Composite gel microsphere loaded with nanoparticle medicine and preparation method of composite gel microsphere

Abstract

The invention belongs to the field of biomedical engineering, and discloses a composite gel microsphere loaded with a nanoparticle drug and a preparation method of the composite gel microsphere. The drug-loaded nanoparticles and the drugs which are added in the preparation process of the drug-loaded nanoparticles and are not encapsulated by the nanoparticles are automatically encapsulated in the microspheres, so that the drug loading capacity is favorably improved, and the drug loss is reduced.

Description

Technical Field

[0001] The invention belongs to the field of biomedical engineering, and in particular relates to a composite gel microsphere loaded with nanoparticle drugs and a preparation method thereof. Background Art

[0002] Cancer is one of the most common causes of death worldwide, accounting for nearly 10 million deaths in 2020. Currently, there are a variety of treatments for cancer, including surgery, radiotherapy, hormone (endocrine) therapy, targeted therapy, immunotherapy, chemotherapy, and monoclonal antibody therapy. Although surgical treatment is effective, for patients with disease that cannot undergo tumor resection, systemic therapy is the standard of care, aimed at achieving disease control and improving survival rates. In some cases, tumor shrinkage may make radical resection possible. Transcatheter arterial chemoembolization (TACE) aims to block the hepatic artery, inhibit blood supply to solid tumors, and achieve local chemotherapy. It is currently widely used in patients with advanced liver cancer who are not suitable for surgical resection.

[0003] At present, the commonly used embolic agents for vascular intervention include gelatin sponge, polyvinyl alcohol (PVA) microspheres, anhydrous alcohol, iodized oil, detachable balloons, spring coils, etc. Among them, drug-loaded microspheres have the characteristics of increasing local drug concentration and reducing systemic toxicity and have received widespread attention. The release of drugs in drug-loaded microspheres can be slowed down by skeleton dissolution, surface dissolution, overall disintegration, water vapor expansion, dissociation diffusion and desorption, making them long-acting preparations, which can reduce the number of drug administrations and eliminate drug peak and valley phenomena. It is currently the most popular embolic agent.

[0004] Hydrogel microspheres are represented by alginate-based hydrogel microspheres. Due to their better elasticity, they show better embolic stability in the treatment of vascular interventional embolization and become a new type of embolic agent for interventional therapy. At the same time, many anti-tumor drugs are clinically used with the help of nanocarriers to achieve solubilization and penetration. How to better integrate the two to achieve high drug loading and long-term local release of drug-loaded microspheres is crucial. The usual practice is to disperse the prepared drug-loaded nanoparticles into the hydrogel matrix and further prepare hydrogel microspheres loaded with nanoparticles. For example: calcium alginate microspheres loaded with PLGA nanoparticles. However, due to the solubility of the nanoparticle material itself, only a small amount of nanoparticles can be dispersed into the sodium alginate solution without affecting the preparation of the gel microspheres, resulting in a very low drug loading in the microspheres. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a composite gel microsphere loaded with nanoparticle drugs and a preparation method thereof. The microspheres automatically encapsulate the drug-loaded nanoparticles and the drugs added during the preparation of the drug-loaded nanoparticles but not encapsulated by the nanoparticles, which helps to increase the drug loading amount and reduce drug loss.

[0006] The above object of the present invention is achieved by the following technical scheme: A method for preparing composite gel microspheres loaded with nanoparticle drugs, comprising the steps of:

[0007] 1. Dissolve the hydrophobically modified amphiphilic sodium alginate to prepare an amphiphilic sodium alginate solution with a concentration of 0.5-30 mg / mL, disperse the drug to be encapsulated in the amphiphilic sodium alginate solution, and use ultrasonic method to prepare a stable drug-loaded nanoparticle suspension with a particle size range of 100-600 nm and a drug loading of 1%-20%, wherein the amphiphilic sodium alginate is obtained by hydrophobically modifying sodium alginate with a weight average molecular weight of 60kD-1000kD; the hydrophobic modification group includes but is not limited to vinyl acetate, phenylalanine ethyl ester, dodecenyl succinic anhydride, etc., and the degree of substitution is 1-20%;

[0008] 2. Dissolve sodium alginate into the drug-loaded nanoparticle suspension prepared in step 1, with the concentration of sodium alginate being between 5-50 mg / mL, and use an ionic crosslinker to prepare composite gel microspheres loaded with nanoparticle drugs through liquid granulation technology.

