Antithrombotic drug-derived carbon dots and preparation method and application thereof

Abstract

The application discloses an anti-thrombotic drug derivative carbon dot and a preparation method and application thereof. The method comprises the following steps: selecting an anti-thrombotic drug as a precursor, wherein the anti-thrombotic drug comprises at least one of an anti-platelet drug with a drug efficacy group, an anti-coagulation drug with a drug efficacy group and a fibrinolytic drug with a drug efficacy group, the molecular weight of the anti-thrombotic drug is 100-2000 Da, the thermal stability decomposition temperature is greater than or equal to 200 DEG C, and the drug efficacy group comprises at least one of a sulfonic acid group, an acetoxy group, an indole ring and a coumarin structure; performing gradient carbonization treatment on the precursor in multiple temperature zones, wherein the multiple temperature zones comprise a low-temperature zone capable of retaining the drug efficacy group, a medium-temperature zone capable of regulating the proportion of carbon hybridization and a high-temperature zone capable of performing heteroatom doping; and performing purification and drying treatment to obtain the anti-thrombotic drug derivative carbon dot. The anti-thrombotic drug derivative carbon dot obtained by the preparation method has both thrombolytic function and high safety, and can relieve the problem of imbalance between the curative effect and safety of the existing anti-thrombotic drug.

Description

Technical Field

[0001] This invention relates to the fields of biomedicine and nanomaterials, and particularly to carbon dots derived from antithrombotic drugs, their preparation methods, and applications. Background Technology

[0002] Thrombotic diseases are currently the leading cause of death, but existing drugs for treating thrombotic diseases have serious limitations due to the imbalance between efficacy and safety. Traditional "carrier + drug" nanodelivery systems suffer from low drug loading efficiency, carrier toxicity, and host-guest separation, making it difficult to meet the needs of preventing or treating thrombotic diseases. Summary of the Invention

[0003] To address the aforementioned issues, this application provides carbon dots derived from antithrombotic drugs, their preparation methods, and applications.

[0004] In a first aspect, this application provides a method for preparing carbon dots derived from antithrombotic drugs, comprising the following steps:

[0005] Antithrombotic drugs were selected as precursors, including at least one of antiplatelet drugs with pharmacophore groups, anticoagulants with pharmacophore groups, and fibrinolytic drugs with pharmacophore groups. The molecular weight of the antithrombotic drugs was 100 Da-2000 Da, the thermal stability decomposition temperature was greater than or equal to 200 °C, and the pharmacophore groups included at least one of sulfonic acid groups, acetoxy groups, indole rings, and coumarin structures. The precursors were subjected to gradient carbonization treatment in multiple temperature zones, including a low-temperature zone that could retain the pharmacophore groups, a medium-temperature zone that controlled the carbon hybridization ratio, and a high-temperature zone for heteroatom doping. Impurities were removed, and the precursors were purified and dried to obtain antithrombotic drug-derived carbon dots.

[0006] According to embodiments of this application, in the step of performing gradient carbonization treatment on the precursor in multiple temperature zones, the low-temperature carbonization treatment includes: processing at a temperature of 70 ℃-90 ℃ for 3 h-5 h; the medium-temperature carbonization treatment includes: processing at a temperature of 110 ℃-130 ℃ for 3 h-5 h; and the high-temperature carbonization treatment includes: processing at a temperature of 170 ℃-190 ℃ for 3 h-5 h.

[0007] According to embodiments of this application, the precursor is subjected to gradient carbonization treatment in multiple temperature zones, including a low-temperature zone capable of retaining pharmacophore groups, a medium-temperature zone for controlling the carbon hybridization ratio, and a high-temperature zone for heteroatom doping. The low-temperature carbonization treatment includes: treatment at a temperature of 75 ℃-85 ℃ for 3.5 h-4.5 h; the medium-temperature carbonization treatment includes: treatment at a temperature of 115 ℃-125 ℃ for 3.5 h-4.5 h; and the high-temperature carbonization treatment includes: treatment at a temperature of 175 ℃-185 ℃ for 3.5 h-4.5 h.

[0008] According to embodiments of this application, an antithrombotic drug is selected as a precursor. The antithrombotic drug includes at least one of an anticoagulant with a pharmacodynamic group, an antiplatelet drug with a pharmacodynamic group, and a tissue plasminogen activator with a pharmacodynamic group. In the step where the molecular weight of the antithrombotic drug is 100 Da-2000 Da and the thermal stability decomposition temperature is greater than or equal to 200 °C, the antithrombotic drug includes any one of aspirin, warfarin sodium, and indobufen.

[0009] According to the embodiments of this application, in the step of removing impurities, purifying, and drying to obtain antithrombotic drug-derived carbon dots, the method for removing impurities and purifying is dialysis. The dialysis conditions are: using a dialysis bag with a molecular weight cutoff of 3500 Da, dialysis with deionized water for 24 h-48 h, and changing the water every 8 h.

[0010] According to the embodiments of this application, in the step of removing impurities, purifying, and drying to obtain antithrombotic drug-derived carbon dots, the drying method is freeze-drying, and the freeze-drying conditions are: -80 ℃ and 0.1 Pa vacuum.

[0011] Secondly, this application provides an antithrombotic drug-derived carbon dot synthesized using the preparation method of the antithrombotic drug-derived carbon dot described in the first aspect.

[0012] According to embodiments of this application, the carbon dots derived from antithrombotic drugs include aspirin carbon dots, warfarin sodium carbon dots, and indobufen carbon dots.

[0013] Thirdly, this application provides a pharmaceutical composition comprising the antithrombotic drug-derived carbon dots described in the second aspect, wherein the antithrombotic drug-derived carbon dots include aspirin carbon dots, warfarin sodium carbon dots, and indobufen carbon dots.

[0014] Fourthly, this application provides the use of the antithrombotic drug-derived carbon dots described in the second aspect and the pharmaceutical composition described in the third aspect in the preparation of antithrombotic drugs and drugs for the prevention or treatment of cerebral vascular occlusion.

[0015] This application has at least the following beneficial effects:

[0016] This application utilizes specific types of antithrombotic drugs with pharmacodynamic groups, molecular weights between 100 Da and 2000 Da, and thermal stability decomposition temperatures greater than or equal to 200 °C as precursors. The precursors undergo gradient carbonization treatment in multiple temperature ranges, including a low-temperature region to retain the pharmacodynamic groups, a medium-temperature region to regulate the carbon hybridization ratio, and a high-temperature region for heteroatom doping. Impurities are removed, and the mixture is purified and dried to synthesize antithrombotic drug-derived carbon dots. These carbon dots not only possess thrombolytic function but also exhibit low cytotoxicity and high safety, balancing the efficacy and bleeding risk of traditional antithrombotic drugs and improving the efficiency and safety of antithrombotic therapy. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the implementation regulations of this application, the drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a TEM image of the carbon dots of aspirin in Example 1 of this application; the scale bar is 50 nm.

[0019] Figure 2 This is a hydrated particle size diagram of the carbon dots in aspirin in Example 1 of this application.

[0020] Figure 3 This is the XRD pattern of aspirin carbon dots in Example 1 of this application.

