A nano hydrogel based on histamine derivatives and its preparation and application method
Preparation of nanohydrogels by precipitation polymerization of acryloyl histamine derivatives solves the problems of limited number of functional monomers and difficulty in controlling drug release, and achieves efficient nanodrug delivery and stable drug release, showing the tumor cells Wide application prospects.
Patent Information
- Application Number
- CN202110854887.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-07-28
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2041-07-28
AI Technical Summary
The number of functional monomers in the existing nanohydrogel drug delivery system is limited, the preparation method is complex, and the addition of surfactants is required, and drug release control in tumor cells is difficult to achieve.
Acryloyl histamine derivatives are used as polymeric monomers to prepare biodegradable reduction-responsive nanohydrogels by precipitation polymerization, and the drug is controlled release using the protonation mechanism of imidazole groups in a weakly acidic environment.
The efficiency and stability of the nanodrug delivery system have been achieved, the drug loading and loading rate have been significantly improved, and the drug release control effect of nanohydrogels in tumor cells is good, showing a wide range of cancer diagnosis, treatment and treatment application prospects.
Smart Images
Figure BDA0003183768450000021 
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of medical polymer materials and chemical drugs, and specifically relates to a nano hydrogel based on histamine derivatives and a preparation and application method thereof. Background Art
[0002] Nano hydrogel material is a kind of polymer interpenetrating network system formed by internal covalently cross-linked polymer skeleton, which is uniformly dispersed in water without dissolving in water after absorbing water and swelling. It has great application value in biomedicine, chemistry and chemical engineering, and electronic information, and has been widely studied. Among them, the relationship between nano hydrogel material and biomedicine is the closest, and it is often used in the development of new drug delivery systems.
[0003] Studies have found that the concentration of glutathione in tumor cells is 5 to 10 times that of normal cells and thousands of times that of glutathione in the blood. Taking advantage of this special environment in tumor cells, the research on reduction-sensitive drug carriers for intracellular targeted drug release has always attracted much attention. At present, the reported drug carriers include biodegradable polymer microspheres, liposome-based nanomicelles, etc. Among them, smart nanohydrogels have received widespread attention in the field of nanodrug delivery system development due to their small size, good biocompatibility, easy modification, flexibility and versatility, and ability to respond to different stimuli. Among the preparation methods of nanohydrogels, precipitation polymerization has the advantages of simple operation, controllable quality, no need to add surfactants and stabilizers, and easy to scale up. However, in the currently reported nanohydrogel drug delivery systems, the number of functional monomers used for precipitation polymerization is very limited. The present invention uses histamine and its derivatives as raw materials, and obtains a series of N, N'-bis (acryloyl) histamine derivative monomers through acrylamidation, and develops a new type of biodegradable reduction-responsive nanohydrogel based on histamine derivatives through precipitation polymerization, which is used to encapsulate functional molecules such as drug molecules, nucleic acids, and dyes. In addition, after the nanohydrogel is taken up by cancer cells, the imidazole groups in the nanohydrogel are easily protonated in the weakly acidic environment of the endosomal body, which helps its endosomal escape and drug controlled release. Therefore, the nanohydrogel in the present invention shows a wide range of application prospects in nano drug delivery and cancer diagnosis and treatment. Summary of the invention
[0004] The purpose of the present invention is to prepare a novel biodegradable reduction-responsive nanohydrogel based on histamine derivatives by precipitation polymerization and evaluate its application potential in nano drug delivery systems.
[0005] The present invention is achieved by the following method:
[0006] The nano hydrogel based on histamine derivatives of the present invention is prepared by precipitation polymerization using acryloyl histamine derivatives as polymerization monomers, adding crosslinking agents and initiators. After the reaction is completed, the double bonds in the acryloyl histamine derivative monomers and the crosslinking agent disappear, and the monomers are connected in a free radical polymerization manner.
[0007] The structure of the acryloyl histamine derivative is:
[0008]
[0009] in,
[0010] R is H or methyl; 1≤n≤6, preferably n=2.
