A drug delivery system targeting blood-brain barrier and its preparation method and application

Abstract

The present invention provides a drug delivery system targeting the blood-brain barrier, and its preparation method and application. The drug delivery system includes a nanocarrier and a drug, wherein the nanocarrier includes a polyamidoamine modified with poloxamer 188. The present invention creatively obtains a nanocarrier by simply modifying the PAMAM-NH2 surface with Pluronic F68, thereby simultaneously endowing the carrier with multiple functions: 1) long circulation; 2) high safety and biocompatibility; 3) inhibition of the passive physical barrier of the BBB and weakening of the active barrier of the BBB; 4) significant increase in cellular drug uptake and good drug sustained-release effect. The nanocarrier has a simple design, low cost, and is more suitable for clinical application, providing new ideas for the design of intelligent nano-drug delivery systems for anti-glioma.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine and relates to a drug delivery system targeting the blood-brain barrier and a preparation method and application thereof. Background Art

[0002] Glioma is one of the common malignant tumors, most of which are primary intracranial malignant tumors. It has the characteristics of high morbidity, high mortality, low cure rate and high recurrence rate, and is one of the current difficulties in tumor treatment. At present, the treatment of glioma is mainly surgery plus chemotherapy and radiotherapy. However, due to the infiltrative and aggressive growth of glioma, the margin between the tumor and normal tissue is not clear. Therefore, the treatment effect of surgery and radiotherapy alone is not good, the prognosis is poor, and recurrence is very easy. Due to the existence of the blood-brain barrier (BBB), most drugs have difficulty entering the brain to exert the best therapeutic effect. The current drug administration methods are mainly intravenous administration, arterial perfusion, opening the blood-brain barrier and intracranial administration. These drug administration methods have problems such as non-aggregated drug distribution, great damage to blood vessels, non-selective opening that increases the chance of other substances entering the brain, and inconvenient administration.

[0003] Therefore, brain-targeted nano-drug delivery systems have been a research hotspot for the treatment of gliomas in recent years. These systems primarily transport drugs into the brain through receptor- and carrier-mediated delivery. However, current brain-targeted nano-drug delivery systems remain suboptimal in terms of BBB crossing, while their biocompatibility, targeted release, and drug release efficiency also need to be improved, resulting in unsatisfactory overall delivery results.

[0004] Therefore, how to design a new nano-drug delivery system to cross the blood-brain barrier and thus improve the therapeutic effect on brain glioma has become an urgent problem to be solved in this field. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a drug delivery system targeting the blood-brain barrier and its preparation method and application.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a drug delivery system targeting the blood-brain barrier, wherein the drug delivery system comprises a nanocarrier and a drug, wherein the nanocarrier comprises a polyamidoamine modified with poloxamer 188.

[0008] Polyamidoamine (PAMAM-NH2) dendrimers are a class of cationic polymer materials commonly used in drug delivery systems. Due to the presence of surface amino groups, PAMAs possess many unique advantages: The amino groups are highly reactive, readily chemically reactive, and readily accessible for ligand attachment; they also exhibit a proton sponge effect, allowing them to escape the endosomal-lysosomal system. PAMAM dendrimers possess hydrophobic cavities and surface functional groups. Since the amino groups on the surface of entire generations of PAMAs are positively charged, they exhibit certain cytotoxic and hemolytic toxicities. These surface functional groups can be modified to load drugs and other therapeutic substances. Pluronic F68 (Pluronic F68) is highly hydrophilic and exhibits a long-circulation effect similar to polyethylene glycol, which can increase the in vivo circulation time of drug delivery systems. Modification of PAMAs with Poloxamer 188 improves their biocompatibility and enhances drug delivery.

[0009] The present invention uses poloxamer 188 (Pluronic F68), which inherently reduces drug resistance, to modify PAMAM to neutralize its surface positive charge, increasing the carrier's biocompatibility and reducing its toxicity to humans. Specifically, Pluronic F68 can adsorb apolipoprotein A-Ⅰ (Apo A-Ⅰ) in plasma, which specifically binds to scavenger receptor class B type Ⅰ (SR-BI), abundant on brain capillary endothelial cells at the blood-brain barrier (BBB). Therefore, this design achieves BBB-crossing through receptor-mediated delivery.

