The purpose of the present paper is to describe p ossibilities and limitations for the determination of the rates of rotational diffusion and Heisenberg spin exchange, obtained from eontinuous-wave electron spin resonance (cw ESR) and ESR tomographic experiments. Model systems including nitroxides as paramagnetic reporter molecules have been examined in order to verify data, which have been obtained from cw ESR and ESR tomography. This has been done with particular emphasis on checking the influence of concentration, temperature, and viscosity on the spectral-spatial properties. These findings have been applied to the evaluation of penetration and permeation studies on human skin, The extracted full spectral information from ESR tomography allows the determination of the above mentioned dynamic parameters for model systems of definite geometry and for samples of human skin. It has been found that the signal-to-noise ratio is critical for all discussed applications.
Noninvasive analysis of liposomal integrity in living animals was successfully accomplished using a new L-Band ESR spectroscopy method. The liberation of CAT-1 from liposomes in vitro and in vivo was monitored by changes in the lineshape of ESR spectra and Heisenberg spin exchange. The significance of liposomal integrity for the formation of a localized drug depot effect was proved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.