Magnetic cluster capable of being driven by magnetic force, preparation method of magnetic cluster and application of magnetic cluster in non-compressible acute bleeding

Abstract

The invention relates to a magnetic cluster capable of being driven by magnetic force, a preparation method of the magnetic cluster and application of the magnetic cluster in non-compressible acute bleeding. The invention relates to an iron oxide nano-particle adsorbent which comprises the following components in parts by weight: 0.5-2 parts of iron oxide nano-particles, 10-40 parts of phosphorylated polyethylene glycol, 10-40 parts of polymethyl methacrylate, 0.4-1.2 parts of lauryl sodium sulfate and 5-20 parts of bovine serum albumin. After entering a blood circulation system through intravenous injection, the magnetic cluster hemostatic nanomaterial is quickly and accurately enriched at a broken blood vessel of an acute bleeding area and physically blocks bleeding at a bleeding site through the magnetic attraction effect of an external magnet placed at the bleeding site, and meanwhile, formation of fibrin clots is accelerated, so that the effect of slowing down bleeding is achieved.

Description

Technical Field

[0001] The invention relates to a nano hemostatic agent, in particular to a magnetic cluster that can be driven by magnetic force, a preparation method thereof and application thereof in incompressible acute bleeding. Background Art

[0002] In pre-hospital rescue, acute bleeding is the most common emergency in the emergency department. War, road traffic accidents, personal injury, extreme sports, surgery and natural disasters may cause acute bleeding due to rupture of human arteries or damage to internal organs. Due to the limited compensation of the body, massive bleeding will lead to a serious shortage of effective circulating blood in the body. When the amount of bleeding exceeds about 15% of the total blood volume of the human body, symptoms such as decreased pulse pressure, insufficient blood supply to the heart and brain, weak heart function, confusion and coma will appear. If the amount of bleeding continues to increase, it will quickly lead to organ failure in the body, greatly increasing the mortality rate of patients. According to statistics, acute traumatic bleeding is one of the main causes of acute death. Therefore, convenient, fast and effective hemostasis measures can save many lives that may be lost.

[0003] Clinically, there are different hemostasis methods for acute bleeding according to the different bleeding locations. For acute bleeding on the trunk surface or on the body surface that can be touched, the most common hemostasis method is local compression hemostasis. Local compression hemostasis mainly uses dry sterile gauze to press the bleeding point, absorb wound exudate, and keep the wound dry to achieve the purpose of hemostasis. However, if compression hemostasis is unsuccessful or damages large blood vessels, resulting in excessive bleeding, compression hemostasis is no longer applicable at this time. A disposable tourniquet, elastic bandage, etc. can be used to restrain the proximal end of the limb where the bleeding point is located, thereby blocking the blood flow supplying the wound to achieve the purpose of hemostasis. However, once the restraint time is too long, it may affect the blood supply of the entire limb, and in severe cases may cause limb necrosis. In addition, gelatin sponge packing and hemostasis can be used for hemostasis. For patients with non-trunk acute bleeding that cannot be compressed, such as the junction, and severe internal bleeding, there is currently no method to stop bleeding immediately. Surgical treatment is the only solution, and hemostatic drugs and blood pressure reduction are often required to assist in hemostasis. Once the time is delayed too long, the patient's bleeding volume will increase, which will greatly increase the risk of death. For example, more than 1.2 million people die in road traffic accidents every year, of which more than 480,000 are caused by failure to stop bleeding in time. These patients are often patients with internal bleeding who cannot be stopped by compression or packing. Therefore, it is urgent to find new methods for stopping bleeding in non-compressible bleeding.