[0011] The initiator is: azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN) or 4,4'-azobis(4-cyanovaleric acid); the crosslinking agent is: N,N'-bis(methacryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystamine, N,N'-bis(methacryloyl)cystine, N,N'-bis(acryloyl)cystinamide or polyethylene glycol dimethacrylate.
[0012] The present invention also provides a method for preparing the nano hydrogel based on histamine derivatives, comprising the following steps:
[0013] (1) preparing acryloyl histamine derivatives;
[0014] (2) dissolving the acryloyl histamine derivative in an organic solvent and stirring until the mixture is completely dissolved;
[0015] (3) adding a crosslinking agent and a free radical polymerization initiator to the solution of step (2) to react;
[0016] (4) After the reaction is completed, centrifuge at high speed and discard the supernatant;
[0017] (5) Washing and freeze-drying the lower solid layer after centrifugation to obtain nano hydrogel powder based on histamine derivatives.
[0018] The method for preparing the nano hydrogel based on histamine derivatives, wherein:
[0019] In the step (1), the structure of the acryloyl histamine derivative is as shown in the above structure, and is prepared by the following method:
[0020] The primary amine compound containing imidazole group is used as raw material, and amidation reaction is carried out with acryloyl chloride or methacryloyl chloride under low temperature conditions to obtain acryloyl histamine derivatives.
[0021] Specifically, the steps include:
[0022] The primary amine compound containing imidazole group is dissolved in water and ice-bathed at 0-5°C for 10-30 minutes. In an argon atmosphere, an aqueous NaOH solution (NaOH is 3 times the equivalent of the primary amine compound containing imidazole group) and an anhydrous dichloromethane solution of acryloyl chloride or methacryloyl chloride (acryloyl chloride or methacryloyl chloride is 1 times the equivalent of the primary amine compound containing imidazole group) are slowly dripped into the aqueous solution of the primary amine compound containing imidazole group at the same time, and stirred. After the dripping is completed, the reaction is carried out at 0-25°C for 2-4 hours. The obtained crude product is purified by elution with dichloromethane:methanol=10:1-30:1 to obtain the target product acryloyl histamine derivative.
[0023] In the step (2), the weight volume concentration of the acryloyl histamine derivative is 0.1 to 200 mg / mL, preferably 0.1 to 50 mg / mL; the selected organic solvent is acetonitrile, anhydrous ethanol or a mixed solvent of acetonitrile and anhydrous ethanol in any proportion.
[0024] In the step (3), the selected initiator for free radical polymerization is: azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN) or 4,4'-azobis(4-cyanovaleric acid); and the amount thereof is: so that its weight volume concentration in the solution is 0.1 to 0.75 mg / mL.
[0025] In the step (3), the cross-linking agent is selected from: N,N'-bis(methacryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystamine, N,N'-bis(methacryloyl)cystine, N,N'-bis(acryloyl)cystinamide or polyethylene glycol dimethacrylate; and the amount thereof is: so that its weight volume concentration in the solution is 0.1 to 40 mg / mL, preferably 0.5 to 20 mg / mL.
[0026] In the step (3), the reaction temperature is 25 to 90° C. and the reaction time is 30 to 90 min.
[0027] In the step (4), the centrifugal speed is 7000-15000 r / min; and the centrifugal time is 10-30 min.
[0028] In the step (5), the solvent selected for washing the lower layer solid is: water, acetonitrile, ethanol, tetrahydrofuran, dichloromethane, methanol, acetone, ethyl acetate, carbon tetrachloride, 1,4-dioxane, ethylene glycol, cyclohexane or n-hexane; preferably: acetonitrile.
[0029] The present invention also provides a method for applying the nano hydrogel based on histamine derivatives in loading materials, which specifically includes:
[0030] The prepared histamine derivative-based nanohydrogel (referred to as nanohydrogel) powder is dispersed in water, then mixed with the drug molecules, nucleic acids or functional dyes to be encapsulated, stirred at room temperature for 8 to 48 hours, subjected to high-speed centrifugation, the supernatant is transferred, the lower layer is washed, and freeze-dried to obtain the histamine derivative-based loaded nanohydrogel (referred to as loaded nanohydrogel).
