Nano-carbon–iodine calcium alginate microsphere, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are a nano-carbon–iodine calcium alginate microsphere and a preparation method therefor. In the microsphere, the development capability of iodine under X-ray is enhanced by means of adding nano-carbon, and thus the microsphere provides a good approach for solving the problem whereby an embolic agent cannot be developed under X-ray in clinical application. The microsphere has a simple preparation method and has good stability and safety. Experiments confirm that the microsphere can be developed under conventional interventional X-ray examination equipment, such as CT and DSA; and animal experiments confirm that the microsphere has good X-ray developing performance and a good embolization effect.

Description

Nano-carbon-iodine calcium alginate microspheres and preparation method and application thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical materials, and particularly relates to a nano-carbon-iodine calcium alginate microsphere and a preparation method and application thereof. BACKGROUND

[0002] Embolic microspheres are commonly used embolic materials in the process of interventional therapy of primary liver cancer. Although there are many types of embolic microspheres that can be used in clinical practice, the common problem faced is that the material itself cannot be developed under X-ray. The operation needs to be assisted by iodine-containing contrast agent imaging. The surgeon sees the contrast agent rather than the embolic agent. The clinician actually wants to observe the embolic agent rather than the contrast agent. The actual development agent in the operation is disconnected with the imaging needs of the therapeutic embolic material.

[0003] The development effect of the existing barium sulfate calcium alginate microspheres (Wang Q, Qian K, Liu S, et al. X-ray visible and uniform alginate microspheres loaded with in situ synthesized BaSO4 nanoparticles for in vivo transcatheter arterial embolization[J]. Biomacromolecules. 2015 Apr 13;16(4):1240-6.) in the current research is slightly better than calcium, but the toxicity threshold of barium is low, which may limit its wide application by clinicians. Tantalum nanoparticle calcium alginate (Zeng J, Li L, Zhang H, et al. Radiopaque and uniform alginate microspheres loaded with tantalum nanoparticles for real-time imaging during transcatheter arterial embolization[J]. Theranostics. 2018 Aug 10;8(17):4591-4600.) is expensive, and its toxicity needs to be further clarified. The iodinated oil microspheres of calcium alginate (Yi Hongfu, Ren Dongwen, Bao Decai, et al. Preparation of radioautographic calcium alginate embolic microspheres[J]. Functional Materials, 2006, 37(12): 1988-1990.) have good imaging properties, but the degraded iodinated oil is a liquid embolic material, which may be displaced, has poor adaptability to some organs, and has limited storage time after preparation, which makes it difficult for clinical application.

[0004] Nano carbon black is a new type of carbon-based nanomaterial, which has high drug loading capacity, good biocompatibility, and adjustable physical and chemical properties. In recent years, it has been widely used in the medical field. Application of nano carbon black in biomedical imaging: Nano carbon black can achieve good dispersibility and biocompatibility through surface modification, and can be used as an imaging probe in imaging technology. Nano carbon black can be used as a raw material for MRI contrast agents, and its high absorption and high scattering rate can enhance the imaging effect of the corresponding imaging technology. Nano carbon black can be used as a good drug carrier and is widely used in pharmaceuticals. Nano carbon black-based biomaterials and biological tissue engineering materials can be prepared to achieve the repair and regeneration of biological materials. In addition, nano carbon black can also be widely used in the manufacture of artificial joints. The wide application prospect of nano carbon black is not only limited to drugs, imaging and materials, but also can be applied to tumor treatment, artificial organ manufacturing and other fields (Klein AL, Nugent g, Cavendish J, Geldenhuys WJ, Sriram K, Porter D, Fladeland R, Lockman PR, Sherman JH. Nanoparticles as a Tool in Neuro-Oncology Theranostics. Pharmaceutics. 2021 Jun 24;13(7):948.). SUMMARY

[0005] The purpose of the present application is to provide a nano carbon-iodine calcium alginate microsphere and its preparation method and application, which can overcome the problem of embolism agent imaging, has high product stability, simple preparation process, can realize industrialized production, and has high clinical application value.

