Embolization microsphere as well as preparation method and application thereof

Abstract

The invention provides an embolism microsphere as well as a preparation method and application thereof. The embolism microsphere is prepared by polymerizing sodium vinyl phosphate and sodium acrylate in a molar ratio of 1: (6-12). The obtained embolism microspheres have large drug loading capacity, so that the treatment effect can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of medical technology, and particularly relates to an embolic microsphere, a preparation method thereof, and an application thereof. Background Art

[0002] As one of the most major cancers, liver cancer has received increasing attention. Transcatheter arterial chemoembolization (TACE) has been widely used in the treatment of liver cancer due to its small trauma, good curative effect, and relatively mild adverse reactions. During the operation, a catheter is first inserted into the blood vessels of the tumor site through the blood vessels, and then an embolic agent containing drugs is injected. The embolic agent is delivered to the tumor site through the catheter, blocking the blood vessels while slowly releasing the drugs, killing the tumor cells while blocking their blood supply, so that the tumor cells lack nutrition and thus atrophy and die. This treatment method reduces the systemic drug exposure, thereby reducing the incidence of adverse reactions.

[0003] Since embolic microspheres have better drug-loading capacity and embolization effect compared with lipiodol and embolization particles, they are widely used. Among them, the drug-loaded embolic microspheres can slowly release drugs after being implanted into the human body by using the mechanism of ion exchange while embolizing blood vessels and blocking the nutrient supply of the tumor site, so as to achieve the purpose of killing tumor cells.

[0004] During the operation, the embolic microspheres need to adsorb chemotherapy drugs in advance and then be injected into the human body through a catheter. Therefore, the ability of embolic microspheres to rapidly adsorb a large amount of drugs after being mixed with chemotherapy drugs is one of the main research directions at present, which can shorten the preoperative preparation time on the one hand and deliver a large amount of drugs to the tumor site on the other hand to achieve a better therapeutic effect.

[0005] One of the main current drug-loading methods is to introduce carboxyl groups using acrylic compounds to adsorb cationic drugs. Patent CN114533939A discloses a sodium polyacrylate microsphere, which uses acrylate compounds as monomers and is polymerized with a cross-linking agent to obtain a sodium polyacrylate embolic microsphere after hydrolysis. Since this microsphere only uses sodium acrylate as a monomer, the drug adsorption amount is about 10 mg / g. The drug-loading capacity of this type of microsphere is relatively low, and it is difficult to deliver a large amount of drugs to the liver, thus affecting the curative effect.

[0006] Therefore, it is a problem that needs to be solved by those skilled in the art to develop an embolic microsphere that can adsorb a large amount of drugs faster to improve the therapeutic effect. Summary of the Invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide an embolic microsphere, a preparation method thereof, and an application thereof. The embolic microsphere has a large drug-loading capacity, thereby improving the therapeutic effect.

[0008] To achieve the above object, the present invention provides an embolization microsphere, which is prepared by polymerizing sodium vinyl phosphate and sodium acrylate with a molar ratio of 1:6-12.

[0009] According to a specific embodiment of the present invention, preferably, the molar ratio of sodium vinyl phosphate to sodium acrylate is 1:8.

[0010] The present invention also provides a method for preparing the above embolization microsphere, which comprises the following steps:

[0011] (1) Mix sodium vinyl phosphate and sodium acrylate in water to obtain an aqueous monomer solution, and then add a crosslinking agent and an initiator to obtain an aqueous phase;

[0012] (2) Mix an emulsifier in an oil solvent to obtain an oil phase;

[0013] (3) Add the aqueous phase obtained in step (1) to the oil phase obtained in step (2), after emulsification, add a catalyst, and react to obtain the embolization microsphere.

[0014] According to a specific embodiment of the present invention, preferably, in step (1), the mass fraction of the sum of sodium vinyl phosphate and sodium acrylate in the aqueous monomer solution is 30%-50%.

[0015] According to a specific embodiment of the present invention, preferably, in step (1), calculated based on the total mass of the monomers being 100%, the addition amount of the initiator is 0.1%-3%.