[0009] Wherein, the drugs in step 1 are various drugs and auxiliary drugs for treating tumors, including but not limited to doxorubicin hydrochloride, paclitaxel, oxaliplatin, and carboplatin;

[0010] Wherein, the concentration of sodium alginate in step 2 is 5-40 g / L;

[0011] Wherein, the ionic crosslinking agent in step 2 is a divalent cation or a trivalent cation, and the divalent cation includes Ca 2+ , Cu 2+ , Fe 2+ , Sr 2+ 、Zn 2+ and Ba 2+ ; Trivalent cations include Fe 3+ , Ga 3+ ;

[0012] Among them, the liquid particleization technology in step 2 includes co-directional / axial flow preparation technology, electrostatic droplet method, electrostatic atomization preparation technology, vibration effect preparation technology, centrifugal field preparation technology, microchannel array preparation technology, emulsification-external gelation technology, and emulsification-internal gelation technology.

[0013] Another object of the present invention is to protect the composite gel microspheres loaded with nanoparticle drugs prepared by the above-mentioned method for preparing composite gel microspheres loaded with nanoparticle drugs.

[0014] Another object of the present invention is to protect the application of the composite gel microspheres loaded with nanoparticle drugs.

[0015] Furthermore, the application of the composite gel microspheres loaded with nanoparticle drugs is specifically used for tumor interventional embolization.

[0016] The beneficial effects of the present invention compared with the prior art are:

[0017] 1. The biggest difference between the present invention and the prior art is that the prior art adds the prepared nanoparticle solution (such as PLGA nanoparticles) to the sodium alginate solution used to prepare the gel microspheres. In order to ensure that the sodium alginate can form stable and spherical gel microspheres, the amount of nanoparticle solution that can be added is very limited, thus resulting in a low drug loading of the gel microspheres. The present invention, on the other hand, uses the principle of like-for-like to prepare the drug-loaded nanoparticle carrier using the same substrate alginate as the gel microspheres, and uses the nanoparticle solution of the amphiphilic sodium alginate after drug loading as a buffer to directly dissolve the sodium alginate, that is, the sodium alginate solution contains all the nanoparticle drugs and the drugs not encapsulated by the nanoparticles, and all of them are encapsulated in the cross-linked gel microspheres, thereby achieving a high drug loading and encapsulation rate.

[0018] 2. The material for preparing microspheres is sodium alginate, which has good biocompatibility. At the same time, amphiphilic sodium alginate nanoparticles fill the spatial network of calcium alginate microspheres to improve the strength of the microspheres.

[0019] 3. The drug exists in the nanoparticles and alginate gel. Through the two-stage sustained release process of drug release in the gel and drug release in the nanoparticles, it can not only meet the rapid achievement of high drug concentration in the early stage of embolization, but also realize the long-term slow release of the drug, which is beneficial to killing tumor cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] Figure 1 is an optical micrograph of nanoparticle composite gel microspheres;

[0022] Figure 2 This is a scanning electron microscope observation image of nanoparticle composite gel microspheres. DETAILED DESCRIPTION

[0023] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0024] Example 1

[0025] (1) A certain amount of amphiphilic polyvinyl acetate-sodium alginate was dissolved in (0.02M) PBS at pH = 7.4 and stirred overnight. The resulting amphiphilic sodium alginate concentration was 2 mg / mL. Doxorubicin (DOX) was added thereto at a final concentration of 0.3 mg / mL. After DOX and amphiphilic sodium alginate SA-g-PVAc were evenly mixed, an amphiphilic sodium alginate nanoparticle solution loaded with doxorubicin was obtained.

[0026] (2) Sodium alginate solid was dissolved in the drug-loaded nanoparticle solution prepared in step (1), the sodium alginate concentration was 15 mg / mL, and calcium carbonate was added as the water phase. Liquid paraffin was used as the oil phase, and the water and oil phases were mixed in a ratio of 1:5. After stirring to form a stable emulsion, glacial acetic acid was added dropwise to dissociate Ca 2+ , and gelation reaction was carried out for 10 minutes. Deionized water was added to break the emulsion, and then the gel beads were washed with a 1% Tween aqueous solution to obtain composite gel microspheres loaded with doxorubicin nanoparticles. The particle size of the composite microspheres was 167 μm (see Figure 1 ).

[0027] (3) Take half of the composite gel microspheres loaded with doxorubicin nanoparticles obtained in step (2), dry them, weigh them, and observe them under a scanning electron microscope. The surface is relatively smooth (see Figure 2 ).