[0010] Preferably, the poloxamer 188-modified polyamidoamine is prepared by a preparation method comprising the following steps:

[0011] (1) Succinic anhydride, poloxamer 188, a solvent and a catalyst, triethylamine, are mixed to react to obtain F68-SA;

[0012] (2) F68-SA, NHS, EDC, triethylamine and a solvent are mixed and reacted to activate the carboxyl group to obtain an activated product;

[0013] (3) Mixing the polyamide-amine with the activated product and reacting them to obtain the product.

[0014] Theoretically, poloxamer 188-modified polyamidoamine prepared by any method can be used as a nanocarrier. However, the encapsulation efficiency and drug loading capacity of nanocarriers prepared by different methods vary. By using the above-mentioned preparation method of the present invention, the various parameters are coordinated with each other, and the drug loading effect of the obtained nanocarrier is better than that of other preparation methods.

[0015] Preferably, the reaction temperature in step (1) is 60-80°C, for example, 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, etc., preferably 64.1-65.9°C, and the reaction time is 20-30h, for example, 20h, 21h, 22h, 23h, 24h, 25h, 26h, 27h, 28h, 29h, 30h, etc.

[0016] Preferably, the molar ratio of succinic anhydride to poloxamer 188 in step (1) is (1-3):(1-3).

[0017] Specific numerical values in the above (1-3) include 1, 1.2, 1.5, 1.7, 2, 2.2, 2.5, 2.7, 3, etc.

[0018] Preferably, the solvent in step (1) comprises tetrahydrofuran.

[0019] Preferably, the reaction in step (1) further includes removing the solvent and drying.

[0020] Preferably, the reaction temperature in step (2) is 15-30°C, for example, 15°C, 17°C, 20°C, 22°C, 25°C, 27°C, 30°C, etc., preferably 20.1-21.9°C, and the reaction time is 3-6h, for example, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, etc., preferably 241-269min.

[0021] Preferably, the molar ratio of F68-SA, NHS, EDC and triethylamine in step (2) is (60-70):(2-6):(2-6):(2-4).

[0022] The specific numerical values in the above (60-70) include 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, etc.

[0023] Specific numerical values in the above (2-6) include 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, etc.

[0024] Specific numerical values in the above (2-4) include 2, 2.2, 2.5, 2.7, 3, 3.2, 3.5, 3.7, 4, etc.

[0025] Preferably, the solvent in step (2) comprises dimethyl sulfoxide.

[0026] Preferably, the reaction temperature in step (3) is 15-40°C, for example, 15°C, 17°C, 20°C, 22°C, 25°C, 27°C, 30°C, 32°C, 35°C, 37°C, 40°C, etc., preferably 20.1-21.9°C, and the reaction time is 60-90h, for example, 60h, 62h, 65h, 67h, 70h, 72h, 75h, 77h, 80h, 82h, 85h, 87h, 90h, etc., preferably 85.1-86.9h.

[0027] Preferably, the molar ratio of the polyamidoamine to poloxamer 188 is (60-70):(0.5-1.5).

[0028] The specific numerical values in the above (60-70) include 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, etc.

[0029] Specific numerical values in the above (0.5-1.5) include 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc.

[0030] Preferably, step (3) further includes drying after the reaction.

[0031] Preferably, the drying method includes freeze-drying.

[0032] Preferably, purification is further included before drying.

[0033] Preferably, the purification method comprises dialysis.

[0034] Preferably, the drug comprises doxorubicin.

[0035] In a second aspect, the present invention provides a method for preparing the blood-brain barrier-targeted drug delivery system as described in the first aspect, the preparation method comprising: mixing the drug, the nanocarrier and the solvent, and reacting to obtain the drug.

[0036] Preferably, the reaction is carried out in the dark, the reaction temperature is 33-40°C, for example, 33°C, 34°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, etc., and the reaction time is 18-30h, for example, 18h, 20h, 22h, 24h, 26h, 28h, 30h, etc.

[0037] Preferably, the molar ratio of the drug to the nanocarrier is (5-20):1, preferably (8-12):1.

[0038] Specific numerical values in the above (5-20) include 5, 6, 7, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc.

[0039] When the molar ratio of the drug to the nanocarrier is (8-12):1, the comprehensive results of drug encapsulation efficiency and drug loading are better.

[0040] Preferably, the solvent comprises methanol.

[0041] Preferably, the reaction further includes removing the solvent and purification.

[0042] Preferably, the purification method comprises dialysis.

[0043] In a third aspect, the present invention provides use of the blood-brain barrier-targeted drug delivery system as described in the first aspect in preparing a drug delivery system for treating brain glioma.