[0031] The carrier includes: drug molecules, nucleic acids and functional dyes.
[0032] The drugs include: anti-tumor drugs, antibacterial drugs, and anti-inflammatory drugs, wherein the anti-tumor drugs include: paclitaxel, doxorubicin, and erlotinib, the antibacterial drugs include: metronidazole benzoate, cefuroxime sodium, and rifampicin, and the anti-inflammatory drugs include: dexamethasone and chloramphenicol; the nucleic acids include DNA and RNA.
[0033] The preferred encapsulated objects are erlotinib and single-stranded DNA consisting of 20 A bases, namely polyA.
[0034] The weight ratio of the drug to the nano hydrogel powder is (1-10):5, preferably (2-4):5; the final concentration of the selected drug is 0.05-10 mg / mL, preferably 0.1-2 mg / mL.
[0035] The lower layer is washed with methanol or ethanol as solvent.
[0036] The drug-loaded nano-hydrogel obtained by the method of the present invention has a particle size of 30 to 500 nm, preferably in the range of 30 to 100 nm, a drug loading amount of more than 20%, controllable size and good stability; the DNA-loaded nano-hydrogel obtained has a particle size of 30 to 500 nm, and a DNA encapsulation rate of more than 90%.
[0037] The invention obtains a series of histamine derivatives by amidating the amino group of a primary amine compound containing an imidazole group, and uses the derivatives as raw materials to prepare nano hydrogels carrying substances (drug molecules, nucleic acids or functional dyes).
[0038] Compared with the prior art, the present invention has the following advantages:
[0039] 1. The nano-hydrogel prepared by using histamine derivatives as polymerization monomers has simple polymerization monomers, can adopt precipitation polymerization technology, is short in time, does not require the addition of emulsifiers or stabilizers, has a mild reaction and is easy to control, and the preparation process is very simple.
[0040] 2. The nano hydrogel prepared by the present invention has good stability and reduction sensitivity. Since the nano hydrogel is formed by covalent cross-linking, its stability is significantly higher than that of other nano hydrogels prepared by self-assembly through intermolecular forces. Figure 5It can be seen that the degradation of the nano-hydrogel can reach 90% after 20 minutes under the condition of 10 mM glutathione, showing good reduction sensitivity.
[0041] 3. The nano hydrogel prepared by the present invention contains a large number of amide groups inside and a large number of imidazole groups on the surface, so when encapsulating drugs (such as erlotinib), the drug loading can be increased through intermolecular interactions such as hydrogen bonds; the drug loading can reach more than 27%, and the encapsulation rate can reach more than 63%. The DNA encapsulation rate reaches 99.94%. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 N-[2-(4-imidazolyl)ethyl]acrylamide prepared in Example 1 of the present invention 1 H NMR spectrum;
[0043] Figure 2 The infrared spectra of the nano-hydrogel PNIEAA, the monomer N-[2-(4-imidazolyl)ethyl]acrylamide and the cross-linking agent N,N'-bis(acryloyl)cystamine prepared in Example 1 of the present invention are shown;
[0044] Figure 3 This is a particle size distribution diagram of the erlotinib-loaded nanohydrogel ELB-PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide prepared in Example 2 of the present invention;
[0045] Figure 4 This is a scanning electron micrograph of the erlotinib-loaded nanohydrogel ELB-PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide prepared in Example 2 of the present invention;
[0046] Figure 5 This is a degradation kinetic curve of the nano-hydrogel PNIEAA in Example 5 of the present invention under the condition of 10 mM glutathione;
[0047] Figure 6 This is a release behavior curve of erlotinib in Example 6 of the present invention under the condition of PBS pH 7.4. DETAILED DESCRIPTION
[0048] In order to further illustrate the present invention, the nano-hydrogel based on histamine derivatives provided by the present invention is described in detail below in conjunction with examples.
