Brush-like polymer polypeptide drug delivery system as well as preparation method and application thereof

Abstract

The invention discloses a brush-like polymer polypeptide drug delivery system and a preparation method and application thereof, and belongs to the technical field of polymer chemistry and biological medicines.The brush-like polymer polypeptide drug delivery system is obtained by a click reaction or a cycloaddition reaction of a polydisulfide main chain, a modified polypeptide drug and a polybetaine polymer, through the unique brush-shaped structure of the brush-shaped polymer, the polypeptide drug can be effectively protected from being degraded for a long time, the transmembrane transport and permeability of the polypeptide drug are improved, the technical scheme provides a new solution for clinical application of the polypeptide drug, and the polypeptide drug can be used for treatment of various diseases, especially diabetes mellitus or research and development of vaccines.

Description

Technical Field

[0001] The present invention relates to the field of polymer chemistry and biomedicine technology, and in particular to a brush polymer polypeptide drug delivery system and a preparation method and application thereof. Background Art

[0002] Diabetes mellitus is a major chronic disease that poses a serious threat to human health. Type 2 diabetes (T2DM) accounts for the majority of cases and is the predominant form of diabetes. It is generally caused by defects in insulin secretion and / or action. Typical symptoms of T2DM are polyuria, polydipsia, polyphagia, and weight loss: polyuria, polydipsia, polyphagia, and weight loss. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are an important clinical treatment for T2DM. They activate the GLP-1 receptor, enhancing insulin secretion and inhibiting glucagon secretion in a glucose-dependent manner, thereby lowering blood glucose. They have garnered widespread attention due to their remarkable efficacy and high safety profile. However, all currently marketed GLP-1RAs are peptide drugs that are rapidly degraded in vivo by dipeptidyl peptidase IV (DPP-IV), resulting in a short half-life and significantly limiting their clinical utility. Furthermore, most GLP-1 analogs can only be administered via injection, and their frequent gastrointestinal side effects and low bioavailability significantly impact patient compliance.

[0003] Drug delivery systems, through the rational design of specific carriers (such as lipid nanoparticles, polymer carriers, and self-opening capsules), achieve precise drug release, enhanced efficacy and reduced toxicity, and targeted therapy, and have broad application prospects in the pharmaceutical field. Drug delivery systems can effectively protect peptide drugs from enzymatic degradation and significantly improve their penetration efficiency in gastrointestinal epithelial cells.

[0004] Chinese patent document with publication number CN116173188A discloses oral GLP-1 analog solid lipid nanoparticles, their preparation method and application. The oral GLP-1 analog solid lipid nanoparticles of the invention are made from a GLP-1 analog, a first lipid material and a second lipid material by a solvent diffusion method. The first lipid material is at least one of monostearate glyceryl, distearate glyceryl, stearic acid, oleic acid, octadecanol and behenate glyceryl, and the second lipid material is at least one of a cationic lipid, a zwitterionic lipid or an ionizable cationic lipid. The solid lipid nanoparticles can protect the GLP-1 analog from gastrointestinal damage.

[0005] Chinese patent document publication number CN106729717A discloses a sustained-release microsphere preparation of a GLP-1 analog and ziconotide combination, which comprises a GLP-1 analog, ziconotide, a biodegradable and biocompatible polymer material, a stabilizer, and a lyoprotectant. The combined use of a GLP-1 analog and ziconotide can effectively treat diabetes and its PDN complications.

[0006] Although current mainstream peptide delivery systems (such as liposomes, hydrogels, etc.) have made significant progress, polymer GLP-1 peptide delivery systems constructed based on covalent bond forces are still a blank area. Summary of the Invention

[0007] In response to the problems in the existing technology, such as poor water solubility, large toxic side effects, and poor pharmacokinetics of polypeptide drugs, the present invention provides a brush polymer polypeptide drug delivery system. Through the unique brush-like structure of the brush polymer, it can effectively protect polypeptide drugs and enhance cell permeability, providing a new solution for the clinical application of polypeptide drugs.

