Visual nano composite material for magnetic resonance imaging for treating osteosarcoma and preparation method thereof

Abstract

The invention discloses a visual nano composite material for magnetic resonance imaging for treating osteosarcoma, and belongs to the technical field of nano materials. The nano composite material is prepared from the following raw materials in parts by mass: a gadolinium contrast agent, a modified natural polymer, a medicine component, a cross-linking agent, a stabilizer and a photoinitiator, the modified natural polymer comprises modified polylactic acid and modified chitosan; the medicine components comprise the Apatinib and the GSK-J4, and the mass ratio of the Apatinib to the GSK-J4 is (2 to 5) to (0.5 to 1); the gadolinium contrast agent comprises DOTA, glutamic acid and gadolinium ions, and the molar ratio of DOTA to glutamic acid to gadolinium ions is 1: (4-6): (2-3). The efficient, safe and multifunctional nano composite material is developed through a fine formula design, an innovative preparation process and a synergistic effect of functional components, and the material not only can provide high-quality magnetic resonance imaging, but also can realize targeted delivery and controlled release of drugs, and provides a new possibility for treatment of osteosarcoma.

Description

Technical Field

[0001] The invention belongs to the technical field of nano materials, and in particular relates to a visualized nano composite material for magnetic resonance imaging for treating osteosarcoma and a preparation method thereof. Background Art

[0002] Osteosarcoma, also known as osteogenic sarcoma or osteogenic sarcoma, is a malignant connective tissue tumor characterized by the ability of tumor cells to directly produce tumor bone and bone-like tissue. Osteosarcoma ranks first among primary malignant tumors, accounting for about 20-34% of all primary malignant bone tumors. It is highly malignant and has a very poor prognosis. It can metastasize to the lungs within a few months, and the survival rate after amputation for 3-5 years is only 5-20%.

[0003] Treatment of osteosarcoma usually involves a multidisciplinary approach that includes the following aspects:

[0004] (1) Drug therapy: Chemotherapy is given before surgery to reduce the size of the tumor, reduce the difficulty of surgery, and evaluate the tumor's response to chemotherapy drugs. Commonly used chemotherapy drugs include methotrexate, doxorubicin, cisplatin, and ifosfamide.

[0005] (2) Surgical treatment: Resection of the tumor and a certain range of healthy tissue around it, while preserving limb function as much as possible.

[0006] (3) Radiotherapy: as an auxiliary treatment method.

[0007] (4) Targeted therapy and immunotherapy: With the deepening of our understanding of the biological mechanisms of osteosarcoma, targeted therapy and immunotherapy are becoming research hotspots, but this therapy is still in the clinical trial stage.

[0008] (5) Gene therapy: Osteosarcoma involves multiple genetic abnormalities. The goal of gene therapy is to target these abnormal genes, but it is still in the clinical trial stage.

[0009] In recent years, nanotechnology has rapidly entered the field of tumor treatment. Active or passive targeted therapy and even gene therapy using nanomaterials as carriers can not only reduce the toxic and side effects caused by the nonspecific distribution of chemotherapy drugs, but also target tumor stem cells, resist multidrug resistance, and improve the anti-cancer efficacy of drugs. Although nanocomposites for the treatment of osteosarcoma can bring many advantages in design and application, there are also some potential disadvantages:

[0010] (1) Biocompatibility issues: The components of nanocomposites may have certain cytotoxicity and are difficult to degrade and eliminate in the body. Long-term accumulation may cause organ damage.

[0011] (2) Stability issues: Nanocomposites are prone to deterioration during long-term storage and in extreme environments, causing drug ineffectiveness.