[0006] In order to achieve the above-mentioned purpose of the application, the following technical solutions are provided:

[0007] The present application provides a kind of nano carbon-iodine calcium alginate microsphere, the microsphere includes nano carbon powder, iodine and calcium alginate, the iodine is located in the interior of calcium alginate microsphere, and the nano carbon powder is coated in the interior of calcium alginate microsphere.The iodine loading rate of the microsphere is 35%-50%, and the carbon loading rate is 30%-50%.

[0008] The present application also provides a preparation method of nano carbon-iodine calcium alginate microsphere, comprising the following steps:

[0009] 1) prepare an aqueous solution of sodium alginate containing iodine;

[0010] 2) prepare an aqueous solution containing a crosslinking agent;

[0011] 3) preparing a first suspension of the nanometer carbon powder and the liquid, and mixing the suspension with the aqueous solution of the iodine-containing sodium alginate prepared in step 1) to form a second suspension;

[0012] 4) placing the second suspension obtained in step 3) in a syringe, and then injecting the syringe into the aqueous solution of the crosslinking agent prepared in step 2) under stirring to obtain nanometer carbon-iodine calcium alginate microspheres;

[0013] 5) filtering and drying the nanometer carbon-iodine calcium alginate microspheres obtained in step 4);

[0014] 6) sieving the microspheres obtained in step 5) and sterilizing the microspheres under irradiation of a cobalt 60.

[0015] Preferably, the liquid is one or more of water, anhydrous ethanol, propanol or Tween 80.

[0016] Preferably, the crosslinking agent is a divalent metal cation compound selected from one or more of magnesium chloride, zinc chloride, copper chloride, barium chloride, ferrous sulfate, magnesium sulfate, zinc sulfate, calcium chloride, calcium hypochlorite, calcium bromide or calcium iodide.

[0017] Preferably, the aqueous solution of the iodine-containing sodium alginate is a solution of potassium iodide and sodium alginate dissolved in water, wherein the mass ratio of potassium iodide to sodium alginate is potassium iodide:sodium alginate = 5-10:0.1-2.0, and the mass concentration of the aqueous solution of the sodium alginate is 10-20 mg / mL.

[0018] Preferably, the mass concentration of the aqueous solution of the crosslinking agent is 20-150 mg / mL.

[0019] Preferably, the first suspension contains 0.05-0.15 g of the nanometer carbon powder per milliliter of the solution; and the mass ratio of the sodium alginate to the nanometer carbon powder in the second suspension is 2-3:1.

[0020] Preferably, the nanometer carbon powder has a particle size of 2-500 nm.

[0021] Preferably, the sieved microspheres in step 6) have a diameter of 20-900 μm.

[0022] The application also provides use of the nanometer carbon-iodine calcium alginate microspheres in preparation of a developing embolism material.

[0023] Advantages

[0024] The application provides a kind of nano carbon-calcium alginate iodine microspheres and preparation method thereof, the microspheres are strengthened by adding nano carbon to enhance the X-ray development ability of iodine, which is a better solution to the problem of embolic agent in clinical application that cannot be imaged under X-ray, and the preparation method is simple, has good stability and safety, and experiments have proved that it can be developed under conventional X-ray examination equipment CT, DSA, which can achieve (1) visual in imaging, which is convenient for clinical embolization effect positive evaluation, (2) help diagnose the cause, suspicious ectopic embolization disease diagnosis after interventional operation plays a role in diagnosis, and plays a decisive role in the treatment of related diseases. (3) real-time precision in clinical operation process, nano carbon-calcium alginate iodine microspheres can solve the problem of X-ray development in the process of intervention. (4) animal experiments have proved that it has good X-ray imaging performance and embolization effect. (5) The addition of nano carbon powder may carry drugs and deliver drugs in the future. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the morphology of the nano carbon-calcium alginate iodine microspheres prepared in Example 1 under optical microscope;

[0026] Figure 2 is the Fourier infrared spectroscopy spectrum of the nano carbon-calcium alginate iodine microspheres prepared in Example 1;

[0027] Figure 3 is the X-ray diffraction detection spectrum of the nano carbon-calcium alginate iodine microspheres prepared in Example 1;

[0028] Figure 4 is the naked eye observation of the nano carbon-calcium alginate iodine microspheres prepared in Example 1, which is black granular and settled at the bottom of the syringe; the syringe is placed under a digital gastrointestinal machine for observation, and the results show that the development is clear; it is placed under DSA for observation, and the granular development can be seen, and the particle density is uniform; the syringe is placed in the author's femoral external row CT for detection, and it is found that the development is clear, and the density is close to bone density.

