1: Physiol Meas. 2008 Oct 9;29(11):1247-1254. [Epub ahead of print] Retrievable micro-inserts containing oxygen sensors for monitoring tissue oxygenation using EPR oximetry. Dinguizli M, Beghein N, Gallez B. Tissue oxygenation is a crucial parameter in various physiopathological situations and can influence the therapeutic response of tumours. EPR oximetry is a reliable method for assessing and monitoring oxygen levels in vivo over long periods of time. Among the different paramagnetic oxygen sensors available for EPR oximetry, lithium phthalocyanine (LiPc) is a serious candidate for in vivo applications because of its narrow linewidth and its high signal-to-noise ratio. To enhance the biocompatibility of the sensors, fluoropolymer Teflon AF2400 was used to make cylindrical micro-inserts containing LiPc crystals. This new micro-pellet design has several advantages for in vivo studies, including the possibility of being able to choose the implant size, a high sensor content, the facility of in vivo insertion and complete protection with preservation of the oxygen sensor's characteristics. The response to oxygen and the kinetics of this response were tested using in vivo EPR: no differences were observed between micro-inserts and uncoated LiPc crystals. Pellets implanted in vivo in muscles conserved their responsiveness over a long period of time ( approximately two months), which is much longer than the few days of stability observed using LiPc crystals without protection by the implant. Finally, evaluation of the biocompatibility of the implants revealed no inflammatory reaction around the implantation area. PMID: 18843166 [PubMed - as supplied by publisher] Related Links Development and evaluation of biocompatible films of polytetrafluoroethylene polymers holding lithium phthalocyanine crystals for their use in EPR oximetry. [Biosens Bioelectron. 2006] PMID:16368480 Mechanism of oxygen-induced EPR line broadening in lithium phthalocyanine microcrystals. [J Magn Reson. 2004] PMID:15324756 Preparation and EPR studies of lithium phthalocyanine radical as an oxymetric probe. [Free Radic Biol Med. 1998] PMID:9655524 Effect of RSR13, an allosteric hemoglobin modifier, on oxygenation in murine tumors: an in vivo electron paramagnetic resonance oximetry and bold MRI study. [Int J Radiat Oncol Biol Phys. 2004] PMID:15183487 Microencapsulation of paramagnetic particles by pyrroxylin to preserve their responsiveness to oxygen when used as sensors for in vivo EPR oximetry. [Magn Reson Med. 1999] PMID:10398966