[0004] The rapid development of nanotechnology in recent years has provided a new path for the preparation of effective hemostatic materials. Among them, magnetic nanomaterials are the only inorganic nanomaterials currently approved by the FDA for clinical use. Due to its rich and adjustable magnetic properties and good biocompatibility, it has a wide range of applications in biomedicine: including magnetic resonance contrast agents, magnetic tracers for breast cancer lymph node dissection, magnetic induction hyperthermia, magnetically controlled micro-nano robots, and magnetic thermal freezing tissue rewarming. Some of these technologies have been widely used in clinical practice. Some teams have also reported that magnetic fluids made of magnetic nanomaterials use the magnetic attraction of magnets placed at the wound location to adsorb magnetic fluids to designated areas of the wound to reduce or even stop blood flow. However, this technology is currently limited by the characteristics of the material itself. The obtained magnetic fluid needs to be dispersed in an organic solvent to obtain a strong magnetic attraction. Therefore, at this stage, it can only simulate bleeding and hemostasis in vitro, and cannot be used for in vivo research. Summary of the invention

[0005] In order to solve the technical problems existing in the background technology, the present invention provides a magnetic cluster that can be driven by magnetic force, a preparation method thereof and its application in incompressible acute bleeding. After the magnetic cluster hemostatic nanomaterial enters the blood circulation system through intravenous injection, it is quickly and accurately enriched in the ruptured blood vessels in the acute bleeding area through the magnetic attraction of an external magnet placed at the bleeding site, physically blocking the bleeding point while accelerating the formation of fibrin clots, thereby playing a role in slowing down bleeding.

[0006] The technical solution of the present invention is: the present invention is a magnetic cluster nanomaterial that can be driven by magnetic force, characterized in that: the components of the magnetic cluster nanomaterial that can be driven by magnetic force are, by mass, 0.5-2 parts of iron oxide nanoparticles, 10-40 parts of phosphorylated polyethylene glycol, 10-40 parts of polymethyl methacrylate, 0.4-1.2 parts of sodium dodecyl sulfate, and 5-20 parts of bovine serum albumin.

[0007] A method for preparing the above-mentioned magnetic cluster nanomaterial that can be driven by magnetic force is special in that the method comprises the following steps:

[0008] 1) Dissolve 10-40 parts of phosphorylated polyethylene glycol and 7.5-30 parts of bromoisobutyryloxyethylphosphonic acid in 1 mL of chloroform, stir evenly, then add the mixture dropwise to 0.5-2 parts of iron oxide nanoparticles, and stir at room temperature for at least 12 hours; then, centrifuge and wash the obtained product using a mixture of acetone / diethyl ether in a volume ratio of 2:1, 4000g, 5min, and repeat three times; disperse the obtained product IO@PEG / BiBEP in a dimethylformamide solution for later use;

[0009] 2) 0.5-1.5 parts of methyl methacrylate are slowly added to the IO@PEG / BiBEP obtained in the previous step, and the reaction system is degassed with nitrogen for 30 minutes, and then 20-40 parts of cuprous bromide and 100-150 parts of tri[2-(dimethylamino)ethyl]amine are added to the reaction system, and the reaction substances are mixed evenly and reacted in a 40° C. water bath for 12 hours; after the reaction is completed, the obtained product IO@PEG / PMMA is separated by magnetic attraction and dispersed in a chloroform solution for later use;

[0010] 3) 0.5-2 parts of the IO@PEG / PMMA synthesized in the previous step were taken, and 0.4-1.2 parts of sodium dodecyl sulfate solution were slowly added thereto, and then ultrasonic emulsification was performed at 100 W for 5 minutes using an ultrasonic cell disruptor; the obtained reaction solution was stirred at room temperature for at least 10 hours to remove the organic solvent, and a magnetic cluster nanomaterial soluble in water was obtained.

[0011] Furthermore, step 3) further includes step 4) slowly dropping different volumes of 0.01 mg / mL bovine serum albumin (BSA) solution into the magnetic cluster nanomaterial obtained in step 3), then gently vortexing the reaction solution several times to evenly disperse the BSA in the reaction solution, incubating at room temperature for at least 30 minutes, and separating the product by magnetic attraction to obtain the final product, which is a magnetic cluster that can be driven by magnetic force.