[0021] Figure 4 This is an XPS image of the carbon dots of aspirin in Example 1 of this application.

[0022] Figure 5 This is the FTIR image of the carbon dots of aspirin in Example 1 of this application.

[0023] Figure 6 This is a UV-VIS image of the aspirin carbon dots in Example 1 of this application.

[0024] Figure 7 This is a cytotoxicity diagram of aspirin carbon dots in Example 1 of this application.

[0025] Figure 8 This is a thrombolytic test diagram of aspirin carbon dots in Example 1 of this application.

[0026] Figure 9 The contents of the reactor after the preparation of aspirin carbon dots in Comparative Example 1 of this application.

[0027] Figure 10 This is a TEM image of the carbon dots of sodium thiamethoxam in Example 2 of this application; the scale bar is 50 nm.

[0028] Figure 11 This is a hydrated particle size diagram of sodium phloroglucinol carbon dots in Example 2 of this application.

[0029] Figure 12 This is the XRD pattern of sodium thiamethoxam carbon dots in Example 2 of this application.

[0030] Figure 13 This is an XPS image of the carbon dots of sodium thiamethoxam in Example 2 of this application.

[0031] Figure 14 This is the FTIR image of the carbon dots of sodium thiamethoxam in Example 2 of this application.

[0032] Figure 15 This is the UV-VIS image of the carbon dots of sodium thiamethoxam in Example 2 of this application.

[0033] Figure 16 This is a cytotoxicity diagram of sodium phloroglucinol carbon dots in Example 2 of this application.

[0034] Figure 17 This is a test diagram of the thrombolytic effect of sodium thiamethoxam carbon dots in Example 2 of this application.

[0035] Figure 18 This is a test diagram of the thrombolytic effect of sodium thiamethoxam in Example 2 of this application.

[0036] Figure 19 This is a TEM image of the indobufen carbon dots in Example 3 of this application; the scale bar is 50 nm.

[0037] Figure 20 The hydrated particle size diagram of the indobufen carbon dots in Example 3 of the application is shown.

[0038] Figure 21 The image shows the XRD pattern of the indobufen carbon dots in Example 3 of the application.

[0039] Figure 22 XPS image of the indobufen carbon dots in Example 3 of the application.

[0040] Figure 23 The image shows the FTIR spectrum of the indobufen carbon dots in Example 3 of the application.

[0041] Figure 24 The UV-VIS image of the indobufen carbon dots in Example 3 of the application is shown.

[0042] Figure 25 This is a cytotoxicity diagram of the indobufen carbon dots in Example 3 of the application.

[0043] Figure 26 This is a test diagram of the thrombolytic effect of indobufen carbon dots in Example 3 of the application. Detailed Implementation

[0044] To make the purpose, technical solution, and beneficial technical effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the implementation details described in this specification are merely for illustrative purposes and are not intended to limit the scope of this application.

[0045] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, although not explicitly stated, every point or individual value between the endpoints of the range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit and combined with any other point or individual value or with other lower or upper limits to form a range not explicitly stated.

[0046] In the description of this application, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, and "multiple" in "one or more" means two or more.

[0047] The foregoing description of this application is not intended to describe every disclosed implementation or method. Instead, the following description provides more specific examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments, which can be used in various combinations. The examples listed are representative only and should not be construed as exhaustive.

[0048] Thrombotic diseases are the leading cause of death worldwide. Thrombosis refers to the process by which blood clots within the heart or blood vessels, or where blood components such as platelets, white blood cells, and red blood cells clump together to form a solid mass called a thrombus. Thrombus formation can be influenced by numerous factors, but the process generally involves two steps: platelet activation and a coagulation reaction.

[0049] Currently, existing therapeutic drugs are classified into antiplatelet drugs, anticoagulants, and fibrinolytic drugs, but all have serious limitations. Traditional small-molecule antiplatelet drugs pose a risk of systemic bleeding due to non-targeted distribution; for example, aspirin can cause gastrointestinal bleeding in 15-20% of cases. Novel oral anticoagulants have low bioavailability and carry the risk of irreversible bleeding; for example, rivaroxaban has a bioavailability of only 66%. Large-molecule biological fibrinolytic drugs have short half-lives and poor stability; for example, the tissue plasminogen activator tPA has a half-life of <5 min. Meanwhile, traditional "carrier + drug" nanodelivery systems face problems such as low drug loading efficiency, carrier toxicity, and host-guest separation, making it difficult to meet clinical needs.

[0050] Based on this, this application provides antithrombotic drug-derived carbon dots, their preparation method and application. The preparation method uses a gradient carbonization process during the carbonization of the drug to synthesize antithrombotic drug-derived carbon dots. These carbon dots have both pharmacological activity and safety, and have the function of dissolving thrombi. They can be used to prepare antithrombotic drugs and drugs for the prevention or treatment of cerebrovascular occlusion.

[0051] The first aspect of this application is to provide a method for preparing carbon dots derived from antithrombotic drugs, comprising the following steps:

[0052] S100: Select an antithrombotic drug as a precursor. The antithrombotic drug includes at least one of the following: an antiplatelet drug with a pharmacologically active group, an anticoagulant drug with a pharmacologically active group, and a fibrinolytic drug with a pharmacologically active group. The molecular weight of the antithrombotic drug is 100 Da-2000 Da, the thermal stability decomposition temperature is greater than or equal to 200 ℃, and the pharmacologically active group includes at least one of the following: sulfonic acid group, acetoxy group, indole ring, and coumarin structure.

[0053] S200: The precursor is subjected to gradient carbonization in multiple temperature zones, including a low temperature zone that can retain the pharmacologically active group, a medium temperature zone that controls the carbon hybridization ratio, and a high temperature zone for heteroatom doping.

[0054] S300: Remove impurities, purify, and dry to obtain carbon dots derived from antithrombotic drugs.

[0055] Antithrombotic drugs are screened as precursors based on molecular weight, thermal stability, and pharmacodynamic groups to ensure that the selected antithrombotic drugs can be used to synthesize corresponding carbon dots without losing their pharmacodynamic activity. The precursors are subjected to gradient carbonization in multiple temperature zones, during which the precursors synthesize the corresponding carbon dots through self-condensation. Self-condensation reduces reagent consumption and contamination, and minimizes the formation of byproducts. The resulting solid powder, obtained through dialysis and freeze-drying, represents the antithrombotic drug-derived carbon dots. This method can synthesize antithrombotic drug-derived carbon dots that possess both pharmacodynamic activity and safety, balancing the efficacy and bleeding risk of traditional antithrombotic drugs, and improving the efficiency and safety of antithrombotic therapy.

[0056] In some embodiments, the step of performing gradient carbonization treatment on the precursor in multiple temperature zones includes: low-temperature carbonization treatment including: treatment at a temperature of 70 ℃-90 ℃ for 3 h-5 h; medium-temperature carbonization treatment including: treatment at a temperature of 110 ℃-130 ℃ for 3 h-5 h; and high-temperature carbonization treatment including: treatment at a temperature of 170 ℃-190 ℃ for 3 h-5 h.