[0044] The numerical range described in the present invention includes not only the point values listed above, but also any point values between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] This invention creatively creates a nanocarrier by simply modifying the PAMAM-NH2 surface with Pluronic F68, simultaneously endowing the carrier with multiple functionalities: ① long circulation; ② high safety and biocompatibility; ③ inhibition of the passive physical barrier of the BBB and weakening of the active barrier of the BBB; and ④ significant enhancement of cellular drug uptake and sustained release. This nanocarrier is simple in design, low in cost, and more suitable for clinical application, providing new insights into the design of intelligent nano-drug delivery systems for treating gliomas.

[0047] After being encapsulated in PAMAM-F68, the drug can target the scavenger receptors of bEnd.3 cells by adsorbing Apo A-Ⅰ via Pluronic F68, thereby increasing the uptake of PAMAM-F68 by bEnd.3 cells. The drug, encapsulated in PAMAM-F68, successfully crosses the BBB barrier and exerts an anti-proliferative effect on C6 cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is the result of the in vitro BBB crossing experiment of nanocarriers. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0050] In the following examples, unless otherwise specified, all reagents and consumables were purchased from conventional reagent manufacturers in the field; unless otherwise specified, the experimental methods and technical means used were conventional methods and means in the field.

[0051] Example 1

[0052] In this example, nanocarrier PAMAM-F68 (PAMAM-NH2-Pluronic F68), ie, Pluronic F68-modified PAMAM, was synthesized.

[0053] 1. Weigh 0.05 g of succinic anhydride (SA, 0.5 mmol) and 4.15 g of Pluronic F68 (0.5 mmol, purchased from Aladdin), dissolve them in 20 mL of anhydrous tetrahydrofuran in a 100 mL round-bottom flask (molar ratio SA:F68 = 1:1.5), add 3 drops of triethylamine as a catalyst, and reflux with stirring at 65°C for 28 h.

[0054] 2. After the reaction is completed, cool and remove the solvent by rotary evaporation under reduced pressure, and add 20 mL of distilled water to fully dissolve the product.

[0055] 3. Divide the above solution into two portions and transfer them into two dialysis bags (MWCO=1000) using a disposable dropper. Purify and dialyze them with distilled water in a 1000 mL beaker for 48 h.

[0056] 4. After dialysis, sprinkle PEG10000 (polyethylene glycol, purchased from Macklin) on the dialysis bag to concentrate the liquid in the bag to about 10 mL. The concentrated liquid is then divided into vials (approximately 2 mL per vial), pre-frozen at -20°C for about 2 hours, then refrigerated at -80°C overnight, and lyophilized for 48 hours to obtain a white powder, which is Pluronic F68-SA.

[0057] 5. Weigh 1.8685 g of Pluronic F68-SA, 0.0012 g of NHS (N-hydroxysuccinimide), and 0.0015 mL of triethylamine into a round-bottom flask, add 20 mL of anhydrous dimethyl sulfoxide (DMSO), and then dissolve 0.002 g of EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide) in 2 mL of anhydrous DMSO. Then add the dissolved EDC solution to a mixed solution of Pluronic F68-SA, NHS, and triethylamine (molar ratio Pluronic F68:NHS:EDC:triethylamine = 64:3:3:3, where the ratio of NHS to EDC can be appropriately increased). Stir the reaction in a water bath at 21°C for 250 min to activate the carboxyl groups.

[0058] 6. Take 307.5 μL of PAMAM-NH2 solution (methanol as solvent, containing 50 mg PAMAM-NH2, PAMAM-NH2-G4.0 purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.) into a vial, evaporate the methanol, then add 3 mL of anhydrous DMSO to dissolve it, then aspirate it with a syringe and slowly add it dropwise to the activated product obtained in step 5 (molar ratio PluronicF68:PAMAM-NH2=64:1), and stir at 21°C for 86 h.

[0059] 7. Divide the solution obtained in step 6 above into two portions, transfer them into two dialysis bags (MWCO = 10,000, the dialysis bags need to be cut and activated in advance: boil them in boiling water for 15 minutes and let them cool before use) using a disposable dropper, and dialyze them against distilled water for 3 days.

[0060] 8. Then sprinkle PEG10000 on the dialysis bag to concentrate the liquid in the bag to about 10 mL. Then divide the concentrated liquid into vials, pre-freeze at -20°C for about 2 hours, and then freeze in a -80°C refrigerator overnight. Freeze for 48 hours to obtain a white solid, which is PAMAM-NH2-Pluronic F68.