[0012] (3) Single function: Nanocomposites have the function of treating osteosarcoma, but they do not have visual diagnostic functions and cannot accurately locate tumors and deliver drugs. Summary of the invention

[0013] The purpose of the present invention is to provide a visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma, so as to solve the problems of biocompatibility and storage stability of the above nanomaterials as carriers for treating osteosarcoma. The present invention develops an efficient, safe and multifunctional nanocomposite material through a sophisticated formula design, which can not only provide high-quality magnetic resonance imaging, but also achieve targeted delivery and controlled release of drugs, providing new possibilities for the treatment of osteosarcoma.

[0014] To achieve the above object, the present invention provides a visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma. The nanocomposite material comprises the following raw materials in parts by mass:

[0015]

[0016]

[0017] Preferably, the drug component comprises Apatinib and GSK-J4, and the mass ratio of Apatinib to GSK-J4 is (2-5): (0.5-1).

[0018] Preferably, the gadolinium contrast agent comprises DOTA, glutamic acid and gadolinium ions, and the molar ratio of DOTA:glutamic acid:gadolinium ions is 1:(4-6):(2-3).

[0019] At present, nanomedicine has been used in the treatment of many diseases, but in the process of clinical use, it does not have a visual diagnosis function and cannot achieve the effect of integrated diagnosis and treatment, which limits the development of nanomedicine. The present invention creatively combines gadolinium contrast agents and drug components in a nanocomposite material at the same time. The use of gadolinium contrast agents can significantly enhance the signal intensity of magnetic resonance imaging, help to more accurately identify and locate the position and range of osteosarcoma, and contribute to more accurate diagnosis and treatment. In addition, the drug components in the nanocomposite material can be encapsulated and delivered to the osteosarcoma lesion to achieve targeted therapy, provide therapeutic effects and reduce side effects. In addition, the present invention uses modified natural polymers as a matrix, which can provide good biocompatibility, and the material can be naturally degraded in the body, reducing the risk of long-term existence.

[0020] During the research and development process, the inventors also found that although the addition of gadolinium contrast agents and drug components can achieve integrated diagnosis and treatment of nano-composite materials, the addition of gadolinium contrast agents will, on the one hand, affect the stability of the nano-composite materials and their own imaging effect will also deteriorate. On the other hand, it is also necessary to consider the storage time and transportation conditions of the overall nano-composite materials after mixing with drug molecules.

[0021] The inventors have found that certain modifications to the gadolinium contrast agent can increase the stability and imaging effect of the gadolinium contrast agent. The present invention uses glutamic acid to modify DOTA, which can increase the binding force between the chelating agent and the gadolinium ion, thereby forming a stable gadolinium chelate. This stable structure can reduce the release of gadolinium ions in the body. In addition, the preparation of the gadolinium contrast agent under a specific ratio can further increase its imaging effect. Once the ratio between DOTA, glutamic acid and gadolinium ions is changed, the magnetic resonance imaging effect will be deteriorated.

[0022] Preferably, the preparation method of gadolinium contrast agent is:

[0023] Glutamic acid is dissolved in N,N-dimethylformamide, and then DOTA is added to perform amino acid modification to obtain a modified chelating agent;

[0024] The modified chelating agent is dissolved in water and gadolinium ions are added, heated for reaction, filtered, washed and dried to obtain a gadolinium contrast agent.

[0025] Preferably, the preparation method of modified polylactic acid is:

[0026] Add 300-500g of toluene to 200-300g of polylactic acid to dissolve the polylactic acid, then add 40-60g of maleic anhydride and 2-5g of 2,5-dimethyl-2,5-di-tert-butylperoxy-hexane after heating the temperature to 80-90°C, and react for 3-5 hours under heat preservation and stirring. After the reaction is completed, add methanol for precipitation, and wash repeatedly with methanol to remove unreacted maleic anhydride, and put the washed product into a constant temperature blast drying oven at 80-90°C for drying to obtain maleic anhydride grafted polylactic acid;

