Doxorubicin-tetravalent platinum drug-norcantharidin three-drug combination nano-drug and preparation method and application thereof

Abstract

The application discloses a doxorubicin-quadruple platinum drug-norcantharidin three-drug combination nano drug and a preparation method and application thereof, and belongs to the technical field of medical materials. 2+ The application constructs a novel nano drug through coordination of doxorubicin and a quadruple platinum drug modified by norcantharidin, and then polymerizes polydopamine with a mild photothermal effect to prepare a nano drug for the three-drug combination of doxorubicin, the quadruple platinum drug and norcantharidin. The nano drug has the ability of controlled release of drugs under acidity and reduction, can realize photothermal conversion to generate a mild photothermal effect under laser irradiation, has a better tumor cell killing effect, has the ability of consumption of glutathione and generation of hydroxyl radicals, can enter cancer cells through an endocytosis mode and release DOX, and provides a new idea for multi-drug combination, chemotherapy-chemical kinetics treatment-photothermal treatment multi-mode combined treatment.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical materials technology, specifically relating to a nanomedicine combining doxorubicin, tetravalent platinum, and norepinephrine, its preparation method, and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] As is well known, doxorubicin is an antitumor antibiotic with a broad antitumor spectrum, effective against various tumors. It is a cell cycle nonspecific drug, killing tumor cells at various growth stages. However, it also has serious side effects: cardiotoxicity, which can lead to heart failure and bone marrow suppression in severe cases. Scientists have conducted extensive research on doxorubicin and are working step by step to overcome its inherent toxicity, hoping to maximize its anticancer effects. Cisplatin is a platinum(II)-based chemotherapy drug used as first-line antitumor treatment for many cancers, such as breast cancer, cervical cancer, lung cancer, and liver cancer. However, its nonspecific distribution throughout the body severely affects clinical use and causes a series of serious consequences. Therefore, it is urgent to modify it to maximize its anticancer effect. Norcantharidin is a demethylated analog of cantharidin, possessing properties such as inhibiting cell proliferation, autophagy, migration, metastasis, inducing apoptosis, and enhancing anticancer immunity. It is easier to synthesize, has fewer side effects, causing only mild gastrointestinal side effects and no urinary system adverse reactions.

[0004] Chemotherapy has been widely used in clinical anti-tumor treatment, but chemotherapy alone often fails to achieve the desired results. The main reason is that chemotherapy drugs lack specificity in their delivery to tumor tissues and reach very low concentrations at the tumor site. Furthermore, long-term use of chemotherapy drugs can lead to drug resistance in tumor cells, resulting in treatment failure, recurrence, or metastasis. Patent CN110051858A discloses a type of polysaccharide-drug composite nanoparticle, using Ganoderma lucidum polysaccharide as the main chain, covalently bonded with norcantharidin, doxorubicin, and (Z)-diamminedichloroplatinum to prepare low-toxicity composite nanoparticles. This allows the two drugs to significantly inhibit tumor cells even at low concentrations, overcoming the problems of drug resistance and toxic side effects of anticancer drugs. However, its use in cancer treatment remains a single-drug therapy, and further improvements in treatment efficacy are needed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a nanomedicine combining doxorubicin, tetravalent platinum, and norepinephrine, along with its preparation method and application. The nanomedicine provided by this invention has multiple therapeutic modes and can significantly improve anti-cancer effects.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a nanomedicine comprising a nanoparticle core and polydopamine encapsulated on the surface of the core, wherein the nanoparticles are self-assembled from a tetravalent platinum drug modified with norepinephrine and doxorubicin under the coordination of metal ions.

[0008] A second aspect of the present invention provides a method for preparing the above-mentioned nanomedicine, comprising:

[0009] Add an aqueous solution of tetravalent platinum drug modified with norepinephrine to an aqueous solution of metal salt, then add an aqueous solution of doxorubicin hydrochloride, and react at room temperature in the dark to obtain nanoparticles;

[0010] Nanoparticles were dispersed in water, dopamine hydrochloride was added, and the mixture was stirred. Then ammonia was added, and the mixture was stirred in the dark to produce a nanomedicine.

[0011] A third aspect of the present invention provides the application of the above-described nanomedicine or the nanomedicine prepared by the above-described preparation method in the preparation of antitumor drugs.

[0012] In a fourth aspect, the present invention provides an antitumor drug, comprising the nanomedicine described above or the nanomedicine prepared by the preparation method described above.

[0013] The beneficial effects of this invention are as follows:

[0014] This invention uses tetravalent platinum drug modified with demethylcantharidin (D-Pt-D) and small molecule doxorubicin (DOX) as raw materials to construct novel nanomedicines DDC NPs through metal coordination. Subsequently, polydopamine with mild photothermal activity is polymerized to prepare nanomedicines PDDC NPs containing DOX, tetravalent platinum drug, and demethylcantharidin in combination. PDDC NPs exhibit extremely high drug loading. Dynamic light scattering studies show that PDDC NPs are stable at pH 7.4, while the particle size and particle size distribution change drastically under acidic and reducing conditions, indicating that the prepared nanomedicines are pH and reduction responsive. In vitro drug release results also show that PDDC NPs have the ability to controllably release drugs under acidic and reducing conditions. In vitro photothermal experiments show that PDDC NPs can achieve photothermal conversion under 880 nm laser irradiation, producing a mild photothermal effect. PDDC NPs also have the ability to consume glutathione and generate hydroxyl radicals. Cellular experiments showed that PDDC NPs can enter cancer cells via endocytosis and release DOX. Compared with small molecule DOX and small molecule D-Pt-D, PDDC NPs exhibited the best tumor cell killing effect under 880nm light irradiation. In summary, PDDC NPs are a promising multifunctional nanomedicine, providing new ideas for multi-drug combination therapy and multimodal combined therapy of chemotherapy-chemokinetic therapy-photothermal therapy. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 A schematic diagram illustrating the preparation and mechanism of action of the nanomedicine PDDC NPs provided by this invention;

[0017] Figure 2 The NMR and IR spectra of OH-Pt-OH and D-Pt-D prepared in Example 1 of this invention are shown, where A represents the NMR and IR spectra of OH-Pt-OH. 1 H-NMR spectrum; B is D-Pt-D 1 H-NMR spectrum; C is the FT-IR spectrum of OH-Pt-OH and D-Pt-D;

[0018] Figure 3The images show the spectra of nanoparticles and nanomedicines prepared in Example 1 of this invention. A represents the UV-Vis absorption spectra of DOX, D-Pt-D, CuCl2·2H2O, DDC NPs, and PDDC NPs in DMSO; B represents the UV-Vis absorption spectra of DOX, D-Pt-D, CuCl2·2H2O, DDC NPs, and PDDC NPs in deionized water; C represents the fluorescence spectra of DOX, D-Pt-D, CuCl2·2H2O, DDC NPs, and PDDC NPs in DMSO; and D represents the fluorescence spectra of DOX, D-Pt-D, CuCl2·2H2O, DDC NPs, and PDDC NPs in deionized water.