[0029] Figure 5 is the in vitro liver imaging of the nano carbon-calcium alginate iodine microspheres prepared in Example 1, the square graph represents the development of 0.1 milliliter of microspheres and 1 milliliter of 0.9 sodium chloride solution injected into the syringe; the prototype graph represents the development of 0.2 milliliter of microspheres and 1 milliliter of 0.9 sodium chloride solution injected into the syringe, and the arrow represents the control group. As can be seen from the image, 0.1 milliliter can see faint development, 0.2 milliliter clear development, and the imaging performance increases with the increase of concentration.

[0030] Figure 6 is the CT imaging of the nano carbon-calcium alginate iodine microspheres prepared in Example 1 in the in vitro pig liver blood vessels; a represents the horizontal plane image, the horizontal plane can see high density granular imaging, along the blood vessel running, and the granular imaging can be seen in the distal blood vessels; b represents the transverse plane image, which can see the high density shadow of the transverse plane along the blood vessel running, and the granular and strip distribution embolization particles can be seen around.

[0031] Figure 7 is the CT imaging results of the carbon-iodine calcium alginate microspheres prepared in Example 1 in a rabbit embolization experiment. The control group is biosphere embolization microspheres (300-500 μm). a represents a cross-sectional view, and high-density images can be seen in the liver and heart; b is a coronal view, and high-density images can be seen in the mediastinum, chest, liver, and abdominal cavity; c is a sagittal view, and high-density images can be seen in the mediastinum, chest, liver, and abdominal cavity; d is a three-dimensional adjusted view, and high-density images close to the bone density can be seen in the chest and abdominal cavity. The above results show that the carbon-iodine calcium alginate microspheres have good CT imaging performance.

[0032] Figure 8 is the results of the rabbit ear median artery embolization experiment of the carbon-iodine calcium alginate microspheres prepared in Example 1. a Preoperative: The rabbit ear median artery is clearly visible, the surrounding blood vessels are thin, and the course is natural. b Immediately after operation: The rabbit ear median artery is clearly visible, dilated, and the internal black embolization microspheres, the surrounding blood vessels are dilated and hyperemic, and the distal part can see black embolization particles, the course is less natural. c 24 hours after operation: The rabbit ear median artery is clearly visible, the dilation is increased, and the internal black embolization microspheres, the surrounding blood vessels are dilated and hyperemic; the black embolization particles are more clearly visible in the fine blood vessels, and the course is natural. d 48 hours after operation: The rabbit ear median artery is clearly visible, the dilation is weakened, and the internal black embolization microspheres are reduced, the surrounding blood vessels are dilated and hyperemic; the black embolization particles are more clearly visible in the fine blood vessels, and the course is natural and the color is lighter. e 72 hours after operation: The rabbit ear median artery is clearly visible, the dilation is weakened, and the internal black embolization microspheres are unchanged, the surrounding blood vessels are dilated and hyperemic; the black embolization particles are more clearly visible in the fine blood vessels, and the course is natural and the color is lighter. DETAILED DESCRIPTION

[0033] In order to deepen the understanding of the present application, the present application will be further described below in conjunction with examples and drawings, which are only used to explain the present application and do not constitute a limitation on the scope of protection of the present application.

[0034] The nanometer carbon powder in the following examples is purchased from Suzhou Carbon Fortune Graphene Technology Co., Ltd., and the particle size is 2-500 nm.

