阅读说明：本技术 一种用于动脉粥样硬化治疗的纳米磁性材料及其制备方法 (Nano magnetic material for treating atherosclerosis and preparation method thereof ) 是由 冯增兴 吴韬 李可 张静汶 夏娜 闫誉馨 马尼康 于 2020-05-20 设计创作，主要内容包括：本发明公开了一种用于动脉粥样硬化治疗的纳米磁性材料及其制备方法,利用生物质材料制备一种超顺磁纳米Fe<Sub>3</Sub>O<Sub>4</Sub>,其表面被ICG和聚乙二醇修饰,制备得到的纳米磁性材料将被注射到人体中,瞄准并积累在富含脂质的冠状动脉斑块中,随后用808nm激光照射局部和远端的斑块来溶解脂质,用于动脉粥样硬化的荧光及磁共振双模态成像诊断和近红外光热治疗。本发明提出的纳米磁性材料及其制备方法应用前景较好,使用近红外热处理来溶解脂质,从而逆转其形成,在治疗动脉粥样硬化方面的效果较好。(The invention discloses a nano magnetic material for treating atherosclerosis and a preparation method thereof, and a biomass material is used for preparing superparamagnetic nano Fe 3 O 4 The surface of the nano magnetic material is modified by ICG and polyethylene glycol, the prepared nano magnetic material is injected into a human body, is aimed and accumulated in a coronary plaque rich in lipid, and then the local and distal plaques are irradiated by 808nm laser to dissolve the lipid for atherosclerosisThe fluorescence and magnetic resonance bimodal imaging diagnosis and the near infrared photothermal therapy. The nano magnetic material and the preparation method thereof have good application prospect, and the near infrared heat treatment is used for dissolving lipid so as to reverse the formation of the lipid, so that the nano magnetic material has good effect on treating atherosclerosis.)

1. A preparation method of a nano magnetic material for treating atherosclerosis is characterized by comprising the following specific steps:

(1) corn stover, which had a content of 15.39 wt% of Fe2O3, was cut into 1 cm-long pieces, washed with tap water to remove contaminants, and then dried in a vacuum oven at a temperature of 75 to 82 ℃ for 9 hours. The dried corn stalks are stored for later use at-12 ℃.

(2) 200 g of stored corn straws are compacted to 300kg/m in a stainless steel reactor by adopting a spiral feeder³Then, degassing was performed, and 2 wt% sulfuric acid was injected to stir the reaction at 110 ℃ for 5 hours. The solid-to-liquid ratio of the corn straws to the sulfuric acid is 3: 1 (w/w). After the reaction was complete, the reactor was cooled to below 50 ℃. The wet material was then filtered using a vacuum pump to separate the solid phase from the liquid prehydrolyzate. The liquid prehydrolyzate was neutralized to pH 10 with 1M sodium hydroxide solution. The liquid prehydrolyzate was filtered again, the pH was adjusted to 7 with 1M sulfuric acid solution, and then diluted to 16ml for further use.

(3) FeCl with a volume of 4ml and a concentration of 2mmol is added at a stirring rate of 600r/min₃The solution was added to 16mL of the above prehydrolyzate having a pH of 7 to obtain a mixed solution. The pH of the mixed solution was adjusted to 10 by dropwise addition of an ammonia hydroxide solution having a molar concentration of 25 mol%. Stirring the mixture for 30min at a stirring speed of 600r/min by a machine, transferring the mixed solution into a 50ml reaction kettle with a Teflon coating, heating the mixed solution in an oven to 150 ℃, and carrying out hydrothermal treatment for 36h to obtain black colloid. The solid product was separated from the liquid phase by centrifugation at 1500rpm for 45 minutes, followed by three washes with deionized water to remove residual reactants. And drying the final product in a vacuum drying oven at 50 ℃ for 8h to obtain black powder, namely the prepared nano magnetic material SPIO.

2. The nano magnetic material for treating atherosclerosis, which is characterized in that the nano magnetic material SPIO prepared by the method in claim 1 has the function of guiding photo-thermal treatment of atherosclerosis by virtue of fluorescence and magnetic resonance bimodal imaging through ICG NIRF molecular imaging agent and near infrared spectrum irradiation.

3. The nanomagnetic material for the treatment of atherosclerosis according to claim 2, wherein the near infrared spectrum irradiation is specifically far and local irradiation of a target area with 808nm laser, and the irradiation is performed for 20min every 24 hours.

4. The nanomagnetic material for the treatment of atherosclerosis according to claim 2, wherein the ICG is an FDA-approved amphiphilic NIR fluorochrome. The absorption peak of the compound in blood is 805nm, and the emission peak is 830 nm; the molecular formula is C43H47N2O6S2Na, and the molecular weight is 775 da.