[0019] Figure 4 XPS spectrum of DDC NPs nanoparticles prepared in Example 1 of this invention;

[0020] Figure 5 The Tyndall effect diagrams of DDC NPs and PDDC NPs prepared in Example 1 of the present invention are shown below; wherein, A is the Tyndall effect diagram of DDC NPs in DMSO; B is the Tyndall effect diagram of DDC NPs in deionized water; C is the Tyndall effect diagram of PDDC NPs in DMSO; and D is the Tyndall effect diagram of PDDC NPs in deionized water.

[0021] Figure 6 The images show the morphology of the DDC NPs and PDDC NPs prepared in Example 1 of this invention; where A is the particle size distribution of the DDC NPs; B is the particle size distribution of the PDDC NPs; C is the TEM image of the DDC NPs; and D is the TEM image of the PDDC NPs.

[0022] Figure 7 The diagram shows the stability and responsiveness of the DDC NPs prepared in Example 1 of this invention; where A is the average particle size variation of DDC NPs in different solutions; and B is the dispersibility variation of DDC NPs in different solutions.

[0023] Figure 8 The figures show the stability and responsiveness characterization of PDDC NPs prepared in Example 1 of this invention; where A is the average particle size variation of PDDC NPs in different solutions; and B is the dispersibility variation of PDDC NPs in different solutions.

[0024] Figure 9 The image shows the photothermal effect of PDDC NPs prepared in Example 1 of this invention; where A represents the PDDC NPs under different laser irradiation concentrations (808 nm, 1.5 W / cm²). 2A) is the photothermal effect diagram of PDDC NPs under different laser intensities (0.5 mg / mL); B) is the photothermal effect diagram of PDDC NPs (0.5 mg / mL) under 808 nm laser (1.5 W / cm²). 2 Photothermal stability curves under irradiation; the relationship between the negative natural logarithm of D (-ln(θ)) and the cooling time of PDDC NPs;

[0025] Figure 10 PDDC NPs prepared in Example 1 of this invention at different concentrations at 808 nm (1.5 W / cm²) 2 Thermal infrared images;

[0026] Figure 11 The graphs show the GSH and H2O2 consumption results of the PDDC NPs prepared in Example 1 of this invention; where A is the GSH consumption curve of PDDC NPs (0.1 mg / mL); B is the GSH consumption curve of PDDC NPs (0.2 mg / mL); C is the H2O2 consumption curve of PDDC NPs at different concentrations; and D is the H2O2 consumption curve of PDDC NPs (0.1 mg / mL).

[0027] Figure 12 The in vitro drug release curves of PDDC NPs prepared in Example 1 of the present invention are shown; wherein, A is the release curve of DOX, B is the release curve of Pt, and C is the release curve of DMC.

[0028] Figure 13 The images show the in vitro cell endocytosis of PDDC NPs prepared in Example 1 of this invention; where A is a CLSM image (scale bar: 25 μm) of HeLa cells incubated with small molecule DOX and PDDC NPs for 1, 3, and 6 h; B is a flow cytometry analysis of HeLa cells incubated with small molecule DOX and PDDC NPs for 1, 3, and 6 h; C is a CLSM image (scale bar: 25 μm) of MCF-7 cells incubated with small molecule DOX and PDDC NPs for 1, 3, and 6 h; and D is a flow cytometry analysis of MCF-7 cells incubated with small molecule DOX and PDDC NPs for 1, 3, and 6 h.

[0029] Figure 14 Cell viability of HeLa cells incubated with different concentrations of DOX+D-Pt-D and PDDC NPs for 24 h (A) and 48 h (B) under darkness or laser irradiation;

[0030] Figure 15 The images show the DLS (A) and TEM (B) images of the iron-coordinated nanoparticles DDC NPs obtained in Example 8 of this invention.

[0031] Figure 16This is the standard curve of DOX at 484nm;

[0032] Figure 17 This refers to the drug loading of the PDDC NPs obtained in Example 1 of the present invention. Detailed Implementation

[0033] Chemotherapy has been widely used in clinical anti-tumor treatment, but chemotherapy alone often fails to achieve the desired results. The main reason is that chemotherapeutic drugs lack specificity in their delivery to tumor tissues and reach very low concentrations at the tumor site. Furthermore, long-term use of chemotherapy drugs can lead to drug resistance in tumor cells, resulting in treatment failure, recurrence, or metastasis. Therefore, chemokinetic therapy (CDT) has gradually come into the research spotlight. CDT is a novel approach that utilizes the tumor microenvironment to activate nanomedicines, causing a Fenton-like reaction that generates highly oxidizing hydroxyl radicals for tumor treatment. The use of exogenous metal ions to induce chemokinetic therapy has been extensively studied. Copper is a common metal and a transition metal element with redox activity. Under normal chemical reaction and physiological conditions, oxidized Cu... 2+ It can be converted into reduced Cu. + Copper ions participate in various biochemical reactions by donating or accepting electrons. Among these, copper mediates the Fenton reaction, catalyzing the synthesis of the most reactive hydroxyl radicals, leading to increased ROS concentrations in tumor cells and ultimately killing them. Furthermore, copper can oxidize reduced glutathione to oxidized glutathione disulfide, resulting in the depletion of the antioxidant glutathione and interfering with the glutathione-related antioxidant defense system. Once this system is disrupted, its ability to scavenge highly reactive hydroxyl groups weakens, leading to tumor cell apoptosis.

[0034] With in-depth research into photothermal therapy (PTT) and photodynamic therapy (PDT), they are gaining increasing attention in cancer treatment. PTT converts near-infrared (NIR) light energy into heat energy using photothermal agents, enabling rapid and effective killing of tumor cells exposed to photosensitizers and laser irradiation. However, uneven distribution of the photosensitizer significantly reduces PTT efficiency, and the large amount of heat generated by PTT may damage normal cells and tissues. Therefore, selecting a suitable photosensitizer is essential. Dopamine has strong absorption properties, with high absorption peaks in both the visible and near-infrared spectral regions. This makes it an excellent optical material. Under light irradiation, the energy absorbed in dopamine can be converted into heat energy, thereby raising the temperature to achieve a mild photothermal effect. Furthermore, dopamine has good biocompatibility, expanding its application in cancer treatment.

[0035] Nowadays, single treatment methods can no longer meet people's needs, and long-term use of chemotherapy drugs can lead to drug resistance in cancer patients, which will greatly reduce the anti-cancer effect of chemotherapy drugs.