[0008] The specific technical solutions adopted are as follows:

[0009] A brush polymer polypeptide drug delivery system is obtained by a click reaction or cycloaddition reaction between a polydisulfide backbone, a modified polypeptide drug, and a polybetaine polymer;

[0010] The structural formula of the polydisulfide main chain is:

[0011]

[0012] Wherein, x is an integer of 1-500, y is an integer of 1-2000, and z is an integer of 1-1000; R2 is a quencher residue, and R3 is selected from any one of the following structural formulas: Indicates the connection location;

[0013]

[0014] R1 and R3 are the same, or are methyl or methoxy;

[0015] The amino acid side chain of the modified polypeptide drug is modified with a reactive group X, which is a functional group capable of undergoing a click reaction or a cycloaddition reaction with R1 or R3;

[0016] The structural formula of the polybetaine polymer is:

[0017]

[0018] wherein n is an integer from 1 to 500, and A is a chain transfer agent residue;

[0019] The reactive group X in the modified polypeptide drug and R in the polybetaine polymer are independently selected from any one of the following structural formulas;

[0020]

[0021] Indicates the connection location.

[0022] The present invention designs a structural design for a polypeptide drug delivery system. Through the reaction between a polydisulfide backbone, a modified polypeptide drug (with reactive groups modified on the amino acid side chains) and a polybetaine polymer, a large number of short side chains are grafted onto the long backbone to form a high-density "brush-like" structure in which the polypeptide drug is encapsulated, thereby improving the stability of the polypeptide drug. The polybetaine polymer in the side chain greatly enhances the water solubility and transmembrane transport ability.

[0023] Preferably, when the polydisulfide backbone, the modified polypeptide drug and the polybetaine polymer undergo a click reaction or a cycloaddition reaction, the molar ratio is 1:1-20:1-200.

[0024] Preferably, the polypeptide drug is GLP-1 (the terminal amino acid residue is a thiol group).

[0025] The present invention also provides a method for preparing the brush-like polymer polypeptide drug delivery system, comprising: in an organic solvent system, first subjecting a polydisulfide backbone and at least one modified polypeptide drug to a click reaction or a cycloaddition reaction, and then adding a polybetaine polymer to undergo a click reaction or a cycloaddition reaction to prepare the brush-like polymer polypeptide drug delivery system; when the click reaction occurs, the reaction conditions are 0-60°C for 2-48 hours, and when the cycloaddition reaction occurs, the reaction conditions are 25-100°C for 1-72 hours.

[0026] Specifically, the polydisulfide main chain can be synthesized according to the description in Chinese patent document CN118557742A. When synthesizing the polydisulfide main chain, the quencher includes 2,2,2-trifluoroethyl acrylate.

[0027] Furthermore, the preparation method of the modified polypeptide drug includes: in an organic solvent system, using a compound containing a maleimide group and a reactive group X to undergo a nucleophilic addition reaction with the polypeptide drug to obtain the modified polypeptide drug.

[0028] Preferably, the conditions of the nucleophilic addition reaction are 20-40° C. and 0.5-72 h.

[0029] Furthermore, the preparation method of the polybetaine polymer comprises: in an organic solvent system, using dimethylaminoethyl methacrylate and a compound containing a halogen and a carboxyl protecting group to carry out a nucleophilic substitution reaction to obtain a first intermediate; then using a chain transfer reagent, an initiator, and the first intermediate to carry out a reversible addition-fragmentation chain transfer polymerization reaction to obtain a second intermediate; removing the carboxyl protecting group of the second intermediate and further exposing the thiol group, and then carrying out a nucleophilic addition reaction with a compound containing a maleimide group and a reactive group R to prepare the polybetaine polymer.

[0030] Preferably, when preparing the first intermediate, the conditions of the nucleophilic substitution reaction are 20-40° C., 0.5-72 h.

[0031] Preferably, when preparing the second intermediate, the reversible addition-fragmentation chain transfer polymerization reaction is carried out at 70-80° C. for 6-12 hours.