[0049] Example 1
[0050] Preparation of nanohydrogel based on N-[2-(4-imidazolyl)ethyl]acrylamide:
[0051] (1) Preparation of acrylyl histamine derivative N-[2-(4-imidazolyl)ethyl]acrylamide;
[0052] Dissolve 4.0 g of histamine dihydrochloride in 20 mL of pure water and place in an ice bath at 0-5°C for 10 min. In an argon atmosphere, slowly drop a NaOH aqueous solution (2.62 g NaOH, 20 mL of pure water) and an anhydrous dichloromethane solution of acryloyl chloride (1.967 g acryloyl chloride, 20 mL of anhydrous dichloromethane) into the aqueous solution of histamine dihydrochloride at the same time, stir vigorously, and complete the addition within 1 h. After the addition is complete, react at 25°C for 4 h. After the reaction is completed, transfer to a separatory funnel, let stand to separate the liquids, take the water layer, spin dry and dissolve it with 200 mL of ethanol, remove insoluble matter by suction filtration, and evaporate the filtrate. The crude product is purified by silica gel column chromatography, eluted with dichloromethane: methanol = 10:1, and the eluate is spin dried and dried in a vacuum drying oven to obtain 1.682 g of the target product N-[2-(4-imidazolyl)ethyl] as a white solid powder with a yield of 46.85%.
[0053] Its structure is:
[0054] The NMR results are as follows Figure 1 shown.
[0055] (2) Weigh the prepared N-[2-(4-imidazolyl)ethyl]acrylamide monomer (175 mg, 1.061 mmol) and dissolve it in 40 mL of acetonitrile, stirring until it is completely dissolved.
[0056] (3) Add N,N'-bis(acryloyl)cystamine (75 mg, 0.288 mmol) and initiator AIBN (5 mg, 0.030 mmol) to the solution of step (2), and ultrasonicate for 10 min. Heat in a water bath, and heat the water temperature from room temperature to 83°C in about 30 min. Continue the reaction for 60 min, then stop the reaction and cool to room temperature.
[0057] (4) The above solution was transferred to a 15 mL centrifuge tube, and then centrifuged at 8000 r / min for 10 min. The supernatant was transferred, acetonitrile was added, and ultrasonic dispersion was performed for 30 min. Then, the supernatant was centrifuged at 8000 r / min for 10 min, and the supernatant was discarded.
[0058] (5) Add acetonitrile to the lower solid layer after centrifugation and disperse it ultrasonically for 30 minutes to obtain a turbid solution. After freeze-drying, white nano-hydrogel PNIEAA powder is obtained.
[0059] The infrared spectra of the prepared nano-hydrogel PNIEAA, monomer N-[2-(4-imidazolyl)ethyl]acrylamide and cross-linking agent N,N'-bis(acryloyl)cystamine are compared as shown in the figure. Figure 2 shown.
[0060] Example 2
[0061] Application method of nanohydrogel PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide in drug-carrying erlotinib:
[0062] Weigh 6 mg of erlotinib (ELB) and dissolve it in 1 mL of methanol; weigh 10 mg of the nanohydrogel PNIEAA prepared in Example 1 and disperse it in 5 mL of ultrapure water. Under ultrasonic conditions, slowly drip the methanol solution of ELB into the nanohydrogel PNIEAA aqueous dispersion, and then stir at room temperature in the dark for 24 hours. After 24 hours, centrifuge (10000 rpm, 10 min), wash the lower precipitate with methanol twice, disperse it in a small amount of water, and freeze-dry to obtain the drug-loaded (erlotinib) nanohydrogel ELB-PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide.
[0063] The collected supernatant was dried by rotation and then dissolved with a certain amount of ethanol, and the concentration of free erlotinib was detected by UV-visible spectrophotometer. The lower solid layer was freeze-dried to obtain erlotinib-loaded nanohydrogel, with a drug loading of 27.56% and an encapsulation rate of 63.40%.
