CN112656960B - Mitochondria-controlled iron-based magnetic coordination polymer nanoparticle and preparation method and application thereof - Google Patents

Abstract

The invention discloses a mitochondria-controlled iron-based magnetic coordination polymer nanoparticle and a preparation method and application thereof, belonging to the technical field of medicines. The polymeric nanoparticle comprises: dopamine-modified hyaluronic acid, iron oxide nanoparticles and dichloroacetic acid-modified cisplatin; wherein: the hydroxyl of the catechol on the dopamine is in coordination complexing with the ferric oxide, and the polycarboxyl on the hyaluronic acid is in coordination complexing with the platinum atom. The polymer nanoparticles combine dichloroacetic acid and cisplatin, so that intracellular H can be greatly increased through mitochondria and NOX double-acting sites in tumor cells ₂ O ₂ Of (1) containsThe high-toxicity active oxygen hydroxyl free radicals are generated by catalyzing the high-toxicity active oxygen hydroxyl free radicals with magnetic iron oxide, so that tumor cell apoptosis is initiated; in addition, magnetic iron oxide can produce T ₂ The magnetic resonance imaging effect can accurately obtain the spatial position and size information of the tumor.

Description

A kind of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles and preparation method thereof and application

technical field

The invention belongs to the technical field of medicine, and in particular relates to a mitochondria-regulated iron-based magnetic coordination polymer nanoparticle and a preparation method and application thereof.

Background technique

Cisplatin, as a broad-spectrum anticancer drug, is one of the most widely used chemotherapeutic drugs in clinical practice, and is often used in the treatment of lung cancer, testicular cancer, ovarian cancer, sarcoma and other diseases. However, the low therapeutic effect, high toxicity and side effects of cisplatin, especially the drug resistance of cisplatin, often limit its application in clinical treatment. At present, other chemotherapeutic drugs or biosimilars are often used in combination with cisplatin in clinical practice to improve the therapeutic effect. Therefore, there is an urgent need to develop a therapeutic system that can improve the sensitivity of tumors to cisplatin.

After cisplatin enters tumor cells, it usually targets the nucleus to react with the nucleophilic site of DNA to form an adduct, resulting in cross-linking of DNA to destroy its ability of transcription and replication, thereby exerting its anti-tumor effect. In addition, cisplatin can also activate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) in tumor cells, convert O ₂ into O ₂ • ^- , and in superoxide dismutase (SOD) Under the action, H ₂ O ₂ is generated, which increases the level of intracellular oxidation. The introduction of iron-based materials can utilize the Fenton reaction to convert H ₂ O ₂ into highly toxic hydroxyl radicals, further enhancing the antitumor efficacy of cisplatin. However, the content of hydrogen peroxide produced by cisplatin alone is not enough to trigger a high-intensity Fenton reaction, so it is difficult to significantly improve its anti-tumor efficacy.

Dichloroacetic acid (DCA) is a small molecule compound because it can target mitochondria, inhibit pyruvate dehydrogenase kinase (PDK), activate the activity of pyruvate dehydrogenase (PDH), and convert glucose oxidation from glycolysis It is transferred to the aerobic oxidative pathway, so it is often used clinically to treat lactic acidosis. Mitochondria are an important place for intracellular oxidation. The introduction of dichloroacetic acid into tumor cells can activate mitochondrial oxidation function and greatly enhance the level of intracellular oxidation. Dichloroacetic acid has been widely used in the treatment of certain cancers, such as lung cancer, breast cancer, glioblastoma, etc. In addition, while activating mitochondrial oxidative activity, dichloroacetic acid also promotes the release of mitochondrial apoptosis-related factors, which will further increase the sensitivity of tumor cells to apoptosis.