Technical Field

The invention relates to the field of preparation of nano magnetic materials, in particular to a nano magnetic material for treating atherosclerosis and a preparation method thereof.

Background

Cardiovascular disease is a leading cause of morbidity and mortality in developed countries, which is rising with the aging population. The pathological basis for a common cardiovascular disease is atherosclerosis, a chronic inflammatory state that occurs in the walls of blood vessels. Atherosclerosis is caused by a mild inflammation and eventually forms atheromatous plaques in the vessel wall through various steps. The formation of such plaques is associated with cholesterol and lipid deposition and infiltration of inflammatory cells and has a major impact on the vascular intima. Coronary plaque rich in fat is prone to rupture, and ruptured atherosclerotic plaque and the resulting thrombotic complications are the main causes of myocardial infarction and sudden cardiac death.

Indocyanine green (ICG) is a near-infrared dye that not only has efficient photothermal properties and biosafety, but also can be used as a fluorescence imaging probe for guiding near-infrared photothermal therapy (PTT). ICG is also an amphiphilic near infrared fluorescence (NIRF) agent that has been approved by the U.S. food and drug administration for near infrared fluorescence imaging in ophthalmology. ICG has been shown to bind to lipoproteins and accumulate in inflamed tissues, meaning it can be used as a targeted agent. The absorption and emission maxima of ICG in the near infrared region are around 740nm and 800nm, respectively. It was found that when ICG was used to detect lipid rich inflammatory atherosclerotic plaques, the near infrared fluorescence image of the atherosclerotic sections appeared as a strong signal, whereas the near infrared fluorescence signal from non-lesioned normal segments was almost negligible. In summary, the near-infrared photothermal and fluorescence properties make ICG applicable to infrared photothermal therapy and near-infrared fluorescence imaging.

In the last decade, scientists have given special attention to solutions involving multimodal nanomaterials, such as magnetic and fluorescent properties, thereby expanding the range of potential applications of nanomaterials. Magnetic iron nanoparticles (Fe)₃O₄NPs) have the characteristics of high specific surface area, superparamagnetism, nontoxicity, biodegradability and high optical absorption in the near infrared region, so that the NPs become a potential choice in the application of infrared photothermal therapy. Further, Fe₃O₄Is a typical magnetic resonance contrast agent and is widely used for biological imaging, biological diagnosis and treatment.

Macrophages are thought to play an important role in plaque formation and rupture, and therefore they are the most promising targets for the detection and treatment of atherosclerosis. Kosuge and colleagues report that single-walled carbon nanotubes have good application prospects in cell imaging and thermal therapy, and may be applied to thermal destruction of vascular macrophages.

Disclosure of Invention

The invention aims to provide a nano magnetic material for treating atherosclerosis and a preparation method thereof aiming at the defects of the prior art, and the biomass material is used for preparing superparamagnetic nano Fe₃O₄The surface of the compound is modified by ICG and polyethylene glycol, and the compound is used for fluorescence and magnetic resonance bimodal imaging diagnosis and near-infrared photothermal therapy of atherosclerosis.

The purpose of the invention is realized by the following technical scheme: a preparation method of a nano magnetic material for treating atherosclerosis comprises the following specific steps:

(1) corn stover, which had a content of 15.39 wt% of Fe2O3, was cut into 1 cm-long pieces, washed with tap water to remove contaminants, and then dried in a vacuum oven at a temperature of 75 to 82 ℃ for 9 hours. The dried corn stalks are stored for later use at-12 ℃.

(2) 200 g of stored corn straws are compacted to 300kg/m in a stainless steel reactor by adopting a spiral feeder³Then, degassing was performed, and 2 wt% sulfuric acid was injected to stir the reaction at 110 ℃ for 5 hours. The solid-to-liquid ratio of the corn straws to the sulfuric acid is 3: 1 (w/w). After the reaction was complete, the reactor was cooled to below 50 ℃. The wet material was then filtered using a vacuum pump to separate the solid phase from the liquid prehydrolyzate. The liquid prehydrolyzate was neutralized to pH 10 with 1M sodium hydroxide solution. The liquid prehydrolyzate was filtered again, the pH was adjusted to 7 with 1M sulfuric acid solution, and then diluted to 16ml for further use.

(3) FeCl with a volume of 4ml and a concentration of 2mmol is added at a stirring rate of 600r/min₃The solution was added to 16mL of the above prehydrolyzate having a pH of 7 to obtain a mixed solution. The pH of the mixed solution was adjusted to 10 by dropwise addition of an ammonia hydroxide solution having a molar concentration of 25 mol%. Stirring the mixture for 30min at a stirring speed of 600r/min by a machine, transferring the mixed solution into a 50ml reaction kettle with a Teflon coating, heating the mixed solution in an oven to 150 ℃, and carrying out hydrothermal treatment for 36h to obtain black colloid. The solid product was separated from the liquid phase by centrifugation at 1500rpm for 45 minutes, followed by three washes with deionized water to remove residual reactants. And drying the final product in a vacuum drying oven at 50 ℃ for 8h to obtain black powder, namely the prepared nano magnetic material SPIO.