[0012] An application of the magnetic cluster nanomaterial that can be driven by magnetic force in incompressible acute hemorrhage.

[0013] The present invention provides a magnetic cluster that can be driven by magnetic force, a preparation method thereof, and an application thereof in incompressible acute hemorrhage. A magnetic cluster nanomaterial based on clinically approved iron oxide nanoparticles is constructed, and then biocompatible bovine serum albumin is used to wrap the surface of the magnetic cluster to construct a biocompatible magnetic cluster. After the magnetic cluster hemostatic nanomaterial enters the blood circulation system through intravenous injection, it is quickly and accurately enriched at the ruptured blood vessels in the acute bleeding area through the magnetic attraction of an external magnet placed at the bleeding site, and the formation of fibrin clots is accelerated while the bleeding site is physically blocked, thereby slowing down the bleeding. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 TEM image of B@MC, particle size: 220.36±20.72nm;

[0015] Figure 2 is the UV-visible absorption spectrum of B@MC;

[0016] Figure 3 is the enrichment of B@MC under an external magnetic field;

[0017] Figure 4 To study the toxicity of B@MC to AML-12 and HUVEC cells (chemiluminescence method);

[0018] Figure 5 Toxicity study of B@MC on AML-12 and HUVEC cells (dead and live cell staining method, scale bar: 200 μm);

[0019] Figure 6 The effect of intravenous injection of B@MC on the weight gain of mice;

[0020] Figure 7 The effect of intravenous injection of B@MC on liver and kidney function in mice;

[0021] Figure 8 The effects of intravenous injection of B@MC on the main organs of mice: heart, liver, spleen, lung, and kidney;

[0022] Fig. 9 The hemolytic effect of B@MC on red blood cells in vitro;

[0023] Fig.10 (a) Operation diagram of magnetically driven enrichment of B@MC at the bleeding point of the inferior vena cava; (b) Enrichment of B@MC in the inferior vena cava of rats under magnetic drive; (c) Quantitative analysis of acute bleeding in the inferior vena cava of rats under different treatment conditions;

[0024] Fig.11 (a) Acute bleeding of the mouse tail under different treatment conditions; (b) Quantitative analysis of acute bleeding of the mouse tail under different treatment conditions;

[0025] Fig.12 (a) The enrichment of magnetically driven B@MC at the bleeding points in mouse liver; (b) Quantitative analysis of acute bleeding in mouse liver under different treatment conditions. DETAILED DESCRIPTION

[0026] The specific embodiment of the magnetic cluster nanomaterial that can be driven by magnetic force of the present invention comprises, by weight, 0.5-2 parts of iron oxide nanoparticles, 10-40 parts of phosphorylated polyethylene glycol, 10-40 parts of polymethyl methacrylate, 0.4-1.2 parts of sodium dodecyl sulfate, and 5-20 parts of bovine serum albumin.

[0027] In the specific embodiment of the present invention, the synthesis of B@MC is mainly divided into the following steps:

[0028] 1) Dissolve 10-40 parts of phosphorylated polyethylene glycol (P-PEG) and 7.5-30 parts of bromoisobutyloxyethylphosphonic acid (BiBEP) in 1 mL of chloroform, stir evenly, then add the mixture dropwise into 0.5-2 parts of iron oxide nanoparticles (IO NPs), and stir at room temperature for at least 12 hours; then, centrifuge and wash the obtained product with a mixture of acetone / diethyl ether in a volume ratio of 2:1 at 4000 g for 5 minutes, repeat three times; disperse the obtained product IO@PEG / BiBEP in a dimethylformamide solution for later use;

[0029] 2) Slowly add 0.5-1.5 parts of methyl methacrylate (MMA) to the IO@PEG / BiBEP obtained in the previous step, degas the reaction system with nitrogen for 30 minutes, add 20-40 parts of cuprous bromide and 100-50 parts of tri[2-(dimethylamino)ethyl]amine to the reaction system, mix the reaction materials evenly and react in a 40°C water bath for 12 hours. After the reaction is completed, separate the obtained product IO@PEG / PMMA by magnetic attraction and disperse it in a chloroform solution for later use;

