- Intracellular pH measurements using perfluorocarbon nanoemulsions
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We report the synthesis and formulation of unique perfluorocarbon (PFC) nanoemulsions enabling intracellular pH measurements in living cells via fluorescent microscopy and flow cytometry. These nanoemulsions are formulated to readily enter cells upon coincubation and contain two cyanine-based fluorescent reporters covalently bound to the PFC molecules, specifically Cy3-PFC and CypHer5-PFC conjugates. The spectral and pH-sensing properties of the nanoemulsions were characterized in vitro and showed the unaltered spectral behavior of dyes after formulation. In rat 9L glioma cells loaded with nanoemulsion, the local pH of nanoemulsions was longitudinally quantified using optical microscopy and flow cytometry and displayed a steady decrease in pH to a level of 5.5 over 3 h, indicating rapid uptake of nanoemulsion to acidic compartments. Overall, these reagents enable real-time optical detection of intracellular pH in living cells in response to pharmacological manipulations. Moreover, recent approaches for in vivo cell tracking using magnetic resonance imaging (MRI) employ intracellular PFC nanoemulsion probes to track cells using 19F MRI. However, the intracellular fate of these imaging probes is poorly understood. The pH-sensing nanoemulsions allow the study of the fate of the PFC tracer inside the labeled cell, which is important for understanding the PFC cell loading dynamics, nanoemulsion stability and cell viability over time.
- Patrick, Michael J.,Janjic, Jelena M.,Teng, Haibing,O'Hear, Meredith R.,Brown, Cortlyn W.,Stokum, Jesse A.,Schmidt, Brigitte F.,Ahrens, Eric T.,Waggoner, Alan S.
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supporting information
p. 18445 - 18457
(2014/01/06)
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- A universal and ready-to-use heterotrifunctional cross-linking reagent for facile synthetic access to sophisticated bioconjugates
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We describe for the first time, the synthesis and some bioconjugation applications of an original heterotrifunctional cross-linking reagent (also named tripod) bearing three different bioorthogonal functional groups which are fully compatible amongst themselves. Contrary to the first generation tripod recently reported by us (Org. Biomol. Chem., 2008, 6, 3065), the use of an azido group instead of the nucleophile-sensitive active carbamate moiety enables us to reach the targeted chemical orthogonality without the use of temporary aminooxy- and thiol protecting groups. Thus, the preparation of sophisticated bioconjugates through the sequential derivatisation of the tripod by means of copper-mediated 1,3-dipolar cycloaddition, oxime ligation and aqueous compatible mild thiol-alkylation reactions, is significantly simpler and more convenient. The chemoselective bioconjugation protocols were optimised through the preparation of FRET cassettes based on cyanine and/or xanthene fluorescent dye pairs and subsequent anchoring to fragile biomolecules. The applicability of this universal cross-linking reagent was also illustrated by the preparation of biochips suitable for aflatoxin B1 detection through the SPIT-FRI method.
- Clave, Guillaume,Volland, Herve,Flaender, Melanie,Gasparutto, Didier,Romieu, Anthony,Renard, Pierre-Yves
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experimental part
p. 4329 - 4345
(2010/11/18)
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- Aryldithioethyloxycarbonyl (Ardec): A new family of amine protecting groups removable under Mild reducing conditions and their applications to peptide synthesis
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The development of phenyl-dithioethyloxycarbonyl (Phdec) and 2-pyridyldithioethyloxycarbonyl (Pydec) protecting groups, which are thiollabile urethanes, is described. These new disulfide-based protecting groups were introduced onto the ε-amino group of L-
- Lapeyre, Milaine,Leprince, Jerome,Massonneau, Marc,Oulyadi, Hassan,Renard, Pierre-Yves,Romieu, Anthony,Turcatti, Gerardo,Vaudry, Hubert
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p. 3655 - 3671
(2008/02/05)
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