[0035] Example 1 Preparation of nanometer carbon-iodine calcium alginate microspheres

[0036] 1) Weigh 10 g of potassium iodide into container A;

[0037] 2) Weigh 1.5 g of sodium alginate into the potassium iodide container A;

[0038] 3) Add 100 mL of double-distilled water to container A to form a ratio of potassium iodide (g) : sodium alginate (g) : water (mL) = 10:1.5:100; place the solution in container A in a blender (100 r / min) and stir overnight until the sodium alginate is completely dissolved;

[0039] 4) Prepare 75 mg / mL calcium chloride aqueous solution as crosslinking agent, stand for 2 hours for standby;

[0040] 5) Take 5 mL of anhydrous ethanol and place it in container B, weigh 0.5 g of nano-carbon powder and place it in B, form a first suspension of nano-carbon powder and anhydrous ethanol, add it to container A before preparing the microspheres, form a ratio of potassium iodide (g): sodium alginate (g): water (mL): anhydrous ethanol (mL): nano-carbon powder (g) = 10:1.5:100:5:0.5, stir for more than 5 minutes to form a second suspension;

[0041] 6) Place the second suspension prepared in step 5 in a 10 mL syringe, the inner diameter of the syringe needle is 22G-23G,

[0042] Push it into the calcium chloride aqueous solution prepared in step 4) under stirring, the stirring speed is about 500 r / min, the push speed is about 5 mL / min, the distance between the syringe needle and the liquid level is controlled at 25-50 cm, and the push is uniform;

[0043] 7) After the push is completed, continue to stir for 30 minutes; filter out the liquid containing calcium chloride after the microspheres are formed, wash the nano-carbon-iodine calcium alginate microspheres with double distilled water for 2 times, then filter out the liquid and reserve the nano-carbon-iodine calcium alginate microspheres;

[0044] 8) Place the nano-carbon-iodine calcium alginate microspheres in a vacuum freeze dryer (-55°C) for drying for more than 14 hours;

[0045] 9) Place the prepared microspheres in a 20-900 um diameter sieve for screening, and prepare 20-900 um diameter microspheres;

[0046] 10) Place the sieved microspheres above under a cobalt 60 line for irradiation sterilization for 30 minutes.

[0047] Example 2 Preparation of nano-carbon-iodine calcium alginate microspheres

[0048] 1) Weigh 10 g of potassium iodide and place it in container A;

[0049] 2) Weigh 1.2 g of sodium alginate and place it in container A with potassium iodide;

[0050] 3) Add 100 mL of double distilled water to container A to form a ratio of potassium iodide (g): sodium alginate (g): water (mL) = 10:1.2:100; place the solution in container A in a stirrer (100 r / min) and stir overnight until the sodium alginate is completely dissolved;

[0051] 4) Prepare 100 mg / mL calcium chloride aqueous solution as crosslinking agent, stand for 2 hours for standby;

[0052] 5) Take 5 mL of propanol and place it in container B. Take 0.5 g of nanocarbon powder and place it in B. Form a first suspension of nanocarbon powder and anhydrous ethanol. Add the first suspension to container A before preparing the microspheres to form a second suspension of potassium iodide (g): sodium alginate (g): water (mL): anhydrous ethanol (mL): nanocarbon powder (g) = 10:1.2:100:5:0.5. Stir for more than 5 minutes to form the second suspension;

[0053] 6) Place the second suspension prepared in step 5 in a 10 mL syringe. The inner diameter of the syringe needle is 22G-223G,

[0054] Push the syringe into the magnesium chloride aqueous solution prepared in step 4) that is in a stirring state. The stirring speed is about 500 r / min, the pushing speed is about 5 mL / min, the distance between the syringe needle and the liquid level is controlled to be 25-50 cm, and the pushing is uniform;

[0055] 7) After the pushing is completed, continue to stir for 30 minutes. Filter out the liquid containing calcium chloride after the spheres are formed. Wash the nanocarbon-iodine calcium alginate microspheres with double distilled water for 2 times, filter out the liquid, and retain the nanocarbon-iodine calcium alginate microspheres;

[0056] 8) Place the nanocarbon-iodine calcium alginate microspheres in a vacuum freeze dryer (-55°C) and dry for more than 14 hours;

[0057] 9) Place the prepared microspheres in a 20-900 um diameter sieve for screening to prepare microspheres with a diameter of 20-900 um;

[0058] 10) Place the sieved microspheres in a cobalt 60 column and irradiate for 30 minutes.

