X-ray developable elastic embolism microsphere as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of medical materials, and particularly relates to an X-ray developable elastic embolism microsphere as well as a preparation method and application thereof.The preparation method of the X-ray developable elastic embolism microsphere comprises the following steps: respectively weighing Dox and a lipid carrier DSPE-PEG2000-SH, and respectively dissolving the Dox and the lipid carrier DSPE-PEG2000-SH in a pre-prepared organic solvent; uniformly mixing the prepared solutions in proportion, removing the organic solvent, then adding deionized water to dissolve the lipid medicine membrane, heating in a water bath, cooling and filtering to obtain a Dox-m solution; and dropwise adding liquid gallium into the Dox-m solution, carrying out ultrasonic treatment, screening, and cleaning to obtain the elastic embolism microsphere. The elastic embolism microsphere provided by the invention not only can overcome the defects of the existing embolism material, but also can provide a safer, more efficient and multifunctional novel material for interventional therapy, and has important clinical significance.

Description

Technical Field

[0001] The invention belongs to the technical field of medical materials, and in particular relates to an elastic embolic microsphere developable by X-rays, and a preparation method and application thereof. Background Art

[0002] With the continuous advancement of medical technology and the growing clinical needs, embolization therapy, as an important interventional therapy, has shown broad application prospects in the fields of tumor treatment, vascular malformations, hemorrhagic diseases, etc. However, existing embolization materials still have many limitations in meeting clinical treatment needs.

[0003] Traditional embolic microspheres, such as DC Bead, HepaSphere, CalliSpheres, etc., although they can achieve the effect of vascular embolization to a certain extent, have obvious deficiencies in terms of development performance, elasticity and flexibility, embolization time, and multifunctional integration. Specifically, the development effect of these microspheres under imaging equipment such as X-ray, CT or DSA is poor, and it is difficult for doctors to observe the position and distribution of microspheres in blood vessels in real time and accurately, which increases the difficulty and risk of operation. At the same time, the biodegradation rate of existing microspheres is relatively fast, which makes it difficult to maintain the embolization effect for a long time, and patients may need to undergo repeated treatments. In addition, the drug loading capacity of these microspheres is limited, the drug release rate is difficult to control, and effective drug sustained release cannot be achieved. Moreover, they are relatively single in function and difficult to be used in combination with other treatment methods such as chemotherapy and hyperthermia.

[0004] In recent years, liquid metal has shown great application potential in the field of embolic materials due to its unique physical and chemical properties. Liquid metal (such as gallium, indium, tin alloy, etc.) has low melting point, high thermal conductivity, high electrical conductivity and good fluidity. Its nanoparticles or microspheres have high development performance under X-rays, which can significantly improve the visualization effect of embolic materials. At the same time, the thermal therapy properties of liquid metal can also be combined with the embolic function to achieve synergistic treatment of embolism and thermal therapy, providing new ideas for interventional treatment.

[0005] However, the application of liquid metal in the preparation of embolic microspheres still faces many challenges. On the one hand, it is necessary to ensure that the microspheres have good elasticity and flexibility to adapt to the dynamic environment of blood vessels, such as vascular expansion and contraction, blood flow impact, etc., to avoid the displacement or rupture of microspheres in blood vessels. On the other hand, it is necessary to optimize the composite method of liquid metal and polymer materials to ensure that the microspheres achieve a better balance between elasticity and development performance. At the same time, factors such as the biocompatibility of the microspheres, drug loading capacity, and simplicity and uniformity of the preparation method also need to be considered.

[0006] In addition, although there have been some reports on the research of visualized drug-loaded embolic microspheres based on liquid metal, these microspheres still need to be further optimized and improved in terms of elasticity, development effect, embolic time, and multifunctional integration. In particular, in clinical applications, an embolic microsphere that can simultaneously meet the requirements of elasticity, development performance, drug loading and sustained release capacity, and multifunctional integration is needed to improve the accuracy, safety, and effectiveness of embolic therapy.

[0007] Therefore, the present invention aims to develop an X-ray-developable elastic embolic microsphere through innovative design and material combination, so as to solve the key problems of existing embolic microspheres in clinical applications and promote the further development of embolic technology in the fields of tumor treatment and so on. Summary of the invention

[0008] In order to solve the above technical problems, the present invention proposes an X-ray developable elastic embolic microsphere and its preparation method and application, which can not only overcome the shortcomings of existing embolic materials, but also provide a safer, more efficient and multifunctional new material for interventional treatment, which has important clinical significance.

[0009] To achieve the above object, the present invention provides a method for preparing elastic embolic microspheres that can be developed by X-rays, characterized in that it comprises the following steps:

[0010] Liquid gallium is dropped into the solution, and then ultrasonic treatment is performed to generate microspheres, and the particle size of the microspheres is screened to obtain elastic embolic microspheres;

[0011] The solution is PBS solution, chitosan oligosaccharide solution or drug-loaded micelle solution.