[0027] 100-150g of maleic anhydride grafted polylactic acid is dissolved in 400ml of tetrahydrofuran, and then 10-15g of hydroxymethylamine is added, and the mixture is reacted at room temperature for 5-15 minutes. After separation, purification and drying, the product is dissolved in a mixed solvent formed by 400ml of tetrahydrofuran and dimethylformamide, 25-50g of polyethylene glycol with a molecular weight of 1000 and 5-10g of 1,6-hexamethylene diisocyanate are dissolved in the mixed solvent, the three components are mixed evenly, and the mixture is reacted at 50-70°C for 2-5 hours. After separation and purification, the product is dissolved in a mixed solvent, 50-100g of galactose dissolved in the mixed solvent is added, and the mixture is reacted at 50-80°C for 2-5 hours to obtain modified polylactic acid.

[0028] Preferably, according to the mass fraction, the preparation method of modified chitosan is:

[0029] At room temperature, 1 to 5 parts of galactose and 10 to 20 parts of acetic anhydride are reacted in pyridine for 48 to 72 hours, extracted with dichloromethane, washed with saturated sodium bicarbonate, dried, filtered and concentrated to obtain acetylated galactose; 3 to 5 parts of mercaptopropionic acid and 0.5 to 1.5 parts of boron trifluoride ether are added to the acetylated galactose and reacted in dichloromethane for 10 to 20 hours; methanol is added, the pH value is adjusted to 11 with triethylamine, and the reaction is carried out for 4 to 8 hours to obtain galactosylmercaptopropionic acid;

[0030] 3 to 5 parts of galactosylmercaptopropionic acid, 3 to 5 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 3 to 5 parts of N-hydroxysuccinimide are mixed, stirred in dimethyl sulfoxide for 1 to 3 hours, and then a chitosan solution whose pH value is adjusted to 6 in advance is added, stirred for 12 to 48 hours, dialyzed for 3 days using ultrapure water in a dialysis bag with a molecular weight cutoff of 13000Da, and freeze-dried to obtain modified chitosan.

[0031] The modified polylactic acid and modified chitosan in the present invention are the main components of the nanocomposite material. The polylactic acid is first grafted with maleic anhydride to obtain a new functional group, which not only improves its binding force with drug molecules and other molecules, but also improves its physical and chemical properties, making it easier to react with galactose. Adding galactose can increase the targeting of the material and improve the ability to be recognized and taken up by cells. The modified polylactic acid can better adsorb and encapsulate drug components, thereby improving the delivery efficiency and therapeutic effect of the drug. The modified chitosan chemically modifies chitosan, and the pores and surface properties of chitosan are regulated, so that fine control of drug release can be achieved.

[0032] Preferably, the cross-linking agent is one of glutaraldehyde, glyoxal, malondialdehyde, succinaldehyde or a mixture thereof.

[0033] Preferably, the stabilizer includes a light stabilizer and a heat stabilizer.

[0034] Preferably, the mass ratio of the light stabilizer to the heat stabilizer is (1-3):(4-6).

[0035] Preferably, the light stabilizer is one of hydroxybenzotriazole or hydroxytriazine.

[0036] Preferably, the heat stabilizer is one of lecithin or soybean lecithin.

[0037] Preferably, the photoinitiator is one of 4-phenoxybenzophenone, 2-(4-phenyl)-4,6-diphenyl-1,3,5-triazine and 9,10-anthraquinone.

[0038] Preferably, the preparation method of the nanocomposite material is:

[0039] Step 1: dissolving a gadolinium contrast agent, a modified natural polymer, and a cross-linking agent in a mixture of water and DMSO to obtain a first solution;

[0040] Step 2: dissolving the drug component and the stabilizer in a mixture of water and DMSO to obtain a second solution;

[0041] Step 3: Evenly mix the first solution, the second solution and the photoinitiator, react under ultraviolet light for 5 to 10 hours, filter, wash and dry to obtain a nanocomposite material.