[0036] Therefore, this invention develops a novel nanomedicine that, combined with multiple therapeutic modalities, can significantly enhance anti-cancer efficacy. This invention first uses small-molecule DOX and tetravalent platinum drugs modified with norcantharidin as raw materials to self-assemble carrier-free nanomedicines DDC NPs under the coordination of metal ions. Then, surface polymerization of polydopamine constructs novel nanomedicines PDDC NPs to achieve multi-modal synergistic anti-tumor effects through chemotherapy, chemokinetic therapy, and photothermal therapy (e.g., Figure 1 (As described above). First, dopamine, under near-infrared light irradiation, exerts its mild photothermal effect and releases the encapsulated drug. Second, the copper ions in the drug can undergo chemokinetic therapy, reducing the glutathione content in tumor cells, increasing the content of hydroxyl free radicals, and accelerating tumor cell death. Finally, chemotherapeutic drugs such as doxorubicin, platinum(IV) drugs, and norcantharidin can further kill tumor cells and enhance the tumor treatment effect. The nanomedicine provided by this invention can significantly improve the anti-tumor effect through chemotherapy, chemokinetic therapy, and photothermal therapy.

[0037] The innovative aspects of the nanomedicine PDDC NPs provided by this invention are:

[0038] ① The preparation of carrier-free nanomedicines via small molecule co-assembly is simple;

[0039] ② Achieve co-delivery of three chemotherapy drugs—DOX, platinum-based drugs, and desmethylcantharidin—through a simple, integrated nanomedicine delivery system;

[0040] ③ Metal ions (Fe 3+ Gd 3+ Mn 2+ Co 2+ Ni 2+ and Cu 2+ (etc.) can be driven to self-assemble through metal coordination and also have chemokinetic therapeutic effects;

[0041] ④PDDC NPs have a synergistic anti-tumor effect through chemotherapy, chemokinetic therapy, and photothermal therapy.

[0042] Specifically, the present invention provides a nanomedicine combining doxorubicin, tetravalent platinum, and norepinephrine. The nanomedicine comprises nanoparticles and polydopamine coated on the surface of the nanoparticles. The nanoparticles are obtained by self-assembly of norepinephrine-modified (DMC) tetravalent platinum and doxorubicin (DOX) under the coordination of metal ions.

[0043] According to the present invention, the structure of the tetravalent platinum drug modified with norcantharidin is as follows:

[0044]

[0045] It should be noted that the nanomedicine provided by this invention has an extremely high drug loading capacity. This invention does not have specific requirements on the amount of doxorubicin in the nanomedicine; those skilled in the art can select an appropriate loading amount according to actual needs. This invention also does not have specific requirements on the thickness of the outer shell polydopamine, as long as it completely covers the core.

[0046] In some embodiments of the present invention, the metal ion is selected from Fe. 3+ Gd 3+ Mn 2+ Co 2+ Ni 2+ and Cu 2+ One of them.

[0047] In some embodiments of the present invention, the nanoparticles are spherical with a particle size of 140-180 nm.

[0048] In some embodiments of the present invention, the nanomedicine is spherical with a particle size of 200-250 nm.

[0049] The present invention also provides a method for preparing the above-mentioned nanomedicine, comprising:

[0050] Add an aqueous solution of tetravalent platinum drug modified with norepinephrine to an aqueous solution of metal salt, then add an aqueous solution of doxorubicin hydrochloride, and react at room temperature in the dark to obtain nanoparticles;

[0051] Nanoparticles were dispersed in water, dopamine hydrochloride was added, and the mixture was stirred. Then ammonia was added, and the mixture was stirred in the dark to produce a nanomedicine.

[0052] In some embodiments of the present invention, the mass ratio of doxorubicin hydrochloride (DOX), tetravalent platinum drug modified with norcantharidin (D-Pt-D), and metal salt is 1:1:0.5-1, specifically 1:1:0.5, 1:1:0.6, 1:1:0.7, 1:1:0.8, 1:1:0.9, 1:1:1, etc., preferably 1:1:0.6.

[0053] It should be noted that the metal salts include one of the following: iron salts, copper salts, gadolinium salts, manganese salts, cobalt salts, and nickel salts. The iron salts include, but are not limited to, ferric chloride, ferric sulfate, or ferric nitrate. The copper salts include, but are not limited to, one or more of copper chloride, copper sulfate, or copper nitrate, preferably copper chloride or its hydrate. The gadolinium salts include, but are not limited to, gadolinium chloride or gadolinium nitrate. The manganese salts include, but are not limited to, manganese sulfate. The cobalt salts include, but are not limited to, cobalt chloride, cobalt sulfate, and cobalt nitrate. The nickel salts include, but are not limited to, nickel chloride, nickel sulfate, and nickel nitrate.

[0054] In some embodiments of the present invention, the mass ratio of the nanoparticles to dopamine hydrochloride is 3-5:1, specifically 3:1, 4:1, 5:1, etc., preferably 4:1.

[0055] In some embodiments of the present invention, after the reaction at room temperature in the dark or the reaction with stirring in the dark is completed, the reaction solution is dialyzed and freeze-dried to obtain the target product;

[0056] The molecular weight cutoff for dialysis is 900-1100D, preferably 1000D.

[0057] In some embodiments of the present invention, the synthetic route of the norcantharidin-modified tetravalent platinum drug is as follows:

[0058]

[0059]

[0060] The preparation method includes the following steps:

[0061] Cisplatin, water, and hydrogen peroxide were mixed and reacted at room temperature in the dark to obtain a hydroxyl-modified tetravalent platinum drug.

[0062] Under nitrogen protection and at 65-75℃, hydroxyl-modified tetravalent platinum and norcantharidin react in the dark to obtain norcantharidin-modified tetravalent platinum.

[0063] According to the present invention, cisplatin, water, and hydrogen peroxide are mixed and reacted in the dark at room temperature. After the reaction is completed, the mixture is filtered under reduced pressure, the filter residue is washed with an organic solvent, and then dried under vacuum in the dark to obtain a hydroxyl-modified tetravalent platinum drug. The organic solvent is preferably one or more of acetone, diethyl ether, chloroform, and ethanol, preferably acetone and diethyl ether. The vacuum drying temperature in the dark is preferably 30-50°C, more preferably 40°C.

[0064] In some embodiments of the present invention, the preferred ratio of cisplatin, water and hydrogen peroxide is 1g:5-10mL:8-12mL, and more preferably 1g:8mL:10mL.

[0065] According to this invention, a hydroxyl-modified tetravalent platinum drug, norcantharidin, and an organic solvent are mixed and then reacted under nitrogen protection at 65-75°C in the dark. After the reaction is complete, the mixture is filtered under reduced pressure, then precipitated with diethyl ether, washed with methanol and acetone, then precipitated again with diethyl ether, and finally dried under vacuum in the dark to obtain the norcantharidin-modified tetravalent platinum drug. The organic solvent is preferably one or more of N,N-dimethylformamide, acetone, and chloroform, with N,N-dimethylformamide being the most preferred.