Therefore, the present invention expects to design a therapeutic system that can improve the sensitivity of tumors to cisplatin.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a mitochondria-regulated iron-based magnetic coordination polymer nanoparticle that enhances the anti-tumor sensitivity of cisplatin. The polymer nanoparticle uses dopamine-modified hyaluronic acid and magnetic iron oxide to form a coordination polymer, and simultaneously loads dichloroacetic acid-modified cisplatin, thereby preparing a mitochondria-regulated iron-based magnetic coordination nanopolymer.

In order to achieve the above object, the technical scheme of the present invention is as follows:

A mitochondria-regulated iron-based magnetic coordination polymer nanoparticle, comprising: dopamine-modified hyaluronic acid, iron oxide nanoparticles and dichloroacetic acid-modified cisplatin;

Among them: the ortho-diphenol hydroxyl group on dopamine is complexed with iron oxide through coordination, and the polycarboxyl group on hyaluronic acid is complexed with platinum atom through coordination.

Further, the particle size of the coordination polymer nanoparticles is 140-180 nm.

The preparation method of above-mentioned coordination polymer nanoparticles, comprises the following steps:

Step 1, dissolving hyaluronic acid, EDC and NHS in pH6.8 PBS buffer, adding dopamine hydrochloride aqueous solution, and performing the reaction under nitrogen protection to obtain dopamine-modified hyaluronic acid;

Step 2, adding the iron oxide nanoparticle aqueous solution to the aqueous solution of dopamine-modified hyaluronic acid, adjusting the pH to 6.0, and stirring the reaction to obtain an iron oxide-dopamine-modified hyaluronic acid coordination polymer;

Step 3, adding cisplatin into the H ₂ O ₂ solution, and performing a reaction to obtain hydroxylated cisplatin, adding the hydroxylated cisplatin to acetone, and adding dichloroacetyl chloride dropwise under stirring conditions to carry out the reaction, and after the reaction is completed, the The reaction is added dropwise to ether to obtain cisplatin modified with dichloroacetic acid;

Step 4, adding dichloroacetic acid-modified cisplatin to the iron oxide-dopamine-modified hyaluronic acid coordination polymer obtained in step 2, and stirring the reaction to obtain coordination polymer nanoparticles.

Further, in step 1, the molar ratio of hyaluronic acid, EDC, NHS is 1:5～10:5～10, the molar ratio of dopamine hydrochloride and hyaluronic acid is 5～10:1, and the reaction condition is 20～10 25℃, 12~24h.

Further, in step 2, the feeding mass ratio of iron oxide nanoparticles and dopamine-modified hyaluronic acid is 1:2~4, and the reaction conditions are 20~25°C and 2~6h.

Further, in step 3, the molar ratio of cisplatin and H ₂ O ₂ is 1:2~4, and the reaction conditions are 50~70 ° C, 3~6h; the molar ratio of hydroxylated cisplatin and dichloroacetyl chloride is It is 1:2~4, and the reaction conditions are 20-25℃, 12~24h.

Further, in step 4, the mass ratio of the materials of the dichloroacetic acid-modified cisplatin and the iron oxide-dopamine-modified hyaluronic acid coordination polymer is 1:5-10, and the reaction is performed for 48-72 hours.

The coordination polymer nanoparticle of the invention takes dopamine hyaluronic acid as the core, and is loaded with magnetic iron oxide and cisplatin modified with dichloroacetic acid. The polycarboxyl group on the acid coordinates with the platinum atom to achieve the loading. In tumor cells, through acid hydrolysis and reduction, cisplatin and dichloroacetic acid are released, and the intracellular H ₂ O ₂ content is enhanced through NOX and PDH enzymatic reactions, respectively; iron oxide can be released in the acidic environment of tumor cells. Free iron ions can effectively catalyze H ₂ O ₂ to generate highly toxic hydroxyl radicals. In addition, cisplatin can further promote the killing effect of tumors by interfering with its key target-nuclear DNA, and dichloroacetic acid can activate the mitochondrial apoptosis pathway through the change of mitochondrial membrane potential and the efflux of pro-apoptotic factors. At the same time, the nanoparticle also has the function of T ₂ magnetic resonance imaging, which can be used for the diagnosis and treatment of tumors.