[0032] Optionally, the chain transfer reagent can be any one of 4-cyano-4-(thiobenzoyl)pentanoic acid, 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid, 4-((((2-carboxyethyl)thio)thiocarbonyl)thio)-4-cyanopentanoic acid, 4-cyano-4-[[(propylthio)thiomethyl]thio]pentanoic acid, 2-(ethylmercaptothioformylthio)-2-methylpropionic acid, 4-cyano-4-(((ethylthio)thiocarbonyl)thio)pentanoic acid, etc.

[0033] Optionally, the initiator includes azobisisobutyronitrile and azobisisoheptanenitrile.

[0034] Preferably, trifluoroacetic acid is used to remove the carboxyl protecting group of the second intermediate, and n-propylamine is added to remove the thiocarbonyl group to expose the sulfhydryl group.

[0035] Preferably, when preparing the polybetaine polymer, the conditions for the nucleophilic addition reaction are 20-40° C. and 0.5-72 h.

[0036] The present invention also provides the use of the brush polymer polypeptide drug delivery system in the preparation of disease treatment products, including but not limited to diabetes treatment products.

[0037] The present invention also provides the use of the brush-like polymer polypeptide drug delivery system in the preparation of disease prevention products.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The drug delivery system provided by the present invention can efficiently deliver polypeptide drugs with poor water solubility and difficulty entering cells into cells. It innovatively utilizes brush-like polymers to control the release of polypeptide drugs, improve the stability of polypeptide drugs, and extend their half-life. The process route for the synthesis of this drug delivery system has not been reported in the prior art.

[0040] (2) The method of the present invention utilizes covalent bonding to graft the modified polypeptide drug onto the polydisulfide backbone, which has a strong binding force. The introduction of polybetaine polymer not only protects the polypeptide drug in terms of spatial structure, but also improves the overall water solubility and reduces immunogenicity, thereby avoiding immune clearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Polydisulfide backbone PLA 100 In CDCl3 1 H-NMR spectrum (400 MHz).

[0042] Figure 2 The first intermediate CB-TBU in CDCl3 1 H-NMR spectrum (400 MHz).

[0043] Figure 3 The second intermediate P(CB-TBU) 50 In D2O 1 H-NMR spectrum (400 MHz).

[0044] Figure 4 The third intermediate PCB 50 In D2O 1 H-NMR spectrum (400 MHz).

[0045] Figure 5 Polybetaine polymer DBCO-PCB 50 In D2O 1 H-NMR spectrum (400 MHz).

[0046] Figure 6 This is the mass spectrum of the modified peptide drug GLP-1-DBCO.

[0047] Figure 7 Brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Zeta potential test results and average hydrated diameter and its distribution statistics.

[0048] Figure 8 are polydisulfide backbone and PLA 100 Polydisulfide backbone PLA coupled to GLP-1100 -GLP-1, brush-like polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Infrared spectrum of .

[0049] Figure 9 For peptide drug GLP-1 and brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Diagram of enzymatic digestion in a pancreatic environment.

[0050] Figure 10 For peptide drug GLP-1 and brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Degradation curve in pancreatic enzyme environment.

[0051] Figure 11 For peptide drug GLP-1 and brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Confocal microscopy of entry into human colorectal adenocarcinoma (Caco-2) cells.

[0052] Figure 12 Brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Flow cytometric plot of entry into human colorectal adenocarcinoma (Caco-2) cells.

[0053] Figure 13 Brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Diagram of transmembrane transport in the Caco-2 model.

