Development of biocompatible oxygen-permeable films holding paramagnetic carbon particles: Evaluation of their performance and stability in EPR oximetry

✍ Scribed by Jiang He; Nelson Beghein; Paul Ceroke; R.B. Clarkson; Harold M. Swartz; Bernard Gallez

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 127 KB
• Volume: 46
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1234

✦ Synopsis

Abstract

EPR oximetry using paramagnetic particles relies on the measurement of the EPR linewidth, which is directly related to the pO~2~. It was previously found that some of the paramagnetic materials with optimal EPR spectroscopic properties in vitro may lose their responsiveness to oxygen in tissues (change of the calibration curve of the EPR linewidth as a function of the pO~2~). We hypothesized that coating paramagnetic particle materials could improve the stability of response, as well as the biocompatibility. In this study, very thin films holding paramagnetic materials were prepared with different biopolymers (cellulose acetate, cellulose triacetate, cellulose nitrate, silicone, and polyurethane) that already are accepted for clinical applications. Their performance was evaluated in EPR oximetry by measuring the stability of the calibration curves (EPR linewidth as a function of pO~2~) after a prolonged period in an aqueous environment
(1 week in saline) or in vivo (implantation for 3 weeks under the skin of mice). We found that one type of silicone film was able to stabilize the responsiveness of an intrinsically unstable carbon material (a wood char). Magn Reson Med 46:610–614, 2001. © 2001 Wiley‐Liss, Inc.