Description of drawings

Figure 1 is a schematic diagram of the synthesis of dopamine-modified hyaluronic acid (A) and a schematic diagram of the synthesis of dichloroacetic acid-modified cisplatin (B).

Figure 2 shows the 1H NMR spectrum analysis of dopamine-modified hyaluronic acid (A), the 1H NMR spectrum of dichloroacetic acid-modified cisplatin (B), and the mass spectrometry of dichloroacetic acid-modified cisplatin (C)

Figure 3 shows the relevant in vitro characterization diagrams of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles: particle size distribution diagram (A), particle size stability diagram (B).

Figure 4 is the zeta potential map of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles.

Figure 5 is a graph showing the in vitro catalytic hydrogen peroxide efficiency of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles.

Figure 6 is a graph showing the release curve of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles in vitro.

Figure 7 is an in vitro magnetic resonance imaging image of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles.

Figure 8 is a graph showing the cytotoxicity of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles.

Figure 9 is a graph of cell-related characterization after the action of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles: mitochondrial membrane potential graph (A) and intracellular reactive oxygen species content graph (B).

Figure 10 is an in vivo magnetic resonance imaging image of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles.

FIG. 11 is a graph showing the relevant pharmacodynamic data of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles in vivo.

Detailed ways

In the present invention, a mitochondria-regulated iron-based magnetic coordination polymer nanoparticle for enhancing the anti-tumor sensitivity of cisplatin is provided. Cisplatin realizes drug loading through the coordination and complexation of the ortho-diphenol hydroxyl group on dopamine and iron oxide, and the coordination of the polycarboxylate group on hyaluronic acid with platinum atoms. In tumor cells, through acid hydrolysis and reduction, cisplatin and dichloroacetic acid are released, and the intracellular H ₂ O ₂ content is enhanced through NOX and PDH enzymatic reactions, respectively; iron oxide can be released in the acidic environment of tumor cells. Free iron ions can effectively catalyze H ₂ O ₂ to generate highly toxic hydroxyl radicals. In addition, cisplatin can further promote the killing effect of tumors by interfering with its key target-nuclear DNA, and dichloroacetic acid can activate the mitochondrial apoptosis pathway through the change of mitochondrial membrane potential and the efflux of pro-apoptotic factors. At the same time, the nanoparticle also has the function of T ₂ magnetic resonance imaging, which can be used for the diagnosis and treatment of tumors.

The coordination polymer nanoparticles are firstly to form a coordination polymer by coordinating dopamine-modified hyaluronic acid and magnetic iron oxide nanoparticles, and then loading the dichloroacetic acid-modified cisplatin through the coordination between platinum atoms and carboxyl groups. obtained from the above-mentioned polymers. The particle size of the coordination polymer nanoparticle is 140-180 nm, preferably 160-170 nm; the drug load is 6%-10%, preferably 8%.

The above-mentioned coordination polymer nanoparticles are prepared by the following method:

(1) Take hyaluronic acid, EDC and NHS, dissolve them in PBS buffer with pH 6.8 according to the molar ratio of 1:5~10:5~10, and react for 15~30min.

(2) Dissolving dopamine hydrochloride in ultrapure water and adding it to the mixed solution of step (1), reacting under nitrogen protection for 12-24 hours, the molar ratio of dopamine hydrochloride and hyaluronic acid is 5-10:1.

(3) The reaction solution in step (2) is added to a dialysis bag of 8000-12000 Da, and dialyzed in ultrapure water for 24 hours, and the dialyzed solution is freeze-dried to obtain off-white dopamine-modified hyaluronic acid.

(4) Dissolving the iron oxide nanoparticles in ultrapure water to obtain an aqueous solution of iron oxide nanoparticles.