[0057] In some embodiments, the precursor is subjected to gradient carbonization treatment in multiple temperature zones, including a low-temperature zone that retains pharmacophore groups, a medium-temperature zone that controls the carbon hybridization ratio, and a high-temperature zone for heteroatom doping. The low-temperature carbonization treatment includes: treatment at a temperature of 75 ℃-85 ℃ for 3.5 h-4.5 h; the medium-temperature carbonization treatment includes: treatment at a temperature of 115 ℃-125 ℃ for 3.5 h-4.5 h; and the high-temperature carbonization treatment includes: treatment at a temperature of 175 ℃-185 ℃ for 3.5 h-4.5 h.

[0058] As an example, the temperature for carbonization in the low-temperature zone can be 70 ℃, 73 ℃, 75 ℃, 76 ℃, 77 ℃, 78 ℃, 79 ℃, 80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃, 85 ℃, 88 ℃, or 90 ℃; the carbonization time in the low-temperature zone can be 3 h, 3.3 h, 3.5 h, 3.6 h, 3.7 h, 3.8 h, 3.9 h, 4.0 h, 4.1 h, 4.2 h, 4.3 h, 4.4 h, 4.5 h, 4.8 h, or 5 h.

[0059] As an example, the temperature for the intermediate-temperature carbonization treatment can be 110 ℃, 113 ℃, 115 ℃, 116 ℃, 117 ℃, 118 ℃, 119 ℃, 120 ℃, 121 ℃, 122 ℃, 123 ℃, 124 ℃, 125 ℃, 128 ℃, or 130 ℃; the time for the intermediate-temperature carbonization treatment can be 3 h, 3.3 h, 3.5 h, 3.6 h, 3.7 h, 3.8 h, 3.9 h, 4.0 h, 4.1 h, 4.2 h, 4.3 h, 4.4 h, 4.5 h, 4.8 h, or 5 h.

[0060] As an example, the carbonization temperature in the high-temperature zone can be 170 ℃, 173 ℃, 175 ℃, 176 ℃, 177 ℃, 178 ℃, 179 ℃, 180 ℃, 181 ℃, 182 ℃, 183 ℃, 184 ℃, 185 ℃, 188 ℃, or 190 ℃; the carbonization time in the high-temperature zone can be 3 h, 3.3 h, 3.5 h, 3.6 h, 3.7 h, 3.8 h, 3.9 h, 4.0 h, 4.1 h, 4.2 h, 4.3 h, 4.4 h, 4.5 h, 4.8 h, or 5 h.

[0061] The specific steps for S100 are as follows:

[0062] An antithrombotic drug was selected as a precursor, and a precursor solution was prepared. The antithrombotic drug included at least one of the following: antiplatelet drugs with pharmacodynamic groups, anticoagulants with pharmacodynamic groups, and fibrinolytic drugs with pharmacodynamic groups. The molecular weight of the antithrombotic drug was 100 Da-2000 Da, and its thermal stability decomposition temperature was greater than or equal to 200 °C.

[0063] Screening was conducted based on indicators such as molecular weight, thermal stability, and pharmacodynamic groups, and antithrombotic drugs were selected as precursors.

[0064] Specific criteria for raw material screening include: antithrombotic drugs must simultaneously meet the following requirements: molecular weight between 100-2000 Da, thermal stability with a decomposition temperature greater than or equal to 200 ℃, high thermal stability, and the presence of a pharmacophore with antithrombotic efficacy. The pharmacophore includes at least one of the following: sulfonic acid group, acetoxy group, indole ring, and coumarin structure.

[0065] Indole rings refer to heterocycles formed by the fusion of a benzene ring and a pyrrole ring through the sharing of two carbon atoms, with the following structure: .

[0066] The coumarin structure refers to a heterocycle consisting of a benzene ring and an α-pyranone ring (lactone ring), with the following structure: .

[0067] Preferably, the pharmacophore group may also include at least one of a hydroxyl group and a carboxylic acid group.

[0068] Preferably, the antithrombotic drugs that can serve as precursors include any one of aspirin (containing an acetoxy group), warfarin sodium (containing a coumarin structure and a hydroxyl group), or indobufen (containing a carboxylic acid group and an indole ring).

[0069] Aspirin is an antiplatelet drug that irreversibly acetylates arachidonic acid cyclooxygenase, preventing its conversion into prostaglandin G2. This blocks the formation of thromboxane A2, a platelet aggregation activator, thereby inhibiting platelet adhesion and aggregation, affecting thrombus formation, and exerting an antiplatelet aggregation effect.

[0070] Warfarin sodium is an anticoagulant that exerts its antithrombotic effect by interfering with the cyclic tautomerism of vitamin K and the formation of its 2,3-epoxides. Vitamin K is required for the synthesis of coagulation factors II, III, IX, and X in the liver. Warfarin sodium has a similar structure to vitamin K, resulting in a competitive antagonistic effect, thereby inhibiting the synthesis of coagulation factors and thus exerting its antithrombotic effect.

[0071] Indobufen is an antiplatelet drug that can reversibly inhibit arachidonic acid metabolism, reversibly inhibit thromboxane B2 (TXB2) synthesis and the release / activation of various platelet factors, effectively blocking the platelet cascade reaction and preventing thrombosis.

[0072] This application utilizes a synergistic gradient carbonization process. By screening precursor drugs containing specific antithrombotic pharmacodynamic groups such as sulfonic acid groups, acetoxy groups, indole rings, or coumarin structures, key pharmacodynamic groups are retained in the low-temperature region (50-80 °C), the carbon core structure is regulated in the medium-temperature region (80-120 °C), and heteroatom doping is achieved in the high-temperature region (120-180 °C). This process successfully transforms drug molecules into carbon dots with uniform size (3–5 nm). These carbon dots inherit the antithrombotic activity of the parent drug and enhance the interfacial interaction with thrombi through nanoscale effects. Simultaneously, the retained functional groups (such as acetoxy groups) and doped atoms (N / O) on the surface endow them with good biocompatibility and low cytotoxicity. This significantly reduces the risk of systemic bleeding while improving thrombolytic efficiency, effectively solving the key problem of balancing efficacy and safety in traditional antithrombotic drugs.

[0073] In some embodiments, other reagents can be added to the antithrombotic drug as a precursor to promote the synthesis of carbon dots derived from the antithrombotic drug. For example, ethylenediamine can be added to an aspirin solution as a nitrogen source to promote heteroatom doping condensation and obtain a precursor solution; sodium hydroxide can be added to an indobufen solution to provide an alkaline environment, which can make indobufen dissolve better in water to obtain a precursor solution, which is beneficial for subsequent hydrothermal carbonization.

[0074] The specific steps for S200 are as follows:

[0075] The precursor solution is placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor is then placed in an oven with multiple temperature zones for gradient carbonization treatment. These zones include a low-temperature zone to preserve the activity of the pharmacophore groups, a medium-temperature zone to adjust the carbon hybridization ratio (sp² / sp³ carbon ratio) to enhance the quantum confinement effect, and a high-temperature zone to control the surface states through heteroatom doping.