[0066] In some embodiments of the present invention, the mass ratio of the hydroxyl-modified tetravalent platinum drug to norcantharidin is preferably 1:1.8-2.2.

[0067] The present invention also provides the application of the above-described nanomedicine or the nanomedicine prepared by the above-described preparation method in the preparation of antitumor drugs.

[0068] According to the present invention, the tumor includes, but is not limited to, cervical cancer and breast cancer.

[0069] The present invention also provides an antitumor drug, including the above-described nanomedicine or the nanomedicine prepared by the above-described preparation method.

[0070] In some embodiments of the present invention, the antitumor drug further includes pharmaceutically acceptable excipients, including but not limited to lactose, glucose, sorbitol, mannitol, xylitol, maltitol, starch, gum arabic, gelatin, calcium phosphate, cellulose, microcrystalline cellulose, polyvinylpyrrolidone, water, and mineral oil. No specific limitations are made herein.

[0071] According to the present invention, the tumor includes, but is not limited to, cervical cancer and breast cancer.

[0072] This invention uses tetravalent platinum drug modified with desmethylcantharidin (D-Pt-D) and small molecule doxorubicin (DOX) as raw materials to construct novel nanomedicines DDC NPs through metal ion coordination. Subsequently, polydopamine with mild photothermal activity is polymerized to prepare nanomedicines PDDC NPs containing DOX, tetravalent platinum drug, and desmethylcantharidin in combination. PDDC NPs exhibit extremely high drug loading. Dynamic light scattering studies show that PDDC NPs are stable at pH 7.4, while the particle size and particle size distribution change drastically under acidic and reducing conditions, indicating that the prepared nanomedicines are pH and reduction responsive. In vitro drug release results also show that PDDC NPs have the ability to release drugs in a controlled manner under acidic and reducing conditions. In vitro photothermal experiments show that PDDC NPs can achieve photothermal conversion under 880 nm laser irradiation, producing a mild photothermal effect. PDDC NPs also have the ability to consume glutathione and generate hydroxyl radicals. Cellular experiments showed that PDDC NPs can enter cancer cells via endocytosis and release DOX. Compared with small molecule DOX and small molecule D-Pt-D, PDDC NPs exhibited the best tumor cell killing effect under 880nm light irradiation. In summary, PDDC NPs are a promising multifunctional nanomedicine, providing new ideas for multi-drug combination therapy and multimodal combined therapy of chemotherapy-chemokinetic therapy-photothermal therapy.

[0073] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0074] Example 1

[0075] A method for preparing a nanomedicine includes the following steps:

[0076] 1. Synthesis of OH-Pt-OH and D-Pt-D

[0077] At room temperature, 1 g of cisplatin was weighed and added to 8 mL of H2O and 10 mL of H2O2. After reacting in the dark for 24 h, the mixture was filtered under reduced pressure. The residue was washed with acetone and ether, respectively, and then dried in a vacuum drying oven at 40 °C in the dark for 24 h to obtain a yellow powdery solid product (i.e., a hydroxyl-modified tetravalent platinum drug), named OH-Pt-OH.

[0078] 0.6 g (1.8 mmol) of OH-Pt-OH and 1.21 g (7.19 mmol) of norcantharidin (DMC) were weighed into a round-bottom flask, and 17 mL of DMF was added. The mixture was then reacted at 70 °C in the dark for 10 h under nitrogen protection. The reaction solution was then filtered under reduced pressure, precipitated with diethyl ether, washed with methanol and acetone, and then precipitated with diethyl ether again. Finally, the product was dried in a vacuum drying oven at 37 °C in the dark to obtain a light white powdery solid product (i.e., tetravalent platinum modified with norcantharidin), named D-Pt-D.

[0079] 2. Synthesis of DDC NPs

[0080] Doxorubicin hydrochloride (DOX) (20 mg, 17.24 mM), D-Pt-D (20 mg, 14.92 mM), and CuCl2·2H2O (12 mg, 3.519 mM) were dissolved in water respectively. Then, D-Pt-D solution was added to the CuCl2·2H2O solution under sonication, followed by dropwise addition of DOX solution while stirring. The reaction was then carried out at room temperature in the dark for 5 h. The reaction solution was dialyzed (MWCO: 1000D) for 24 h, and finally freeze-dried to obtain a solid (i.e., nanoparticles), which were named DDC NPs.

[0081] Note: Taking doxorubicin hydrochloride as an example, "20mg, 17.24mM" means that 20mg of doxorubicin hydrochloride is dissolved in water to obtain a doxorubicin hydrochloride solution with a concentration of 17.24mM. Therefore, the mass ratio between doxorubicin hydrochloride, D-Pt-D, and CuCl2·2H2O is clear.

[0082] 3. Synthesis of PDDC NPs

[0083] 40 mg of DDC NPs were dispersed in ultrapure water. After 5 hours, 2 mL of dopamine hydrochloride solution (10 mg, 26.37 mM) was added, and the mixture was stirred for 30 minutes. Then, 1.03 mL of ammonia solution (1.556 M) was added, and the mixture was stirred in the dark for 10 hours. The reaction solution was dialyzed (MWCO: 1000 D) for 24 hours and finally freeze-dried to obtain a solid (i.e., nanomedicine), which was named PDDC NPs.

[0084] Experimental Example 1

[0085] The OH-Pt-OH, D-Pt-D, DDC NPs, and PDDC NPs used in this experiment were all prepared in Example 1.

[0086] 1. Structural characterization

[0087] 1.1 Structural characterization of OH-Pt-OH and D-Pt-D

[0088] OH-Pt-OH and D-Pt-D were synthesized according to the designed synthetic route, and then... 1 H-NMR and FT-IR confirmed its successful synthesis. Figure 2 ).Depend on Figure 2 As shown in (B), the signal peak at δ = 6.17 ppm is a characteristic peak of -NH3. The signal peaks at δ = 4.6–4.8 ppm are characteristic peaks of the methine (-CH) group attached to the oxygen atom on the six-membered ring of DMC. The signal peaks at δ = 2.9–3.0 ppm are characteristic peaks of the methine (-CH) group attached to platinum and carboxyl groups on the six-membered ring of DMC. Furthermore, combining... Figure 2 The FT-IR spectrum in (C) confirms the successful synthesis of OH-Pt-OH and D-Pt-D.