(5) Dissolving the dopamine-modified hyaluronic acid in step (3) in ultrapure water, adding it to the iron oxide nanoparticle aqueous solution in step (4), the mass ratio of iron oxide nanoparticles and dopamine-modified hyaluronic acid The ratio is 1:2~4, the pH is adjusted to 6.0 with NaOH solution, and the reaction is stirred at room temperature for 2~6 h to form an iron oxide-dopamine modified hyaluronic acid coordination polymer solution.

(6) Add cisplatin into the H ₂ O ₂ solution, the molar ratio of cisplatin and H ₂ O ₂ is 1:2~4, react at 50~70℃ for 3~6h, and remove the solution by rotary evaporation Hydroxylated cisplatin is obtained.

(7) The hydroxylated cisplatin in step (6) is added to the acetone solvent, and the dichloroacetyl chloride solution is added dropwise under stirring conditions, and the reaction is performed for 12 to 24 hours. The moles of the hydroxylated cisplatin and the dichloroacetyl chloride are The ratio is 1:2~4.

(8) The reaction solution in step (7) is added dropwise to the ether solution, and the volume ratio of the reaction solution to the ether solution is 1:10 to obtain a yellow precipitate, which is dried to obtain dichloroacetic acid-modified cisplatin.

(9) Dissolving the dichloroacetic acid-modified cisplatin in step (8) in ultrapure water, adding it to the coordination polymer nanoparticle solution in step (5) under constant stirring, dichloroacetic acid-modified cisplatin The mass ratio of the material to the coordination polymer nanoparticle is 1:5~10, and the reaction is performed for 48~72 hours to prepare a crude solution of the coordination polymer nanoparticle.

(10) Dialyzing the crude product solution in step (9) with a dialysis bag with a molecular weight of 3500 Da to remove unloaded free drug to obtain a final coordination polymer nanoparticle solution.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments, but should not be construed as limiting the present invention. Modifications or substitutions made to the methods, steps or conditions of the present invention without departing from the spirit and essence of the present invention all belong to the scope of the present invention. In the examples, the experimental methods without specifying the specific conditions and the reagents without specifying the formula are all in accordance with the conventional conditions in the art.

Example 1

The nanoparticles are prepared as follows:

(1) Dissolve 100 mg of hyaluronic acid (HA), 120 mg of EDC, and 70 mg of NHS in 25 mL of pH 6.8 PBS buffer and react in a 50 mL round-bottom flask for 15 min.

(2) 120 mg of dopamine hydrochloride (Dopa) was dissolved in ultrapure water and added to the mixed solution of step (1), and reacted under nitrogen protection for 12 hours.

(3) The reaction solution in step (2) is added to a dialysis bag of 8000-12000 Da, and dialyzed in ultrapure water for 24 hours, the water is changed every 2 hours, and the dialyzed solution is freeze-dried to obtain a gray-white dopamine-modified transparent acid (DPA).

(4) Dissolving 1 mg of iron oxide nanoparticles in 5 mL of ultrapure water to obtain an aqueous solution of iron oxide nanoparticles.

(5) Dissolve 10 mg of the dopamine-modified hyaluronic acid in step (3) in 5 mL of ultrapure water, add it to the iron oxide nanoparticle aqueous solution in step (4), adjust the pH to 6.0 with NaOH solution, and stir at room temperature The reaction was carried out for 2 h to form a coordination polymer nanoparticle solution (FeO·DPA).

(6) 150 μmol of cisplatin (Pt) was added to 10 mL of H ₂ O ₂ solution, reacted at 60 °C for 4 h, and the solution was removed by rotary evaporation to obtain hydroxylated cisplatin (Pt-OH).

(7) The hydroxylated cisplatin in step (6) was added to 7 mL of acetone solvent, and 300 μmol of dichloroacetyl chloride solution was added dropwise under stirring conditions, and the reaction was carried out for 12 h.

(8) The reaction solution in step (7) was added dropwise to 25 mL of ether solution to obtain a yellow precipitate, which was dried to obtain dichloroacetic acid-modified cisplatin (DPt).