[0054] Figure 14 Brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Results of subcutaneous injection in mice. DETAILED DESCRIPTION

[0055] The present invention will be further described below with reference to the following examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0056] Example 1

[0057] (1) Synthesis of polydisulfide backbone

[0058]

[0059] Thioctic acid (15.0 g, 72.5 mmol, 1 eq) was added to a 500 mL round-bottom flask, and 100 mL of tetrahydrofuran (THF) was added under nitrogen protection to dissolve the mixture. 100 mL of dichloromethane solution containing N, N'-carbonyldiimidazole (CDI) (12.85 g, 80.2 mmol, 1.1 eq) and 4-dimethylaminopyridine (DMAP) (0.9 g, 72.38 mmol, 1.0 eq) was slowly added dropwise under ice bath conditions, and the mixture was naturally warmed to room temperature. After stirring for half an hour, 3-azidopropanol (7.32 g, 72.5 mmol, 1 eq) was added, and then the reaction was allowed to react at room temperature for 16 h. 150 mL of saturated brine was added to the reaction solution for washing and extraction, which was repeated three times. A certain amount of anhydrous sodium sulfate was added to the obtained organic phase, dried, filtered, and concentrated under reduced pressure to obtain a crude product. The crude product was separated and purified by silica gel column chromatography (petroleum ether: dichloromethane = 3:1) to obtain a yellow viscous liquid thioctic acid derivative monomer (17.81 g, yield 85.1%).

[0060]

[0061] The lipoic acid derivative monomer (878.6 mg, 3.04 mmol, 1 eq) synthesized in the above steps was placed in a 2 mL sample vial, and tetramethylguanidine (5.5 μL, 0.04 mmol, 0.0125 eq) was added and mixed thoroughly. Then, 100 μL of ultra-dry THF solution of azidopolyethylene glycol thiol (N3-PEG2000-SH) (86.9 mg, 0.04 mmol, 0.0125 eq) was added to the reaction solution. After stirring at room temperature and the reaction reached the target degree of polymerization, 100 μL of THF solution of 2,2,2-trifluoroethyl acrylate (101 μL, 0.80 mmol, 0.125 eq) was added thereto. After stirring the reaction for 1 h, the reaction solution was repeatedly precipitated in ice ether three times and vacuum dried to obtain a polydisulfide backbone (PLA 100 , 715 mg, 74% yield), which in CDCl3 1 H-NMR spectrum (400MHz) Figure 1 shown.

[0062] (2) Synthesis of polybetaine polymer

[0063]

[0064] Dimethylaminoethyl methacrylate (786 mg, 5 mmol) was placed in a 50 mL flask equipped with a magnetic stirring bar, and 20 mL of anhydrous acetonitrile was added. Under ice bath conditions, tert-butyl bromoacetate (1072.5 mg, 5.5 mmol) was slowly added. The ice bath was removed and the mixture was stirred at 25 ° C for 20 h. The reaction progress was monitored by TLC and concentrated under reduced pressure to obtain a concentrate. The concentrate was precipitated with 3×30 mL of cold ether and dried in vacuo to obtain the first intermediate (CB-TBU, 1.2 g, yield 88.2%). 1 H-NMR spectrum (400MHz) Figure 2 shown.

[0065]

[0066] The polymer was constructed using the first intermediate as a monomer by reversible addition-fragmentation chain transfer polymerization (RAFT). The first intermediate CB-TBU (1088.8 mg, 4.0 mmol) was weighed and added to a 5.0 mL glass vial equipped with a magnetic stirring bar. 1 mL of anhydrous N,N-dimethylformamide was then added, followed by 4-cyano-4-(phenylthiocarbamoylthio)pentanoic acid (22.4 mg, 0.08 mmol) and azobisisobutyronitrile (AIBN, 1.31 mg, 0.008 mmol). Under a N2 atmosphere, the mixture was purged for 20 minutes and then sampled at the origin. In a nitrogen-filled glove box, the mixture was stirred at 70°C for 6.5 hours, and the color was observed to change from pink to deep red. The reaction progress was monitored by NMR. The concentrate was concentrated under reduced pressure, precipitated with 3×30 mL of cold ether, and dried in vacuo to obtain the pink second intermediate (P(CB-TBU) 50 , 1032 mg, 93% yield), the second intermediate in D2O 1 H-NMR spectrum (400MHz) Figure 3 shown.

