Electron spin resonance imaging studies

Kroll, C. et al., Influence of drug treatment on the microacidity in rat and human skin — an in vitro electron spin resonance imaging study, Pharrn. Res., 18, 525, 2001. 

Lurie DJ (1996) Commentary electron spin resonance imaging studies of biological systems. British Journal of Radiology 69 983. 

Shin, Y. K., and Freed, J. H. (1989), Dynamic imaging of lateral diffusion by electron spin resonance and study of rotational dynamics in model membranes. Effect of cholesterol, Biophys. J., 55, 537-550. 

Various optical detection methods have been used to measure pH in vivo. Fluorescence ratio imaging microscopy using an inverted microscope was used to determine intracellular pH in tumor cells [5], NMR spectroscopy was used to continuously monitor temperature-induced pH changes in fish to study the role of intracellular pH in the maintenance of protein function [27], Additionally, NMR spectroscopy was used to map in-vivo extracellular pH in rat brain gliomas [3], Electron spin resonance (ESR), which is operated at a lower resonance, has been adapted for in-vivo pH measurements because it provides a sufficient RF penetration for deep body organs [28], The non-destructive determination of tissue pH using near-infrared diffuse reflectance spectroscopy (NIRS) has been employed for pH measurements in the muscle during... 

In addition, for imaging studies, only liposome-encapsulated gadolinium was used successfully [222, 223], In a more recent study, electron spin resonance (ESR) was applied successfully to investigate the integrity of MLV and the possibility of a depot effect after the s.c. injection in mice [224],... 

Shin Y-K, Ewert U, Budil DE, Ereed JH. Microscopic versus macroscopic diffusion in model membranes by electron spin resonance spectral-spatial imaging. Biophys. J. 1991 59 950-957. Trauble H, Sackmann E. Studies of the crystaUine-hquid crystalline phase transition of lipid model membranes, m. Structure of a steroid-lecitin system below and above the hpid-phase transition. J. Am. Chem. Soc. 1972 94 4499-4510. 

Several studies were performed to obtain a detailed insight into the interactions between vesicles and skin. Most studies focused on penetration characioisiics of vesicles or vesicle constituents. In a study by Gabrijelcic ei al. (65). a spin probe (A L) was loaded in liposomes and the liposomes were applied to the skin. The translational mobility of the probe was detected. The mobility of the probe was mea.sured with electron paramagnetic resonance imaging (EPRl). Gabrijelcic et al. compared encapsulated of the probe in liquid state and gel stme vesicles... 

Figure 9.7. Freeze-fracture TEM images and corresponding ESR spectra of the lipid nanoparticles labeled with cholestane, 0.025%. Top SEN (glyceryl behenate), middle NEC (glyceryl behenate/MCT 8 2) and bottom emulsion (MCT). Reprinted from J. Control. Rel., Vol. 119, C. Braem et al., Interaction of drug molecules with carrier systems as studied by parelectric spectroscopy and electron spin resonance, 128-135, Copyright (2004), with permission from Elsevier.

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