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Magnetic nanoparticles can promote many attractive functions in biomedicine, which may contribute to the prevention of human disease but also may be potentially harmful. In the present study, the interaction of Fe2O3 nanoparticles with human hemoglobin (Hb) was studied by fluorescence, circular dichroism and UV/vis spectroscopies. Fluorescence data revealed that the fluorescence quenching of Hb by Fe2O3 nanoparticles was the result of the formed complex of Fe2O3 nanoparticles-Hb. Binding constants and other thermodynamic parameters were determined at three different temperatures. The hydrophobic interactions are the predominant intermolecular forces to stabilize the complex. Circular dichroism studies did not show any changes in the content of secondary structure of hemoglobin after Fe2O3 nanoparticles treatment. This study provides important insight into the interaction of Fe2O3 nanoparticles with hemoglobin, which may be a useful guideline for further using of these nanoparticles in biomedical applications. [ABSTRACT FROM AUTHOR]

The optical properties of pig heart tissue were measured after in vivo ablation therapy had been performed during open-heart surgery. In vitro samples of normal and ablated tissue were subjected to measurements with an optically integrating sphere set-up in the region 470-900 nm. Three independent measurements were made: total transmittance, total reflectance and collimated transmittance, which made it possible to extract the absorption and scattering coefficients and the scattering anisotropy factor g, using an inverse Monte Carlo model. Between 470 and 700 nm, only the reduced scattering coefficient and absorption could be evaluated. The absorption spectra were fitted to known tissue chromophore spectra, so that the concentrations of haemoglobin and myoglobin could be estimated. The reduced scattering coefficient was compared with Mie computations to provide Mie equivalent average radii. Most of the absorption was from myoglobin, whereas haemoglobin absorption was negligible. Metmyoglobin was formed in the ablated tissue, which could yield a spectral signature to distinguish the ablated tissue with a simple optical probe to monitor the ablation therapy. The reduced scattering coefficient increased by, on average, 50% in the ablated tissue, which corresponded to a slight decrease in the Mie equivalent radius. [ABSTRACT FROM AUTHOR]

The author comments on studies which investigated the safety and efficacy of peginesatide in patients with chronic kidney disease (CKD). He references one study which showed that the efficacy of dose-adjusted peginesatide to increase and/or maintain haemoglobin levels. The author discusses the clinical background of peginesatide.