[0067]

[0068] Weigh the second intermediate P(CB-TBU) 50 (1000 mg) was added to a 20.0 mL glass vial equipped with a magnetic stirring bar, and then 6 mL of trifluoroacetic acid (TFA) was added. The reaction was stirred at 25 ° C in a fume hood for 6.0 hours. The color was observed to change from dark red to brown. The reaction progress was monitored by NMR. After the reaction was completed, the concentrate was concentrated under reduced pressure to obtain a concentrate, and 1 M sodium carbonate (Na2CO3) solution was added thereto until no bubbles were generated. After 24 hours of dialysis in ultrapure water using a dialysis membrane with a molecular weight cutoff (MWCO: 3000), the pink third intermediate (PCB) was obtained after freeze-drying. 50, 769 mg, 97% yield), the third intermediate in D2O 1 H-NMR spectrum (400MHz) Figure 4 shown.

[0069]

[0070] Weigh the third intermediate PCB 50 (220 mg, 0.02 mmol) was added to a 5.0 mL glass vial equipped with a magnetic stirring bar, and then 1 mL of methanol and 1 mL of dimethyl sulfoxide were added, and n-propylamine (8.4 μL, 0.10 mmol) was added. In a nitrogen-filled glove box, the mixture was stirred at 25°C for 1.5 h, and the color was observed to change from pink to colorless. Then, 0.5 M tris(2-carboxyethyl)phosphine solution (80 μL, 0.04 mmol) was added to the above glass vial and stirred at 25°C for 0.5 h. DBCO-maleimide (42.7 mg, 0.10 mmol) shown in the above formula was weighed and transferred to the above glass vial. The mixture was stirred at 25°C for 12 h. A dialysis membrane with a molecular weight cutoff (MWCO: 1000) was used to prepare the polymer solution to an appropriate concentration and transferred to a dialysis bag. After dialysis in ultrapure water for 24 hours, the solution was freeze-dried to obtain a light yellow polybetaine polymer (DBCO-PCB) 50 , 207 mg, yield 89%). Polybetaine polymer in D2O 1 H-NMR spectrum (400MHz) Figure 5 shown.

[0071] (3) Synthesis of modified peptide drugs

[0072]

[0073] The DBCO-maleimide (10.12 mg, 23.7 μmol) and GLP-1 peptide (20 mg, 5.90 μmol) shown in the above formula were added to a 5.0 mL glass vial equipped with a magnetic stirring bar, and then anhydrous dimethyl sulfoxide was added. The mixture was stirred at 25°C for 5.0 h, precipitated with 3×10 mL of cold ether, and vacuum dried to obtain a modified peptide drug (GLP-1-DBCO, 18 mg, 82.3% yield) as a white solid. The mass spectrum of GLP-1-DBCO on matrix-assisted laser desorption tandem time-of-flight mass spectrometry is shown below. Figure 6 shown.

[0074] (4) Synthesis of brush polymer polypeptide drug delivery system

[0075]

[0076] Take the polydisulfide main chain PLA obtained in step (1) 100 (9.1 mg, 0.135 μmol, equivalent to 13.5 μmol of azide site moles) was added to a 2.0 mL epoxide tube, and then 0.30 mL of dimethyl sulfoxide was added. The functional group-modified peptide drug GLP-1-DBCO (5.0 mg, 1.35 μmol) in step (3) was dissolved in 0.30 mL of dimethyl sulfoxide and then transferred to the above epoxide tube. The reaction was carried out at a constant temperature of 60 ° C for 12.0 h to obtain a polydisulfide backbone PLA coupled to GLP-1. 100 -GLP-1 reaction solution.