[0016] According to a specific embodiment of the present invention, preferably, in step (1), calculated based on the total mass of the monomers being 100%, the addition amount of the crosslinking agent is 0.2%-2%. Controlling the amounts of the auxiliaries (initiator, crosslinking agent) in the reaction system helps the microspheres to form. Among them, the initiator can generate free radicals and cause polymerization between olefin molecules. An excessive concentration of the initiator will cause the free radicals to be generated too quickly, resulting in a decrease in the degree of polymerization; the crosslinking agent is used to connect two molecular chains to form a network structure, thereby forming hydrogel microspheres. An excessively low content causes the microspheres not to form, and an excessively high content causes the water absorption of the microspheres to decrease.

[0017] According to a specific embodiment of the present invention, preferably, in step (1), the initiator includes persulfate.

[0018] According to a specific embodiment of the present invention, preferably, in step (1), the crosslinking agent includes acrylamide compounds.

[0019] According to a specific embodiment of the present invention, preferably, in step (1), the crosslinking agent includes N,N'-methylenebisacrylamide. This crosslinking agent is soluble in water and has two double bond functional groups that can react quickly and efficiently.

[0020] According to a specific embodiment of the present invention, preferably, in step (2), the emulsifier includes cellulose acetate butyrate. The emulsifier enables the aqueous phase and the oil phase to form a good emulsion, and the generated microspheres are more uniform.

[0021] According to a specific embodiment of the present invention, preferably, in step (2), the oil solvent includes butyl acetate. The oil phase formed by dissolving cellulose acetate butyrate in butyl acetate can make the water-in-oil droplets more stable and avoid droplet coalescence.

[0022] According to a specific embodiment of the present invention, preferably, in step (2), the mass-volume ratio concentration of the emulsifier in the oil phase is 1% - 10%.

[0023] According to a specific embodiment of the present invention, preferably, in step (3), the volume ratio of the aqueous phase to the oil phase is 0.01 - 1:1.

[0024] According to a specific embodiment of the present invention, preferably, in step (3), the emulsification speed is 10 - 800 rpm / min. By controlling the mixing ratio of the aqueous phase and the oil phase and the stirring speed, a stable and uniformly dispersed water-in-oil emulsion is formed.

[0025] According to a specific embodiment of the present invention, preferably, in step (3), the catalyst includes tetramethylethylenediamine. Tetramethylethylenediamine and persulfate are used in combination to initiate a redox radical polymerization reaction to prepare microspheres.

[0026] According to a specific embodiment of the present invention, preferably, in step (3), the reaction temperature is 50 - 70 °C, more preferably 60 °C. This temperature condition is favorable for initiating the radical polymerization reaction and promoting the formation of microspheres; the reaction time is 60 - 240 min.

[0027] The present invention also provides a drug-loaded embolization microsphere, which is obtained by further loading an anti-tumor drug on the above-mentioned embolization microsphere.

[0028] According to a specific embodiment of the present invention, preferably, the anti-tumor drug includes doxorubicin.

[0029] The present invention also provides the use of the above-mentioned embolization microsphere or the above-mentioned drug-loaded embolization microsphere in the preparation of an embolization treatment drug.

[0030] According to a specific embodiment of the present invention, preferably, the embolization treatment drug is a drug for treating tumors.

[0031] The present invention has the following beneficial effects:

[0032] (1) The preparation method of the embolization microspheres of the present invention uses a mixture of sodium vinyl phosphate and acrylic monomers as the functional monomer. The introduction of sodium vinyl phosphate increases the drug loading capacity of the sodium polyacrylate microspheres, enabling them to deliver more drugs to the target location, thereby enhancing the therapeutic effect.