[0076] During the gradient carbonization process, the low-temperature carbonization process, which preserves the activity of the pharmacophore groups, enables the drug to undergo prepolymerization, resulting in a prepolymer that retains the activity of the pharmacophore groups of the antithrombotic drug. The medium-temperature carbonization process, which regulates the carbon hybridization ratio, allows the sp² / sp³ carbon ratio to be controlled to form a core-shell structure, enhancing the quantum confinement effect of the carbon dots derived from the antithrombotic drug. The high-temperature carbonization process, which performs heteroatom doping, enables N / S / O heteroatom doping, regulating the surface states to hybridize the groups with the carbon skeleton, allowing pharmacophore groups, hydrophilic groups, etc., to be distributed on the shell surface.

[0077] The degree of carbonization of drugs during carbonization is affected by reaction temperature and time. Specifically, as the reaction temperature increases and the time extends, the degree of carbonization increases, and the carbon core size gradually increases. Increased carbon core size leads to an increased shell surface area of ​​the carbon dots, resulting in an increase in pharmacodynamic and hydrophilic groups distributed on the shell surface. This enhances the therapeutic efficacy and biocompatibility of the carbon dots, while reducing the drug's cytotoxicity and side effects.

[0078] In some embodiments, during the gradient carbonization treatment of the precursor in multiple temperature zones, one or more temperature gradients can be further set for any one or more temperature zones. All temperatures within the temperature gradient fall within the temperature range of that zone, and the total treatment time for all temperature gradients does not exceed the time range of that temperature zone. For example, the treatment process in the low-temperature zone for retaining the pharmacodynamic groups can be divided into one or more temperature gradients based on different temperatures. These temperature gradients need to satisfy the following conditions: their temperatures are all within the range of 70 °C to 90 °C, and the total treatment time for all temperature gradients is within the range of 3 to 5 hours.

[0079] In some embodiments, antithrombotic drug-derived carbon dots are prepared by direct carbonization, i.e., the precursor is directly carbonized in a high-temperature zone. After the treatment, the drug is found to be clearly charred, adhering to the bottle wall and difficult to remove, thus failing to obtain antithrombotic drug-derived carbon dots.

[0080] The specific steps for S300 are as follows:

[0081] Impurities were removed, and the mixture was purified and dried to obtain antithrombotic drug-derived carbon dots with a size of 3 nm-5 nm (e.g., 3 nm, 3.5 nm, 4.0 nm, 4.5 nm, or 5.0 nm).

[0082] In some embodiments, in the step of removing impurities, purifying, and drying to obtain antithrombotic drug-derived carbon dots, the method for removing impurities and purifying is dialysis. The dialysis conditions are as follows: using a dialysis bag with a molecular weight cutoff of 3500 Da, dialysis with deionized water for 24-48 h (e.g., 24 h, 26 h, 28 h, 30 h, 32 h, 34 h, 38 h, 40 h, 42 h, 44 h, or 48 h), and changing the water every 8 h.

[0083] In some embodiments, in the step of removing impurities, purifying, and drying to obtain antithrombotic drug-derived carbon dots, the drying method is freeze-drying, and the freeze-drying conditions are: -80 ℃ and 0.1 Pa vacuum.

[0084] A second aspect of this application is to provide antithrombotic drug-derived carbon dots synthesized by the preparation method described in the first aspect.

[0085] In some embodiments, antithrombotic drug-derived carbon dots include: aspirin carbon dots, warfarin sodium carbon dots, or indobufen carbon dots.

[0086] The absorption and efficacy of orally administered solid drugs depend on the water solubility of their active ingredients and their permeability through visceral mucosa, with dissolution being the controlling step in the absorption process. Water-insoluble drugs, due to their inability to dissolve effectively in digestive juices, limit their effectiveness. For example, antithrombotic drugs like aspirin and indobufen are water-insoluble, with only a portion being absorbed to exert their therapeutic effect, significantly limiting their thrombolytic activity. In practice, to address this issue, the dosage is often increased to enhance absorption and thus maximize the drug's thrombolytic effect. However, increasing the dosage further increases the cytotoxicity and side effects associated with drug use.

[0087] The aspirin and indobufen carbon dots provided in the second aspect of this application are both water-soluble and can dissolve more effectively in digestive fluids. Drugs prepared using these carbon dots have a low effective dose, which not only allows for better thrombolytic effects but also reduces cytotoxicity and side effects associated with drug use, resulting in high safety. Furthermore, aspirin and indobufen carbon dots can be prepared into injections, granules, and other dosage forms, enabling them to exert their thrombolytic effects more quickly.

[0088] The structure of the synthesized antithrombotic drug-derived carbon dots was characterized. The particle size of the antithrombotic drug-derived carbon dots was detected by transmission electron microscopy (TEM) and nanoparticle size and zeta potential meter. The structure of the antithrombotic drug-derived carbon dots was detected by polycrystalline X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The functional groups of the antithrombotic drug-derived carbon dots were analyzed by Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible-near-infrared spectrophotometer (UV-VIS).

[0089] Functional validation of antithrombotic drug-derived carbon dots was conducted. Safety experiments were performed to verify the toxic effects of these carbon dots on normal cells. L929 mouse fibroblasts, a widely used model cell for toxicity evaluation, were used in the experiments. Cell viability was measured at 450 nm using an ELISA reader (OD value), indirectly characterizing the cytotoxicity of the antithrombotic drug-derived carbon dots. The thrombolytic effect of the antithrombotic drug-derived carbon dots was verified through an in vitro clot dissolution experiment. SPF-grade mouse ocular blood was used in the experiment, and the absorbance at 540 nm (OD value) was measured using a UV-Vis near-infrared spectrophotometer (UV-VIS) to reflect the amount of hemoglobin released, indirectly characterizing the degree of clot dissolution.

[0090] An embodiment of the third aspect of this application provides a pharmaceutical composition comprising the antithrombotic drug-derived carbon dots described in the second aspect.

[0091] In some embodiments, antithrombotic drug-derived carbon dots include: aspirin carbon dots, warfarin sodium carbon dots, or indobufen carbon dots.

[0092] Preferably, the pharmaceutical composition further includes a pharmaceutically acceptable carrier or excipient.

[0093] In some embodiments, the pharmaceutically acceptable carrier is one or more of xylitol, mannitol, lactose, fructose, dextran, glucose, polyvinylpyrrolidone, low molecular weight dextran, sodium chloride, calcium gluconate, or calcium phosphate; the excipients may be antioxidant complexing agents, fillers, matrix materials, etc.

[0094] The fourth aspect of this application describes the application of the antithrombotic drug-derived carbon dots described in the second aspect and the pharmaceutical composition including the antithrombotic drug-derived carbon dots described in the third aspect in the preparation of antithrombotic drugs, drugs for the prevention or treatment of cerebrovascular occlusion, etc.

[0095] In some embodiments, the dosage form of the drug includes at least one of injection, tablet, capsule, and granule.

[0096] The carbon dots derived from antithrombotic drugs contain pharmacodynamic groups of the antithrombotic drugs on their surface, enabling them to dissolve and prevent blood clots. Their small size (3-5 nm) allows for better contact with blood clots, increasing the contact area. These two aspects synergistically enhance thrombolytic efficiency, fully leveraging their antithrombotic, preventative, and therapeutic effects on cerebral vascular occlusion. Therefore, antithrombotic drug-derived carbon dots can be applied to the preparation of drugs for antithrombosis and the prevention or treatment of cerebral vascular occlusion.