[0042] Therefore, the present invention adopts the above-mentioned visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma, which has the following beneficial effects:

[0043] 1. The present invention forms a chelate with high stability through the precise proportion of DOTA, glutamic acid and gadolinium ions, which reduces the dissociation of gadolinium ions and the potential toxicity risk, while maintaining a good magnetic resonance imaging effect.

[0044] 2. The modified polylactic acid and modified chitosan of the present invention have a synergistic effect. The modified polylactic acid improves the biocompatibility, drug loading capacity and targeting through maleic anhydride grafting and further functionalization, and the modified chitosan increases the antibacterial property and biological activity. The reasonable ratio of the two ensures the comprehensive performance of the material such as temperature stability and light stability.

[0045] 3. The present invention achieves uniform dispersion and close coupling at the nanoscale by mixing various components under specific conditions and performing photochemical reactions, thereby improving the uniformity and functionality of the material.

[0046] The technical solution of the present invention is further described in detail below through embodiments. DETAILED DESCRIPTION

[0047] The present invention will be further described below. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and a specific operation process, but the present invention is not limited to this embodiment.

[0048] Example 1

[0049] This embodiment provides a visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma. The nanocomposite material includes the following raw materials in parts by weight:

[0050]

[0051] The modified natural polymer includes modified polylactic acid and modified chitosan, wherein the mass ratio of the modified polylactic acid to the modified chitosan is 7:3;

[0052] The drug ingredients include Apatinib and GSK-J4, and the mass ratio of Apatinib to GSK-J4 is 2:1;

[0053] Apatinib, also known as apatinib, is a molecular targeted anti-tumor drug purchased from Jiangsu Hengrui Medicine Co., Ltd.

[0054] GSK-J4, CAS No.: 1373423-53-0, was purchased from Shanghai Ruihui Chemical Technology Co., Ltd.

[0055] The gadolinium contrast agent includes DOTA, glutamic acid and gadolinium ions, and the molar ratio of DOTA:glutamic acid:gadolinium ions is 1:5:3.

[0056] The chemical structure of DOTA is as follows:

[0057]

[0058] The cross-linking agent is glutaraldehyde.

[0059] The stabilizer includes a light stabilizer and a heat stabilizer. The mass ratio of the light stabilizer to the heat stabilizer is 2:5. The light stabilizer is hydroxybenzotriazole; the heat stabilizer is lecithin.

[0060] The photoinitiator was 4-phenoxybenzophenone.

[0061] The preparation method of gadolinium contrast agent is as follows:

[0062] 5 mmol of glutamic acid was dissolved in 50 mL of N, N-dimethylformamide, and then 1 mmol of DOTA was added. After reacting at room temperature for 5 hours, the mixture was separated and purified by high performance liquid chromatography and freeze-dried to obtain a modified chelating agent.

[0063] The modified chelating agent was dissolved in 50 mL of water and 3 mmol of gadolinium ions were added, and the mixture was heated at 90° C. for 20 min, filtered, washed, and dried to obtain a gadolinium contrast agent.

[0064] The preparation method of modified polylactic acid is:

[0065] Weigh 200g of polylactic acid and add it to a three-necked flask with a stirrer, add 300g of toluene to dissolve the polylactic acid, then put the three-necked flask into a constant temperature water bath at 90°C, and after the temperature of the material in the flask rises to 90°C, add 40g of maleic anhydride and 2g of initiator (2,5-dimethyl-2,5-di-tert-butylperoxy-hexane), and react for 3 hours under insulation and stirring. After the reaction is completed, add 200g of methanol for precipitation, and wash repeatedly with methanol to remove unreacted maleic anhydride, and put the washed product into a constant temperature blast drying oven at 80°C for drying to obtain maleic anhydride grafted polylactic acid. Polylactic acid was purchased from Shanghai Hengyuan Biotechnology Development Co., Ltd., CAS No.: 26100-51-6. Maleic anhydride was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0066] Take 100g maleic anhydride grafted polylactic acid of raw material, dissolve in 400ml tetrahydrofuran, add this solution in 12g hydroxymethylamine, react at room temperature for 10 minutes, the product is separated and purified and dried, and then dissolved in 400ml THF (tetrahydrofuran) / DMF (dimethylformamide) (V / V 3: 1) mixed solvent, 25g polyethylene glycol with a molecular weight of 1000 and 8 grams of 1,6-hexamethylene diisocyanate (HDI) are dissolved in the mixed solvent, the three components are mixed and reacted at 60°C for 2 hours, the product is separated and purified, dissolved in a mixed solvent, 50g galactose dissolved in a mixed solvent is added, and reacted at 60°C for 2 hours to obtain modified polylactic acid. Polyethylene glycol is purchased from Nantong Fanbo Chemical Co., Ltd., polyethylene glycol PEG-1000.