[0061] Example 2 - Safety of PAMAM-NH2-Pluronic F68

[0062] The anti-proliferation ability of the vector on C6 cells was investigated by CCK-8 assay. 100 mL of C6 cells in the logarithmic growth phase were taken and 8×10 3Cells were seeded at a density of 100 cells / well in a 96-well plate and incubated in a 5% CO2, 37°C incubator for 24 hours. The blank vector PAMAM-NH2 and PAMAM-NH2-PluronicF68 were diluted to different concentrations (1, 5, 10, 50, 100, 500, and 1000 mg / mL) in culture medium and sterilized by filtration through a 0.22 μm microporous filter. 100 mL of each solution was pipetted into the wells, and six replicate wells were prepared. A control group received 100 mL of DMEM culture medium, and a cell-free group served as a blank control. The cells were incubated in a 5% CO2, 37°C incubator for 48 hours. At the end of the time, 10 mL of CCK8 reagent was added to each well, and the cells were incubated for another 2 hours. The absorbance (OD) was measured at 450 nm using a microplate reader. The effects of different concentrations of PAMAM-NH2 and PAMAM-NH2-PluronicF68 on the in vitro cell viability of C6 cells were calculated using the cell viability calculation formula. IC50 values were calculated using GraphPad Prism 5 software.

[0063] The results showed that cell survival decreased with increasing PAMAM-NH2 concentration over 48 hours, reaching 50% at 117.2 mg / mL. Within 48 hours, cell survival remained around 100% with increasing PAMAM-NH2-Pluronic F68 concentration, indicating that PAMAM-NH2-Pluronic F68 concentrations between 1 and 1000 mg had no significant killing effect on cells.

[0064] Example 3 - Investigation of the Adsorption Capacity of PAMAM-NH2-Pluronic F68 on Apo A-Ⅰ

[0065] (1) Drawing of standard curve

[0066] Accurately measure 100 μL of each Apo A-I standard solution at concentrations of 0, 1.4, 4, 12, 37, and 111 ng / mL and add it to the ELISA plate. Follow the procedure described under "Determination of Apo A-I Content" and plot the absorbance (OD) as the abscissa against the Apo A-I concentration (C) as the ordinate to generate a standard curve. Prepare a 2 mg / mL PAMAM-NH2-Pluronic F68 colloidal solution. Accurately measure 100 μL of this PAMAM-NH2-Pluronic F68 colloidal solution and incubate it with 100 μL of the 12 ng / mL, 37 ng / mL, and 111 ng / mL Apo A-I standard solutions, respectively, at 37°C for 3 h. After the incubation, all the liquid was transferred to an ultrafiltration tube and centrifuged at 10,000 r / min for 10 min. The liquid separated from the ultrafiltration membrane (containing Apo A-Ⅰ not adsorbed by the preparation) was taken and operated according to the "Determination of Apo A-Ⅰ Content" item. The OD value was recorded and inserted into the standard curve to calculate the concentration of unadsorbed Apo A-Ⅰ. Finally, the adsorption rate of Apo A-Ⅰ by PAMAM-NH2-Pluronic F68 micelles was calculated.

[0067] (2) Determination of Apo A-Ⅰ content

[0068] 100 μL of standard or test sample was added to each well of the enzyme-labeled plate in sequence, gently shaken to mix, covered with a plate sticker, incubated at 37°C for 60 minutes, discarded the liquid in the well, dried, and washed 3 times with 200 μL / well of washing solution, soaking for 2 minutes each time, and dried. 100 μL of horseradish peroxidase marker (HRP) working solution was added to each well, gently shaken to mix, covered with a plate sticker, incubated at 37°C for 60 minutes, discarded the liquid in the well, dried, and washed 5 times according to the above method and dried. Then 90 μL of substrate solution was added to each well in sequence, and color was developed at 37°C in the dark for 20 minutes. Finally, 50 μL of stop solution was added to each well in sequence to terminate the reaction. Within 5 minutes after the reaction was terminated, the optical density (OD value) of each well was measured in sequence at a wavelength of 450 nm using an enzyme labeler.