[0097] Example

[0098] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on weight, and all reagents, cells, and animals used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing. The instruments used in the embodiments are also commercially available.

[0099] The equipment and reagents used in Examples 1-6 and Comparative Examples 1-10 are as follows:

[0100] 1. Transmission electron microscope (TEM, H-7650B), instrument serial number 08019685, made in Japan, manufactured by Hitachi, model B.

[0101] 2. Nanoparticle size and zeta potential meter, instrument number 11025898, made in the UK, manufactured by Malvern Instruments, model Zetasizer Nano ZS.

[0102] 3. Polycrystalline X-ray diffractometer (XRD), instrument serial number 00001139, made in Germany, manufactured by Bruker, model D8 ADVANCE.

[0103] 4. X-ray photoelectron spectroscopy (XPS), the model used is Thermo Scientific K-Alpha from the United States.

[0104] 5. Fourier transform infrared spectroscopy (FTIR), using the American Thermo Fisher Scientific Nicoleti S20.

[0105] 6. Ultraviolet-Vis-NearInfrared Spectrophotometer (UV-VIS), instrument serial number 22026567, made in Japan, manufactured by HITACHI, model UH5700.

[0106] 7. The microplate reader is a Thermo Fisher Scientific Multiskan FC microplate reader.

[0107] 8. Aspirin, brand name TargetMol, product number T0005.

[0108] 9. Warfarin sodium, brand name Xinhengyan (purchased from Beijing Kaiguo Technology Co., Ltd.)

[0109] (Company), purity ≥98%.

[0110] 10. Indobufen, brand name Xinhengyan, product number AB068975.

[0111] 11. L929 mouse fibroblasts, purchased from Shangen Biotechnology, catalog number SNL-402.

[0112] 12. DMEM culture medium, brand name VivaCell, catalog number C3113-0500.

[0113] 13. SPF-grade mice were purchased from Vital River, mouse type: C57, female, blood collection age: 2 months.

[0114] 14. Ticagrelor, brand name Solarbio (purchased from Beijing Solarbio Technology Co., Ltd.)

[0115] Limited Liability Company), with a purity of ≥98%.

[0116] 15. Dabigatran ester, brand name Xinhengyan, purity ≥98%.

[0117] 16. Apixaban, brand name: Dibai (purchased from Shangqiong Zhunfei Hai Dibai Biotechnology Co., Ltd.)

[0118] Limited Liability Company), with a purity of ≥98%.

[0119] 17. Rivaroxaban, brand name Xinhengyan (purchased from Beijing Kaiguo Technology Co., Ltd.)

[0120] (Company), purity ≥98%.

[0121] Example 1

[0122] This embodiment provides a method for preparing aspirin carbon dots, their structure, and functional characterization.

[0123] I. Preparation method of aspirin carbon dots

[0124] Dissolve 1 g of aspirin in 6 mL of deionized water and add 0.5 mL of ethylenediamine. Mix well to obtain the precursor solution.

[0125] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (80 °C for 4 h) to preserve the pharmacologically active groups, a medium-temperature zone (120 °C for 4 h) to control the carbon hybridization ratio, and a high-temperature zone (180 °C for 4 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0126] A dialysis bag with a molecular weight cutoff of 3500 Da was used, and deionized water was dialyzed for 24-48 h, with the water changed every 8 h. After dialysis, the solid was freeze-dried at -80 ℃ and 0.1 Pa vacuum to obtain a powdered solid.

[0127] II. Structural Characterization of Aspirin Carbon Dots

[0128] Structural characterization: Transmission electron microscopy (TEM) showed that the particle size of aspirin carbon dots was 3-5 nm. Figure 1 The hydrated particle size of aspirin carbon dots was determined by a nanoparticle size and zeta potential analyzer using dynamic light scattering. The deviation between the hydrated particle size and the TEM results was ≤1 nm. Figure 2 ),like Figure 2 As shown, the volume (%) value is 0 in the size range of less than 1 nm and greater than 3 nm; the structure of aspirin carbon dots was detected by polycrystalline X-ray diffraction (XRD), and the results showed that the aspirin carbon dots had no obvious crystallization peaks and no amorphous carbon structure. Figure 3 X-ray photoelectron spectroscopy (XPS) was used to detect the elements contained in the carbon dots of aspirin, confirming that the carbon dots of aspirin contain C, N, and O elements. Figure 4 Fourier transform infrared spectroscopy (FTIR) Figure 5 ) and UV-Vis-NIR spectrophotometer (UV-VIS) Figure 6 The carbon dot structure information of aspirin was confirmed by testing.

[0129] III. Functional Characterization of Aspirin Carbon Dots

[0130] 1. Safety Verification: L929 mouse fibroblasts were used in the experiment. Aspirin carbon dots were prepared into solutions with concentrations of 0 μg / mL, 50 μg / mL, 100 μg / mL, 200 μg / mL, and 500 μg / mL in DMEM medium, and sterilized by filtration through a 0.22 μm filter membrane. L929 mouse fibroblasts in the logarithmic growth phase were then inoculated with 1×10⁻⁶ cells. 4 Cells were seeded at a density of [number] cells / well in 96-well plates and cultured at 37 ℃ in a 5% CO2 incubator for 24 h until cell adhesion was achieved. The original DMEM medium was discarded, and 100 μL of DMEM medium containing different concentrations of carbon dots was added to each well (five replicates for each concentration). The control group received an equal volume of DMEM medium without carbon dots. After another 24 h of culture, 10 μL of CCK-8 solution was added to each well, and the cells were incubated in the dark for 2 h. The absorbance (OD value) at 450 nm was measured using a microplate reader. The OD value was positively correlated with cell viability and negatively correlated with the cytotoxicity of aspirin carbon dots; that is, the higher the OD value, the higher the cell viability and the lower the cytotoxicity of aspirin carbon dots. The experimental results are as follows: Figure 7 As shown, L929 mouse fibroblasts maintained high cell viability even at high concentrations of aspirin carbon dots. At a concentration of 400 μg / mL, L929 mouse fibroblasts still maintained high cell viability, indicating that high concentrations of aspirin carbon dots had low cytotoxicity to L929 mouse fibroblasts. This demonstrates that aspirin carbon dots have low cytotoxicity and high safety.

[0131] 2. In vitro thrombolysis validation: SPF-grade mice weighing 20-25 g were used. 0.5 mL of blood was collected by enucleation and placed in a 1.5 mL centrifuge tube. The blood was incubated at 37 ℃ for 12 h to form a blood clot. The clot was washed three times with physiological saline to remove serum, yielding fresh mouse blood clots, each weighing approximately 20 mg. A 1000 μg / mL aspirin carbon dot solution was prepared using physiological saline. 4 mL of the carbon dot solution was added to a reagent tube and incubated on a shaker at 37 ℃ and 100 rpm. At 2 h, 4 h, and 12 h, 0.2 mL of the supernatant from each tube was carefully aspirated, and the absorbance (OD value) at 540 nm was measured using UV-VIS. The experimental results are as follows: Figure 8 As shown, the supernatant after adding aspirin carbon dots exhibited a significant characteristic absorption peak at 540 nm, indicating a substantial increase in hemoglobin release from the blood clot after the addition of aspirin carbon dots. Furthermore, the hemoglobin release from the blood clot increased significantly with increasing incubation time between aspirin carbon dots and the blood clot. These results demonstrate that aspirin carbon dots effectively promote hemoglobin release from the blood clot, and the 3-5 nm nanometer size of the aspirin carbon dots enhances the contact area between the aspirin carbon dots and the blood clot, synergistically improving thrombolytic efficiency.