[0028] (4) Take the other half of the composite gel microspheres loaded with doxorubicin nanoparticles obtained in step (2) and dissolve them in a certain volume of 0.055 mol / L -1 The microspheres were completely broken by ultrasonic oscillation in sodium citrate, and the supernatant was centrifuged and detected by UV-visible spectrophotometer. The drug loading of nanoparticle composite gel microspheres was 1.8% and the encapsulation efficiency was 59%.

[0029] Comparative Example 1

[0030] (1) Adriamycin hydrochloride liposomes with a drug loading of 5% and a particle size of 150 nm were prepared by combining the ethanol injection method with the ammonium sulfate gradient method.

[0031] (2) The doxorubicin hydrochloride liposomes were fully mixed with 2% sodium alginate solution at a volume ratio of 1:3, and calcium carbonate was added as the water phase. Liquid paraffin was used as the oil phase, and the water and oil phases were mixed and stirred for 30 minutes. After a stable emulsion was formed, glacial acetic acid was added dropwise to dissociate the Ca 2+ The gelation reaction was carried out for 10 minutes. Deionized water was added to break the emulsion, and then the gel beads were washed with a 1% Tween aqueous solution to obtain composite gel microspheres loaded with doxorubicin nanoparticles. The particle size of the composite microspheres was 234 μm.

[0032] (3) Take half of the composite gel microspheres loaded with doxorubicin nanoparticles obtained in step (2), dry them, and then weigh them.

[0033] (4) Take the other half of the composite gel microspheres loaded with doxorubicin nanoparticles obtained in step (2) and dissolve them in a certain volume of 0.055 mol / L -1 The microspheres were completely broken by ultrasonic oscillation in sodium citrate, and the supernatant was centrifuged and detected by UV-visible spectrophotometer. The drug loading of nanoparticle composite gel microspheres was 0.4% and the encapsulation efficiency was 62%.

[0034] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A method for preparing composite gel microspheres loaded with nanoparticle drugs, characterized in that the steps include: S1. Dissolving hydrophobically modified amphiphilic sodium alginate to prepare an amphiphilic sodium alginate solution with a concentration of 0.5-30 mg / mL, dispersing the drug to be encapsulated in the amphiphilic sodium alginate solution, and using an ultrasonic method to prepare a stable drug-loaded nanoparticle suspension with a particle size range of 100-600 nm and a drug loading of 1%-20%, wherein the amphiphilic sodium alginate is obtained by hydrophobically modifying sodium alginate with a weight average molecular weight of 60kD-1000kD; the hydrophobic modification group includes but is not limited to vinyl acetate, ethyl phenylalanine, dodecenyl succinic anhydride, etc., and the degree of substitution is 1-20%; S2. Dissolve sodium alginate into the drug-loaded nanoparticle suspension prepared in step S1, wherein the concentration of sodium alginate is between 5-50 mg / mL, and use an ionic crosslinking agent and liquid granulation technology to prepare composite gel microspheres loaded with nanoparticle drugs.

2. The method for preparing composite gel microspheres loaded with nanoparticle drugs according to claim 1, characterized in that: The drugs in step S1 are various drugs and auxiliary drugs for treating tumors, including but not limited to doxorubicin hydrochloride, paclitaxel, oxaliplatin, and carboplatin.

3. The method for preparing composite gel microspheres loaded with nanoparticle drugs according to claim 1, characterized in that: The sodium alginate concentration in step S2 is 5-40 g / L.

4. The method for preparing composite gel microspheres loaded with nanoparticle drugs according to claim 1, characterized in that: The ionic crosslinking agent in step S2 is a divalent cation or a trivalent cation, wherein the divalent cation includes Ca 2+ , Cu 2+ , Fe 2+ , Sr 2+ 、Zn 2+ and Ba 2+ ; Trivalent cations include Fe 3+ , Ga 3+ .

5. The method for preparing composite gel microspheres loaded with nanoparticle drugs according to claim 1, characterized in that: The liquid particle formation technology in step S2 includes co-directional / axial flow preparation technology, electrostatic droplet method, electrostatic atomization preparation technology, vibration effect preparation technology, centrifugal field preparation technology, microchannel array preparation technology, emulsification-external gelation technology, and emulsification-internal gelation technology.

6. A composite gel microsphere loaded with nanoparticle drugs, characterized in that: It is prepared according to the preparation method of claim 1.

7. Use of the composite gel microspheres loaded with nanoparticle drugs as claimed in claim 6.

8. The use of composite gel microspheres loaded with nanoparticle drugs according to claim 7, characterized in that: Specifically used for tumor interventional embolization.

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