[0059] Example 3 Preparation of nanocarbon-iodine calcium alginate microspheres

[0060] 1) Take 10 g of potassium iodide and place it in container A;

[0061] 2) Take 1.5 g of sodium alginate and place it in container A with the potassium iodide;

[0062] 3) Add 100 mL of double distilled water to container A to form a ratio of potassium iodide (g): sodium alginate (g): water (mL) = 10:1.5:100. Place the solution in container A in a stirrer (100 r / min) and stir overnight until the sodium alginate is completely dissolved;

[0063] 4) Prepare a 120 mg / mL calcium chloride aqueous solution as a crosslinking agent and let it stand for 2 hours for standby;

[0064] 5) Take 5 mL Tween 80 and place it in container B, take 0.75 g of nanometer carbon powder and place it in B, form a first suspension of nanometer carbon powder and anhydrous ethanol, add it to container A before preparing the microspheres, form a second suspension of KI (g) : sodium alginate (g) : water (mL) : anhydrous ethanol (mL) : nanometer carbon powder (g) = 10:1.5:100:5:0.75, stir for more than 5 minutes;

[0065] 6) Place the second suspension prepared in step 5 in a 10 mL syringe, the inner diameter of the syringe needle is 22G-223G,

[0066] Push it into the zinc sulfate aqueous solution prepared in step 4) under stirring, the stirring speed is about 500 r / min, the push speed is about 5 mL / min, the distance between the syringe needle and the liquid level is controlled at 25-50 cm, and the push is uniform;

[0067] 7) After the push is completed, continue to stir for 30 minutes; filter out the liquid containing calcium chloride after the microspheres are formed, rinse the nanometer carbon-iodine calcium alginate microspheres with double distilled water for 2 times, then filter out the liquid and reserve the nanometer carbon-iodine calcium alginate microspheres;

[0068] 8) Place the nanometer carbon-iodine calcium alginate microspheres in a vacuum freeze dryer (-55°C) and dry for more than 14 hours;

[0069] 9) Place the prepared microspheres in a 20-900 um diameter sieve for screening, and prepare 20-900 um diameter microspheres respectively;

[0070] 10) Place the sieved microspheres above under a cobalt 60 line for irradiation sterilization for 30 minutes.

[0071] Characterization and testing

[0072] 1) Under an optical microscope, measure the particle size of the microspheres with a micrometer, and the shape is shown in Figure 1, which is the morphology of the nanometer carbon-iodine calcium alginate microspheres prepared in Example 1 under an optical microscope, wherein a is the image of the nanometer carbon-iodine calcium alginate microspheres prepared after being placed in a 5 mL syringe and observed with the naked eye, the overall color of the calcium alginate microspheres is black, which is the same as the color of the carbon powder, and there is no free carbon powder in the solution in the syringe; b is a 10 times magnification image of the optical microscope, the microspheres in the microsphere shape image a are broken by pulling, and the carbon powder morphology is observed, c is a 40 times magnification image of b. Figure c and d show that the carbon powder is tightly combined with the calcium alginate, and the carbon powder is coated with calcium alginate after being broken.

[0073] 2) The prepared microspheres were placed in a Fourier infrared instrument for detection: the results showed that the specific peak values were 3423.9, 1630.43, and 563.86, and there were specific absorption peaks.

[0074] 3) The prepared microspheres were placed in an X-ray diffractometer for detection, and the results are shown in Figure 3; the results showed that there were mixed morphologies, and the smooth curve below was considered to be a nano-carbon crystal structure, which was consistent with our design expectations;

[0075] 4) Iodine drug loading, carbon drug loading, carbon encapsulation rate, iodine encapsulation rate, and water absorption rate testing

[0076] The test method is as follows:

[0077] Packaged I = total I - unencapsulated I, iodine encapsulation rate% = packaged I / total I * 100%, performed in 3 batches, and the average value was taken. 1.5% (concentration unit 1.5g / 100mL) starch indicator, sodium thiosulfate titration solution (0.1mol / L), 7.5% (7.5g / 100mL) calcium chloride solution 500mL were prepared respectively. Collect all the nano-carbon-iodine alginate solutions and flushing solutions during the injection process of Example 1 as a mixed solution, and weigh these unencapsulated nano-carbon-iodine alginate solutions and flushing solutions. The above mixed solution was titrated with the prepared sodium thiosulfate titration solution (0.1mol / L), and at the near end point, 2ml of starch indicator was added, and the titration was continued until the blue color disappeared. Every 1ml of sodium thiosulfate titration solution (0.1mol / L) was equivalent to 12.69mg of I2, and the amount of iodine not encapsulated into the calcium alginate microspheres was calculated. The results were taken as the average value after 3 measurements.

[0078] 0.3g of freeze-dried carbon-iodine calcium alginate microspheres freeze-dried powder was weighed with a balance and placed in 3 different beakers, with 0.1g of iodine alginate calcium microspheres in each bottle. The calcium alginate microspheres were dissolved with 3% sodium citrate solution to release iodine, and sodium thiosulfate solution was used for titration, and 1.5% starch was used for color development at the end. The iodine content was calculated by sodium thiosulfate solution. Iodine drug loading rate% = iodine / total nano-carbon-iodine calcium alginate microspheres * 100%, and the average value was taken for three times.

[0079] Carbon encapsulation rate determination. Weigh 2.5ml syringe, draw 2ml of prepared nano-carbon-iodine alginate solution and weigh, subtract the weight of the syringe as the weight of the nano-carbon-iodine alginate solution. The solution in the syringe was prepared into microspheres, then washed repeatedly with normal saline, and after standing, centrifuged, the unencapsulated carbon powder floated on the liquid above, and presented black, and the supernatant was discarded. The floating material was dried, then freeze-dried and weighed, which was the unencapsulated carbon powder. Encapsulated carbon = total carbon - unencapsulated carbon, carbon encapsulation rate% = encapsulated carbon / total carbon * 100%, and the average value of the measurement results was taken after repeating the experiment three times.

[0080] Carbon drug loading rate determination method: 2 mL of the prepared nano-carbon-iodine sodium alginate solution was used to prepare microspheres. After preparation, the syringe was rinsed three times with calcium chloride to ensure that all sodium alginate was converted into calcium alginate. The prepared carbon-iodine calcium alginate microspheres were centrifuged, the liquid was discarded, and the microspheres were freeze-dried. The reconstituted carbon-iodine calcium alginate microspheres were then weighed. Since the carbon encapsulation rate was close to 100%, the carbon in the solution represented the amount of carbon loaded into the microspheres. Carbon drug loading rate = (carbon / total carbon-iodine calcium alginate microspheres) * 100%, and the average of three values ​​was taken.

[0081] Weigh the empty vial, place the prepared microspheres from Example 1 into the vial, invert it onto filter paper, and wait for the water to be absorbed. Weigh the vial again and subtract the weight of the empty vial to obtain the wet weight (B). Freeze-dry the weighed vial, weigh it again after freeze-drying, and subtract the weight of the empty vial to obtain the dry weight (G). Compare the dry weight to obtain the water swelling rate, and repeat the process three times, taking the average value.

[0082] The average iodine encapsulation efficiency of the nano-carbon-iodine sodium alginate microspheres prepared in Example 1 was 70.31 ± 1.08%; the iodine loading rate was 44.7%; the average nano-carbon encapsulation efficiency was 98.0%; the carbon loading rate was 30.99%; and the average water absorption rate was 1070%.

[0083] The nano-carbon-iodine sodium alginate microspheres prepared in Example 2 had an average iodine encapsulation efficiency of 60.59 ± 2.10%, an iodine loading rate of 38.5%, an average nano-carbon encapsulation efficiency of 98.5%, a carbon loading rate of 39.99%, and an average water absorption rate of 1120%.

