Method for manufacturing KMnF<3> nuclear magnetic resonance imaging contrast agents

Abstract

The invention discloses a method for manufacturing KMnF<3> nuclear magnetic resonance imaging contrast agents. The method includes accurately weighing corresponding raw materials including KF.2H<2>O and MnCl<2>.4H<2>O according to a molar ratio of 3:1; adding a proper quantity of potassium oleate into the raw materials; dissolving the raw materials and the potassium oleate into anhydrous ethanol; and uniformly stirring the anhydrous ethanol with the raw materials and the potassium oleate to obtain a mixture, then adding the mixture into a sealed reaction container, and heating the mixture at the temperature of 160 DEG C for 24 hours to obtain KMnF<3> spherical particles with particle sizes of 15nm. The KMnF<3> spherical particles are uniform in particle size distribution. The method has the advantages that nanometer crystals manufactured by the method are low in cell toxicity and high in biocompatibility after being modified, the contrast agents are high in relaxation efficiency (of 23.15mM.S<-1>) and low in r2 / r1 ratio (of 3.23), and can be used for contrast-enhanced imaging for brains of mice as shown by primary animal nuclear magnetic resonance imaging experiments by the aid of colloidal solution manufactured by the KMnF<3> nuclear magnetic resonance imaging contrast agents; and the in-vivo retaining time of the KMnF<3> nuclear magnetic resonance imaging contrast agents is proper, and the KMnF<3> nuclear magnetic resonance imaging contrast agents can be used as novel medical nuclear magnetic resonance contrast agents.

Description

technical field [0001] The present invention relates to a kind of KMnF 3 A method for preparing a magnetic resonance imaging contrast agent. Background technique [0002] NMR is a technique that uses the resonance of the hydrogen nuclei of water molecules in body fluids or tissues to image. It is very sensitive to small differences in physicochemical properties of different organs or tissues. In medicine, it is often used to distinguish different tissues and detect diseases that cause changes in physical and chemical properties, such as tumors. Due to the local magnetic field generated by electron spin in some paramagnetic and superparamagnetic particles, the magnetic resonance relaxation time T of its neighboring hydrogen nuclei can be changed 1 and T 2 , and the concentration of these particles is higher where the composition is different, so it is usually used as a contrast agent to improve the contrast of MRI. At present, more researches include superparamagne...

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Problems solved by technology

At present, more researches include superparamagnetic iron oxide, manganese, gadolinium and other contrast agents, among which superparamagnetic iron oxide is used as T 2 Contrast agents have been clinically used as contrast agents for the liver, but as negative contrast agents, such contrast agents can cause susceptibility artifacts and overlap with signals such as calcification and blood flow in the body, making diagnosis difficult

Therefore, its application is limited; while T 1 Class contrast agents can avoid these problems, the current commercial T 1 Contrast agents mainly contain Gd 3+ contrast agent, although Gd 3+ There are 7 unpaired electrons in the outermost layer, which has a high magnetic moment and is conducive to contrast-enhanced imaging, but Gd 3+ As a heavy metal element, it will cause harm to the human body after entering the human body. In order to solve this problem, Mn with 5 unpaired electrons, strong paramagnetism and low toxicity 2+ Contrast agents began to develop slowly, in which MnCl 2 Has been widely used in the field of imaging to observe the fine structure of the brain and neural activity, but MnCl 2 It will cause damage to the human heart; and by preparing MnO nanoparticles with uniform size and modifying them into composite particles with better biocompatibility, good contrast effects can also be obtained, but at present, the relaxation efficiency of Mn-based contrast agents Generally low, the reason is that Mn in MnO nanoparticles is unstable and easily oxidized to a high valence state

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