[0132] Example 2

[0133] This embodiment provides a method for preparing warfarin sodium carbon dots, and their structure and functional characterization.

[0134] I. Preparation method of warfarin sodium carbon dots

[0135] Dissolve 1 g of warfarin sodium in 6 mL of deionized water and mix well to obtain a precursor solution.

[0136] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (80 °C for 4 h) to preserve the pharmacologically active groups, a medium-temperature zone (120 °C for 4 h) to control the carbon hybridization ratio, and a high-temperature zone (180 °C for 4 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0137] A dialysis bag with a molecular weight cutoff of 3500 Da was used, and deionized water was dialyzed for 24-48 h, with the water changed every 8 h. After dialysis, the solid was freeze-dried at -80 ℃ and 0.1 Pa vacuum to obtain a powdered solid.

[0138] II. Structural Characterization of Warfarin Sodium Carbon Dots

[0139] Structural characterization: Transmission electron microscopy (TEM) showed that the particle size of warfarin sodium carbon dots was 3-5 nm. Figure 10 The hydrated particle size of warfarin sodium carbon dots was determined by a nanoparticle size and zeta potential analyzer using dynamic light scattering. The deviation between the hydrated particle size and the TEM results was ≤1 nm. Figure 11 ),like Figure 11 As shown, the volume (%) value is 0 in the size range of less than 1.9 nm and greater than 10 nm; the structure of warfarin sodium carbon dots was detected by polycrystalline X-ray diffraction (XRD), and the results showed that the warfarin sodium carbon dots had no obvious crystallization peaks and no amorphous carbon structure. Figure 12 X-ray photoelectron spectroscopy (XPS) was used to detect the elements contained in the carbon dots of warfarin sodium, confirming that the carbon dots of warfarin sodium contain C, N, and O elements. Figure 13 Fourier transform infrared spectroscopy (FTIR) Figure 14 ) and UV-Vis-NIR spectrophotometer (UV-VIS) Figure 15 The carbon dot structure information of sodium warfarin was confirmed by testing.

[0140] III. Functional Characterization of Warfarin Sodium Carbon Dots

[0141] 1. Safety Verification: L929 mouse fibroblasts were used in the experiment. Warfarin sodium carbon dots were prepared into solutions with concentrations of 0 μg / mL, 50 μg / mL, 100 μg / mL, 200 μg / mL, and 500 μg / mL in DMEM medium, and sterilized by filtration through a 0.22 μm filter membrane. L929 mouse fibroblasts in the logarithmic growth phase were then inoculated with 1×10⁻⁶ cells. 4 Cells were seeded at a density of 1 cell / well in 96-well plates and cultured at 37 ℃ in a 5% CO2 incubator for 24 h until cell adhesion was achieved. The original DMEM medium was discarded, and 100 μL of DMEM medium containing different concentrations of carbon dots was added to each well (5 replicates per concentration). The control group received an equal volume of DMEM medium without carbon dots. After another 24 h of culture, 10 μL of CCK-8 solution was added to each well, and the plates were incubated in the dark for 2 h. The absorbance (OD value) at 450 nm was measured using a microplate reader. Safety verification results are as follows: Figure 16 As shown, L929 mouse fibroblasts maintained a high survival rate under high concentrations of warfarin sodium carbon dots. Even at a warfarin sodium carbon dot concentration of 800 μg / mL, L929 mouse fibroblasts still maintained high cell viability, indicating that high concentrations of warfarin sodium carbon dots had low cytotoxicity to L929 mouse fibroblasts. This demonstrates that warfarin sodium carbon dots have low cytotoxicity and high safety.

[0142] 2. In vitro thrombolysis validation: SPF-grade mice weighing 20-25 g were used. 0.5 mL of blood was collected by enucleation and placed in a 1.5 mL centrifuge tube. The blood was incubated at 37 ℃ for 12 h to form a blood clot. The clot was washed three times with physiological saline to remove serum, yielding fresh mouse blood clots, each weighing approximately 20 mg. Warfarin sodium carbon dots and warfarin sodium solution with a concentration of 1000 μg / mL were prepared using physiological saline. 4 mL of each solution was added to separate test tubes, and the tubes were incubated at 37 ℃ and 100 rpm in a shaker. At 2 h, 4 h, and 12 h, 0.2 mL of the supernatant from each tube was carefully aspirated, and the absorbance (OD value) at 540 nm was measured using UV-VIS. The experimental results are as follows: Figure 17 , Figure 18As shown, the characteristic absorption peak intensity at 540 nm of the supernatant with added warfarin sodium carbon dots was significantly higher than that of the supernatant without added warfarin sodium. This indicates that, compared to adding warfarin sodium, adding warfarin sodium carbon dots significantly increases the release of hemoglobin from the blood clot. Furthermore, the release of hemoglobin from the blood clot also significantly increases with the increase in incubation time between warfarin sodium carbon dots and the blood clot. These results demonstrate that, compared to warfarin sodium, warfarin sodium carbon dots are more effective in promoting the release of hemoglobin from the blood clot. This is due, on the one hand, to the thrombolytic effect of warfarin sodium carbon dots; and on the other hand, to the smaller size of the warfarin sodium carbon dots (3-5 nm), which enhances the contact area with the blood clot and synergistically improves the thrombolytic efficiency.

[0143] Example 3

[0144] This embodiment provides a method for preparing indobufen carbon dots, and their structure and functional characterization.

[0145] I. Preparation method of indobufen carbon dots

[0146] Dissolve 1 g of indobufen in 6 mL of deionized water and add 4 mL of 1 M NaOH solution. Mix well to obtain the precursor solution.

[0147] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (80 °C for 4 h) to preserve the pharmacologically active groups, a medium-temperature zone (120 °C for 4 h) to control the carbon hybridization ratio, and a high-temperature zone (180 °C for 4 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0148] A dialysis bag with a molecular weight cutoff of 3500 Da was used, and deionized water was dialyzed for 24-48 h, with the water changed every 8 h. After dialysis, the solid was freeze-dried at -80 ℃ and 0.1 Pa vacuum to obtain a powdered solid.

[0149] II. Structural Characterization of Indobufen Carbon Dots

[0150] Structural characterization: Transmission electron microscopy (TEM) showed that the particle size of indobufen carbon dots was 3-5 nm. Figure 19 The hydrated particle size of indobufen carbon dots was determined by a nanoparticle size and zeta potential analyzer using dynamic light scattering. The deviation between the hydrated particle size and the TEM results was ≤1 nm. Figure 20 ),like Figure 20As shown, the volume (%) value is 0 in the size range of less than 2 nm and greater than 8 nm; the structure of indobufen carbon dots was detected by polycrystalline X-ray diffraction (XRD), and the results showed that the indobufen carbon dots had no obvious crystallization peaks and no amorphous carbon structure. Figure 21 X-ray photoelectron spectroscopy (XPS) was used to detect the elements contained in the carbon dots of indobufen, confirming that the carbon dots contain C, N, and O elements. Figure 22 Fourier transform infrared spectroscopy (FTIR) Figure 23 ) and UV-Vis-NIR spectrophotometer (UV-VIS) Figure 24 The carbon dot structure information of indobufen was confirmed by detection.