[0084] The nano-carbon-iodine sodium alginate microspheres prepared in Example 3 had an average iodine encapsulation efficiency of 65.42 ± 3.10%, an iodine loading rate of 43.3%, an average nano-carbon encapsulation efficiency of 98.3%, a carbon loading rate of 33.01%, and an average water absorption rate of 1221%.

[0085] 5) Development performance testing

[0086] Microsphere imaging performance test: 5 ml of the prepared nano-carbon-iodine calcium alginate microsphere suspension was placed on a digital gastrointestinal machine, a DSA machine, and observed on the patient's thigh. Clinical X-ray fluoroscopy mode (voltage 80 kVp, current 529 mA, delay 65 ms, 7 frames / second) and standard Allura Xper image processing were used, along with X-ray radiography mode (120 kVp, 350 mA, 0.5 mm collimator, field of view (FOV) 22x22 cm). Figure 4 shows the naked-eye image of the nano-carbon-iodine calcium alginate microsphere suspension, which appears black and granular. The suspension was clearly visualized on the digital gastrointestinal machine. Under DSA, the microspheres were clearly visualized as granules. In vitro imaging and CT imaging showed clear visualization with a density close to bone density, significantly higher than muscle density.

[0087] 6) In vitro liver experiment.

[0088] Take one piece of commercially available pig liver, one syringe, and an appropriate amount of heparin saline. First, rinse the pig liver with heparin saline repeatedly through the pig portal vein and hepatic artery to remove the thrombus, and then use it. Inject 0.1 g / mL carbon-iodine alginate calcium microspheres with 1.2 mL of physiological saline suspension into the parenchyma of the pig liver, and inject the same volume of commercially available BIOSPHERE 300-500 μm microspheres into the parenchyma of the pig liver. Place it under the DSA machine and observe the development effect. As shown in Figure 5, the nano-carbon-iodine alginate calcium microspheres in the experimental group develop in the pig liver, and the square mark represents 0.1 g, and the round mark represents 0.2 g. In the 0.1 g group, 0.2 g group, the dosage increases, and the development clarity increases. The control group (arrow mark) has no development.

[0089] Take 0.1 g / mL of nano-carbon-iodine alginate calcium microspheres prepared, one piece of commercially available pig liver, one syringe, and an appropriate amount of heparin saline. First, rinse the pig liver with heparin saline repeatedly through the pig portal vein and hepatic artery to remove the thrombus, and then use it. Inject 0.1 g of nano-carbon-iodine alginate calcium microspheres with 1 mL of physiological saline suspension into the parenchyma of the pig liver, and inject the same volume of commercially available BIOSPHERE 300-500 um microspheres into the parenchyma of the pig liver. Place it under the CT machine and observe the development effect. As shown in Figure 6, the left image shows the liver positioning image of nano-carbon-iodine alginate calcium microspheres in the isolated pig liver, showing high-density development of particles arranged along the blood vessels; the right image shows the cross-section, and the results show that the microspheres have high-density development and clear imaging.

[0090] 7) Application of nano-carbon-iodine alginate calcium microspheres (rabbit in vivo development experiment and rabbit ear median artery embolization experiment)

[0091] Rabbit in vivo experiment: New Zealand albino rabbits (Nanjing Drum Tower Hospital Animal Experiment Center) were adult, female, weighing 4.0-5.0 kg, and were approved by the Nanjing Drum Tower Hospital Animal Ethics Committee. Food and water were freely consumed. The prepared microspheres were injected into the liver, lung, and heart of the rabbits, and the development was observed. The results are shown in Figure 7.

