Preparation method and application of DACe (at) ET nano-drug
By preparing DACe@ET nanodrugs, the modification and targeted design of gold nanoparticles and ceria core-shell structure nanoparticles were solved, and the regulation of iron in the brain and the recovery of redox balance were achieved, and a new therapeutic strategy was provided.
Patent Information
- Application Number
- CN202510574309.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2025-08-15
AI Technical Summary
The prior art lacks effective therapeutic strategies to regulate iron homeostasis and oxidative stress in cerebral amyloid vascular disease (CAA), especially inadequate treatment options for targeted astrocytes and oxidative stress.
DACe@ET nanodrug was prepared, and the amino polyethylene glycol maleimide and astrocyte homing peptide DAG were modified to achieve regulation of iron homeostasis and redox equilibrium in the brain, and the bionic catalytic activity of CeO2-like SOD-like and CAT-like enzymes was used to eliminate free radicals, and the PLC inhibitor ET-18-OCH3 was loaded to target astrocytes.
DACe@ET nanodrugs can effectively reduce the abnormal accumulation of iron in the brain of CAA model mice, restore redox balance, improve the bioavailability of drugs, and provide new therapeutic strategies through targeted treatment of CAA.
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Figure CN120478400A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of biomedicine and nanomaterial technology, and specifically relates to a DACe@ET nanodrug and its application in the treatment of cerebral amyloid angiopathy (CAA), aiming to solve the problems of iron homeostasis imbalance and oxidative stress associated with CAA. Background Art
[0002] Cerebral amyloid angiopathy (CAA) is a neurodegenerative disease characterized by abnormal deposition of amyloid-β (Aβ) in cerebral blood vessels, often leading to blood-brain barrier (BBB) damage, cerebral hemorrhage, and cognitive impairment. Currently, effective treatment strategies for CAA remain limited, particularly for regulating iron homeostasis and alleviating oxidative stress.
[0003] Numerous studies have shown that iron homeostasis imbalance is one of the important factors for the occurrence and development of CAA. Astrocytes are key regulators of brain iron metabolism, and their dysfunction may exacerbate Fe 2+ Abnormal accumulation of iron β-actin accelerates Aβ deposition and induces neurotoxicity. Furthermore, oxidative stress is a key pathological mechanism in the development of CAA. Excessive reactive oxygen species (ROS) exacerbate inflammatory responses and disrupt the blood-brain barrier. Therefore, the development of a novel nanomedicine that can precisely target astrocytes, simultaneously regulate iron homeostasis, and scavenge ROS is of great significance for the prevention and treatment of CAA. Summary of the Invention
[0004] In view of the shortcomings of the existing technology, the present invention provides a preparation method and application of DACe@ET nanomedicine.
[0005] Technical solution:
[0006] A method for preparing DACe@ET nanomedicine comprises the following steps:
[0007] Step 1, synthesizing gold (Au) nanoparticles: adding a pre-cooled sodium borohydride (NaBH4) solution to a mixed solution of tetrachloroauric acid (HAuCl4) and cetyltrimethylammonium bromide (CTAB), and stirring at room temperature. After the reaction is complete, the Au nanoparticles are collected by centrifugation and further purified to obtain the target product, and the product is lyophilized to obtain a powder sample;
[0008] Step 2, synthesizing Au / CeO2 core-shell structured nanoparticles: adding CTAB solution to the solution of Au nanoparticles prepared in step 1, stirring at room temperature, then adding EDTA-NH3 solution and Ce(NO3)3 solution in sequence, continuing to stir, and finally placing the mixture in an oil bath for reaction. After the reaction is completed, the obtained product is centrifuged and resuspended to obtain Au / CeO2 core-shell structured nanoparticles;
[0009] Step 3, modification of amino polyethylene glycol maleimide (NH2-PEG 2000 -Mal) and astrocyte homing peptide DAG: The Au / CeO2 core-shell structure nanoparticles prepared in step 2 were resuspended in deionized water, and then NH2-PEG 2000 -Mal, after magnetic stirring at room temperature, unbound NH2-PEG was removed by centrifugation 2000 -Mal, then add astrocyte homing peptide DAG to the system and continue stirring at room temperature to achieve covalent coupling of peptide molecules;
[0010] Step 4, preparation of DACe@ET nanodrug: ET-18-OCH3 was added to the product described in step 3, and stirred at room temperature. Subsequently, the mixture was centrifuged to remove unbound free substances to obtain DACe@ET nanodrug.