[0069] The results showed that the adsorption rates of PAMAM-NH2-Pluronic F68 micelles for 12 ng / mL, 37 ng / mL and 111 ng / mL ApoA-Ⅰ were 88%, 96% and 97%, respectively, indicating that PAMAM-NH2-Pluronic F68 micelles have a high adsorption rate for Apo A-Ⅰ. The connection of Pluronic F68 to the PAMAM-NH2 surface does not affect the adsorption of Pluronic F68 on Apo A-Ⅰ, and it can be used as a carrier to achieve BBB targeting.

[0070] Example 4 - Synthesis of the drug system PAMAM-F68-DOX

[0071] DOX (doxorubicin) free stock solution: Weigh 5 mg of doxorubicin hydrochloride, add an appropriate amount of 10 mL of methanol and acetone (1:1, v / v) mixed solvent to dissolve, add 25 μL of triethylamine, stir at room temperature for 12 h, remove the hydrochloride, and remove the solvent and excess triethylamine by rotary evaporation at 37°C. Redissolve with an appropriate amount of organic solvent (methanol) to prepare a DOX free stock solution with a concentration of 1 mg / mL.

[0072] Accurately measure an appropriate amount of dehydrochlorinated DOX free stock solution into a 50 mL round-bottom flask. Weigh the appropriate amount of PAMAM-F68 polymer (to achieve a molar ratio of 1:10) into an appropriate amount of methanol solution. Add this to the round-bottom flask and stir at 37°C in the dark for 24 hours. Remove the organic solvents triethylamine and methanol under reduced pressure (rotary evaporation). Add a small amount (5 mL) of distilled water to fully hydrate and dissolve the solution. Remove unencapsulated free drug (NWCO = 1000D) by dialysis. Dialysis against distilled water for 12 hours is performed to obtain the drug system PAMAM-F68-DOX.

[0073] Example 5 - In vitro trans-BBB effect of PAMAM-NH2-F68

[0074] (1) Construction of the BBB model

[0075] Rat brain microvascular endothelial cells bEnd.3 were cultured at a rate of 1×10 5 Cells were cultured in Millicell suspension cell culture inserts for one week, with the medium changed every other day. 0.5 mL of cell suspension was added to each well of the donor reservoir, and 1.5 mL of fresh culture medium was added to each well of the receiver reservoir. The transmembrane electrical resistance (TEER) of the BBB model was measured using a Millcell@-ERS resistance meter, with a TEER greater than 200 Ω / cm selected. 2 The following experiments were performed in the upper chamber of the Transwell. C6 cells were plated at 5×10 5 The cells were seeded into another 6-well plate at a density of 100 cells / well and cultured for 24 hours. 2 The upper chamber of the Transwell was transferred to the wells plated with C6 cells and co-cultured for 24 hours to establish an in vitro bEnd.3-C6 co-culture model.

[0076] (2) Leakage test

[0077] Models with complete cell fusion under microscopy were selected as the experimental group, while a donor well without cell inoculation served as the blank control group. At the start of the test, culture medium was added to the cell inserts and corresponding wells of the multi-well plate (receiver well) of the model, ensuring that the liquid level in the donor well was 0.5 cm higher than that in the receiver well. The cells were placed in a 37°C incubator and the liquid level was observed after 0, 2, and 4 hours. A positive leakage test was considered if the difference between the internal and external liquid levels remained unchanged; otherwise, it was considered negative.

[0078] (3) Investigation of carrier transport efficiency across the BBB

[0079] 1 mL of nanocarrier (PAMAM-F68-DOX) or nanocarrier + Apo A-Ⅰ (PAMAM-F68-DOX + Apo A-Ⅰ) was added to the upper layer of the transwell chamber. 200 μL of the culture medium was sampled from the lower layer at 0.5, 1, 2, 4, 6, and 12 hours, and the lower layer medium solution was replenished with PBS. The fluorescence intensity of the nanocarrier before addition and the fluorescence intensity of the sampled lower layer were measured using a fluorescence spectrophotometer. The percentage of blood-brain barrier crossing was calculated according to the following formula.

[0080] Transport efficiency (%) = (fluorescence intensity of culture medium in transwell receptor / fluorescence intensity of nanoparticle solution before administration) × 100%.