[0089] 1.2 Characterization of DDC NPs and PDDC NPs

[0090] DDCNPs were synthesized by means of metal coordination and non-covalent interactions of DOX, D-Pt-D, and CuCl2·2H2O. PDDCNPs were then obtained by coating their surfaces with a layer of polydopamine. The successful preparation of DDCNPs and PDDCNPs was confirmed by UV-Vis spectrophotometry, fluorescence spectrophotometry, DLS, and TEM, respectively, and their particle size and microstructure were characterized.

[0091] First, such as Figure 3 As shown in the UV-Vis absorption spectra of (A) and (B), the characteristic absorption peak of DOX appeared in the solutions of both DDC NPs and PDDC NPs, with a significant red shift, consistent with the fluorescence spectra. Figure 3 Combining (C) and (D) in the above, we have preliminarily demonstrated the successful coordination of DDC NPs and PDDC NPs, as well as the successful loading of DOX. Furthermore, combining the XPS of DDC NPs... Figure 4 Analysis shows that D-Pt-D and CuCl2·2H2O were also successfully assembled. Figure 5 The Tyndall effect further demonstrates the successful assembly of DDC NPs and PDDC NPs.

[0092] like Figure 6 As shown in (A) and (B), the particle sizes of DDC NPs and PDDC NPs are 159.9 nm and 225.7 nm, respectively. Additionally... Figure 6Images (C) and (D) show TEM images of DDC NPs and PDDC NPs, revealing that both have a spherical morphology. Suitable particle size and morphology contribute to the better EPR effect of DDC NPs and PDDC NPs. These results also demonstrate the successful preparation of DDC NPs and PDDC NPs.

[0093] 2. Drug loading

[0094] DOX solutions of different concentrations were prepared using DMSO as solvent, and the UV-Vis absorption spectra of each solution were measured. A standard curve for DOX was plotted using the absorbance values ​​at the maximum absorption peak. Figure 16 2 mg of PDDC NPs was added to 15 mL of DMSO and dissolved by sonication. The absorbance at the maximum absorption peak of the solution was then measured by UV-Vis spectrophotometry. Figure 17 ), to calculate the drug loading (DLC) of PDDC NPs.

[0095] The drug loading of Pt was determined by ICP.

[0096] The drug loading of demethylcantharidin was characterized by high performance liquid chromatography.

[0097]

[0098] 3. Stability and responsiveness testing of DDC NPs and PDDC NPs

[0099] To investigate the stability and responsiveness of DDC NPs and PDDC NPs in vivo blood circulation and tumor microenvironment, the particle size of DDC NPs and PDDC NPs under different conditions was measured over time using DLS and UV-Vis. Taking DDCNPs as an example, (1) DDC NPs were dispersed in PBS at pH 7.4, and the particle size of the samples was measured at 0, 1, 2, 4, 6, 12, and 24 h; (2) DDC NPs were dispersed in PBS at pH 5.0, and the particle size of the samples was measured at 0, 1, 2, 4, 6, 12, and 24 h; (3) DDC NPs were dispersed in PBS at pH 7.4 with 20 mM GSH added, and the particle size of the samples was measured at 0, 1, 2, 4, 6, 12, and 24 h; (4) DDC NPs were dispersed in PBS at pH 5.0 with 20 mM GSH added, and the particle size of the samples was measured at 0, 1, 2, 4, 6, 12, and 24 h. PDDC NPs were measured using the same method. In each test group, the concentration of both DDC NPs and PDDC NPs was 1 mg / mL.

[0100] Experimental results:

[0101] The stability of nanomedicines helps them maintain their structure and activity in vivo, thereby improving therapeutic efficacy and prolonging circulation time, reducing drug loss during elimination. The responsiveness of nanomedicines enables precision treatment, reduces toxic side effects on normal tissues, and enhances therapeutic effects. For example... Figure 8 As shown, when PDDC NPs were dispersed in PBS at pH 7.4, the particle size changes at different time points were negligible with continuous stirring, demonstrating the good stability of PDDC NPs. However, significant changes in particle size occurred immediately after 1 hour of addition to the three solutions. This may be due to the Cu in the PDDC NPs. 2+ The reaction between Pt(Ⅳ) and GSH at high concentrations caused the PDDC NPs to cleave, thereby destroying the structure of the nanoparticles.

[0102] Meanwhile, DDC NPs were also characterized for stability and responsiveness using the same method as PDDC NPs, and similar results were observed. For example... Figure 7 As shown, DDC NPs also exhibit good stability and responsiveness.

[0103] 3. In vitro photothermal performance testing of PDDC NPs

[0104] 3.1 Concentration-dependent and laser-dependent photothermal properties of PDDC NPs

[0105] Different concentrations of PDDC NPs solutions (0, 0.2, 0.4, 0.6, 0.8 mg / mL) were prepared, and 200 μL of each solution was placed in a 96-well plate. An 808 nm laser (1.5 W / cm²) was used for microscopy. 2 The solution was irradiated for 10 minutes, with temperature changes recorded every 20 seconds. Secondly, infrared thermal imaging was used to record the thermal images of PDDC NPs solutions (0.2, 0.4, 0.6, 0.8 mg / mL) at 0, 2, 4, 6, 8, and 10 minutes. Finally, a PDDC NPs solution with a concentration of 0.5 mg / mL was prepared and subjected to different powers (0.4, 0.8, 1.2, 1.6 W / cm²). 2 The solution was irradiated with an 808nm laser for 10 minutes, and the temperature change of the solution was recorded every 20 seconds.

[0106] 3.2 Photothermal stability and photothermal conversion efficiency of PDDC NPs

[0107] Prepare a PDDC NPs solution (0.5 mg / mL), and transfer 200 μL of the solution to a 96-well plate. Use 1.5 W / cm² water. 2The solution was irradiated with an 808nm laser for 10 minutes, and then the light source was turned off and allowed to cool naturally for 10 minutes. This heating and cooling cycle was repeated 5 times. The temperature change was recorded every 20 seconds during the entire process to study the photothermal stability of the sample.

[0108] The photothermal conversion efficiency of PDDC NPs was calculated using the formula reported in the report:

[0109]

[0110] Among them, T max and T sur Q represents the highest temperature of the solution and the ambient temperature, respectively. s For the heat dissipation of the solvent used, I is the power of the laser used, and A is the heat dissipation of the solvent used. 808 nm The absorbance of the PDDC NPs solution used is at 808 nm. h and A are the heat transfer coefficient and the sample cell surface area, respectively. The formula for calculating hA is as follows:

[0111]

[0112] Where, m D and C D Given the mass and specific heat of the solvent used (4.2 J / g for water), τ s Let τ be the time constant for heat transfer in the system. s The calculation formula is as follows:

[0113]

[0114] Where t represents time, and θ is the unit driving force, which is dimensionless and defined by the following formula:

[0115]

[0116] Where T represents the temperature at a certain moment.