(9) Dissolve 1 mg of cisplatin modified with dichloroacetic acid in step (8) in 1 mL of ultrapure water, add it to the coordination polymer nanoparticle solution in step (5) under constant stirring, and react for 48 hours to prepare A crude solution of coordination polymer nanoparticles was obtained.

(10) The crude product solution in step (9) is dialyzed with a dialysis bag with a molecular weight of 3500Da, dialyzed for 6 hours, and the water is changed every 2 hours to remove the unloaded free drug to obtain the final coordination polymer nanoparticle solution (DPt @FeO DPA).

Figure 1 is a schematic diagram of the synthesis process of dopamine-modified hyaluronic acid (A), and a schematic diagram of the synthesis process of dichloroacetic acid-modified cisplatin (B).

Figure 2 shows the hydrogen NMR spectrum of dopamine-modified hyaluronic acid (A). The spectrum shows the characteristic hydrogen spectrum peaks of dopamine and hyaluronic acid, which proves that dopamine was successfully modified on hyaluronic acid; dichloroacetic acid modified Cisplatin H NMR spectrum (B) and mass spectrum (C), the spectrum shows the amino hydrogen spectrum peak of cisplatin, the hydrogen spectrum peak of dichloromethyl, and the modified cisplatin with dichloroacetic acid, which proved successful Synthesis of dichloroacetic acid-modified cisplatin.

Figure 3 shows the relevant in vitro characterization diagrams of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles: particle size distribution diagram (A), particle size stability diagram (B). It can be seen from the figure that the prepared drug-loaded coordination polymeric nanoparticles have an average particle size of 167.6 nm, and have good stability in pH 7.4 PBS buffer and 10% FBS medium for 48 hours.

Figure 4 is the zeta potential map of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles. It can be seen from the figure that the average zeta potential of the finally prepared drug-loaded coordination polymer nanoparticles is -41.9mV.

Figure 5 is a graph showing the in vitro catalytic hydrogen peroxide efficiency of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles. Add methylene blue, methylene blue + H ₂ O ₂ , methylene blue + DPt @FeO · DPA, and methylene blue + H ₂ O ₂ + DPt @FeO · DPA to 4 ep tubes respectively. The solution was placed in an ultraviolet absorption spectrophotometer to measure the absorption spectrum at 400-800 nm. It can be seen from the figure that neither H ₂ O ₂ nor coordination polymer nanoparticles alone can reduce the characteristic UV absorption peak of methylene blue ₍ MB ₎ . , will greatly reduce the characteristic ultraviolet absorption peak of methyl blue (MB), indicating that under the catalysis of coordination polymer nanoparticles, the decomposition of H ₂ O ₂ produces hydroxyl radicals with high oxidative ability ·OH.

Figure 6 is a graph showing the release curve of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles in vitro. Take DPt@FeO·DPA and put them in 30~50ml release medium (pH7.4, 5.0PBS buffer) respectively, and control the temperature to 37±1℃. Take out 2ml of release medium at 1, 2, 4, 6, 8, 10, 12, 24, and 36h, respectively, and add 2ml of fresh medium. The content of cisplatin was measured by atomic absorption spectrophotometer, and the time-dependent release curve was drawn. It can be seen from the figure that the release of cisplatin is pH-sensitive, up to 60.5% of the drug can be released under the condition of pH 5.0, and only 38.5% of the drug can be released under the condition of pH 7.4.

Figure 7 is an in vitro magnetic resonance imaging image of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles. Configure DPt@FeO·DPA containing 0.5mM iron ions, dilute them into a series of gradient concentrations, and scan them _on a 7.0 T magnetic resonance imager to obtain T magnetic resonance images. (i.e. 1/T ₂ ) make a scatter plot against Fe ion concentration and perform a linear fit. It can be seen from the figure that the relaxation coefficient r2 of the prepared coordination polymer nanoparticles is 217.42Mm ^-1 s ^-1 , which has excellent T ₂ imaging effect and can be used as an efficient T ₂ contrast agent.