A nano-magnetic material for treating atherosclerosis has the function of treating atherosclerosis by fluorescence and magnetic resonance bimodal imaging guide photo-thermal through ICG NIRF molecular developer and near infrared spectrum irradiation.

Further, the near infrared spectrum irradiation is specifically far and local irradiation of a target area by using 808nm laser, and the irradiation is carried out for 20min every 24 hours.

Further, the ICG is FDA approved amphiphilic NIR fluorochrome. The absorption peak of the compound in blood is 805nm, and the emission peak is 830 nm; the molecular formula is C43H47N2O6S2Na, and the molecular weight is 775 da.

The invention has the beneficial effects that:

(1) the invention provides a technical scheme with good application prospect, namely, near-infrared heat treatment is used for dissolving lipid so as to reverse the formation of the lipid.

(2) Indocyanine green (ICG) and polyethylene glycol modified Fe in the invention₃O₄The magnetic resonance double-mode imaging system has the function of guiding photo-thermal treatment of atherosclerosis by fluorescence and magnetic resonance double-mode imaging, and has a good effect on treating atherosclerosis.

Detailed Description

The following further describes the embodiments of the present invention in detail.

The invention provides a preparation method of a nano magnetic material for treating atherosclerosis, which utilizes corn straws to synthesize superparamagnetic magnetite (Fe3O4) nano particles, and comprises the following specific steps:

(1) corn stover, which had a content of 15.39 wt% of Fe2O3, was cut into 1 cm-long pieces, washed with tap water to remove contaminants, and then dried in a vacuum oven at a temperature of 75 to 82 ℃ for 9 hours. The dried corn stalks are stored for later use at-12 ℃.

(2) 200 g of stored corn stover was compacted in a stainless steel reactor using a screw feeder to 300kg/m3, and then degassed, and then 2 wt% sulfuric acid was injected to stir at 110 ℃ for 5 hours. The solid-to-liquid ratio of the corn straws to the sulfuric acid is 3: 1 (w/w). After the reaction was complete, the reactor was cooled to below 50 ℃. The wet material was then filtered using a vacuum pump to separate the solid phase from the liquid prehydrolyzate. The liquid prehydrolyzate was neutralized to pH 10 with sodium hydroxide solution (1M). The liquid prehydrolyzate was filtered again, the pH adjusted to 7 with sulfuric acid solution (1M), and then diluted to 16ml for use.

(3) A volume of 4mL of a 2mmol FeCl3 solution was added to 16mL of the above prehydrolyzate at pH 7 under stirring at 600r/min to obtain a mixed solution. The pH of the mixed solution was adjusted to 10 by dropwise addition of an ammonia hydroxide solution having a molar concentration of 25 mol%. Stirring the mixture for 30min at a stirring speed of 600r/min by a machine, transferring the mixed solution into a 50ml reaction kettle with a Teflon coating, heating the mixed solution in an oven to 150 ℃, and carrying out hydrothermal treatment for 36h to obtain black colloid. The solid product was separated from the liquid phase by centrifugation at 1500rpm for 45 minutes, followed by three washes with deionized water to remove residual reactants. And drying the final product in a vacuum drying oven at 50 ℃ for 8h to obtain black powder, namely the prepared nano magnetic material SPIO.

The nanometer magnetic material SPIO is irradiated by ICG NIRF molecular developer and near infrared spectrum, specifically, 808nm laser is used for far and local irradiation on a target area, and the irradiation is carried out for 20min every 24 hours. The method has the function of treating atherosclerosis by guiding photo-thermal by fluorescence and magnetic resonance bimodal imaging. The ICG is FDA approved amphiphilic NIR fluorochrome. The absorption peak of the compound in blood is 805nm, and the emission peak is 830 nm; the molecular formula is C43H47N2O6S2Na, and the molecular weight is 775 da. .

In the present invention, Fe is supported by a carrier₃O₄The stability of ICG is enhanced, thereby effectively avoiding the degradation of ICG in aqueous solution. The prepared nano-magnetic material is injected into a human body, aims and accumulates in a lipid-rich coronary plaque, and then irradiates local and distal plaques with 808nm laser to dissolve lipids. At the same time, near-infrared fluorescence property and Fe by ICG₃O₄Can detect this process. ICG and polyethylene glycol modified Fe₃O₄Has the functions of fluorescence and magnetic resonance bimodal imaging so as to guide the photothermal therapy of atherosclerosis.

The above-described embodiments are intended to illustrate rather than to limit the invention, and any modifications and variations of the present invention are within the spirit of the invention and the scope of the appended claims.