[0064] The obtained erlotinib-loaded nanohydrogel was tested and characterized by using Malvern laser particle size analyzer and scanning electron microscope. The average dynamic light scattering value was 200.8nm, and the average particle size of the scanning electron microscope was about 40nm. Figure 3 and Figure 4 .
[0065] Example 3
[0066] Application method of nano-hydrogel PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide in drug-carrying doxorubicin hydrochloride:
[0067] 5 mg of doxorubicin hydrochloride (DOX) was weighed and dissolved in 5 mL of PBS, and 10 mg of the nanohydrogel PNIEAA prepared in Example 1 was added, and the two were thoroughly mixed by ultrasonic dispersion, and then stirred at room temperature in the dark for 24 h. After 24 h, centrifugation (10000 rpm, 10 min) was performed, and the lower precipitate was washed once with pure water, dispersed with a small amount of water, and freeze-dried to obtain a drug-loaded (doxorubicin hydrochloride) nanohydrogel DOX-PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide.
[0068] The supernatant was collected and the concentration of free doxorubicin hydrochloride was detected by UV-visible spectrophotometer. The lower solid layer was freeze-dried to obtain doxorubicin hydrochloride loaded nano-hydrogel. The doxorubicin hydrochloride loaded nano-hydrogel prepared in this embodiment had a drug loading of 12.85% and a loading rate of 43.51%.
[0069] Example 4
[0070] Application method of nanohydrogel PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide in drug-carrying paclitaxel:
[0071] Weigh 6 mg of paclitaxel (PTX) and dissolve it in 1 mL of methanol; weigh 10 mg of the nanohydrogel PNIEAA prepared in Example 1 and disperse it in 5 mL of ultrapure water. Under ultrasonic conditions, slowly drip the methanol solution of PTX into the nanohydrogel PNIEAA aqueous dispersion, and then stir it at room temperature in the dark for 24 hours. After 24 hours, centrifuge (10000 rpm, 10 min), wash the lower precipitate with methanol twice, disperse it in a small amount of water, and freeze-dry it to obtain the drug-loaded (paclitaxel) nanohydrogel PTX-PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide.
[0072] The supernatant was collected and the concentration of free paclitaxel was detected by UV. The lower solid layer was freeze-dried to obtain the paclitaxel-loaded nanohydrogel. The paclitaxel-loaded nanohydrogel prepared in this embodiment had a drug loading of 16.18% and a loading rate of 32.17%.
[0073] The above experimental results show that when preparing drug-loaded nanohydrogels, the drug loading and encapsulation rate are different when the carrier interacts with drugs of different structures. The results are as follows:
[0074] Example drug Drug loading (%) Packing rate (%) Example 2 Erlotinib 27.56％ 63.40％ Example 3 Doxorubicin Hydrochloride 12.85％ 43.51％ Example 4 Paclitaxel 16.18％ 32.17％
[0075] Example 5
[0076] Reductive response performance test of nano-hydrogel PNIEAA:
[0077] (1) Non-reducing conditions
[0078] Weigh 10 mg of the powder of the nanohydrogel PNIEAA prepared in Example 1 into a vial, add 5 mL of ultrapure water, and ultrasonically disperse for 10 min. Place the vial in a constant temperature water bath oscillator and oscillate at 37 ° C and 120 rpm. Take 70 μL of each sample at the preset time points (0, 2, 5, 10, 15, 20, 25, 30, 40, 60, 90, 120 min), and use a UV-visible spectrophotometer to detect its transmittance at a wavelength of λ630 nm, and draw a blank control curve.
[0079] (2) Reduction conditions
[0080] Weigh 10 mg of the powder of the nano-hydrogel PNIEAA obtained in Example 1 into a vial, add 5 mL of ultrapure water, and ultrasonically disperse for 10 minutes. Then add 15.4 mg of reduced glutathione (GSH) to the dispersion of the nano-hydrogel PNIEAA to a final concentration of 10 mM. Place the vial in a constant temperature water bath oscillator and oscillate with the temperature set to 37°C and the oscillation frequency set to 120 rpm. As the reaction proceeds, 70 μL of samples are taken at preset time points (0, 2, 5, 10, 15, 20, 25, 30, 40, 60, 90, 120 min), and the transmittance at a wavelength of λ630 nm is detected using a UV-visible spectrophotometer to draw the reduction degradation curve of the nano-hydrogel PNIEAA. The reduction degradation kinetics of the nano-hydrogel PNIEAA prepared in this Example 1 are shown in Figure 5 .Depend on Figure 5 It can be seen that the degradation of the nano-hydrogel PNIEAA can reach 70% after 25 minutes under the condition of 10 mM GSH, showing good reduction sensitivity.
