Nonpolymeric Coatings of Iron Oxide Colloids for Biological Use as Magnetic Resonance Imaging Contrast Agents

Mitochondrial membrane permeabilization produced by PTP, Bax and apoptosis: a 1H-NMR relaxation study

“…From the temperature dependency of T1sw and T2sw, the rotational and diffusional correlation times of structured water t R , t D , and their respective enthalpies E R and E D were calculated (Supplementary text 'Procedure used for the calculation of correlation times t D and t R '), according to previous studies 19 and the cross relaxation model of Gallier et al 9 The contribution of nonwater protons from residual molecules present in the mitochondrial pellet (mainly mannitol) was evaluated on the basis of the concentration ratio of sugars in the mitochondrial pellet versus supernatant, when the mitochondria are isolated from the liver homogenate with a buffer containing 0.3 M saccharose. The concentration of total sugars present in the samples was determined using the method of Dubois et al 24 The exchange process of water molecules between the different compartments was investigated by comparing the relaxation enhancement produced by superparamagnetic magnetite nanoparticles, 10-15 nm mean hydrodynamic diameter, coated with HEDP (1-hydroxyethylidene diphosphonic acid), 25 on the bulk (T1obs, T2obs) and structured water phases (Tlsw and T2sw) in the mitochondrial pellet and its supernatant. The contrast agent was added to the first liver homogenate supernatant, after the centrifugation at 1200 Â g, at the dose of 15 mg Fe/ml.…”

Co-Precipitation and Magnetic Properties of Magnetite Nanoparticles for Potential Biomedical Applications

“…Most of these applications require a high quality control in the production of these magnetic nanoparticles to be nontoxic, chemically stable, and uniform in size, well dispersed under physiological conditions, insensitive to oxidation and agglomeration in the body fluids. The biocompatible magnetite nanoparticles are not toxic at all, and they can be accumulated in different tissues depending on the particle size, which can increase the contrast between the different organs in living systems [1][2][3]. These medical applications require super paramagnetic magnetite with particle sizes ~20 nm [4].…”

Magnetic nanoparticles: Properties and potential applications

“…In this form, however, particles are recognized by the macrophages of the mononuclear phagocyte system and are eliminated from the body [12]. In order to improve biocompatibility, to reduce toxicity and to ensure non-immunogenicity, particles have been encapsulated (e.g., with chitosan, dextran, poly(lactic acid), starch, carbon, polysaccharides, gelatine, and proteins) to yield "stealth" particles [12,18].…”