[0092] We from a variety of different angles for imaging observation (Figure 7) experimental object, a: cross-sectional, b: coronal; c: sagittal; d: three-dimensional imaging. CT scan conditions: CT, tube voltage 120KV, tube current 90 mA, scan range whole body, after scanning the image is 3D reconstruction. CT experiments confirmed in vivo, can be in the liver, chest, heart, gastrointestinal imaging. Preoperative rabbit ear skin, after anesthesia placed on the operating table, rabbit ear artery for puncture observation point, disinfection, coaxial needle puncture into the ear artery, 1 ear injection of positive control microspheres (BIOSPHERE 300-500 μm microspheres, control group), the other injection of carbon alginate calcium microspheres (experimental group). Injection of 0.1 milliliter ball and 0.9 sodium chloride suspension, total volume of 1 milliliter. Through the rabbit ear artery embolization experiments confirmed that there is a good embolic effect, as shown in Figure 8a-e, a preoperative: rabbit ear artery visualization clear, peripheral blood vessels are thin, natural running. b immediately after surgery: rabbit ear artery visualization clear, dilatation, internal black embolic microspheres, peripheral vascular dilation, hyperemia, distal part can be seen black embolic particles, running less natural. c 24 hours after surgery: rabbit ear artery visualization clear, dilatation increased, internal black embolic microspheres, peripheral vascular dilation, hyperemia improved; black embolic particles fine blood vessels more clearly, running natural. d 48 hours after surgery: rabbit ear artery visualization clear, dilatation decreased, internal black embolic microspheres decreased, peripheral vascular dilation, hyperemia disappeared; black embolic particles fine blood vessels more clearly, natural, color faded. e 72 hours after surgery: rabbit ear artery visualization clear, dilatation decreased, internal black embolic microspheres no change, peripheral vascular dilation, hyperemia disappeared; black embolic particles fine blood vessels more clearly, natural, color faded.

[0093] The above only for the preferred embodiments of the present application, and not to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included within the scope of the present application.

Claims

1. A nanocarbon-iodinated calcium alginate microsphere, characterized by, The microspheres comprise nanometer carbon powder, iodine and calcium alginate, the iodine is inside the calcium alginate microspheres, and the nanometer carbon powder is coated inside the calcium alginate microspheres.

2. The nano-carbon-calcium-iodine alginate microspheres according to claim 1, characterized by, The iodine loading rate of the microspheres is 35-50%, and the carbon loading rate is 30-50%.

3. The method of claim 1 or 2, wherein the method is characterized by, The method comprises the following steps: 1) preparing an aqueous solution of sodium alginate containing iodine; 2) preparing an aqueous solution containing a crosslinking agent; 3) preparing a first suspension of nanometer carbon powder and a liquid, and mixing the suspension with the aqueous solution of sodium alginate containing iodine prepared in step 1) to form a second suspension; 4) placing the second suspension obtained in step 3) in a syringe, and then injecting it into the aqueous solution of the crosslinking agent prepared in step 2), which is under stirring, to obtain nanometer carbon-iodine calcium alginate microspheres; 5) filtering and drying the nanometer carbon-iodine calcium alginate microspheres obtained in step 4); 6) screening the microspheres obtained in step 5) and sterilizing them under irradiation of a cobalt 60.

4. The production method according to claim 3, characterized by, The liquid is one or more of water, anhydrous ethanol, propanol or Tween 80.

5. The preparation method according to claim 3, characterized in that, The crosslinking agent is a divalent metal cation compound selected from one or more of magnesium chloride, zinc chloride, copper chloride, barium chloride, ferrous sulfate, magnesium sulfate, zinc sulfate, calcium chloride, calcium hypochlorite, calcium bromide or calcium iodide.

6. The preparation method according to claim 3, characterized in that, The aqueous solution of sodium alginate containing iodine is a solution prepared by dissolving potassium iodide and sodium alginate in water, wherein the mass ratio of potassium iodide to sodium alginate is potassium iodide:sodium alginate = 5-10:0.1-2.0, and the mass concentration of the aqueous solution of sodium alginate is 10-20 mg / mL.

7. The preparation method according to claim 3, characterized in that, The mass concentration of the aqueous solution of the crosslinking agent is 20-150 mg / mL.

8. The preparation method according to claim 3, characterized in that, The first suspension contains 0.05-0.15 g of nanometer carbon powder per milliliter of solution, and the mass ratio of sodium alginate to nanometer carbon powder in the second suspension is 2-3:

1.

9. The preparation method according to claim 3, characterized in that, The particle size of the nanometer carbon powder is 2-500 nm.

10. Use of the nanometer carbon-iodine calcium alginate microspheres of any one of claims 1-9 in the preparation of a developing embolization material.

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