[0030] 3) 0.5-2 parts of IO@PEG / PMMA synthesized in the previous step are slowly added to 0.4-1.2 parts of sodium dodecyl sulfate solution (SDS), and then ultrasonic emulsification is performed at 100 W for 5 minutes using an ultrasonic cell disruptor; the resulting reaction solution is stirred at room temperature for at least 10 hours to remove the organic solvent, thereby obtaining a magnetic cluster nanomaterial IO@PEG / PMMA@SDS soluble in water, referred to as Magnetic Cluster, MC.

[0031] 4) Different volumes of 0.01 mg / mL bovine serum albumin (BSA) solution were slowly dripped into the magnetic cluster nanomaterial IO@PEG / PMMA@SDS, and then the BSA was evenly dispersed in the reaction solution after slight vortex oscillation. After incubation at room temperature for at least 30 min, the product was separated by magnetic adsorption to obtain the final product, which was a magnetically driven magnetic cluster (BSA—Magnetic Cluster, referred to as B@MC).

[0032] In the first embodiment of the present invention:

[0033] 1) Dissolve 10 mg of phosphorylated polyethylene glycol (P-PEG) and 7.5 mg of bromoisobutyloxyethylphosphonic acid (BiBEP) in 1 mL of chloroform, stir evenly, then add the mixture dropwise into 2 mL of iron oxide nanoparticles (IO NPs), and stir at room temperature for at least 12 h; then, centrifuge and wash the obtained product with a mixture of acetone / diethyl ether in a volume ratio of 2:1 at 4000 g for 5 min, repeat three times; disperse the obtained product IO@PEG / BiBEP in a dimethylformamide solution for later use;

[0034] 2) 0.9 mL of methyl methacrylate (MMA), 2 mL of IO@PEG / BiBEP obtained in the previous step and 2.5 mL of dimethylformamide solution were mixed evenly, and the reaction system was degassed with nitrogen for 30 min. Then, 15 mg of cuprous bromide and 80 mg of tri[2-(dimethylamino)ethyl]amine were added to the reaction system. After the reaction substances were mixed evenly, they were reacted in a 40°C water bath for 12 h. After the reaction was completed, the obtained product IO@PEG / PMMA was separated by magnetic attraction and dispersed in a chloroform solution for later use;

[0035] 3) 1.0 mL of the IO@PEG / PMMA synthesized in the previous step was taken, and 4 mL of 0.05 mg / mL sodium dodecyl sulfate solution (SDS) was slowly added thereto, and then ultrasonic emulsification was performed at 100 W for 5 min using an ultrasonic cell disruptor; the resulting reaction solution was stirred at room temperature for at least 10 h to remove the organic solvent, and the magnetic cluster nanomaterial IO@PEG / PMMA@SDS soluble in water was obtained, referred to as Magnetic Cluster, MC.

[0036] 4) Different volumes of 0.01 mg / mL bovine serum albumin (BSA) solution were slowly dripped into the magnetic cluster nanomaterial IO@PEG / PMMA@SDS, and then the BSA was evenly dispersed in the reaction solution after slight vortex oscillation. After incubation at room temperature for at least 30 minutes, the product was separated by magnetic absorption to obtain the final product, a magnetically driven magnetic cluster (BSA-Magnetic Cluster, referred to as B@MC).

[0037] Through optimization of experimental conditions, thermogravimetric analysis, protein content determination and other methods, we determined that the mass ratio of each component in the material is: IO NPs: PEG: SDS: BSA = 1:20:20:1:10 (measured by the amount of iron). In addition, we characterized the physicochemical properties of the synthesized B@MC. Figure 1 As shown in the figure, the synthesized B@MC has uniform size, regular morphology and good dispersion. The particle size is 220.36±20.72nm as detected by transmission electron microscopy. The maximum absorption peak is located at 550nm as detected by UV-visible absorption spectrometer. Figure 2 As shown. The Zeta potential was measured by Malvern particle size analyzer to be -7.61±0.41mV. We also studied the response of B@MC to an external magnetic field. Under the attraction of an external magnetic field, the magnetic clusters can be precisely enriched in the magnetic field area, such as Figure 3 shown.