[0117] Q s It can be obtained through the following formula:

[0118]

[0119] Experimental results:

[0120] Polydopamine, as a photothermal agent, is widely used in photothermal therapy due to its excellent photothermal conversion ability and biocompatibility. For example... Figure 9 As shown in Figure (A), compared with the deionized water control group, with the increase of PDDC NPs concentration, at the same power of 1.5 W / cm², 2The solution temperature increased significantly after irradiation with an 808 nm laser. Specifically, in a 0.8 mg / mL PDDC NPs solution, the temperature increase (ΔT) was 30.7 °C after 10 minutes of laser irradiation. Subsequently, as... Figure 9 As shown in (B), the temperature of the PDDC NPs changes with increasing power. When the power is 1.6 W / cm²... 2 At that time, in a PDDC NPs solution with a concentration of 0.5 mg / mL, the temperature rise (ΔT) was 35.2 °C after 10 min of laser irradiation. This fully demonstrates the power dependence of PDDC NPs.

[0121] Furthermore, the photostability and photothermal conversion efficiency of PDDC NPs were investigated. For example... Figure 9 As shown in (C), under an 808nm laser (1.5W / cm²), 2 After five cycles of repeated irradiation / off, the maximum temperature of the PDDC NPs solution remained essentially unchanged, demonstrating good photostability. Based on the first heat generation-dissipation curve, substituting the values... Figure 9 From the equation relating the negative logarithm of -ln(θ) to the cooling time of PDDC NPs shown in Figure (D), the photothermal conversion efficiency of PDDC NPs is found to be 6.67%.

[0122] Finally, the photothermal imaging of PDDC NPs at different concentrations was further investigated. As shown in Figure 10, the color change trend and the photothermal temperature curve are basically consistent.

[0123] The above photothermal results demonstrate that PDDC NPs possess excellent photothermal performance, exhibiting significant concentration and laser power dependence. They also demonstrate good photostability and photothermal imaging capabilities.

[0124] 4. GSH and H2O2 consumption experiments of PDDC NPs

[0125] 4.1 GSH Consumption Experiment of PDDC NPs

[0126] First, prepare the 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) standard solution (10 mM): Dissolve 39.6 mg of DTNB in ​​Na2HPO4·12H2O (50 mM) and bring the volume to 10 mL in a volumetric flask; Prepare the Tris-HCl buffer solution (0.25 mM): Dissolve 0.3581 g of tris(hydroxymethyl)aminomethane in deionized water, adjust the pH to 8 with concentrated hydrochloric acid, and finally bring the volume to 100 mL with deionized water; Prepare the DTNB analytical solution (0.1 mM): Add 1 mL of the DTNB standard solution (10 mM) to a volumetric flask and bring the volume to 100 mL with the Tris-HCl buffer solution (0.25 mM).

[0127] 4 mg of lyophilized PDDC NPs powder was added to 4 mL of HAc-NaAc buffer solution (pH = 5.5) to prepare a PDDC NPs (1 mg / mL) solution. 1 mL of this solution was added to 9 mL of HAc-NaAc buffer solution (pH = 5.5), followed by the addition of glutathione (GSH) (10 mM, 0.6 mL) in a 37°C water bath. At 0 and 30 min, 0.5 mL of the reaction solution was added to DTNB analytical solution (0.1 mM) pre-controlled at 25°C. After reacting for 5 min, the absorbance at 300-800 nm was measured using a UV spectrophotometer. Simultaneously, 2 mL of the PDDC NPs (1 mg / mL) solution was added to 8 mL of HAc-NaAc buffer solution (pH = 5.5), and then glutathione (GSH) (10 mM, 0.6 mL) was added in a 37°C water bath, repeating the above experiment.

[0128] 4.2 H2O2 Consumption Experiment of PDDC NPs

[0129] First, prepare a 10 mM, 10 mL solution of 3,3',5,5'-tetramethylbenzidine (TMB) in ethanol and 1 M, 10 mL of H₂O₂. Next, add 4 mg of lyophilized PDDC NPs powder to 4 mL of HAc-NaAc buffer (pH = 5.5) to prepare a 1 mg / mL solution of PDDC NPs. Then, prepare solutions of 0, 0.02, 0.04, 0.06, 0.08, and 0.1 mg / mL of PDDC NPs (1 mg / mL) using HAc-NaAc buffer (pH = 5.5), respectively. Add 1 M, 1 mL of H₂O₂ and 10 mM, 100 μL of TMB in ethanol to each solution. After 10 min, measure the absorbance at 400-800 nm using a UV-Vis spectrophotometer. Simultaneously, H2O2 (1M, 1mL) and TMB ethanol solution (10mM, 100μL) were added to a 0.1mg / mL PDDCNPs solution, and the absorbance at 400-800nm ​​was measured using a UV-Vis spectrophotometer after 0, 2, 4, 6, 8, and 10 min of reaction.

[0130] Experimental results:

[0131] like Figure 11As shown in (A) and (B), PDDC NPs undergo cleavage under acidic conditions, releasing copper ions that can react with and consume GSH. When no GSH is added to the solution, an absorption peak of DTNB is observed at 320 nm. When DTNB is mixed with GSH, TNB is generated, producing a corresponding absorption peak at 412 nm, while the absorption peak at 320 nm decreases. When PDDC NPs solution is added to the mixed solution of DTNB and GSH, the absorption peak at 412 nm decreases with time, while the absorption peak at 320 nm increases. This indicates that the copper ions released after the cleavage of PDDC NPs under acidic conditions can react with GSH, thereby reducing the GSH content.

[0132] like Figure 11 As shown in (C), the absorption peak at 652 nm increases with increasing PDDC NPs concentration, indicating that PDDC NPs react with H2O2 to generate ·OH. Meanwhile, at a PDDC NPs concentration of 0.1 mg / mL (… Figure 11 During the middle (D) period, the content of ·OH generated by the reaction of PDDC NPs with H2O2 increases with time, but its content does not change much after 6 minutes.

[0133] In summary, PDDC NPs possess the properties of chemokinetic therapy.

[0134] 5. In vitro drug release assay of PDDC NPs

[0135] 5 mg of lyophilized PDDC NPs powder was dispersed in 5 mL of PBS (pH 7.4), PBS (pH 5.0), PBS (pH 7.4, 20 mM GSH), and PBS (pH 5.0, 20 mM GSH), respectively. The solutions were then placed in dialysis bags (MWCO: 1000D) and subsequently into glass vials containing 45 mL of the corresponding buffer solutions. The vials were shaken in a 37°C water bath. At specified time points (1, 2, 4, 6, 8, 10, 14, 24, 32, 36, and 48 h), 3 mL of dialysate was collected, and the same volume of fresh buffer solution was added. The UV-Vis absorption spectra of the solutions were measured. The cumulative release of DOX at each time point was calculated using standard curves. The cumulative release of Pt at each time point was calculated using the standard curve for Pt measured by ICP. The cumulative release of DMC at each time point was calculated using the standard curve for DMC measured by HPLC.