[0151] III. Functional Characterization of Indobufen Carbon Dots

[0152] 1. Safety Verification: L929 mouse fibroblasts were used in the experiment. Indobufen carbon dots were prepared into solutions with concentrations of 0 μg / mL, 50 μg / mL, 100 μg / mL, 200 μg / mL, and 500 μg / mL in DMEM medium, and sterilized by filtration through a 0.22 μm filter membrane. L929 mouse fibroblasts in the logarithmic growth phase were then inoculated with 1×10⁻⁶ cells. 4 Cells were seeded at a density of [number] cells / well in 96-well plates and cultured at 37 ℃ in a 5% CO2 incubator for 24 h until cell adhesion was achieved. The original DMEM medium was discarded, and 100 μL of DMEM medium containing different concentrations of carbon dots was added to each well (five replicates for each concentration). The control group received an equal volume of DMEM medium without carbon dots. After another 24 h of culture, 10 μL of CCK-8 solution was added to each well, and the plates were incubated in the dark for 2 h. The absorbance (OD value) at 450 nm was measured using a microplate reader. The experimental results are as follows: Figure 25 As shown, when the concentration of indobufen carbon dots was 100 μg / mL, L929 mouse fibroblasts still maintained high cell viability, indicating that high concentrations of indobufen carbon dots had low cytotoxicity to L929 mouse fibroblasts. This demonstrates that indobufen carbon dots have low cytotoxicity and high safety.

[0153] 2. In vitro thrombolysis validation: SPF-grade mice weighing 20-25 g were used. 0.5 mL of blood was collected by enucleation and placed in a 1.5 mL centrifuge tube. The blood was incubated at 37 ℃ for 12 h to form a blood clot. The clot was washed three times with physiological saline to remove serum, yielding fresh mouse blood clots, each weighing approximately 20 mg. A 1000 μg / mL indobufen carbon dot solution was prepared using physiological saline. 4 mL of the carbon dot solution was added to a reagent tube and incubated on a shaker at 37 ℃ and 100 rpm. At 2 h, 4 h, and 12 h, 0.2 mL of the supernatant from each tube was carefully aspirated, and the absorbance (OD value) at 540 nm was measured using UV-VIS. The experimental results are as follows: Figure 26 As shown, the supernatant after adding indobufen carbon dots exhibited a significant characteristic absorption peak at 540 nm. This indicates that the release of hemoglobin from the blood clot significantly increased after the addition of indobufen carbon dots. Furthermore, the release of hemoglobin from the blood clot also significantly increased with the increase of indobufen carbon dots in incubation time. This suggests that indobufen carbon dots can effectively promote the release of hemoglobin from the blood clot, meaning that indobufen carbon dots exert their antithrombotic effect by retaining key pharmacodynamic groups. Simultaneously, the 3-5 nm nanometer size of indobufen carbon dots enhances the contact area with the blood clot, synergistically improving thrombolytic efficiency.

[0154] Example 4

[0155] The preparation method of aspirin carbon dots in Example 4 is similar to that in Example 1, except for the different gradient carbonization steps. Specifically:

[0156] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (82 °C for 4.2 h) to preserve the pharmacologically active groups, a medium-temperature zone (124 °C for 3.8 h) to control the carbon hybridization ratio, and a high-temperature zone (182 °C for 3 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0157] Example 5

[0158] The preparation method of warfarin sodium carbon dots in Example 5 is similar to that in Example 2, except for the different gradient carbonization steps. Specifically:

[0159] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (78 °C for 4.3 h) to preserve the pharmacologically active groups, a medium-temperature zone (122 °C for 3.8 h) to control the carbon hybridization ratio, and a high-temperature zone (182 °C for 4 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0160] Example 6

[0161] The preparation method of indobufen carbon dots in Example 6 is similar to that in Example 3, except for the different gradient carbonization steps. Specifically:

[0162] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (78 °C for 4.5 h) to preserve the pharmacologically active groups, a medium-temperature zone (125 °C for 3.5 h) to control the carbon hybridization ratio, and a high-temperature zone (182 °C for 4.5 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0163] Comparative Example 1

[0164] The preparation method of aspirin carbon dots in Comparative Example 1 is similar to that in Example 1, except that a direct carbonization method is used, which lacks the low-temperature region for preserving pharmacodynamic groups and the medium-temperature region for controlling the carbon hybridization ratio. Specifically:

[0165] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven for carbonization treatment, which involved heating at 180 °C for 4 hours. After heating was stopped, the mixture was allowed to cool to room temperature.

[0166] Comparative Example 1 failed to prepare aspirin carbon dots. The condition inside the reaction vessel after preparation was as follows: Figure 9 As shown, aspirin was found to be in a clearly charred state, adhering to the bottle wall and difficult to remove, making it impossible to obtain aspirin carbon dots.

[0167] Comparative Example 2

[0168] The preparation method of warfarin sodium carbon dots in Comparative Example 2 is similar to that in Example 2, except that a direct carbonization method is used, which lacks the low-temperature region for preserving pharmacodynamic groups and the medium-temperature region for controlling the carbon hybridization ratio. Specifically:

[0169] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven for carbonization treatment, which included heating at 180 °C for 4 hours. After heating was stopped, the mixture was allowed to cool to room temperature.

[0170] Comparative Example 2 could not obtain warfarin sodium carbon dots. After preparation, the situation inside the reaction vessel was observed and it was found that the warfarin sodium was obviously in a coking state and was attached to the bottle wall and difficult to remove, so warfarin sodium carbon dots could not be obtained.

[0171] Comparative Example 3

[0172] The preparation method of indobufen carbon dots in Comparative Example 3 is similar to that in Example 3, except that a direct carbonization method is used, which lacks the low-temperature region for preserving pharmacodynamic groups and the medium-temperature region for controlling the carbon hybridization ratio. Specifically:

[0173] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven for carbonization treatment, which included heating at 180 °C for 4 hours. After heating was stopped, the mixture was allowed to cool to room temperature.

[0174] In Comparative Example 3, indobufen carbon dots could not be prepared. After preparation, the situation inside the reaction vessel was observed and it was found that indobufen was obviously in a coking state and was attached to the bottle wall and difficult to remove, so indobufen carbon dots could not be obtained.

[0175] Comparative Example 4

[0176] The preparation method of aspirin carbon dots in Comparative Example 4 is similar to that in Example 1, except for the different gradient carbonization steps. Specifically:

[0177] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (80 °C for 4 h) to preserve the pharmacologically active groups, a medium-temperature zone (120 °C for 4 h) to control the carbon hybridization ratio, and a high-temperature zone (240 °C for 4 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0178] In Comparative Example 4, the carbonization temperature in the high-temperature zone was too high, making it impossible to prepare aspirin carbon dots.