[0038] Cytotoxicity study of magnetic clusters B@MC:

[0039] Cell culture: AML-12 (normal mouse liver cells) cells were cultured using DMEM / F12 (Dulbecco's modified Eagle's medium / Ham's F-12 medium, DMEM / F12) basal culture medium supplemented with 10% fetal bovine serum (Fetal Bovine Serum, FBS), 0.5% insulin-transferrin-selenium supplement (ITS-G), 40ng / mL dexamethasone and 1% penicillin / streptomycin solution (Penicillin / Streptomycin Solution, P / S) complete culture medium; HUVEC (Human Umbilical Vein Endothelial Cell, human umbilical vein endothelial cells) were cultured using ECM (Endothelial Cell Medium, endothelial cell culture medium) culture medium supplemented with 5% FBS, 1% P / S and endothelial growth factor set complete culture medium.

[0040] Experiment 1: Chemiluminescence determination of B@MC cytotoxicity

[0041] One day in advance, cells were plated at 5 × 10 3The cells / well were inoculated into a 96-well plate with a volume of 100 μL. After overnight culture, the upper culture medium was aspirated and washed once with 100 μL PBS. Complete culture medium containing different concentrations of B@MC was added (the concentration of B@MC was 0, 2, 4, 7, 10, 15, 20, 30 or 50 μg / mL, and three replicates were made for each concentration). After further incubation in a 37°C, 5% CO2 incubator for 24 h, 100 μL CellTiter-Lumi TM Plus II luminescence detection buffer, shake at room temperature for 2 minutes, and incubate in the dark for 10 minutes, then the cell survival can be detected by chemiluminescence.

[0042] The results showed that B@MC had very low toxicity to AML-12 and HUVEC cells. Even at a high concentration of 50 μg / mL, more than 85% of the cells survived. Figure 4 shown.

[0043] Experiment 2: Determination of the cytotoxicity of B@MC by cell death and viability fluorescence staining

[0044] Cells were cultured one day in advance at 2 × 10 4 The cells / well were inoculated into a 6-well plate with a volume of 2 mL. After overnight culture, the upper culture medium was aspirated, and the plates were washed once with 1 mL PBS. Complete culture medium containing different concentrations of B@MC (the concentration of B@MC was 0, 10 or 50 μg / mL) was added respectively. After further incubation in a 37°C, 5% CO2 incubator for 24 h, the plates were washed three times with PBS, and 1 mL Calcein / PI cell activity and cytotoxicity detection reagent was added to each well. After incubation in the dark for 30-60 min, the staining solution was aspirated, and the plates were washed again three times with PBS to observe the fluorescence of the cells under an inverted fluorescence microscope.

[0045] The results once again verified that B@MC indeed had extremely low toxicity to AML-12 and HUVEC cells. Regardless of whether they were co-incubated with low concentrations of 10 μg / mL or high concentrations of 50 μg / mL of B@MC, almost all cells showed green fluorescence, while almost no cells were visible under the red fluorescence indicating dead cells. Figure 5 As shown. This shows that B@MC does have a certain degree of cell compatibility. More than 85% of the cells still survive. This shows that these two polypeptides have almost no damage to body cells within their use concentration range.

[0046] In vivo toxicity experiment of magnetic cluster B@MC

[0047] Experiment 1: Effects of intravenous administration of B@MC on growth and liver and kidney function in mice

[0048] Male Kunming mice weighing ~25g were purchased from the Medical Animal Experiment Center of Xi'an Jiaotong University. 200μL of saline or B@MC (1.0mg / kg) was injected into the mice through the tail vein. Afterwards, the weight gain of the mice was recorded. In addition, blood was collected from the eyeballs of the mice on the 1st, 3rd and 7th days after administration to test the liver and kidney function of the mice. The mice were then killed by cervical dislocation, and the main organs such as lungs, heart, kidneys, liver, and spleen were collected for immunohistochemical staining.