[0136] Experimental results:

[0137] The drug release behavior of PDDC NPs was assessed using dialysis. Figure 12As shown in (A), at pH 7.4, the DOX release was only 13.65% after 48 hours, further demonstrating the stability of PDDC NPs under normal conditions. However, when the pH was acidic, the DOX release increased significantly, reaching 38.86% at 48 hours. Simultaneously, 20 mM GSH was added to PBS at pH 7.4 to verify the sensitivity of PDDC NPs to a reducing environment. The results were consistent with expectations; the DOX release reached 52.37% after adding GSH to PBS at pH 7.4, while it reached 80.45% in an acidic environment. This indicates that the tumor microenvironment can effectively promote the release of DOX from PDDC NPs to exert a chemotherapeutic effect. Furthermore, as... Figure 12 As shown in (B) and (C), the release behavior of Pt and DMC was also investigated. At pH 7.4, the release amounts of Pt and DMC were 15.23% and 14.84%, respectively. This demonstrates the stability of PDDC NPs under normal conditions. However, under the two acidic environments, the release amounts of Pt were 40.56% (pH = 5.0) and 84.65% (pH = 5.0 + 20 mM GSH); the release amounts of DMC were 39.89% (pH = 5.0) and 83.55% (pH = 5.0 + 20 mM GSH). In summary, all these findings indicate that PDDC NPs can release drugs normally to achieve therapeutic effects.

[0138] 6. Cellular-level study of PDDC NPs

[0139] 6.1 Cell Culture

[0140] Human cervical cancer cells (HeLa) and human breast cancer cells (MCF-7) used in the experiment were purchased from the Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences (Shanghai, China). All cells were seeded in cell culture dishes containing DMEM and cultured in a sterile incubator at 37°C, 90% relative humidity, and 5% CO2.

[0141] 6.2 In vitro cell endocytosis and intracellular distribution

[0142] To investigate the uptake of PDDC NPs by cancer cells and the distribution of drugs within cancer cells, HeLa cells were sputtered at a rate of 4 × 10⁻⁶. 5Cells were seeded at a density of 4 × 10⁶ cells / well in six-well plates covered with coverslips. After incubation, culture medium containing small molecule DOX or PDDC NPs was added at different time points (1, 3, and 6 h). After treatment, the cells were first washed three times with PBS, then fixed with 4% paraformaldehyde solution for 20 min. They were then washed three times with PBS, mounted and stained with anti-fluorescence quenching mounting medium containing DAPI, and finally the uptake and distribution of small molecule DOX and PDDC NPs in HeLa cells were observed using confocal laser microscopy (CLSM). Simultaneously, the uptake of PDDC NPs by cancer cells was quantitatively analyzed using flow cytometry. 5 HeLa cells were seeded at 100 cells / well in six-well plates and incubated until adherence. Cells were then treated with small molecule DOX or PDDCNPs at different time points (1, 3, and 6 h). After incubation, the culture medium was removed, and the cells were washed three times with PBS buffer. Cells were then trypsinized, centrifuged, and redispersed in PBS buffer to obtain a cell suspension. Flow cytometry was used to detect the intracellular DOX fluorescence intensity at different time points. MCF-7 cells were also subjected to the same experimental verification.

[0143] 6.3 In vitro cytotoxicity

[0144] The in vitro cytotoxicity of PDDC NPs was assessed using the MTT assay. HeLa cells were inoculated at a concentration of 1 × 10⁻⁶ cells / mL. 4 Cells were seeded at a density of 1 cell / well in 96-well plates and incubated for 24 h. After cell adhesion, DMEM medium containing small molecule DOX plus D-Pt-D and PDDCNPs were added for treatment. The experiment was conducted with the following 5 different treatments: (1) control group, supplemented with medium without drugs; (2) medium containing small molecule DOX and D-Pt-D; (3) medium containing small molecule DOX and D-Pt-D and irradiated with 808 nm laser; (4) medium containing PDDCNPs; (5) medium containing PDDCNPs and irradiated with 808 nm laser. Laser irradiation was performed 6 h after drug administration, with 808 nm (1.5 W / cm²) laser applied. 2 The cells were irradiated with a laser. After treatment and incubation for 24 and 48 hours, MTT solution was added to each well. After another 4 hours of incubation, the culture medium was discarded, and DMSO was added to dissolve the formazan formed within the cells. The absorbance at 490 nm was measured using a multi-mode microplate reader. Cell viability can be calculated using the following formula:

[0145]

[0146] Experimental results:

[0147] Effective endocytosis is a crucial prerequisite for the efficacy of anticancer nanomedicines. Taking HeLa cells as an example, the in vitro cellular properties of PDDC NPs were first investigated using confocal laser fluorescence microscopy (CLSM). PDDC NPs were added to HeLa cells at 1, 3, and 6 hours. A small molecule DOX was used as a control group. Figure 13 As shown in (A), after 1 h of incubation, the fluorescence of HeLa cells treated with small molecule DOX was primarily located in the cell nucleus. However, for HeLa cells treated with PDDC NPs, most of the DOX fluorescence was located in the cytoplasm after 1 h; after 6 h of incubation, DOX was distributed in both the cell nucleus and cytoplasm, indicating that the prepared nanomedicine could effectively release DOX. The results show that PDDC NPs can be absorbed by HeLa cells via endocytosis, while small molecule DOX enters the cells via passive diffusion. Simultaneously, flow cytometry (FCM) was used to quantitatively verify the cellular uptake of small molecule DOX and PDDC NPs. The FCM results confirmed that cellular uptake was time-dependent, consistent with CLSM analysis. Figure 13 (B)). Meanwhile, the results of CLSM and FCM in MCF-7 cells were similar to those in HeLa cells ( Figure 13 In (C) and (D), both demonstrated that PDDC NPs can be effectively internalized by cells and successfully release DOX.

[0148] The in vitro cytotoxicity of HeLa cells using DOX, D-Pt-C, and PDDC NPs with and without 808nm laser irradiation was determined by the MTT assay. Figure 14 As shown, all drugs exhibited progressively enhanced cytotoxic activity with increasing concentration. In the absence of laser irradiation, small-molecule DOX showed strong cytotoxicity. PDDC NPs, after irradiation with an 808nm laser, significantly reduced cell viability, demonstrating excellent PTT (post-transfer) activity. MTT assays suggest that PDDC NPs may be a potential drug for synergistic chemotherapy and PTT therapy.

