TI: Development of biocompatible oxygen-permeable films
holding paramagnetic carbon particles: evaluation of their performance
and stability in EPR oximetry.
AU: He,-J; Beghein,-N; Ceroke,-P; Clarkson,-R-B; Swartz,-H-M;
Gallez,-B
AD: Laboratory of Medicinal Chemistry and Radiopharmacy, Universite
Catholique de Louvain, Brussels, Belgium.
SO: Magn-Reson-Med. 2001 Sep; 46(3): 610-4
JN: Magnetic-resonance-in-medicine
PY: 2001
AB: EPR oximetry using paramagnetic particles relies on the measurement
of the EPR linewidth, which is directly related to the pO2. 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 pO2). 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
pO2) 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). Copyright 2001
Wiley-Liss, Inc.