[0067] The preparation method of modified chitosan is:

[0068] According to the mass fraction, at room temperature, 1 part of galactose and 14 parts of acetic anhydride are reacted in 100 mL of pyridine for 72 hours, extracted with dichloromethane, washed with saturated sodium bicarbonate, dried, filtered and concentrated to obtain acetylated galactose; 4 parts of mercaptopropionic acid and 1 part of boron trifluoride ether are added to the acetylated galactose and reacted in 100 mL of dichloromethane for 16 hours; methanol is added, and the pH value is adjusted to 11 with triethylamine. After reacting for 4 hours, the solvent is removed by rotary evaporation to obtain galactosylmercaptopropionic acid. 4 parts of galactosylmercaptopropionic acid, 4 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI), and 4 parts of N-hydroxysuccinimide (NHS) were mixed, stirred in 100 mL of dimethyl sulfoxide for 1 hour, and chitosan solution with pH adjusted to 6 in advance was added, the number of chitosan additions was 10 parts, the concentration of chitosan solution was 0.5%, stirred for 24 hours, dialyzed in a dialysis bag with a molecular weight cutoff of 13000 Da for 3 days using ultrapure water, and freeze-dried to obtain modified chitosan for standby use. Galactose was purchased from Merck Chemical Technology (Shanghai) Co., Ltd., and chitosan was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0069] This embodiment also provides a method for preparing the nanocomposite material:

[0070] Dissolving gadolinium contrast agent, modified natural polymer, and cross-linking agent in a mixture of water and DMSO to obtain a first solution; the volume ratio of water to DMSO is 20:80;

[0071] Dissolving the drug component and the stabilizer in a mixture of water and DMSO to obtain a second solution; the volume ratio of water to DMSO is 20:80;

[0072] The first solution, the second solution and the photoinitiator are mixed evenly, reacted under ultraviolet light for 6 hours, filtered, washed and dried to obtain a nanocomposite material.

[0073] Example 2

[0074] The difference between this embodiment and embodiment 1 is that the formula of the nanocomposite material is different.

[0075] Nanocomposite materials include the following raw materials in parts by mass:

[0076]

[0077]

[0078] Comparative Example 1

[0079] The difference between this comparative example and Example 1 is that DOTA in the gadolinium contrast agent is replaced by DTPA.

[0080] The chemical structure of DTPA is:

[0081]

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 1 is that glutamic acid in the gadolinium contrast agent is replaced by lysine.

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 1 is that the molar ratio of DOTA, glutamic acid and gadolinium ion in the gadolinium contrast agent is 3:5:3.

[0086] Comparative Example 4

[0087] The difference between this comparative example and Example 1 is that the modified polylactic acid in the modified natural polymer is replaced by polylactic acid.

[0088] Comparative Example 5

[0089] The difference between this comparative example and Example 1 is that the modified chitosan in the modified natural polymer is replaced by chitosan.

[0090] Comparative Example 6

[0091] The difference between this comparative example and Example 1 is that the mass ratio of the modified polylactic acid to the modified chitosan in the modified natural polymer is 7:6.