[0081] Example 6
[0082] Prepare 100mL PBS (containing 1wt% Tween 80) and 100mL PBS solution of GSH at a concentration of 10mM (containing 1wt% Tween 80) as the release medium for the non-reducing blank control group and the reducing condition group, respectively. Then accurately weigh 3mg of the ELB-PNIEAA nanohydrogel prepared in Example 1, disperse it with 2mL PBS, and transfer the ELB-PNIEAA nanohydrogel dispersion to a dialysis bag with a molecular weight cutoff of 14000. Immerse the dialysis bag in 50mL of the release medium and start timing. Incubate in a 37°C constant temperature water bath oscillator with an oscillation frequency set to 120rpm. Then sample 80μL at each preset time point (0min, 5min, 10min, 20min, 30min, 45min, 60min, 1.5h, 3h, 5h, 8h, 12h, 24h, 26h, 28h) and add 80μL of pre-warmed release medium. The absorbance value A of the solution at a wavelength of λ333nm was detected by a UV-visible spectrophotometer. Finally, the cumulative release amount was calculated based on the concentration calibration curve of the ELB PBS solution, and the drug release curve of the ELB-PNIEAA nanohydrogel was drawn.
[0083] The drug release effect of the reduced nano drug-loaded hydrogel prepared in this example is shown in Figure 6 The cumulative drug release of the drug-loaded hydrogel in PBS pH = 7.4 solution and 10 mM glutathione in PBS pH = 7.4 solution within 24 hours was 20% and 72%, respectively.
[0084] Example 7
[0085] Application method of nanohydrogel PNIEAA based on N-[2-(4-imidazolyl)ethyl]acrylamide in DNA loading:
[0086] Weigh 5 mg of the nanohydrogel PNIEAA prepared in Example 1, disperse it in 5 mL PBS (pH = 7.4), and ultrasonically disperse it for 10 min. Add 8 nmol of single-stranded DNA polyA containing 20 A bases (sequence: 5'-AAAAAAAAAAAAAAAAAAAAAAA-3'; molar absorption coefficient E = 243400), and ultrasonically disperse it for 2 min. Stir in the dark for 24 h. Centrifuge, retain the supernatant, and freeze-dry the precipitate to obtain the DNA-loaded nanohydrogel polyA-PNIEAA. Recover the unloaded polyA in the supernatant by ethanol precipitation, add 100 μL PBS to dissolve it, and use a UV-visible spectrophotometer to detect the absorbance value A of the solution at a wavelength of λ260 nm. Calculate the amount of polyA in the supernatant according to the Lambert-Beer law, and calculate the polyA encapsulation rate of the PNIEAA nanohydrogel by the difference method to be 99.94%.
Claims
1. A nano hydrogel based on histamine derivatives, characterized in that: It is prepared by precipitation polymerization using acryloyl histamine derivatives as polymerization monomers, adding crosslinking agents and initiators; The structure of the acryloyl histamine derivative is: in, R is H or methyl; 1≤n≤6; The initiator is: azobisisobutyronitrile, azobisisoheptanenitrile or 4,4'-azobis(4-cyanovaleric acid); The cross-linking agent is: N,N'-bis(methacryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystamine, N,N'-bis(methacryloyl)cystine, N,N'-bis(acryloyl)cystinamide or polyethylene glycol dimethacrylate.
