeled biomolecules such as monoclonal antibodies or antibody fragments for imaging purposes is called immunoscintigraphy. More specifically, when the nuclides used are positron emitters, such as zirconium-89, the technique is referred to as immuno-PET. Currently, there is an urgent need for radionuclides with a half-life which correlates well with the biological kinetics of the biomolecules under question and which can be attached to the proteins by robust labeling chemistry. 90Nb is a promising candidate for in vivo immuno-PET, due its half-life of 14.6h and low β+ energy of Emean=0.35MeV per decay. 95Nb on the other hand, is a convenient alternative for longer-term ex vivo biodistribution studies, due to its longer half-life of (t{\textonehalf}=35days) and its convenient, lower-cost production (reactor-based production). In this proof-of-principle work, the monoclonal antibody bevacizumab (Avastin{\textregistered}) was labeled with 95/90Nb and in vitro and in vivo stability was evaluated in normal Swiss mice and in tumor-bearing SCID mice. Initial ex vivo experiments with 95Nb-bevacizumab showed adequate tumor uptake, however at the same time high uptake in the liver, spleen and kidneys was observed. In order to investigate whether this behavior is due to instability of ⁎Nb-bevacizumab or to the creation of other ⁎Nb species in vivo, we performed biodistribution studies of 95Nb-oxalate, 95Nb-chloride and 95Nb-Df. These potential metabolite species did not show any specific uptake, apart from bone accumulation for 95Nb-oxalate and 95Nb-chloride, which, interestingly, may serve as an {\textquotedblleft}indicator{\textquotedblright} for the release of 90Nb from labeled biomolecules. Concerning the initial uptake of 95Nb-bevacizumab in non-tumor tissue, biodistribution of a higher specific activity radiolabeled antibody sample did show only negligible uptake in the liver, spleen, kidneys or bones. In-vivo imaging of a tumor-bearing SCID mouse after injection with 90Nb-bevacizumab was acquired on an experimental small-animal PET camera, and indeed showed localization of the radiotracer in the tumor area. It is the first time that such results are described in the literature, and indicates promise of application of 90Nb-labeled antibodies for the purposes of immuno-PET.},
	keywords = {Bevacizumab, BIODISTRIBUTION, Labeling, Nb, PET imaging, VEGFR},
	issn = {0969-8051},
	doi = {https://doi.org/10.1016/j.nucmedbio.2016.02.003},
	url = {http://www.sciencedirect.com/science/article/pii/S0969805115300627},
	author = {Valery Radchenko and Penelope Bouziotis and Theodoros Tsotakos and Mari Paravatou-Petsotas and Ana de la Fuente and George Loudos and Adrian L. Harris and Stavros Xanthopoulos and Dmitry Filosofov and Harald Hauser and Michael Eisenhut and Bernard Ponsard and Frank Roesch}
}
@article {POC:POC3403,
	title = {Designing kinetically stable aryltrifluoroborates as 18F-capture agents for PET imaging},
	journal = {Journal of Physical Organic Chemistry},
	volume = {28},
	number = {3},
	year = {2015},
	pages = {210{\textendash}214},
	abstract = {One-step 18F-radiolabeling of peptides and other large biomolecules has been challenged by a critical gap in chemical compatibility between fluoride anion, which is unreactive as a nucleophile in water, and large biomolecules such as peptides that are insoluble in dry solvents. Traditionally, this disparity has been overcome through the preliminary synthesis of an 18F-labeled radioprosthetic group that is appended to peptides following at least one additional step. Ideally, however, peptides should be labeled in a single aqueous step. Hence, we proposed the use of arylboronic acids as captors of aqueous 18F-fluoride ion to simplify the radiosynthesis of 18F-aryltrifluoroborate bioconjugates. Yet, the use of aryltrifluoroborates as radioprosthetic groups can only be considered if kinetically stable ones can be designed. Herein, we discuss the kinetic and thermodynamic parameters review our previous use of a Hammett analysis that can inform the design of kinetically stable~18F-labeled aryltrifluoroborates for use as novel radioprosthetic groups. Copyright {\textcopyright} 2014 John Wiley \& Sons, Ltd.},
	keywords = {aryltrifluoroborate, FLUORIDE, hammett, PET imaging, solvolysis},
	issn = {1099-1395},
	doi = {10.1002/poc.3403},
	url = {http://dx.doi.org/10.1002/poc.3403},
	author = {Liu, Zhibo and Li, Ying and Ting, Richard and Perrin, David M.}
}
@article {ANIE:ANIE201406258,
	title = {An Organotrifluoroborate for Broadly Applicable One-Step 18F-Labeling},
	journal = {Angewandte Chemie International Edition},
	volume = {53},
	number = {44},
	year = {2014},
	pages = {11876{\textendash}11880},
	publisher = {WILEY-VCH Verlag},
	abstract = {A new zwitterionic organotrifluoroborate is appended to three radiosynthons that afford undergo facile bioconjugation to several clinically relevant peptides and one enzyme inhibitor. Molecularly complex bioconjugates are 18F-labeled in a single aqueous step in rapid time (<15 min) without HPLC purification to afford tracers in good yields (>200 mCi, 20{\textendash}40 \%) at high specific activity (>=3 Ci/μmol) and at >98 \% purity. PET imaging shows in vivo stability and tumor uptake.},
	keywords = {18F-labeling, bioconjugation, click chemistry, PEPTIDES, PET imaging},
	issn = {1521-3773},
	doi = {10.1002/anie.201406258},
	url = {http://dx.doi.org/10.1002/anie.201406258},
	author = {Liu, Zhibo and Pourghiasian, Maral and Radtke, Mark Alex and Lau, Joseph and Pan, Jinhe and Dias, Gemma M. and Yapp, Donald and Lin, Kuo-Shyan and B{\'e}nard, Francois and Perrin, David M.}
}
@article {2501,
	title = {Hydrolytic stability of nitrogenous-heteroaryltrifluoroborates under aqueous conditions at near neutral pH},
	journal = {Journal of Fluorine Chemistry},
	volume = {130},
	number = {4},
	year = {2009},
	note = {ISI Document Delivery No.: 434ZRTimes Cited: 4Cited Reference Count: 16Li, Ying Asadi, Ali Perrin, David M.},
	month = {Apr},
	pages = {377-382},
	type = {Article},
	abstract = {The hydrolytic stability of heteroaryltrifluoroborates under physiological conditions has been analyzed by F-19 NMR spectroscopy and is found to be greatly enhanced by the presence of endocyclic ring nitrogens. Stability is further enhanced by the presence of exocyclic electron withdrawing substituents. As with aryltrifluoroborates, NMR analysis suggests that the hydrolysis proceeds via single rate-determining step reflecting loss of the first fluoride atom. The stability of these complexes is significant both in terms of metal catalyzed cross-coupling reactions as well as the potential for generating boronic acid based F-18-PET imaging agents. (C) 2008 Elsevier B.V. All rights reserved.},
	keywords = {aryltrifluoroborate, CROSS-COUPLING REACTIONS, F-19 NMR, Heteroaryltrifluoroborates, Hydrolytic stability, PET, PET imaging, POTASSIUM ARYL, SALTS},
	isbn = {0022-1139},
	url = {<Go to ISI>://000265313400001},
	author = {Li, Y. and Asadi, A. and Perrin,David M.}
}