Figure 8 is a graph showing the cytotoxicity of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles. 4T1 and MB-231 tumor cells were cultured in 96-well plates, respectively, and were equipped with Pt, DPt, Pt@FeO·DPA, and DPt@FeO·DPA with different platinum contents. When the cells grew to 80%~90%, the above solution was added, and the cell killing effect was evaluated by standard MTT method. It can be seen from the figure that the final drug-loaded coordination polymer nanoparticles group significantly enhanced the killing effect of 4T1 and MB-231 tumor cells, and reduced the IC50 value of cisplatin by 48.39% and 82.18%, respectively, which significantly enhanced the cytotoxicity of 4T1 and MB-231 tumor cells. The antitumor sensitivity of cisplatin.

Figure 9 is a graph of cell-related characterization after the action of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles. 4T1 tumor cells were added to a 6-well plate, and when the cells grew to 80%-90%, PBS, FeO·DPA, Pt, DPt, Pt@FeO·DPA, and DPt@FeO·DPA were added respectively. After culturing for 18-30 h, each culture well was washed with PBS, and the mitochondrial membrane potential probe RDM-123 and reactive oxygen species probe DCFH-DA were added respectively, and the fluorescence intensity of each group was observed under a fluorescence microscope. Among them, the mitochondrial membrane potential diagram (A), after using RDM-123 to indicate, it can be seen that the fluorescence intensity of the drug-loaded coordination polymer nanoparticles group is significantly reduced, indicating that the drug-loaded coordination polymer nanoparticles can significantly reduce the mitochondrial membrane potential; Intracellular reactive oxygen species content diagram (B), using the DCFH-DA probe to indicate the reactive oxygen species content, it can be seen that the fluorescence intensity of the drug-loaded coordination polymer nanoparticles group is significantly enhanced, indicating that the drug-loaded coordination polymer nanoparticles can significantly Enhances intracellular reactive oxygen species content.

Figure 10 is an in vivo magnetic resonance imaging image of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles. Three tumor-bearing mice were randomly selected, and the prepared coordination polymer nanoparticle solution was injected into the tail vein, and then the mice were placed on a magnetic resonance imaging scanner for MRI imaging at 0 h, 6 h, and 12 h. It can be seen from the figure that after intravenous injection of the prepared coordination polymer nanoparticles, with the prolongation of time, the tumor site of the mice is significantly darker than the tumor site before the injection of nanoparticles, and the contrast between tumor tissue and surrounding normal tissue It is also more obvious, and the tumor boundary is clearer, indicating that the nanoparticle has a good in vivo magnetic resonance imaging effect.

FIG. 11 is a graph showing the relevant pharmacodynamic data of mitochondria-regulated iron-based magnetic coordination polymer nanoparticles in vivo. The 4T1 tumor-bearing mouse model was used for evaluation and was divided into six groups, namely PBS group, FeO·DPA group, Pt group, DPt group, Pt@FeO·DPA group, and DPt@FeO·DPA group. Thirty tumor-bearing mice were randomly selected, 5 mice in each group, and injected with the above solution on 0, 2, 4, 6, and 8 days, respectively, and the tumor size was measured with a vernier caliper every other day for a total of 21 days. After the experiment, the mice were sacrificed by spinal cord amputation, and the tumors of each group of mice were dissected and collected, weighed and photographed. Tumors in each group were sliced and stained with H&E. Finally, the tumor tissue morphology of each group was observed and photographed with a biological inverted microscope. The tumor inhibition effect graph (A), the tumor inhibition curve graph (B), and the tumor H&E staining graph (C) were obtained. It can be seen from Figures A and B that intravenous injection of the prepared drug-loaded coordination polymer nanoparticles can significantly inhibit the growth of tumors compared with other control groups. As can be seen in Figure C, the tumor in the final drug-loaded coordination polymer nanoparticle group was significantly damaged, with larger intercellular spaces and denser nuclei in the tumor tissue area.