[0077] Then take polybetaine polymer DBCO-PCB 50 (141 mg, 13.5 μmol) was dissolved in 0.8 mL of methanol and slowly added to the reaction solution containing the polydisulfide backbone coupled to GLP-1, and configured into a (MeOH: DMSO = 1: 1) reaction solution, which was shaken at a constant temperature at 60 ° C for 12.0 h. It was then dialyzed with ultrapure water for 24 hours (MWCO: 6000-8000 Da). A centrifugal filtration ultrafiltration tube (10 kDa) was used for further purification and concentration, and the operation was repeated three times. Freeze-dried to obtain the brush-like polymer polypeptide drug delivery system PLA 100 -GLP-1-PCB 50 (131 mg, 95.7% yield).

[0078] Sample analysis

[0079] (1) Performance characterization

[0080] Brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 The Zeta potential test results and the average hydrated diameter and its distribution statistics are shown in the figure below. Figure 7 As shown, its surface Zeta potential is 3.2mV, PLA 100 -GLP-1-PCB 50 The hydrated diameter is about 75 nm, and the surface potential of the nanoparticles is close to neutrality.

[0081] Polydisulfide backbone PLA 100 , polydisulfide backbone PLA coupled to GLP-1 100 -GLP-1 and brush-like polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 The infrared spectrum of Figure 8 As shown, according to the wave number of 2100cm -1The absorption intensity of the azide functional group at the α-D-type ... -1 The azide absorption peak at the position completely disappears, indicating that the brush polymer polypeptide drug delivery system PLA 100 -GLP-1-PCB 50 Successful preparation.

[0082] (2) Degradation experiment

[0083] Figure 9 Represents peptide drug GLP-1 and brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 The effect diagram of trypsin degradation experiment. Figure 10 The results show that the trypsin degradation curve of peptide drug GLP-1 can achieve more than 50% degradation within 5 minutes and 80% degradation within 1 hour under the action of trypsin. The brush polymer peptide drug delivery system PLA prepared by the present invention 100 -GLP-1-PCB 50 Under the action of trypsin, only 30% of the peptide was degraded within 2 hours, proving that the brush-like polymer polypeptide drug delivery system prepared by the present invention can protect the polypeptide drug from being degraded for a long time.

[0084] (3) Cell uptake experiment

[0085] Peptide drug GLP-1 and brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 Confocal microscopy images of human colorectal adenocarcinoma (Caco-2) cells Figure 11 As shown, the results show that the cellular uptake ability of the brush polymer polypeptide drug delivery system prepared by the present invention is significantly stronger than that of the polypeptide drug group.

[0086] Figure 12 Expression of human colorectal adenocarcinoma cells (Caco-2) on the brush-like polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 The results show that the brush-like polymer polypeptide drug delivery system PLA prepared by the present invention 100 -GLP-1-PCB 50 It can enter Caco-2 cells well, which proves that the brush polymer polypeptide drug delivery system prepared by the present invention has excellent polypeptide drug delivery ability.

[0087] (4) Transmembrane transport experiments

[0088] Human colorectal adenocarcinoma cells (Caco-2) were inoculated into transwell chambers to establish a Caco-2 cell model to simulate the intestinal epithelial barrier. Figure 13 Brush polymer peptide drug delivery system PLA 100 -GLP-1-PCB 50 The results showed that the brush polymer polypeptide drug delivery system PLA prepared by the present invention has a better ability to transport drugs across membranes than the blank group and the polypeptide drug group. 100 -GLP-1-PCB 50 It can well cross the membrane and enter the lower chamber. This proves that the brush-like polymer polypeptide drug delivery system prepared by the present invention improves the transmembrane transport and permeability of polypeptide drugs.

[0089] (5) Subcutaneous injection experiment in mice

[0090] Figure 14 The brush-like polymer polypeptide drug delivery system PLA prepared by the present invention 100 -GLP-1-PCB 50 The blood sugar lowering effect diagram of subcutaneous injection of C57BL / 6 mice shows that compared with the blank group and the peptide drug group, the blood sugar lowering effect of the same amount of drug is weaker than that of the peptide drug group, but significantly stronger than that of the blank group. 100 -GLP-1-PCB 50 When the drug dosage was doubled, the effect was significantly stronger than that of the polypeptide drug group, which proved the hypoglycemic effect of the brush-like polymer delivery system prepared by the present invention.