[0049] like Figure 6-8 As shown in the figure, the weight gain of mice after intravenous injection of B@MC was almost the same as that of healthy mice, and the liver and kidney function of the mice measured 1 day, 3 days and 7 days after administration was not significantly different from that of normal mice. At the same time, it can be seen from the staining results of the main organ sections of the mice that no pathological changes were observed in the main organs of the mice in the B@MC administration group, including the heart, liver, spleen, lung and kidney, within seven days, and there was no difference from normal mice. The above results all show that during the 7-day observation period, B@MC had almost no toxic side effects on the survival and growth of mice.

[0050] Experiment 2: Hemolysis experiment of B@MC

[0051] The blood of mice was collected into ethylenediaminetetraacetic acid (EDTA) anticoagulant tubes by eyeball blood sampling, and the tubes were turned upside down to mix the anticoagulant and blood evenly. The tubes were centrifuged at 4°C, 350g for 5 min, and a 1mL pipette tip was used to draw an appropriate amount of red blood cells from the bottom of the tube and mixed with 1mL phosphate buffered saline (PBS, pH=7.4). After gently blowing and mixing, the tubes were centrifuged again at 4°C, 350g for 5 min, and the supernatant was discarded (repeated three times) to obtain pure red blood cells. The red blood cells and PBS solution were mixed to prepare a red blood cell suspension with a volume ratio of 8%. 20μL of 8% red blood cell suspension was added to 20μL of different concentrations of B@MC solution or 1% TritonX-100 solution, and the final concentration of B@MC in the mixed solution was 0, 20, 50, 100, 200, 500 or 1000μg / mL (three replicates were set for each concentration). Afterwards, shake at 1000 rpm for 1 h in a 37°C metal bath shaker. Centrifuge at 350 g for 5 min and collect photos. Then, carefully pipette 20 μL of supernatant into a 96-well plate, and add 180 μL of PBS solution to each well. After slight shaking and mixing, use an ELISA reader to measure the OD value at a wavelength of 576 nm to calculate the hemolysis of red blood cells in each well.

[0052] like Fig. 9As shown in the figure, the results show that as the concentration of B@MC increases, red blood cells can still maintain their structural integrity, and whether it is a low concentration or a high concentration of B@MC, it almost does not induce red blood cell hemolysis. This result further illustrates the feasibility of B@MC for intravenous administration.

[0053] Study on reducing acute bleeding by magnetic clusters B@MC at the in vivo level

[0054] Experiment 1: Magnetic cluster B@MC can effectively reduce the amount of bleeding in acute bleeding of the inferior vena cava in rats

[0055] Male SD rats weighing 250 g were anesthetized with 1.5% pentobarbital and fixed on a small animal operating table with the abdomen facing upward. After skin preparation, the abdominal skin was disinfected with iodine, and a wound of 4 cm was cut along the upper part of the midline of the abdomen to expose the inferior vena cava. The mucosa on the surface of the vein was gently removed with a dry cotton swab, and the nearby fluid was cleaned as much as possible. A puncture bleeding point was made in the center of the vein using a 5 mL syringe needle, and then 0.5 mg / kg of B@MC solution or saline solution was immediately administered from the dorsal vein of the rat penis, and the administration volume was 1 mL. While the drug was pushed, a cylindrical magnet (~550 mT, 8 mm diameter 10 mm height N52 neodymium iron boron magnet) was immediately placed close to the bleeding point. The magnet was placed for 5 minutes, and then the magnet was removed, and continued to wait quietly for 15 minutes, and all bleeding was collected and weighed.

