Abstract: Disclosed is a process of preparing magnetite nanoparticles, comprising the following steps: 1) preparing a ferric salt mixed system, wherein a soluble ferric salt is dissolved in glycol at ambient temperature, and then urea and polyethylene glycol are added and mixed homogeneously to obtain the trivalent iron salt mixed system, the mass ratio of glycol to the trivalent iron salt being 15:1 to 60:1, glycol to urea being 20:1 to 100:1, and glycol to polyethylene glycol being 20:1 to 100:1; 2) reacting, wherein the trivalent iron salt mixed system is transferred into a reaction autoclave, sealed and placed into a heating device to react at a temperature of 200 to 300° C. for 8 to 72 hours; and 3) washing, wherein after the reaction system is naturally cooled down to ambient temperature, the product is taken out, and washed with anhydrous ethanol and water in turn to obtain the magnetite nanoparticles. The soluble iron salt includes ferric chloride, ferric sulfate, ferric acetate and ferric nitrate.

Abstract: The present invention relates to crosslinked dextran magnetic composite microparticles and a preparation process and a using method thereof. The composite microparticles comprise magnetic nanoparticles and dextran with crosslinked structure, wherein the magnetic nanoparticles are dispersed in the dextran with crosslinked structure. The process for preparing the composite microparticles comprises: preparing a dextran solution; synthesizing dextran magnetic composite microparticles; and synthesizing the crosslinked dextran magnetic composite microparticles. The using method of composite microparticles comprises: preparing crosslinked dextran magnetic composite microparticles loaded with anti-cancer drug; and adding a sustained-releasing solution thereto.

Abstract: Disclosed is a process of preparing magnetite nanoparticles, comprising the following steps: 1) preparing a ferric salt mixed system, wherein a soluble ferric salt is dissolved in glycol at ambient temperature, and then urea and polyethylene glycol are added and mixed homogeneously to obtain the trivalent iron salt mixed system, the mass ratio of glycol to the trivalent iron salt being 15:1 to 60:1, glycol to urea being 20:1 to 100:1, and glycol to polyethylene glycol being 20:1 to 100:1; 2) reacting, wherein the trivalent iron salt mixed system is transferred into a reaction autoclave, sealed and placed into a heating device to react at a temperature of 200 to 300° C. for 8 to 72 hours; and 3) washing, wherein after the reaction system is naturally cooled down to ambient temperature, the product is taken out, and washed with anhydrous ethanol and water in turn to obtain the magnetite nanoparticles. The soluble iron salt includes ferric chloride, ferric sulfate, ferric acetate and ferric nitrate.