1: J Magn Reson. 2009 Apr;197(2):176-80. Epub 2008 Dec 24. Nano-emulsions of fluorinated trityl radicals as sensors for EPR oximetry. Charlier N, Driesschaert B, Wauthoz N, Beghein N, Préat V, Amighi K, Marchand-Brynaert J, Gallez B. Université catholique de Louvain, Laboratory of Biomedical Magnetic Resonance, REMA, Brussels, Belgium. This article reports the development and evaluation of two nano-emulsions (F45T-03/HFB and F15T-03/PFOB) containing fluorinated trityl radicals dissolved in perfluorocarbons. Preparation with a high-pressure homogenizer conferred sub-micronic size to both nano-emulsions. In vitro and in vivo EPR spectroscopy showed that the nano-emulsions had much greater oxygen sensitivity than the hydrophilic trityl, CT-03. In vivo experiments in rodents confirmed the ability of the nano-emulsions to follow the changes in oxygen concentration after induced ischemia. Histological evaluation of the tissue injected with the nano-emulsions revealed some acute toxicity for the F45T-03/HFB nano-emulsion but none for the F15T-03/PFOB nano-emulsion. These new formulations should be considered for further EPR oximetry experiments in pathophysiological situations where subtle changes in tissue oxygenation are expected. PMID: 19128993 [PubMed - in process] Related Links Synthesis of two persistent fluorinated tetrathiatriarylmethyl (TAM) radicals for biomedical EPR applications. [Bioorg Med Chem Lett. 2008] PMID:18640034 Retrievable micro-inserts containing oxygen sensors for monitoring tissue oxygenation using EPR oximetry. [Physiol Meas. 2008] PMID:18843166 Esterified trityl radicals as intracellular oxygen probes. [Free Radic Biol Med. 2009] PMID:19135524 Carbon blacks as EPR sensors for localized measurements of tissue oxygenation. [Magn Reson Med. 2004] PMID:15170849 Increased bioavailability of a transdermal application of a nano-sized emulsion preparation. [Int J Pharm. 2008] PMID:17706902