[0056] like Fig.10 As shown in (a, b), under magnetic drive, B@MC can be accurately enriched at the bleeding point and physically block the bleeding point to reduce bleeding. Quantitative analysis by inductively coupled plasma mass spectrometer (ICP-MS) shows that ~40% of B@MC can be enriched at the bleeding point and its vicinity. Fig.10 (c) The bleeding volume experiment also shows that the bleeding volume of the saline injection alone and saline plus magnetic field group is large, both about 3g, and the addition of magnetic field alone does not reduce the bleeding volume, and there is no significant difference from the saline group; while the administration of B@MC slightly reduces the bleeding volume, and the bleeding volume is reduced to ~2.7g, which may be due to the presence of B@MC in the blood, which changes the coagulation of rats to a certain extent. After adding the external magnetic field, the bleeding volume of the inferior vena cava is significantly reduced, and the bleeding volume is reduced to about 1g, which is ~67% less than that of the saline group, indicating that B@MC can indeed be driven by the external magnetic force to enrich at the acute bleeding site of the inferior vena cava, thereby reducing bleeding.

[0057] Experiment 2: Magnetic cluster B@MC can effectively reduce the amount of bleeding in acute tail hemorrhage in mice

[0058] Male Kunming mice weighing 30 g were anesthetized with isoflurane and fixed on a small animal operating table in a prone position. A syringe was inserted into the mouse tail vein from the upper 1 / 2 of the mouse tail, and the mouse tail was cut off from the 1 / 2 position. At the same time of cutting, physiological saline solution or B@MC solution was immediately injected into the mouse from the mouse tail vein. The dosage was 1.0 mg / kg of B@MC solution, and the administration volume was 200 μL. At the same time as the drug was pushed, a cylindrical magnet (~550 mT, 8 mm diameter 10 mm height N52 NdFeB magnet) was immediately placed above the mouse tail close to the bleeding point. The magnet was placed for 10 minutes, and then the magnet was removed and continued to wait quietly for 15 minutes to collect all bleeding and weigh it.

[0059] like Fig.11 As shown, both the saline group and the saline plus magnetic field group had heavy bleeding after cutting off 1 / 2 of the tail, with an average amount of bleeding of about 0.85-0.95g. There was no significant difference between the two groups, indicating that whether or not the magnetic field was loaded had almost no effect on the coagulation of mice. The amount of tail bleeding in the B@MC group was slightly reduced, at about 0.73g. This may be related to the fact that B@MC entered the mouse body and affected the coagulation function of the mouse. The amount of tail bleeding in the B@MC plus magnetic field group was significantly reduced, at about 0.42g, which was a decrease of ~55% compared with the saline group, indicating that B@MC can indeed be driven by external magnetic force to enrich at the acute bleeding site of the mouse tail, thereby reducing bleeding.

[0060] Experiment 3: Magnetic cluster B@MC can effectively reduce the amount of acute hepatic bleeding in mice

[0061] Male Kunming mice weighing 30 g were anesthetized with isoflurane and fixed in a supine position on a small animal operating table. The mouse's abdominal hair was shaved and disinfected with iodine. An incision of about 1-1.5 cm was made along the midline of the abdomen below the liver. Carefully squeeze out one lobe of the mouse liver with a cotton swab and place it on gauze. The gauze was used to clean the liquid near the liver as much as possible. Subsequently, the liver was transferred to a round filter paper lined with a sealing film. First, an insulin injection needle containing saline or B@MC solution was inserted into the mouse's tail vein, and then a razor blade was used to make an incision of about 5 mm wide and 2 mm deep in the middle of the mouse liver lobe. Immediately, saline or B@MC solution was injected into the mouse through the tail vein. While the drug was pushed, a cylindrical magnet (~550 mT, 10 mm diameter 10 mm height N52 neodymium iron boron magnet) was immediately placed close to the liver above the bleeding site of the mouse. The dosage was 1.0 mg / kg of B@MC solution, and the administration volume was 200 μL. The magnet was placed for 10 minutes, after which it was removed and the rats continued to wait quietly for 15 minutes to collect and weigh all the bleeding.

