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]

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