[0149] In summary, DDC NPs were obtained by coordinating copper ions with DOX and D-Pt-D, and then PDDC NPs were obtained by further self-assembly after coating their surface with a layer of dopamine. PDDC NPs exhibit suitable particle size and distribution, spherical morphology, significant photothermal conversion capability, pH and GSH responsiveness, corresponding controllable drug release curves, and chemokinetic therapeutic effects. In vitro cell experiments showed that PDDC NPs could be effectively internalized by cancer cells and exhibited significant cytotoxicity under 808 nm laser irradiation. Therefore, PDDC NPs are a potential nano-anticancer drug for synergistic chemotherapy-PTT-chemokinetic therapy.

[0150] Example 2

[0151] A method for preparing a nanomedicine differs from Example 1 in that: at room temperature, 1g of cisplatin is weighed and added to 5mL H2O and 8mL H2O2, while the remaining steps are the same as in Example 1.

[0152] Example 3

[0153] A method for preparing a nanomedicine differs from Example 1 in that: at room temperature, 1g of cisplatin is weighed and added to 10mL of H2O and 12mL of H2O2, while the remaining steps are the same as in Example 1.

[0154] Example 4

[0155] A method for preparing a nanomedicine differs from Example 1 in that: OH-Pt-OH (0.6g) and norcantharidin (DMC) (1.08g) are weighed and poured into a round-bottom flask, while the remaining steps are the same as in Example 1.

[0156] Example 5

[0157] A method for preparing a nanomedicine differs from Example 1 in that: OH-Pt-OH (0.6g) and norcantharidin (DMC) (1.32g) are weighed and poured into a round-bottom flask, while the remaining steps are the same as in Example 1.

[0158] Example 6

[0159] A method for preparing a nanomedicine differs from Example 1 in that: DDC NPs (30 mg) are dispersed in ultrapure water, and 2 mL of dopamine hydrochloride solution (10 mg, 26.37 mM) is added after 5 h. The remaining steps are the same as in Example 1.

[0160] Example 7

[0161] A method for preparing a nanomedicine differs from Example 1 in that: DDC NPs (50 mg) are dispersed in ultrapure water, and 2 mL of dopamine hydrochloride solution (10 mg, 26.37 mM) is added after 5 h. The remaining steps are the same as in Example 1.

[0162] Example 8

[0163] A method for preparing nanomedicine differs from Example 1 in that FeCl3 is used instead of CuCl2·2H2O, while the concentration of FeCl3 in the solution remains 3.519 mM. The remaining steps are the same as in Example 1. The iron-coordinated nanoparticles (DDC NPs) obtained in this example have a particle size of 176.3 nm and a PDI of 0.209 (…). Figure 15(A)

[0164] Testing revealed that the nanomedicines obtained in Examples 2-8 exhibited similar performance to those obtained in Example 1. They also possessed the ability to controllably release drugs under acidic and reducing conditions, could achieve photothermal conversion under laser irradiation to produce a mild photothermal effect, had tumor cell killing effects, could consume glutathione and generate hydroxyl radicals, could enter cancer cells through endocytosis and release DOX, and could significantly enhance anti-tumor effects through chemotherapy, chemokinetic therapy, and photothermal therapy.

[0165] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A nanomedicine, characterized in that, It includes nanoparticles and polydopamine coated on the surface of the nanoparticles. The nanoparticles are self-assembled by the coordination of a tetravalent platinum drug modified with norepinephrine and doxorubicin hydrochloride under the coordination of metal ions. The metal ion is Cu. 2+ ; The method for preparing the nanomedicine includes the following steps: adding a tetravalent platinum drug aqueous solution modified with norepinephrine to a copper salt aqueous solution, then adding an aqueous solution of doxorubicin hydrochloride, reacting at room temperature in the dark to obtain nanoparticles; Nanoparticles were dispersed in water, dopamine hydrochloride was added, and the mixture was stirred. Then ammonia was added, and the mixture was stirred in the dark to obtain nanomedicine. The structure of the tetravalent platinum drug modified with norcantharidin is as follows: 。 2. The nanomedicine as described in claim 1, characterized in that, The nanoparticles are spherical with a particle size of 140-180 nm.

3. The nanomedicine as described in claim 1, characterized in that, The nanomedicine is spherical with a particle size of 200-250 nm.

4. A method for preparing a nanomedicine according to any one of claims 1-3, characterized in that, include: Add an aqueous solution of tetravalent platinum drug modified with norepinephrine to an aqueous solution of copper salt, then add an aqueous solution of doxorubicin hydrochloride, and react at room temperature in the dark to obtain nanoparticles; Nanoparticles were dispersed in water, dopamine hydrochloride was added, and the mixture was stirred. Then ammonia was added, and the mixture was stirred in the dark to produce a nanomedicine.

5. The preparation method according to claim 4, characterized in that, The preparation method of the norepinephrine-modified tetravalent platinum drug includes the following steps: Cisplatin, water, and hydrogen peroxide were mixed and reacted at room temperature in the dark to obtain a hydroxyl-modified tetravalent platinum drug. Under nitrogen protection and at 65-75℃, hydroxyl-modified tetravalent platinum and norcantharidin react in the dark to obtain norcantharidin-modified tetravalent platinum.

6. The preparation method according to claim 5, characterized in that, The ratio of cisplatin, water, and hydrogen peroxide used is 1g:5-10 mL:8-12 mL.

7. The preparation method according to claim 5, characterized in that, The mass ratio of the hydroxyl-modified tetravalent platinum drug to norcantharidin is 1:1.8-2.

2.

8. The preparation method according to claim 5, characterized in that, The structure of the hydroxyl-modified tetravalent platinum drug is as follows: 。 9. The preparation method according to claim 4, characterized in that, The mass ratio of doxorubicin hydrochloride, tetravalent platinum drug modified with norcantharidin, and copper salt is 1:1:0.5-1.

10. The preparation method according to claim 4, characterized in that, The mass ratio of the nanoparticles to dopamine hydrochloride is 3-5:

1.

11. The preparation method according to claim 10, characterized in that, The mass ratio of the nanoparticles to dopamine hydrochloride is 4:

1.

12. The preparation method according to claim 4, characterized in that, After the reaction is completed at room temperature in the dark or by stirring in the dark, the reaction solution is dialyzed and freeze-dried to obtain the target product. The molecular weight cutoff for the dialysis is 900-1100 D.

13. The use of a nanomedicine according to any one of claims 1-3 or a nanomedicine prepared by any one of claims 4-12 in the preparation of an antitumor drug.

14. The application of the nanomedicine as described in claim 13 in the preparation of antitumor drugs, characterized in that, The tumors mentioned are cervical cancer and breast cancer.

15. An antitumor drug, characterized in that, This includes nanomedicines according to any one of claims 1-3 or nanomedicines prepared by any one of claims 4-12.

16. The antitumor drug of claim 15, further comprising pharmaceutically acceptable excipients.

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