[0062] like Fig.12 As shown in (a), after B@MC was injected into the tail vein, a magnet was placed at the wound, and B@MC could be enriched at the bleeding wound. From the amount of bleeding, it can be seen that, similar to the previous results, the amount of bleeding in the saline group and the saline plus magnetic field group was relatively large, about ~210 mg. The application of magnetic field induction alone did not improve the bleeding of the wound. After intravenous injection of B@MC, the amount of bleeding in the mouse liver wound was slightly reduced to about 180 mg; when B@MC was injected intravenously and an external magnetic field was applied at the same time, the amount of bleeding was significantly reduced to about 110 mg, which was reduced by ~48% compared with the saline group. The results show that B@MC can indeed improve the bleeding of the mouse liver incision wound through external magnetic field driving.

[0063] The above are only specific embodiments disclosed in the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

[0064] The content of the present invention and the technical content not specifically described in the above embodiments are the same as the prior art.

[0065] The present invention is not limited to the above embodiments, and all of the contents of the present invention can be implemented and have the above good effects.

Claims

1. A magnetic cluster nanomaterial that can be driven by magnetic force, characterized in that: The magnetic cluster nanomaterial that can be driven by magnetic force comprises, by weight, 0.5-2 parts of iron oxide nanoparticles, 10-40 parts of phosphorylated polyethylene glycol, 10-40 parts of polymethyl methacrylate, 0.4-1.2 parts of sodium dodecyl sulfate, and 5-20 parts of bovine serum albumin.

2. A method for preparing the magnetic cluster nanomaterial that can be driven by magnetic force according to claim 1, characterized in that: The method comprises the following steps: 1) Dissolve 10-40 parts of phosphorylated polyethylene glycol and 7.5-30 parts of bromoisobutyryloxyethylphosphonic acid in 1 mL of chloroform, stir evenly, then add the mixture dropwise to 0.5-2 parts of iron oxide nanoparticles, and stir at room temperature for at least 12 hours; then, centrifuge and wash the obtained product using a mixture of acetone / diethyl ether in a volume ratio of 2:1, 4000g, 5min, and repeat three times; disperse the obtained product IO@PEG / BiBEP in a dimethylformamide solution for later use; 2) 0.5-1.5 parts of methyl methacrylate are slowly added to the IO@PEG / BiBEP obtained in the previous step, and the reaction system is degassed with nitrogen for 30 minutes, and then 20-40 parts of cuprous bromide and 100-150 parts of tri[2-(dimethylamino)ethyl]amine are added to the reaction system, and the reaction substances are mixed evenly and reacted in a 40° C. water bath for 12 hours; after the reaction is completed, the obtained product IO@PEG / PMMA is separated by magnetic attraction and dispersed in a chloroform solution for later use; 3) 0.5-2 parts of the IO@PEG / PMMA synthesized in the previous step were taken, and 0.4-1.2 parts of sodium dodecyl sulfate solution were slowly added thereto, and then ultrasonic emulsification was performed at 100 W for 5 minutes using an ultrasonic cell disruptor; the obtained reaction solution was stirred at room temperature for at least 10 hours to remove the organic solvent, and a magnetic cluster nanomaterial soluble in water was obtained.

3. The method for preparing a magnetic cluster nanomaterial that can be driven by magnetic force according to claim 2, characterized in that: The step 3) further includes the step 4) of slowly dripping different volumes of 0.01 mg / mL bovine serum albumin solution into the magnetic cluster nanomaterial obtained in the step 3), then gently vortexing several times to evenly disperse the BSA in the reaction solution, incubating at room temperature for at least 30 minutes, and separating the product by magnetic attraction to obtain the final product, which is a magnetic cluster that can be driven by magnetic force.

4. Use of the magnetically drivable magnetic cluster nanomaterial according to claim 1 in incompressible acute hemorrhage.

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