[0081] See the results Figure 1 The trans-BBB transport efficiency of both PAMAM-F68-DOX and PAMAM-F68-DOX+Apo A-Ⅰ was time-dependent, but differences in transport efficiency between the two groups were observed over time. Within 2 hours, the transport efficiency of the PAMAM-F68-DOX+Apo A-Ⅰ group increased slightly compared to the PAMAM-F68-DOX group, but the difference was not significant. Between 4 and 12 hours, the transport efficiency of the PAMAM-F68-DOX+Apo AI group increased significantly, differing significantly from the PAMAM-F68-DOX group. This suggests that PAMAM-F68 can enhance trans-BBB transport efficiency by specifically binding to scavenger receptors on bEnd.3 cells after adsorbing Apo AI.

[0082] Example 6 - Investigation of the in vivo targeting effect of PAMAM-NH2-F68

[0083] A C6 glioma-bearing mouse model was established and randomly divided into two groups. Equal doses of DiR@PAMAM and DiR@PAMAM-F68 were injected via the tail vein. The distribution of DiR@PAMAM and DiR@PAMAM-F68 in the mice was analyzed using an in vivo imaging system 4, 12, 24, and 48 hours after injection.

[0084] The results showed that the intensity of the fluorescence signal in the brain of the DiR@PAMAM-F68 group was stronger than that of the DiR@PAMAM group, indicating that DiR@PAMAM-F68 adsorbs Apo A-Ⅰ in the blood and binds to scavenger receptors on the BBB, thereby crossing the BBB and reaching the tumor site. Over time, the fluorescence signal at the glioma site in the DiR@PAMAM-F68 group gradually increased, and its intensity remained higher than that of the DiR@PAMAM group, indicating that Pluronic F68 has a good ability to adsorb Apo A-Ⅰ and target the BBB.

[0085] Tumor-bearing mice were treated with PAMAM-F68-DOX and PAMAM–DOX respectively. The results showed that, in comparison, PAMAM-F68-DOX could significantly reduce tumor volume and prolong mouse survival time, indicating that using PAMAM-F68 as a nanocarrier can significantly improve the therapeutic effect of the drug delivery system for brain glioma.

[0086] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate a drug delivery system targeting the blood-brain barrier, its preparation method, and its application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary ingredients, selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

[0087] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0088] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. Application of a drug delivery system targeting the blood-brain barrier in the preparation of a drug delivery system for treating gliomas. The blood-brain barrier-targeted drug delivery system comprises a nanocarrier and a drug, wherein the nanocarrier comprises a polyamidoamine modified with poloxamer 188; The drug is doxorubicin; The poloxamer 188-modified polyamidoamine is prepared by a preparation method comprising the following steps: (1) Succinic anhydride, poloxamer 188, a solvent and a catalyst, triethylamine, are mixed to react to obtain F68-SA; (2) F68-SA, NHS, EDC, triethylamine and a solvent are mixed and reacted to activate the carboxyl group to obtain an activated product; (3) Mixing the polyamide-amine with the activated product and reacting them to obtain the product.

2. The use according to claim 1, characterized in that The reaction temperature in step (1) is 60-80° C., and the reaction time is 20-30 h.

3. The use according to claim 2, characterized in that The molar ratio of succinic anhydride to poloxamer 188 in step (1) is (1-3):(1-3); The solvent in step (1) comprises tetrahydrofuran; After the reaction in step (1), the solvent is removed and dried.

4. The use according to claim 3, characterized in that The reaction temperature in step (2) is 15-30° C., and the reaction time is 3-6 h; In step (2), the molar ratio of F68-SA, NHS, EDC and triethylamine is (60-70):(2-6):(2-6):(2-4); The solvent in step (2) includes dimethyl sulfoxide.

5. The use according to claim 4, characterized in that The reaction temperature in step (3) is 15-40° C., and the reaction time is 60-90 h; The molar ratio of the polyamidoamine to poloxamer 188 is (60-70):(0.5-1.5); After the reaction in step (3), drying is also included; The drying method includes freeze-drying; The drying step also includes purification; The purification method includes dialysis.

6. The use according to claim 1, wherein The preparation method of the drug delivery system targeting the blood-brain barrier comprises: mixing the drug, the nanocarrier and the solvent, and reacting them to obtain the drug.

7. The use according to claim 6, characterized in that The reaction is carried out in the dark at a temperature of 33-40° C. for 18-30 h.

8. The use according to claim 6 or 7, characterized in that The molar ratio of the drug to the nanocarrier is (5-20):

1.

9. The use according to claim 8, characterized in that The molar ratio of the drug to the nanocarrier is (8-12):1; The solvent includes methanol; The reaction also includes removing the solvent and purifying; The purification method includes dialysis.

Images