[0012] Furthermore, when the solution is a chitosan solution, finally, non-drug-loaded elastic embolic microspheres are prepared, and the preparation method is as follows:

[0013] Liquid gallium is dropped into a PBS solution or a chitosan oligosaccharide solution, and then ultrasonic treatment is performed, and the elastic embolic microspheres are obtained after screening and washing.

[0014] Furthermore, the solution is a drug-loaded micelle solution, and finally drug-loaded elastic embolic microspheres are prepared. The preparation method is as follows:

[0015] (1) Weigh Dox and lipid carrier DSPE-PEG2000-SH respectively and dissolve them in pre-prepared organic solvents;

[0016] (2) mixing the solution prepared in step (1) in proportion and removing the organic solvent, then adding deionized water to dissolve the lipid film, heating in a water bath, cooling and filtering to obtain a Dox-m solution;

[0017] (3) Liquid gallium is dropped into the Dox-m solution, and then ultrasonic treatment is performed, and the elastic embolic microspheres are obtained after screening and washing.

[0018] Furthermore, the parameters of the ultrasonic treatment are: power of 100 to 300 W, ultrasonication for 1 to 4 seconds, pause for 1 to 4 seconds, and 5 to 20 cycles.

[0019] Furthermore, the mass of liquid gallium is 1 to 1000 g; the concentration of chitosan oligosaccharide is 1 to 100 mg / ml;

[0020] Furthermore, in step (2), the mixing ratio is a mixing ratio of Dox to DSPE-PEG2000-SH of 1:1-1:100 by mass.

[0021] Furthermore, in step (3), when the liquid gallium is dripped into the Dox-m solution, the mass ratio of the liquid gallium to the Dox-m is 10:1 to 1000:1.

[0022] Furthermore, in step (3), the screening is performed by using a cell sieve, a filter, etc. to obtain particles with a diameter of 40 to 200 μm.

[0023] The present invention also provides an elastic embolic microsphere prepared by the preparation method.

[0024] The present invention also provides an application of the elastic embolic microspheres in preparing products for vascular embolism and disease treatment, wherein the diseases include tumors and prostate hyperplasia.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] The present invention successfully prepared a solid surface and liquid internal embolic microsphere (Dox-m / GaMs), which has good elasticity, compressibility and resilience. This design allows the microsphere to be temporarily compressed when delivered through a catheter, adapting to the dynamic environment of the blood vessel, and quickly returning to its original shape after entering the blood vessel, thereby achieving precise vascular embolization and reducing the risk of displacement or rupture.

[0027] The embolic microspheres prepared by the present invention have elastic embolization, drug sustained release, X-ray development and embolization functions. By introducing high-density, high X-ray absorption coefficient gallium-based liquid metal microspheres, the development effect is enhanced, allowing doctors to observe the position and distribution of microspheres in real time and clearly, improving the accuracy and safety of the operation. At the same time, the microspheres can be loaded with drugs to achieve drug sustained release and improve the treatment effect.

[0028] The present invention adopts the template method to prepare microspheres, and ensures the uniformity of the size and performance of the microspheres through precise preparation process and control conditions. This method is simple, efficient, suitable for large-scale production, and provides stable and consistent microsphere products for clinical application.

[0029] The embolic microspheres prepared by the present invention are not only suitable for vascular embolization, but also can be used for TACE treatment of tumors such as liver cancer and lung cancer, and embolic treatment of diseases such as prostatic hyperplasia. Its multifunctionality and good biocompatibility make the microspheres have broad application prospects in the field of interventional treatment.

[0030] The elastic embolic microspheres prepared by the present invention are mainly composed of gallium and have good biocompatibility. No obvious toxicity was observed in animal experiments on mice, rats, rabbits, etc., indicating that the microspheres are safe for use in vivo. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 This is a specific preparation flow chart of Dox-m / GaMs in Example 1 of the present invention;

[0033] Figure 2 This is an optical microscope image of Dox-m / GaMs prepared in Example 1 of the present invention;

[0034] Figure 3 TEM image of Dox-m / GaMs prepared in Example 1 of the present invention;

[0035] Figure 4 This is an elastic model test diagram of Dox-m / GaMs prepared in Example 1 of the present invention;

[0036] Figure 5 DSA images of rabbit ears before and after embolization in Example 3 of the present invention, wherein A represents before embolization and B represents after embolization;

[0037] Figure 6 This is a diagram showing changes in the rabbit ear after embolization in Example 3 of the present invention;

[0038] Figure 7 CT images of the tumor before and after embolization in Example 4 of the present invention.