[0092] Comparative Example 7

[0093] The difference between this comparative example and Example 1 is that the galactose used in the preparation process of the modified chitosan is replaced by glucose.

[0094] Comparative Example 8

[0095] The difference between this comparative example and Example 1 is that the mass ratio of Apatinib to GSK-J4 is 2:3.

[0096] Performance Testing

[0097] (1) In vitro nuclear magnetic resonance imaging effect The in vitro relaxation efficiency of Examples 1 to 2 and Comparative Examples 1 to 8 was measured and obtained. The test results are shown in Table 1.

[0098] Table 1 In vitro relaxation efficiency test results

[0099]

[0100]

[0101] From the above performance test results, it can be seen that the in vitro relaxation performance of Examples 1-2 is good, especially the in vitro relaxation performance of Example 1 is the most outstanding, which is mainly because the use of glutamic acid to modify DOTA can increase the binding force between the chelating agent and the gadolinium ion, thereby forming a stable gadolinium chelate, and this stable structure can reduce the release of gadolinium ions in the body. In addition, the preparation of gadolinium contrast agents at a specific ratio can further improve the in vitro relaxation performance and increase its imaging effect.

[0102] The comparative examples, however, are significantly inferior to the embodiments in terms of the corresponding performance tests because they do not adopt the preferred technical solutions. In comparative example 1, the type of gadolinium ion chelator is changed, and DOTA is replaced by DTPA. The molecular structure of the chelator changes, resulting in a change in the stability of the contrast agent. At the same time, it can be seen that its in vitro relaxation efficiency is reduced, proving that the molecular structure of the chelator has an important influence on the magnetic resonance imaging effect. In comparative example 2, glutamic acid in the gadolinium contrast agent is replaced by lysine. From the results, it can be seen that the type of amino acid is affected, which also leads to a decrease in in vitro relaxation efficiency, which mainly affects the reaction between amino acids and DOTA. Comparative example 3 changes the ratio between DOTA, glutamic acid and gadolinium ions. From the results, it can be seen that it also has a certain influence on the in vitro relaxation efficiency. The decrease in in vitro relaxation efficiency indicates that the ratio of the three directly affects the imaging effect of the gadolinium contrast agent in the nanocomposite material. Comparative Examples 4 and 5 replace modified polylactic acid and modified chitosan with pure polylactic acid and pure chitosan, respectively, which directly affects the performance of gadolinium contrast agent in nanocomposite materials, resulting in decreased in vitro relaxation performance. Comparative Example 7 changes the galactose in modified chitosan to glucose. The molecular spatial structures of galactose and glucose are significantly different. In the process of preparing nanocomposite materials by polymerization reaction, different polymerization structures will be formed, thereby affecting the distribution and in vitro relaxation performance of gadolinium contrast agent. Comparative Example 8 changes the ratio of the two drug molecules, and the in vitro relaxation performance of the nanocomposite material decreases slightly, indicating that although the drug molecules have an effect on the in vitro relaxation performance of the nanocomposite material, the effect is not significant. The above experimental results further demonstrate the importance of the technical solution defined in the present invention for its technical effect.

[0103] (2) Inhibitory effect of nanocomposites on osteosarcoma stem cells in animal models

[0104] Osteosarcoma stem cells were obtained by culturing osteosarcoma 143B cells into tumor spheres. After 5 days of culture, 1×10 7 The single cell suspension of 100 μg / mL was injected orally into the anterior end of the tibia of the right hind limb of female nude mice, 50 μL per mouse. The mice were observed daily, and the long diameter (a) and short diameter (b) of the tumor were measured with a vernier caliper. The formula V (mm 3 )=(a×b 2 ) / 2 to calculate the tumor volume. When the tumor volume reaches 80-100mm 3The animals were randomly divided into 12 groups, 8 in each group. They were blank control group; 10 mg / mL Apatinib free drug group; experimental group using the nanocomposite prepared by the embodiment and comparative example with equal concentration of Apatinib drug component, 0.3 mL was injected into the tail vein once every other day, and the drug was administered for 3 times in succession. 7 days after the end of the drug administration, the mice were killed by cervical dislocation, the tumors were peeled off and weighed, and the tumor growth size was compared. The test results are shown in Table 2.