Example 2

The nanoparticles are prepared as follows:

(1) Dissolve 100 mg of hyaluronic acid (HA), 150 mg of EDC, and 111 mg of NHS in 25 mL of pH 6.8 PBS buffer and react in a 50 mL round-bottom flask for 20 min.

(2) 180 mg of dopamine hydrochloride (Dopa) was dissolved in ultrapure water and added to the mixed solution of step (1), and reacted under nitrogen protection for 18 hours.

(3) The reaction solution in step (2) is added to a dialysis bag of 8000-12000 Da, and dialyzed in ultrapure water for 24 hours, the water is changed every 2 hours, and the dialyzed solution is freeze-dried to obtain a gray-white dopamine-modified transparent acid (DPA).

(4) Dissolving 1 mg of iron oxide nanoparticles in 5 mL of ultrapure water to obtain an aqueous solution of iron oxide nanoparticles.

(5) Dissolve 20 mg of the dopamine-modified hyaluronic acid in step (3) in 5 mL of ultrapure water, add it to the iron oxide nanoparticle aqueous solution in step (4), adjust the pH to 6.0 with NaOH solution, and stir at room temperature The reaction was carried out for 3 h to form a coordination polymer nanoparticle solution (FeO·DPA).

(6) 150 μmol of cisplatin (Pt) was added to 15 mL of H ₂ O ₂ solution, reacted at 60 °C for 5 h, and the solution was removed by rotary evaporation to obtain hydroxylated cisplatin (Pt-OH).

(7) The hydroxylated cisplatin in step (6) was added to 7 mL of acetone solvent, and 400 μmol of dichloroacetyl chloride solution was added dropwise under stirring conditions, and the reaction was carried out for 18 hours.

(8) The reaction solution in step (7) was added dropwise to 25 mL of ether solution to obtain a yellow precipitate, which was dried to obtain dichloroacetic acid-modified cisplatin (DPt).

(9) Dissolve 1.5 mg of cisplatin modified with dichloroacetic acid in step (8) in 1 mL of ultrapure water, add it to the coordination polymer nanoparticle solution in step (5) under constant stirring, and react for 60 hours, The crude solution of coordination polymer nanoparticles was prepared.

(10) The crude product solution in step (9) is dialyzed with a dialysis bag with a molecular weight of 3500Da, dialyzed for 10 hours, and the water is changed every 2 hours to remove the unloaded free drug to obtain the final coordination polymer nanoparticle solution (DPt @FeO DPA).

Example 3

The nanoparticles are prepared as follows:

(1) Dissolve 100 mg of hyaluronic acid (HA), 180 mg of EDC, and 133 mg of NHS in 25 mL of pH 6.8 PBS buffer and react in a 50 mL round-bottom flask for 30 min.

(2) Dissolve 220 mg of dopamine hydrochloride (Dopa) in ultrapure water and add it to the mixed solution of step (1), and react under nitrogen protection for 24 hours.

(3) The reaction solution in step (2) is added to a dialysis bag of 8000-12000 Da, and dialyzed in ultrapure water for 24 hours, the water is changed every 2 hours, and the dialyzed solution is freeze-dried to obtain a gray-white dopamine-modified transparent acid (DPA).

(4) Dissolving 1 mg of iron oxide nanoparticles in 5 mL of ultrapure water to obtain an aqueous solution of iron oxide nanoparticles.

(5) Dissolve 20 mg of the dopamine-modified hyaluronic acid in step (3) in 5 mL of ultrapure water, add it to the iron oxide nanoparticle aqueous solution in step (4), adjust the pH to 6.0 with NaOH solution, and stir at room temperature After 6 h of reaction, a coordination polymer nanoparticle solution (FeO·DPA) was formed.