[0039] Figure 8 This is the volume change of the tumor after embolization in Example 4 of the present invention. DETAILED DESCRIPTION

[0040] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0041] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0042] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0043] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0044] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0045] The present invention will be further described in detail below in conjunction with specific embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0046] Example 1 Preparation of embolic microspheres (Dox-m / GaMs)

[0047] 1. Preparation of drug-loaded micelles:

[0048] 1.1 Prepare a clean workbench in the laboratory and ensure that all instruments and glassware used are strictly cleaned and sterilized to avoid external contamination.

[0049] 1.2 Weigh Dox and lipid carrier DSPE-PEG2000-SH (an amphiphilic lipid) separately and dissolve them in pre-prepared organic solvent (the volume ratio of anhydrous methanol to chloroform is 1:1).

[0050] 1.3 The prepared solution was mixed evenly in a mass ratio of Dox to DSPE-PEG2000-SH of 1:10 (1:20-1:5) to ensure that the drug and the carrier were fully mixed.

[0051] 1.4 Transfer the mixed solution into a 50 ml eggplant-shaped bottle and remove the organic solvent using a rotary evaporator.

[0052] 1.5 After removing the organic solvent, add deionized water to dissolve the lipid film.

[0053] 1.6 Place the eggplant-shaped bottle in a 60°C water bath and heat for 30 minutes to allow the lipid film to fully hydrate; then quickly cool it at -20°C for 4 minutes to promote the formation and stabilization of the microspheres.

[0054] 1.7 Finally, the solution was filtered through a 0.22 μm water filter membrane to remove free Dox and other impurities to obtain a pure Dox-m solution.

[0055] 1.8 Using the same method, prepare Dox-m solutions with mass ratios of Dox to DSPE-PEG2000-SH of 1:5 and 1:20, respectively.

[0056] 2. Preparation of Dox-m / GaMs:

[0057] 2.1 Weigh 0.54 g of liquid gallium and drop it into a 50 ml centrifuge tube containing 3 mL of 5 mg / ml Dox-m solution.

[0058] 2.2 Use an ultrasonic probe to ultrasonically treat the mixed solution containing liquid gallium and Dox-m: the power is 227.5 W, ultrasonication for 1 second, pause for 2 seconds, and 5 cycles.

[0059] 2.3 The treated solution was screened with a 70 μm cell sieve to remove particles with larger diameters and retain particles with a diameter below 70 μm.

[0060] 2.4 The particles were then screened using a 40 μm cell sieve to retain particles with a diameter of 40-70 μm.

[0061] 2.5 The screened particles were washed three times with PBS to obtain Dox-m-loaded Dox-m / GaMs.

[0062] 2.6 Following the same method, Ga liquid metal microspheres (GaMs) without Dox-m loading were prepared in PBS.

[0063] The specific preparation process of Dox-m / GaMs is as follows: Figure 1 shown.

[0064] Example 2 Characterization of Dox-m / GaMs

[0065] 1. The Dox-m / GaMs prepared in Example 1 was placed on a glass slide and placed on the stage of an optical microscope. Its shape and size were observed through an optical microscope. Figure 2 As shown by Figure 2 It can be seen that the microspheres are spherical and the particle size range matches the experimental expectations.

[0066] 2. Dox-m / GaMs was added to the silicon wafer and observed in a field emission scanning electron microscope. The sample surface was irradiated with a high-energy electron beam to obtain a high-resolution microscopic image to further observe the morphology, surface characteristics and size distribution of the microspheres in detail. The final results are as follows: Figure 3 As shown by Figure 3 It can be seen that the size of the Dox-m / GaMs finally prepared is relatively uniform, with a particle size between 40-70 μm.

[0067] 3. Use Microtester to test the elastic model of Dox-m / GaMs. The final results are as follows: Figure 4 As shown by Figure 4 It can be seen that the Dox-m / GaMs finally prepared has good compressibility and rebound ability.

[0068] Example 3 Evaluation of the Vascular Embolization Effect of Dox-m / GaMs

[0069] The rabbit was anesthetized and its central auricular artery was punctured distally with a 24G intravenous indwelling needle. A small amount of normal saline was pushed in to ensure that the indwelling needle was unobstructed. DSA examination was performed to observe the shape and distribution of the rabbit ear blood vessels. 100μL of liquid metal microspheres were drawn with a 1mL syringe, mixed with 900μL PBS and injected into the rabbit ear central artery through the indwelling needle for embolization. After the embolization was completed, DSA examination was performed to evaluate the embolization effect. By comparing the vascular morphology and blood flow before and after embolization, the blocking effect and degree of embolism of the microspheres on the blood vessels were evaluated. The changes in the rabbit ears were observed and recorded every day. In addition, X-ray photography was performed immediately after embolization and at 1 and 2 weeks after embolization to record the location and distribution of the liquid metal microspheres at the embolization site to evaluate the long-term stability of the embolization effect and the biodistribution of the microspheres.