[0033] (2) By adjusting the ratio of sodium vinyl phosphate to acrylic monomers in the present invention, the adsorption amount of the microspheres formed at a specific ratio for cationic chemotherapeutic drugs is improved, thereby shortening the time for loading drugs before use by doctors, facilitating clinical use, and delivering a large amount of drugs to the tumor site, thus enhancing the therapeutic effect. Description of the Drawings

[0034] Figure 1 Photographs under the microscope before and after the microspheres of different concentrations of vinyl phosphoric acid adsorbed drugs.

[0035] Figure 2 It is a cumulative drug release curve graph. Detailed Embodiments

[0036] For a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be construed as a limitation on the scope of implementation of the present invention.

[0037] Unless otherwise specified, the test methods used in the following examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, are reagents and materials that can be obtained from commercial channels.

[0038] Specifically, the compounds used in the examples are as follows:

[0039] Acrylic acid (CAS: 79 - 10 - 7), sodium hydroxide (CAS: 1310 - 73 - 2), sodium vinyl phosphate (CAS: 1746 - 03 - 8), potassium persulfate (CAS: 7727 - 21 - 1), N,N'-methylenebisacrylamide (CAS: 110 - 26 - 9), butyl acetate (CAS: 123 - 86 - 4), cellulose acetate butyrate (CAS: 9004 - 36 - 8), tetramethylethylenediamine (CAS: 110 - 18 - 9).

[0040] Comparative Example 1

[0041] This comparative example provides an embolization microsphere, which is prepared by the following steps:

[0042] (1) After mixing 3 g of acrylic acid with 2.2 g of vinyl phosphonic acid, 8.2 ml of 8 mol / L sodium hydroxide solution was added to form a mixture of sodium acrylate and sodium vinyl phosphate. After cooling to room temperature, 0.07 g of N,N'-methylenebisacrylamide and 0.07 g of potassium persulfate were dissolved into the mixture to form an aqueous solution;

[0043] (2) 1 g of cellulose acetate butyrate was added to 20 ml of butyl acetate. After the cellulose acetate butyrate was dissolved, the above aqueous solution was added, and stirring was continued for 20 minutes (rotation speed 400 r / min). After the aqueous solution was dispersed, it was placed in a 60 °C water bath and stirred for another 10 minutes. Subsequently, 0.2 g of tetramethylethylenediamine was added dropwise. After continuous stirring for 60 minutes, the product was collected, washed, and sieved to obtain microspheres. The image under the microscope is as shown in Figure 1 a1 in

[0044] Determination of the drug loading capacity of the microspheres:

[0045] 1 mL of microspheres was measured, 20 mL of doxorubicin solution with a concentration of 2 mg / mL was added, and after shaking at room temperature for 30 minutes, the absorbance of the solution at a wavelength of 483 nm was detected using a UV spectrophotometer, thereby obtaining the concentration of doxorubicin in the aqueous solution. The mass of doxorubicin that 1 mL of microspheres could adsorb was calculated as: 8.6 mg. The image of the microspheres loaded with doxorubicin under the microscope is as shown in Figure 1 a2 in

[0046] Comparative Example 2

[0047] This comparative example provides an embolic microsphere, which is prepared by the following steps:

[0048] (1) After mixing 3.8 g of acrylic acid with 1.4 g of vinyl phosphonic acid, 9.8 ml of 8 mol / L sodium hydroxide solution was added to form a mixture of sodium acrylate and sodium vinyl phosphate. After cooling to room temperature, 0.07 g of N,N'-methylenebisacrylamide and 0.07 g of potassium persulfate were dissolved into the mixture to form an aqueous solution;

[0049] (2) 1 g of cellulose acetate butyrate was added to 20 ml of butyl acetate. After the cellulose acetate butyrate was dissolved, the above aqueous solution was added, and stirring was continued for 20 minutes (rotation speed 400 r / min). After the aqueous solution was dispersed, it was placed in a 60 °C water bath and stirred for another 10 minutes. Subsequently, 0.2 g of tetramethylethylenediamine was added dropwise. After continuous stirring for 60 minutes, the product was collected, washed, and sieved to obtain microspheres. The image under the microscope is as shown in Figure 1 b1 in

[0050] Determination of the drug loading capacity of the microspheres:

[0051] Measure 1 mL of microspheres, add 20 mL of doxorubicin solution with a concentration of 2 mg / mL, shake for 30 minutes at room temperature, then use an ultraviolet spectrophotometer to detect the absorbance of the solution at a wavelength of 483 nm, so as to obtain the concentration of doxorubicin in the aqueous solution, and calculate that the mass of doxorubicin that can be adsorbed by 1 mL of microspheres is: 11.8 mg. The microscopic image of the microspheres loaded with doxorubicin is as shown in Figure 1 shown in b2 of

[0052] Example 1

[0053] This example provides an embolic microsphere, which is prepared by the following steps:

[0054] (1) Mix 4.2 g of acrylic acid with 1 g of vinyl phosphonic acid, then add 9.6 ml of 8 mol / L sodium hydroxide solution to form a mixture of sodium acrylate and sodium vinyl phosphate. Cool to room temperature, and then dissolve 0.07 g of N,N'-methylenebisacrylamide and 0.07 g of potassium persulfate in the mixture to form an aqueous solution;

[0055] (2) Add 1 g of cellulose acetate butyrate to 20 ml of butyl acetate. After the cellulose acetate butyrate is dissolved, add the above aqueous solution, continuously stir for 20 minutes (rotation speed 400 r / min), disperse the aqueous solution and then put it into a 60 °C water bath and continue to stir for 10 minutes. Then add 0.2 g of tetramethylethylenediamine, continuously stir for 60 minutes, collect the product, wash and sieve to obtain microspheres. The microscopic image is as shown in Figure 1 shown in c1 of

[0056] Determination of the drug loading of microspheres:

[0057] Measure 1 mL of microspheres, add 20 mL of doxorubicin solution with a concentration of 2 mg / mL, shake for 30 minutes at room temperature, then use an ultraviolet spectrophotometer to detect the absorbance of the solution at a wavelength of 483 nm, so as to obtain the concentration of doxorubicin in the aqueous solution, and calculate that the mass of doxorubicin that can be adsorbed by 1 mL of microspheres is: 14.8 mg. The microscopic image of the microspheres loaded with doxorubicin is as shown in Figure 1 shown in c2 of

[0058] Example 2

[0059] This example provides an embolic microsphere, which is prepared by the following steps:

[0060] (1) Mix 4.4 g of acrylic acid with 0.8 g of vinyl phosphonic acid, then add 9.5 ml of 8 mol / L sodium hydroxide solution to form a mixture of sodium acrylate and sodium vinyl phosphate. Cool to room temperature, and then dissolve 0.07 g of N,N'-methylenebisacrylamide and 0.07 g of potassium persulfate in the mixture to form an aqueous solution;

[0061] (2) Add 1 g of cellulose acetate butyrate to 20 ml of butyl acetate. After the cellulose acetate butyrate is dissolved, add the above aqueous solution and continuously stir for 20 minutes (rotation speed 400 r / min). After the aqueous solution is dispersed, place it in a 60 °C water bath and continue to stir for 10 minutes. Then, add 0.2 g of tetramethylethylenediamine dropwise. After continuously stirring for 60 minutes, collect the product, wash it, and sieve it to obtain microspheres. The image under the microscope is as shown in Figure 1 d1 in

[0062] Determination of the drug loading of microspheres:

[0063] Measure 1 mL of microspheres, add 20 mL of doxorubicin solution with a concentration of 2 mg / mL, shake at room temperature for 30 minutes, and then use a UV spectrophotometer to detect the absorbance of the solution at a wavelength of 483 nm, so as to obtain the concentration of doxorubicin in the aqueous solution. Calculate the mass of doxorubicin that can be adsorbed by 1 mL of microspheres as: 17.6 mg. The image of the microspheres loaded with doxorubicin under the microscope is as shown in Figure 1 d2 in

[0064] Determination of the drug sustained release of microspheres:

[0065] Put a beaker containing 500 ml of PBS with pH 7.4 into a 37 °C constant temperature water bath and stir for preheating. Then, add 1 ml of microspheres loaded with doxorubicin (the microspheres can be washed into the beaker with the PBS in the beaker). At the preset time points, take out 200 ml of PBS as a sample, and add 200 ml of fresh PBS to the beaker again to simulate the drug elution process in the body. The concentration of doxorubicin in the sample is tested by using a UV spectrophotometer (UV-2600, Shimadzu) (absorption wavelength: 483 nm). Samples are taken every 1 hour, and the drug elution curve is obtained as a result. As shown in Figure 2 shown, as time increases, the percentage of the released drug in the total drug loading gradually increases.

[0066] Example 3

[0067] This example provides an embolization microsphere, which is prepared by the following steps:

[0068] (1) Mix 4.6 g of acrylic acid and 0.6 g of vinyl phosphonic acid, then add 9.3 ml of 8 mol / L sodium hydroxide solution to form a mixture of sodium acrylate and sodium vinyl phosphate. Cool to room temperature, and then dissolve 0.07 g of N,N'-methylenebisacrylamide and 0.07 g of potassium persulfate in the mixture to form an aqueous solution;

[0069] (2) Add 1 g of cellulose acetate butyrate to 20 ml of butyl acetate. After the cellulose acetate butyrate is dissolved, add the above aqueous solution, and continuously stir for 20 minutes (rotation speed 400 r / min). After the aqueous solution is dispersed, place it in a 60 °C water bath and continue stirring for 10 minutes. Then, add 0.2 g of tetramethylethylenediamine dropwise. After continuously stirring for 60 minutes, collect the product, wash it, and sieve it to obtain microspheres. The image under the microscope is as shown in Figure 1 shown in e1 in

[0070] Determination of the drug loading capacity of the microspheres:

[0071] Measure 1 mL of microspheres, add 20 mL of doxorubicin solution with a concentration of 2 mg / mL, shake it at room temperature for 30 minutes, then use an ultraviolet spectrophotometer to detect the absorbance of the solution at a wavelength of 483 nm, so as to obtain the concentration of doxorubicin in the aqueous solution, and calculate that the mass of doxorubicin adsorbed by 1 mL of microspheres is: 14.2 mg. The image under the microscope after the microspheres are loaded with doxorubicin is as shown in Figure 1 shown in e2 in

[0072] Comparative Example 3

[0073] This comparative example provides an embolization microsphere, which is prepared by the following steps:

[0074] (1) Mix 2.6 g of acrylic acid and 2.6 g of vinylphosphonic acid, then add 10.5 ml of 8 mol / L sodium hydroxide solution to form a mixture of sodium acrylate and sodium vinylphosphonate. Cool it to room temperature, and then dissolve 0.07 g of N,N'-methylenebisacrylamide and 0.07 g of potassium persulfate in the mixture to form an aqueous solution;

[0075] (2) Add 1 g of cellulose acetate butyrate to 20 ml of butyl acetate. After the cellulose acetate butyrate is dissolved, add the above aqueous solution, and continuously stir for 20 minutes (rotation speed 400 r / min). After the aqueous solution is dispersed, place it in a 60 °C water bath and continue stirring for 10 minutes. Then, add 0.2 g of tetramethylethylenediamine dropwise. After continuously stirring for 60 minutes, no microspheres are obtained.

[0076] Comparative Example 4

[0077] This comparative example provides an embolization microsphere, which is prepared by the following steps:

[0078] (1) Add 9 ml of 8 mol / L sodium hydroxide solution to 5.2 g of acrylic acid to form a sodium acrylate solution. Cool it to room temperature, and then dissolve 0.07 g of N,N'-methylenebisacrylamide and 0.07 g of potassium persulfate in the mixture to form an aqueous solution;