(6) 150 μmol of cisplatin (Pt) was added to 20 mL of H ₂ O ₂ solution, reacted at 60 °C for 6 h, and the solution was removed by rotary evaporation to obtain hydroxylated cisplatin (Pt-OH).

(7) The hydroxylated cisplatin in step (6) was added to 7 mL of acetone solvent, and 500 μmol of dichloroacetyl chloride solution was added dropwise under stirring conditions, and the reaction was carried out for 24 hours.

(8) The reaction solution in step (7) was added dropwise to 25 mL of ether solution to obtain a yellow precipitate, which was dried to obtain dichloroacetic acid-modified cisplatin (DPt).

(9) Dissolve 2.0 mg of cisplatin modified with dichloroacetic acid in step (8) in 1 mL of ultrapure water, add it to the coordination polymer nanoparticle solution in step (5) under constant stirring, and react for 48~ 36h, a crude solution of coordination polymer nanoparticles was prepared.

(10) The crude product solution in step (9) is dialyzed with a dialysis bag with a molecular weight of 3500Da, dialyzed for 12 hours, and the water is changed every 2 hours to remove the unloaded free drug to obtain the final coordination polymer nanoparticle solution (DPt @FeO DPA).

Claims (3)

1. a mitochondria-regulated iron-based magnetic coordination polymer nanoparticle is characterized in that: Including: dopamine-modified hyaluronic acid, iron oxide nanoparticles and dichloroacetic acid-modified cisplatin; among which: the ortho-diphenol hydroxyl group on dopamine is complexed with iron oxide, and the polycarboxyl group on hyaluronic acid and platinum atom by coordination complexation; The preparation method of the coordination polymer nanoparticle comprises the following steps: Step 1: Dissolve hyaluronic acid, EDC, and NHS in pH6.8 PBS buffer, add dopamine hydrochloride aqueous solution, and carry out the reaction under nitrogen protection. The molar ratio of hyaluronic acid, EDC, and NHS is 1:5~10: 5-10, the molar ratio of dopamine hydrochloride and hyaluronic acid is 5-10:1, and the reaction conditions are 20-25° C., 12-24 h, to obtain dopamine-modified hyaluronic acid; Step 2, adding the aqueous solution of iron oxide nanoparticles to the aqueous solution of dopamine-modified hyaluronic acid, adjusting the pH to 6.0, and stirring the reaction, the iron oxide nanoparticles and dopamine-modified hyaluronic acid are in a mass ratio of 1:2 to 4, and the reaction The conditions are 20~25℃, 2~6h, and the iron oxide-dopamine modified hyaluronic acid coordination polymer is obtained; Step 3, adding cisplatin into the H ₂ O ₂ solution, the molar ratio of cisplatin and H ₂ O ₂ is 1:2~4, and the reaction is carried out, and the reaction conditions are 50~70 ° C, 3~6h, to obtain hydroxyl cisplatin, hydroxylated cisplatin is added to acetone, and dichloroacetyl chloride is added dropwise under stirring conditions to react, the molar ratio of hydroxylated cisplatin and dichloroacetyl chloride is 1:2~4, and the reaction condition is 20 ~25℃, 12~24h, after the reaction, the reaction was added dropwise to ether to obtain cisplatin modified with dichloroacetic acid; Step 4, adding dichloroacetic acid-modified cisplatin to the iron oxide-dopamine-modified hyaluronic acid coordination polymer obtained in step 2, dichloroacetic acid-modified cisplatin and iron oxide-dopamine-modified hyaluronic acid coordination polymer The mass ratio of the raw materials is 1:5~10, and the reaction is stirred for 48~72h, and then the coordination polymer nanoparticles can be obtained. 2 . The polymer nanoparticle according to claim 1 , wherein the particle size of the coordination polymer nanoparticle is 140-180 nm. 3 . 3. The application of the polymer nanoparticle according to claim 1 in the preparation of a tumor treatment and/or diagnostic drug.

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