[0070] The final result is as follows Figure 5 and Figure 6 As shown, DSA examination before embolization (by Figure 5 The DSA examination after embolization (shown in A) can show the complete arteries and veins of the rabbit ear. Figure 5 In the case shown in Figure B, the contrast agent only exists in the artery and does not enter the rabbit ear vein. This indicates that the microspheres complete vascular embolization after entering the rabbit ear artery. Observe the changes in the rabbit ears every day and record ( Figure 6 ). On the 7th day after the embolization, the color of the embolization site deepened and began to show signs of necrosis. This is because after the embolization, oxygen and nutrients can no longer reach the embolization site. On the 14th day, the ear tip shrinks and its skin tissue becomes dehydrated, dry, and hardened.

[0071] Example 4 Evaluation of the in vivo therapeutic effect of Dox-m / GaMs

[0072] A rabbit ear tumor model was constructed. When the rabbit tumor volume increased to 500 mm 3 Embolization therapy was performed under DSA. Forty rabbits bearing VX2 tumors were randomly divided into 4 groups, namely PBS group, Dox-m group, GaMs group and Dox-m / GaMs group. The central artery of the rabbit ear was punctured in the centripetal direction with a 24G intravenous cannula needle, and an appropriate amount of normal saline was injected to confirm the patency of the indwelling needle. Under fluoroscopy, a small amount of contrast agent was slowly injected to identify the tumor blood supply artery and adjust the indwelling needle to the appropriate position, and then the indwelling needle was fixed. DSA examination was performed before treatment to observe tumor staining and vascular distribution. The same volume of PBS (1mL), Dox-m (1mL, 0.33mg / mL), GaMs (1mL, 500mg / mL) and Dox-m / GaMs (1mL, 500mg / mL) were injected into the central artery of the rabbit ear through the intravenous indwelling needle. In order to determine the location of the microsphere embolism, CT scans were performed on the rabbit ears before and after embolization. The results are shown in Figure 7 As shown in the figure, compared with the CT images before embolization, the density of the tumor area after embolization was significantly increased, and the microspheres inside the tumor could be observed. Figure 8 As shown, the tumor volume in the Dox-m / GaMs group was significantly reduced.

[0073] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing X-ray-developable elastic embolic microspheres, characterized in that: The following steps are involved: Liquid gallium is dropped into the solution, and then ultrasonic treatment is performed to generate microspheres, and the particle size of the microspheres is screened to obtain elastic embolic microspheres; The solution is PBS solution, chitosan oligosaccharide solution or drug-loaded micelle solution.

2. The preparation method according to claim 1, characterized in that: When the solution is a chitosan solution, finally, non-drug-loaded elastic embolic microspheres are prepared, and the preparation method is as follows: Liquid gallium is dropped into a PBS solution or a chitosan oligosaccharide solution for ultrasonic treatment, and then screened and washed to obtain the elastic embolic microspheres.

3. The preparation method according to claim 1, characterized in that: The solution is a drug-loaded micelle solution, and finally drug-loaded elastic embolic microspheres are prepared. The preparation method is as follows: (1) Weigh Dox and lipid carrier DSPE-PEG2000-SH respectively and dissolve them in pre-prepared organic solvents; (2) mixing the solution prepared in step (1) in proportion and removing the organic solvent, then adding deionized water to dissolve the lipid film, heating in a water bath, cooling and filtering to obtain a Dox-m solution; (3) Liquid gallium is dropped into the Dox-m solution, and then ultrasonic treatment is performed, and the elastic embolic microspheres are obtained after screening and washing.

4. The preparation method according to claim 1, characterized in that: The parameters of the ultrasonic treatment are: power of 100-300W, ultrasonication for 1-4 seconds, pause for 1-4 seconds, and 5-20 cycles.

5. The preparation method according to claim 1, characterized in that: The mass of liquid gallium is 1-1000g; the concentration of chitosan oligosaccharide is 1-100mg / ml.

6. The preparation method according to claim 3, characterized in that: In step (2), the proportion is to mix Dox and DSPE-PEG2000-SH in a mass ratio of 1:1-1:

100.

7. The preparation method according to claim 3, characterized in that: In step (3), when the liquid gallium is dripped into the Dox-m solution, the mass ratio of the liquid gallium to the Dox-m is 10:1 to 1000:

1.

8. The preparation method according to claim 3, characterized in that: In step (3), the screening is performed by using a cell sieve, a filter, etc. to obtain particles with a diameter of 40 to 200 μm.

9. An elastic embolic microsphere prepared by the preparation method according to any one of claims 1 to 7.

10. Use of the elastic embolic microspheres according to claim 9 in preparing products for vascular embolism and disease treatment, characterized in that: Such diseases include tumors and prostate hyperplasia.

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