[0105] Table 2 Results of the inhibitory effect on osteosarcoma stem cells

[0106] <![CDATA[Before administration / mm 3 > <![CDATA[After administration / mm 3 > Blank control group 95 - Free drug group 90 50 Example 1 85 32 Example 2 92 40 Comparative Example 1 95 65 Comparative Example 2 98 62 Comparative Example 3 96 66 Comparative Example 4 90 63 Comparative Example 5 88 58 Comparative Example 6 92 57 Comparative Example 7 97 58 Comparative Example 8 93 55

[0107] As can be seen from Table 2, after administering the nanocomposite materials prepared in Examples 1 to 2, the tumor volume was significantly reduced, while after administering the nanocomposite materials prepared in Comparative Examples 1 to 8, the tumor volume did not change much, indicating that the various raw material compositions in the present invention can increase the efficacy of the drug and achieve the treatment of osteosarcoma.

[0108] (3) Stability test

[0109] The free drug group and the nanocomposites prepared in Examples 1 to 2 and Comparative Examples 1 to 8 were placed at 50° C. under natural light for 60 days, and then the in vitro magnetic resonance imaging effect and the change in tumor size 7 days after the end of administration were tested according to the above method. The test results are shown in Table 3.

[0110] Tumor size change = (tumor size before administration - tumor size 7 days after administration) / tumor size before administration × 100%.

[0111] Table 3 Stability test results

[0112] <![CDATA[In vitro relaxation efficacy / mM -1 s -1 > Tumor size change / % Free drug group - 20 Example 1 274 59 Example 2 250 53 Comparative Example 1 132 23 Comparative Example 2 125 22 Comparative Example 3 117 21 Comparative Example 4 134 20 Comparative Example 5 148 22 Comparative Example 6 131 25 Comparative Example 7 155 21 Comparative Example 8 210 23

[0113] It can be seen from Table 3 that the nanocomposites prepared in Examples 1 to 2 can still maintain their in vitro relaxant efficacy and efficacy at a high level when stored at a relatively high temperature and light for 60 days, while the in vitro relaxant efficacy and efficacy of Comparative Examples 1 to 8 are reduced to varying degrees after being treated at a relatively high temperature and light, indicating that all the technical features of the present invention constitute a whole, which can not only improve the in vitro relaxant efficacy and efficacy of the nanocomposites, but also improve the stability of the nanocomposites, making the nanocomposites easy to store and transport.

[0114] Therefore, the present invention adopts a visualized nanocomposite material for magnetic resonance imaging for treating osteosarcoma with the above structure, and develops a highly efficient, safe and multifunctional nanocomposite material for precise treatment and visualized monitoring of osteosarcoma through sophisticated formula design, innovative preparation process and synergistic effect of functional components. This material can not only provide high-quality magnetic resonance imaging, but also achieve targeted delivery and controlled release of drugs, providing new possibilities for the treatment of osteosarcoma.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma, characterized in that: Nanocomposite materials include the following raw materials in parts by mass: The drug ingredients include apatinib and GSK-J4, and the mass ratio of apatinib to GSK-J4 is (2-5):(0.5-1).

2. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 1, characterized in that: The gadolinium contrast agent includes DOTA, glutamic acid and gadolinium ion, and the molar ratio of DOTA:glutamic acid:gadolinium ion is 1:(4-6):(2-3); The preparation method of gadolinium contrast agent is as follows: Glutamic acid is dissolved in N,N-dimethylformamide, and then DOTA is added to perform amino acid modification to obtain a modified chelating agent; The modified chelating agent is dissolved in water and gadolinium ions are added, and the mixture is heated for reaction. After the reaction is completed, the mixture is filtered, and the obtained solid is washed and dried to obtain a gadolinium contrast agent.

3. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 1, characterized in that: The modified natural polymer includes modified polylactic acid and modified chitosan, wherein the mass ratio of the modified polylactic acid to the modified chitosan is (6-8): (2-4); The preparation method of modified polylactic acid is: Toluene is added to the polylactic acid to dissolve the polylactic acid, and then the temperature is raised to 80-90° C., maleic anhydride and 2,5-dimethyl-2,5-di-tert-butylperoxy-hexane are added, and the mixture is reacted for 3-5 hours under heat preservation and stirring. After the reaction is completed, methanol is added for precipitation, and the precipitate is repeatedly washed with methanol to remove unreacted maleic anhydride, and the washed product is placed in a constant temperature blast drying oven at 80-90° C. for drying to obtain maleic anhydride grafted polylactic acid; The maleic anhydride grafted polylactic acid is dissolved in tetrahydrofuran, then added into hydroxymethylamine, and reacted at room temperature for 5 to 15 minutes. The product is separated, purified, dried, and then dissolved in a mixed solvent formed by tetrahydrofuran and dimethylformamide. Polyethylene glycol with a molecular weight of 1000 and 1,6-hexamethylene diisocyanate are dissolved in the mixed solvent. The three components are mixed evenly and reacted at 50 to 70° C. for 2 to 5 hours. The product is separated and purified, dissolved in a mixed solvent, and galactose dissolved in the mixed solvent is added, and reacted at 50 to 80° C. for 2 to 5 hours to obtain modified polylactic acid.

4. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 1, characterized in that: According to the mass fraction, the preparation method of modified chitosan is: At room temperature, galactose and acetic anhydride are reacted in pyridine for 48 to 72 hours, extracted with dichloromethane, washed with saturated sodium bicarbonate, dried, filtered, and concentrated to obtain acetylated galactose; mercaptopropionic acid and boron trifluoride ether are added to the acetylated galactose and reacted in dichloromethane for 10 to 20 hours; methanol is added, and the pH value is adjusted to 11 with triethylamine, and the reaction is carried out for 4 to 8 hours to obtain galactosylmercaptopropionic acid; Galactosylmercaptopropionic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are mixed, stirred in dimethyl sulfoxide for 1 to 3 hours, and then a chitosan solution whose pH value is adjusted to 6 in advance is added, stirred for 12 to 48 hours, dialyzed for 3 days using ultrapure water in a dialysis bag with a molecular weight cutoff of 13000Da, and freeze-dried to obtain modified chitosan.

5. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 1, characterized in that: The cross-linking agent is one of glutaraldehyde, glyoxal, malondialdehyde and succinaldehyde or a mixture thereof.

6. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 1, characterized in that: Stabilizers include light stabilizers and heat stabilizers.

7. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 6, characterized in that: The light stabilizer is one of hydroxybenzotriazole or hydroxytriazine.

8. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 6, characterized in that: The heat stabilizer is one of lecithin or soybean lecithin.

9. The visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to claim 1, characterized in that: The photoinitiator is one of 4-phenoxybenzophenone, 2-(4-phenyl)-4,6-diphenyl-1,3,5-triazine and 9,10-anthraquinone.

10. A method for preparing a visualization nanocomposite material for magnetic resonance imaging for treating osteosarcoma according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: dissolving a gadolinium contrast agent, a modified natural polymer, and a cross-linking agent in a mixture of water and DMSO to obtain a first solution; Step 2: dissolving the drug component and the stabilizer in a mixture of water and DMSO to obtain a second solution; Step 3: Evenly mix the first solution, the second solution and the photoinitiator, react under ultraviolet light for 5 to 10 hours, filter after the reaction, wash and dry the obtained fixative, and finally obtain a visualized nanocomposite material for magnetic resonance imaging for treating osteosarcoma.

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