[0011] Preferably, in step 1, the concentration of the NaBH4 solution is 8-15 mM (preferably 8-12 mM), and the concentration of CTAB is 0.1-0.3 M.
[0012] Preferably, in step 1, the NaBH4 solution is added to the mixed solution of HAuCl4 and CTAB, and the stirring time is 1-3 hours.
[0013] Preferably, in step 1, after the reaction is completed, the centrifugal speed is 7000-9000 rpm and the time is 10-20 min.
[0014] Preferably, in step 2, the concentration of the CTAB solution is 0.02-0.03 M, the concentration of the EDTA-NH3 solution is 0.1-0.2 M, and the concentration of the Ce(NO3)3 solution is 0.1-0.2 M. EDTA-NH3 was purchased from Fuzhou Aisizhi Biotechnology Co., Ltd.
[0015] Preferably, in step 2, the gold nanoparticle solution is prepared by resuspending gold nanoparticle powder in 6-9 mL of deionized water.
[0016] Preferably, in step 2, the CTAB solution and the Au nanoparticle solution are stirred at room temperature for 25-35 minutes.
[0017] Preferably, in step 2, the EDTA-NH3 solution and Ce(NO3)3 solution are added and the stirring time is continued for 10-20 minutes.
[0018] Preferably, in step 2, the reaction time of the oil bath is 4-6 hours.
[0019] Preferably, in step 2, the centrifugal speed is 9000-11000 rpm, and the time is 20-40 min.
[0020] Preferably, in step 3, the concentration of the Au / CeO2 resuspended is 0.5-2 mg / mL, and then the surface is modified with NH2-PEG 2000 -Mal (purchased from Avituo Pharmaceutical Technology Co., Ltd.), Au / CeO2 and NH2-PEG 2000 -Mal mass ratio is 1:1-1:20.
[0021] Preferably, in step 3, the mechanism of DAG peptide coupling is as follows: (1) DAG peptide is positively charged (Zeta potential: 1.22±0.31 mV), which can be adsorbed on the Au / CeO2 surface by electrostatic interaction; (2) the C-terminal thiol group of DAG peptide can bind to NH2-PEG 2000 -Mal maleimide (Mal-) undergoes Michael addition reaction and covalently connects to the Au / CeO2 surface. 2000 -Mal relies on the good adsorption ability of amino groups on the Au / CeO2 surface, which not only improves the biocompatibility of inorganic carriers, but also provides functional sites for the subsequent coupling of DAG peptides. That is, Au / CeO2 core-shell structured nanoparticles are modified with astrocyte homing peptide DAG (DAGRKQKC, Hangzhou Zhongpeptide Biochemical Co., Ltd.) through electrostatic interaction and covalent binding. The DAG peptide feed amount is: NH2-PEG 2000 The molar ratio of -Mal to astrocyte homing peptide DAG was 5:5-5:10.
[0022] Preferably, in step 3, the magnetic stirring time is 1.5-2.5 h, more preferably 2 h.
[0023] Preferably, in step 3, the stirring time is 3-5 hours, more preferably 4 hours.
[0024] Preferably, in step 4, the ET-18-OCH3 drug loading mechanism is as follows: CeO2 in the Au / CeO2 stacks disorderly outside the Au core, forming abundant pores that serve as primary loading sites for ET-18-OCH3. Furthermore, drug molecules can be adsorbed onto the nanoparticle surface via van der Waals forces.
[0025] The concentration of the ET-18-OCH3 is 2-10 μM (preferably 5-7 μM) (ET-18-OCH3 was purchased from MCEMedChemExpress). The drug is magnetically stirred at room temperature for 3-5 hours and loaded on the unique pores or surface of Au / CeO2.
[0026] Preferably, in step 4, the centrifugal speed is 11000-13000 rpm, and the time is 25-35 min.
[0027] DACe@ET nanomedicine was obtained according to the above preparation method.
[0028] DACe@ET nanomedicine includes: Au / CeO2 nanoparticles, whose core is Au nanoparticles and whose outer layer is coated with CeO2 to form a core-shell structure.