[0179] Comparative Example 5

[0180] The preparation method of warfarin sodium carbon dots in Comparative Example 5 is similar to that in Example 2, except for the different gradient carbonization steps. Specifically:

[0181] Dissolve 1 g of warfarin sodium in 6 mL of deionized water and mix well to obtain a precursor solution.

[0182] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (50 °C for 4 h) to preserve the pharmacologically active groups, a medium-temperature zone (120 °C for 4 h) to control the carbon hybridization ratio, and a high-temperature zone (180 °C for 4 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0183] In Comparative Example 5, the carbonization temperature in the low-temperature zone was too low, making it impossible to prepare warfarin sodium carbon dots.

[0184] Comparative Example 6

[0185] The preparation method of the indobufen carbon dots in Comparative Example 6 is similar to that in Example 3, except for the different gradient carbonization steps. Specifically:

[0186] Dissolve 1 g of indobufen in 6 mL of deionized water and add 4 mL of 1 M NaOH solution. Mix well to obtain the precursor solution.

[0187] The precursor solution was placed in a high-pressure reactor lined with polytetrafluoroethylene (PTFE) to prevent interference from metal ions. The high-pressure reactor was then placed in an oven with multiple temperature zones for gradient carbonization. These zones included a low-temperature zone (80 °C for 4 h) to preserve the pharmacologically active groups, a medium-temperature zone (120 °C for 4 h) to control the carbon hybridization ratio, and a high-temperature zone (240 °C for 4 h) for heteroatom doping. After heating was stopped, the mixture was allowed to cool to room temperature.

[0188] In Comparative Example 6, the carbonization temperature in the high-temperature zone was too high, making it impossible to prepare indobufen carbon dots.

[0189] Comparative Examples 7-10

[0190] The preparation methods of the drug carbon dots in Comparative Examples 7-10 are similar to those in Example 1, except that the aspirin in Example 1 is replaced in equal amounts with ticagrelor (Comparative Example 7), dabigatran etexilate (Comparative Example 8), apixaban (Comparative Example 9), or rivaroxaban (Comparative Example 10).

[0191] The antithrombotic drugs in Comparative Examples 7-10 do not contain specific antithrombotic pharmacological groups such as sulfonic acid groups, acetoxy groups, indole rings, or coumarin structures, so indobufen carbon dots cannot be prepared.

[0192] In summary, this application selected antithrombotic drugs with a molecular weight of 100-2000 Da, a thermal decomposition temperature ≥200 ℃, and containing at least one pharmacophore group from the structures of sulfonic acid, acetoxy, indole ring, or coumarin as precursors. Through a multi-temperature gradient carbonization process, while retaining key pharmacophore groups, the carbon core structure was controlled and heteroatom doping was achieved, successfully preparing uniform carbon dots of 3-5 nm. These carbon dots inherit the antithrombotic activity of the parent drug and enhance the thrombus interface through the nanoscale effect. Surface functional groups and heteroatom doping further endow them with good biocompatibility, achieving a significant reduction in bleeding risk while improving thrombolytic efficiency, effectively solving the problem of balancing the efficacy and safety of antithrombotic drugs.

[0193] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any skillful means or substitutions should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing carbon dots derived from antithrombotic drugs, characterized in that, include: An antithrombotic drug is selected as a precursor. The antithrombotic drug includes at least one of an antiplatelet drug with a pharmacologically active group, an anticoagulant drug with a pharmacologically active group, and a fibrinolytic drug with a pharmacologically active group. The molecular weight of the antithrombotic drug is 100 Da-2000 Da, and the thermal stability decomposition temperature is greater than or equal to 200 °C. The pharmacologically active group includes at least one of a sulfonic acid group, an acetoxy group, an indole ring, and a coumarin structure. The precursor is subjected to gradient carbonization treatment in multiple temperature zones, wherein the multiple temperature zones include a low-temperature zone that can retain pharmacophore groups, a medium-temperature zone that controls the carbon hybridization ratio, and a high-temperature zone for heteroatom doping; the low-temperature carbonization treatment includes: treatment at a temperature of 70℃-90℃ for 2h-5h; the medium-temperature carbonization treatment includes: treatment at a temperature of 110℃-130℃ for 3h-5h; and the high-temperature carbonization treatment includes: treatment at a temperature of 170℃-190℃ for 3h-5h. Impurities were removed, and the mixture was purified and dried to obtain carbon dots derived from antithrombotic drugs.

2. The preparation method according to claim 1, characterized in that, The precursor is subjected to gradient carbonization treatment in multiple temperature zones, wherein the multiple temperature zones include a low-temperature zone capable of retaining pharmacophore groups, a medium-temperature zone for controlling the carbon hybridization ratio, and a high-temperature zone for heteroatom doping. The low-temperature carbonization treatment includes: processing at a temperature of 75 ℃-85 ℃ for 3.5 h-4.5 h; The medium-temperature carbonization treatment includes: processing at a temperature of 115 ℃-125 ℃ for 3.5 h-4.5 h; The high-temperature carbonization treatment includes: processing at a temperature of 175 ℃-185 ℃ for 3.5 h-4.5 h.

3. The preparation method according to claim 1, characterized in that, In the step of selecting an antithrombotic drug as a precursor, the antithrombotic drug includes at least one of an anticoagulant drug with a pharmacologically active group, an antiplatelet drug with a pharmacologically active group, and a tissue plasminogen activator with a pharmacologically active group, and the molecular weight of the antithrombotic drug is 100 Da-2000 Da, and the thermal stability decomposition temperature is greater than or equal to 200 °C. The antithrombotic drugs include any one of aspirin, warfarin sodium, and indobufen.

4. The preparation method according to claim 1, characterized in that, In the step of removing impurities, purifying, and drying to obtain antithrombotic drug-derived carbon dots... The purification process for removing impurities is dialysis. The dialysis conditions are as follows: using a dialysis bag with a molecular weight cutoff of 3500 Da, dialysis with deionized water for 24-48 hours, and changing the water every 8 hours.

5. The preparation method according to claim 1, characterized in that, In the step of removing impurities, purifying, and drying to obtain antithrombotic drug-derived carbon dots... The drying method is freeze drying, and the freeze drying conditions are: -80 ℃ and 0.1 Pa vacuum.

6. Antithrombotic drug-derived carbon dots synthesized using the preparation method according to any one of claims 1-5.

7. The antithrombotic drug-derived carbon dot according to claim 6, characterized in that, The aforementioned antithrombotic drug-derived carbon dots include aspirin carbon dots, warfarin sodium carbon dots, and indobufen carbon dots.

8. A pharmaceutical composition, characterized in that, The invention includes the antithrombotic drug-derived carbon dots as described in claim 6, wherein the antithrombotic drug-derived carbon dots include aspirin carbon dots, warfarin sodium carbon dots, and indobufen carbon dots.

9. The use of the antithrombotic drug-derived carbon dots of claim 6 or 7, and the pharmaceutical composition of claim 8, in the preparation of antithrombotic drugs and drugs for the prevention or treatment of cerebrovascular occlusion.

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