[0091] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A brush polymer polypeptide drug delivery system, characterized in that: It is obtained by a click reaction or cycloaddition reaction between a polydisulfide backbone, a modified polypeptide drug and a polybetaine polymer; The structural formula of the polydisulfide main chain is: Wherein, x is an integer of 1-500, y is an integer of 1-2000, and z is an integer of 1-1000; R2 is a quencher residue, and R3 is selected from any one of the following structural formulas: Indicates the connection location; R1 and R3 are the same, or are methyl or methoxy; The amino acid side chain of the modified polypeptide drug is modified with a reactive group X, which is a functional group capable of undergoing a click reaction or a cycloaddition reaction with R1 or R3; The structural formula of the polybetaine polymer is: wherein n is an integer from 1 to 500, and A is a chain transfer agent residue; The reactive group X in the modified polypeptide drug and R in the polybetaine polymer are independently selected from any one of the following structural formulas; Indicates the connection location.

2. The brush polymer polypeptide drug delivery system according to claim 1, characterized in that When the polydisulfide main chain, the modified polypeptide drug and the polybetaine polymer undergo a click reaction or a cycloaddition reaction, the molar ratio is 1:1-20:1-200.

3. The brush polymer polypeptide drug delivery system according to claim 1, characterized in that The polypeptide drug is GLP-1.

4. The method for preparing the brush polymer polypeptide drug delivery system according to any one of claims 1 to 3, characterized in that: include: In an organic solvent system, a polydisulfide backbone and at least one modified polypeptide drug first undergo a click reaction or a cycloaddition reaction, and then a polybetaine polymer is added to undergo a click reaction or a cycloaddition reaction to prepare the brush polymer polypeptide drug delivery system. When the click reaction occurs, the reaction conditions are 0-60° C. for 2-48 hours, and when the cycloaddition reaction occurs, the reaction conditions are 25-100° C. for 1-72 hours.

5. The method for preparing the brush polymer polypeptide drug delivery system according to claim 4, characterized in that: The preparation method of the modified polypeptide drug comprises: in an organic solvent system, using a compound containing a maleimide group and a reactive group X to undergo a nucleophilic addition reaction with the polypeptide drug to obtain the modified polypeptide drug.

6. The method for preparing the brush polymer polypeptide drug delivery system according to claim 5, characterized in that: When preparing the modified polypeptide drug, the conditions for the nucleophilic addition reaction are 20-40° C. and 0.5-72 h.

7. The method for preparing the brush polymer polypeptide drug delivery system according to claim 4, characterized in that: The preparation method of the polybetaine polymer comprises: in an organic solvent system, using dimethylaminoethyl methacrylate and a compound containing halogen and carboxyl protecting groups to carry out a nucleophilic substitution reaction to obtain a first intermediate; then using a chain transfer reagent, an initiator, and the first intermediate to carry out a reversible addition-fragmentation chain transfer polymerization reaction to obtain a second intermediate; removing the carboxyl protecting group of the second intermediate and further exposing the thiol group, and then carrying out a nucleophilic addition reaction with a compound containing a maleimide group and a reactive group R to prepare the polybetaine polymer.

8. The method for preparing the brush polymer polypeptide drug delivery system according to claim 7, characterized in that: When preparing the first intermediate, the conditions for the nucleophilic substitution reaction are 20-40° C., 0.5-72 h; and / or, when preparing the second intermediate, the conditions for the reversible addition-fragmentation chain transfer polymerization reaction are 70-80° C., 6-12 h; and / or, when preparing the polybetaine polymer, the conditions for the nucleophilic addition reaction are 20-40° C., 0.5-72 h.

9. Use of the brush polymer polypeptide drug delivery system according to any one of claims 1 to 3 in the preparation of a disease treatment product.

10. Use of the brush polymer polypeptide drug delivery system according to any one of claims 1 to 3 in the preparation of disease prevention products.

Images