[0079] (2) Add 1 g of cellulose acetate butyrate to 20 ml of butyl acetate. After the cellulose acetate butyrate is dissolved, add the above aqueous solution and continuously stir for 20 minutes (rotation speed 400 r / min). After the aqueous solution is dispersed, place it in a water bath at 60 °C and continue stirring for 10 minutes. Then, add 0.2 g of tetramethylethylenediamine dropwise. After continuously stirring for 60 minutes, collect the product, wash it, and sieve it to obtain microspheres. The image under the microscope is as shown in Figure 1 f1 in

[0080] Determination of the drug loading amount of the microspheres:

[0081] Measure 1 mL of microspheres, add 20 mL of doxorubicin solution with a concentration of 2 mg / mL, shake it at room temperature for 30 minutes, and then use an ultraviolet spectrophotometer to detect the absorbance of the solution at a wavelength of 483 nm, so as to obtain the concentration of doxorubicin in the aqueous solution. Calculate the mass of doxorubicin that can be adsorbed by 1 mL of microspheres as: 13 mg. The image under the microscope after the microspheres are loaded with doxorubicin is as shown in Figure 1 f2 in

[0082] In summary, the microspheres prepared in the above examples have regular spherical shapes, are evenly dispersed, have moderate elasticity, can rapidly adsorb a large amount of chemotherapeutic drugs, and are convenient for clinical use. By introducing sodium ethylene phosphate in a specific ratio, the drug adsorption rate and adsorption amount of the microspheres of the present invention are improved, which is beneficial to delivering more drugs to the target position, thereby increasing the curative effect.

[0083] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An embolization microsphere is prepared by polymerizing sodium vinyl phosphate and sodium acrylate with a molar ratio of 1:6 - 12.

2. The embolization microspheres according to claim 1, wherein, The molar ratio of sodium vinyl phosphate to sodium acrylate is 1:

8.

3. A method for preparing the embolization microsphere according to claim 1 or 2, comprising the following steps: (1) Mix sodium vinyl phosphate and sodium acrylate in water to obtain an aqueous monomer solution, and then add a crosslinking agent and an initiator to obtain an aqueous phase; (2) Mix an emulsifier in an oil solvent to obtain an oil phase; (3) Add the aqueous phase obtained in step (1) to the oil phase obtained in step (2). After emulsification, add a catalyst and react to obtain the embolization microsphere.

4. The preparation method according to claim 3, wherein In step (1), the mass fraction of the sum of sodium vinyl phosphate and sodium acrylate in the aqueous monomer solution is 30% - 50%; Preferably, in step (1), calculated based on the total mass of the monomers being 100%, the addition amount of the initiator is 0.1% - 3%; Preferably, in step (1), calculated based on the total mass of the monomers being 100%, the addition amount of the crosslinking agent is 0.2% - 2%.

5. The preparation method according to claim 3, wherein, In step (1), the initiator includes persulfate; Preferably, in step (1), the crosslinking agent includes acrylamide compounds; Preferably, in step (1), the crosslinking agent includes N,N'-methylenebisacrylamide.

6. The preparation method according to claim 3, wherein, In step (2), the emulsifier includes cellulose acetate butyrate; Preferably, in step (2), the oil solvent includes butyl acetate; Preferably, in step (2), the mass - volume ratio concentration of the emulsifier in the oil phase is 1% - 10%.

7. The preparation method according to claim 3, wherein, In step (3), the volume ratio of the aqueous phase to the oil phase is 0.01 - 1:1; Preferably, in step (3), the emulsification rotation speed is 10 - 800 rpm / min; Preferably, in step (3), the catalyst includes tetramethylethylenediamine; Preferably, in step (3), the reaction temperature is 50 - 70 °C, more preferably 60 °C; the reaction time is 60 - 240 min.

8. A drug - loaded embolization microsphere is obtained by further loading an anti - tumor drug on the embolization microsphere according to claim 1 or 2; Preferably, the anti - tumor drug includes doxorubicin.

9. Use of the embolization microsphere according to claim 1 or 2 or the drug - loaded embolization microsphere according to claim 8 in the preparation of an embolization treatment drug.

10. The application according to claim 9, wherein, The embolization treatment drug is a drug for treating tumors.

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