Abstract: The invention relates to spherical and magnetic silicagel particles which are provided with an increased surface by incorporating SiO2 colloids and produced by a method for inverse dispersion cross-linking of silica sols. The addition of certain metallic oxides to said silica sols and a subsequent tempering make it possible to obtain silicagel particles which exhibit increased nucleic acid binding properties and are used for separating a nucleic acid and isolating biomolecules.

Abstract: The invention relates to biocompatible, thermosensitive polymers that can be heated, with the aid of a high-frequency magnetic alternating field, by encapsulating magnetic and/or metallic colloids or magnetic nanoparticles. As a result of the inductive heating of the polymer matrix, physical structure changes are triggered in the polymer matrix that lead to the bioactive substances encapsulated in the matrix being released within a short period of time. This “stimulus-response” principle is employed for the production of controllable drug depots, contrast-intensifying media for NMR diagnostics or manipulable micro-tools, as media for blocking blood vessels and as controllable porogens in the production of membranes.

Abstract: The invention relates to spherical and magnetic silicagel particles which are provided with an increased surface by incorporating SiO2 colloids and produced by a method for inverse dispersion cross-linking of silica sols. The addition of certain metallic oxides to said silica sols and a subsequent tempering make it possible to obtain silicagel particles which exhibit increased nucleic acid binding properties and are used for separating a nucleic acid and isolating biomolecules.

Abstract: Spherically shaped polyvinyl alcohol (PVAL) polymer particles are prepared encapsulating a magnetic colloid that provides the particles with magnetic properties for use in binding biomolecules. The particles have a size of 1-10 &mgr;m that makes them particularly suitable for use in cell separation/sorting, cleaning biosubstances in suspension and diagnostic assays. The particles are prepared by dispersing a magnetic colloid containing a magnetic material such as a ferromagnetic or superparamagnetic substance in an aqueous solution of polyvinyl alcohol containing reactive hydroxyl groups, adding the resultant mixture to an organic phase containing a mixture of at least two emulsifiers, and adding a water-soluble cross-linking agent such as a dialdehyde that reacts with the hydroxyl groups of polyvinyl alcohol to form the polymer particles. The emulsifiers are miscible in the polyvinyl alcohol solution, and at least one emulsifier is semi-hydrophilic and at least one emulsifier is lipophilic.