2. A method for preparing a nano-hydrogel based on histamine derivatives according to claim 1, characterized in that: The following steps are involved: (1) preparing acryloyl histamine derivatives; (2) dissolving the acryloyl histamine derivative in an organic solvent and stirring until the acryloyl histamine derivative is completely dissolved; the weight volume concentration of the acryloyl histamine derivative is 0.1 to 200 mg / mL; the selected organic solvent is acetonitrile, anhydrous ethanol, or a mixed solvent of acetonitrile and anhydrous ethanol in any proportion; (3) adding a crosslinking agent and a free radical polymerization initiator to the solution of step (2) to carry out a reaction; the selected free radical polymerization initiator is: azobisisobutyronitrile, azobisisoheptanenitrile or 4,4'-azobis(4-cyanovaleric acid); the amount thereof is: such that its weight volume concentration in the solution is 0.1 to 0.75 mg / mL; the selected crosslinking agent is: N,N'-bis(methacryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystine dimethyl ester, N,N'-bis(acryloyl)cystamine, N,N'-bis(methacryloyl)cystine, N,N'-bis(acryloyl)cystinamide or polyethylene glycol dimethacrylate; The dosage is as follows: the weight volume concentration in the solution is 0.1-40 mg / mL; the reaction temperature is 25-90°C, and the reaction time is 30-90 min; (4) After the reaction is completed, centrifuge at high speed and discard the supernatant; (5) Washing and freeze-drying the lower solid layer after centrifugation to obtain nano hydrogel powder based on histamine derivatives.
3. The method for preparing a nano-hydrogel based on histamine derivatives according to claim 2, characterized in that: In the step (1), the method for preparing the acryloyl histamine derivative comprises the following steps: The primary amine compound containing an imidazole group is dissolved in water, and an ice bath is placed at 0-5°C. In an argon atmosphere, an aqueous NaOH solution and an anhydrous dichloromethane solution of acryloyl chloride or methacryloyl chloride are simultaneously and slowly dripped into the aqueous solution of the primary amine compound containing an imidazole group, and stirred. After the dripping is completed, the mixture is reacted at 0-25°C. The obtained crude product is eluted and purified with a mixed solvent of dichloromethane / methanol to obtain the target product, an acryloyl histamine derivative.
4. The method for preparing a nano-hydrogel based on histamine derivatives according to claim 2, characterized in that: In the step (5), the solvent selected for washing the lower layer solid is: water, acetonitrile, ethanol, tetrahydrofuran, dichloromethane, methanol, acetone, ethyl acetate, carbon tetrachloride, 1,4-dioxane, ethylene glycol, cyclohexane or n-hexane.
5. Use of the nanohydrogel based on histamine derivatives according to claim 1 in DNA loading, characterized in that: The DNA contains single-stranded DNA polyA with 20 A bases, and the sequence is 5'-AAAAAAAAAAAAAAAAAAAAAAA-3'; the polyA encapsulation rate reaches 99.94%; and the particle size of the DNA-loaded nano hydrogel is 30-500nm.
6. An application of the nano-hydrogel based on histamine derivatives according to claim 1 in drug delivery, characterized in that: Specifically include: The nano hydrogel powder based on histamine derivatives is dispersed in water, then mixed with drug molecules to be loaded, stirred at room temperature, centrifuged at high speed, the supernatant is transferred, the lower layer is washed, and freeze-dried to obtain the drug-loaded nano hydrogel based on histamine derivatives; the obtained drug-loaded nano hydrogel has a particle size of 30 to 500 nm and a drug loading amount of more than 20%; the weight ratio of the drug to the nano hydrogel powder based on histamine derivatives is (1 to 10):5; and the final drug concentration is 0.05 to 10 mg / mL.
7. The use of the nano-hydrogel based on histamine derivatives in drug loading according to claim 6, characterized in that: The drugs include: paclitaxel, doxorubicin, and erlotinib.
8. The use of the nano-hydrogel based on histamine derivatives in drug delivery according to claim 6, characterized in that: The weight ratio of the drug to the nano hydrogel powder based on histamine derivatives is (2-4):5; the final concentration of the selected drug is 0.1-2 mg / mL.