Abstract:
An improvement is provided to a method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject, of the type including administering to the subject as a contrast agent to enhance such MR image an effective amount of a colloid including superparamagnetic metal oxide particles dispersed in a physiologically acceptable carrier. In accordance with the improvement, the colloid is prepared in a manner that provides a reduction in toxicity in comparison with that associated with administration of the colloid after terminal sterilization. The improvement includes preserving the colloid by lyophilization. The colloid may be lyophilized in the presence of a compatible excipient. The excipient utilized may include a dextran or a citrate anion.
Abstract:
This invention relates to compositions comprising a colloidal or particulate metal oxide which are stabilized by low molecular weight carbohydrates. The carbohydrates are characterized by the fact that (a) they are not retained on the surface of the metal oxide based on the equilibrium room temperature dialysis of about 2 ml of the metal oxide composition at 0.2 M metal concentration against deionized water; and (b) they impart sufficient stability to the metal oxide compositions such that the compositions can withstand heat stress without perceptible aggregation as determined by a prescribed test procedure.
Abstract:
In a method for the synthesis of a colloid including a superparamagnetic metal oxide coated with a polymer, an acidic solution of a metal salt and a polymer may be cooled, and then neutralized by the controlled addition of a cool solution of a base, and may then be converted, by the application of heat, to a homogenous superparamagnetic metal oxide colloid. According to a preferred embodiment, the polymer may be a polysaccharide. In a further embodiment of the invention, the polysaccharide may be dextran and the metal salt may be ferrous and ferric salts, which produces, according to the methods of the invention, a superparamagnetic iron oxide colloid with an extended plasma half-line.
Abstract:
An improvement is provided to a method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject, of the type including administering to the subject as a contrast agent to enhance such MR image an effective amount of a colloid including superparamagnetic metal oxide particles dispersed in a physiologically acceptable carrier. In accordance with the improvement, the colloid is prepared in a manner that provides a reduction in toxicity in comparison with that associated with administration of the colloid after terminal sterilization. The improvement includes preserving the colloid by lyophilization. The colloid may be lyophilized in the presence of a compatible excipient. The excipient utilized may include a dextran or a citrate anion.
Abstract:
An improvement is provided to a method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject, of the type including administering to the subject as a contrast agent to enhance such MR image an effective amount of a colloid including superparamagnetic metal oxide particles dispersed in a physiologically acceptable carrier. In accordance with the improvement, the method includes preparing the colloid in a manner that provides a reduction in toxicity in comparison with that associated with administration of the colloid after terminal sterilization. The improvement may include sterilizing the colloid by filtration. In an additional embodiment, the colloid may be sterilized by filtration and preserved by lyophilization. The colloid may be lyophilized in the presence of a compatible excipient. The excipient utilized may include a dextran or a citrate anion. Other embodiments include related compositions and methods.
Abstract:
L'invention se rapporte à un procédé servant à cibler un agent thérapeutique sur une population cellulaire spécifique, selon lequel un complexe est formé entre l'agent thérapeutique et un polysaccharide susceptible d'interagir avec un récepteur cellulaire, et le complexe qui en résulte est absorbé par la cellule par endocytose induite par récepteur (EMR). Selon un mode de réalisation, un complexe d'un agent thérapeutique contenant du fer et le polysaccharide arabinozalactane peut être formé et utilisé pour fournir du fer par EMR spécifiquement à des hépatocytes.
Abstract:
L'invention se rapporte à un nouveau procédé d'analyse par liaison de ligands, qui se fonde sur les mesures des vitesses de libération de protons par un solvant, ces mesures étant obtenues au moyen d'un spectromètre à résonance magnétique (MR). Le système d'analyse ainsi produit (appelé SMRAS) se fonde sur l'observation selon laquelle l'augmentation des vitesses de libération de protons produite par un matériau magnétique peut être modulée par la liaison de divers analytes à une substance magnétique. Ainsi, la vitesse de libération des protons par le solvant peut être soumise à une interprétation destinée à fournir des informations sur la concentration d'un analyte.
Abstract:
Cette invention concerne des compositions comprenant un oxyde de métal coloïdal ou particulaire lesquelles sont stabilisées par des hydrates de carbone de faible poids moléculaire. Les hydrates de carbone sont caractérisés par le fait que (a) ils ne sont pas retenus à la surface de l'oxyde métallique basé sur la dialyse à température ambiante équilibrée d'environ 2 ml de la composition d'oxyde métallique à une concentration en métal de 0,2 M par rapport à l'eau déionisée; et (b) ils confèrent une stabilité suffisante aux compositions d'oxydes métalliques de sorte que ces dernières peuvent supporter des contraintes thermiques sans agression perceptible, comme cela a pu être déterminé par un procédé de test pré-établi.
Abstract:
Magnetic resonance (MR) contrast agents are described whose in vivo biodistribution is based upon the ability of certain cells to recognize and internalize the MR contrast agents of the present invention, via receptor mediated endocytosis. The RME-type MR contrast agents are comprised of biodegradable superparamagnetic metal oxides associated with macromolecular species including serum proteins, hormones, asialoglycoproteins, galactose-terminal species, polysaccharides, arabinogalactan, or conjugates of these molecules with other polymeric substances such as a poly(organosilane) and dextran. An MR contrast agent prepared from biodegradable superparamagnetic iron oxide and asialofetuin, for example, arabinogalactan, is selectively localized in the hepatocytes of the liver with no significant accumulation in the spleen. The contrast agents provide an enhanced MR image and valuable information regarding the functional or metabolic state of the organ or tissue under examination.
Abstract:
There are provided a carrier for forming a complex with a therapeutic agent for delivery thereof to a cell receptor located on the surface of a target tissue comprising: arabinogalactan modified at a site by a functional residue to produce a derivative in a manner that preserves the useful affinity of the derivative for the cell receptor, and complexes thereof.