[0029] Preferably, in the DACe@ET nanomedicine, the CeO2 shell in the core-shell structure is rich in Ce 3+ and oxygen vacancies, and has SOD-like and CAT-like enzyme biomimetic catalytic activity, that is, the core-shell structure itself has the characteristics: Ce in CeO2 3+ The oxygen vacancies give it functions similar to natural antioxidant enzymes, which can effectively scavenge free radicals and protect nerve cells from oxidative damage.
[0030] For example, the application of the DACe@ET nanomedicine in the treatment of cerebral amyloid angiopathy is a non-diagnostic or non-therapeutic method.
[0031] Preferably, DACe@ET nanomedicine is able to regulate redox balance and reduce iron deposition in the brain.
[0032] Due to the adoption of the above solution, the beneficial effects of the present invention are:
[0033] The DACe@ET nanomedicine of this invention enhances its bioavailability by increasing its antioxidant capacity and improving its cellular uptake. Furthermore, by modifying the Au / CeO2 surface with the astrocyte-homing peptide DAG, the drug can precisely target perivascular astrocytes, a key lesion site in CAA. Furthermore, the drug is loaded with the PLC inhibitor ET-18-OCH3 to restore iron homeostasis.
[0034] The DACe@ET nanomedicine of the present invention can effectively reduce the abnormal accumulation of iron in the brain of CAA model mice and restore the redox balance in the brain, indicating that it has excellent brain iron homeostasis regulation ability. This study provides a new treatment strategy for CAA and other neurodegenerative diseases. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 These are the basic properties of Au / CeO2 in Example 1 of the present invention.
[0036] Figure 2 This is an investigation of the SOD-like and CAT-like properties of Example 1 of the present invention.
[0037] Figure 3NH2-PEG of Example 1 of the present invention 2000 -Mal and astrocyte homing peptide DAG dosage screening.
[0038] Figure 4 Characterization of DACe@ET in Example 1 of the present invention.
[0039] Figure 5 This is the in vitro hemolysis experiment of Example 2 of the present invention.
[0040] Figure 6 This is an investigation of the cellular efficacy and antioxidant capacity of Example 2 of the present invention.
[0041] Figure 7 The in vivo efficacy of Example 2 of the present invention is to reduce iron deposition. DETAILED DESCRIPTION
[0042] To further illustrate the technical means and effects of the present invention, the technical solutions of the present invention are further described below with reference to the accompanying drawings and specific implementation methods, but the present invention is not limited to the scope of the embodiments.
[0043] Example 1: Synthesis and property evaluation of nanosystems
[0044] Step 1 Synthesis and characterization of Au / CeO2 core-shell nanoparticles
[0045] The method for synthesizing Au / CeO2 core-shell structured nanoparticles provided in this embodiment comprises the following steps:
[0046] (1.1) Preparation of Au nanoparticles: Pre-cooled NaBH4 solution (10 mM, 600 μL) was quickly added to a mixed solution of HAuCl4 (10 mM, 250 μL) and CTAB (0.1 M, 9.75 mL) and allowed to react for 2 min under vigorous stirring. Subsequently, the stirring rate was reduced and slow stirring was continued for 2 h to ensure uniform growth of the nanoparticles (diameter of approximately 20 nm, Figure 1 A).
[0047] (1.2) Preparation of Au / CeO2: CTAB (7 mL, 0.025 M) solution was added to an 8 mL Au nanoparticle solution and stirred at room temperature for 30 min. EDTA-NH3 solution (0.8 mL) and cerium nitrate (Ce(NO3)3) (0.1 M) solution were then added, followed by stirring for 15 min. The mixed solution was placed in an oil bath and reacted for 5 h. After the reaction, the resulting product was centrifuged and resuspended to obtain Au / CeO2 core-shell nanoparticles.
[0048] Characterization of Au / CeO2 core-shell structured nanoparticles:
[0049] Transmission electron microscopy (TEM, JEM-2100) and high-resolution transmission electron microscopy (HRTEM) characterization results are as follows Figure 1 As shown in A, the Au core is surrounded by a CeO2 shell layer with an overall particle size of about 70 nm, forming an obvious core-shell structure described in step 1.2.
[0050] X-ray diffraction (XRD, Rigaku Miniflex 600) Figure 1 As shown in Figure B, the Au / CeO2 core-shell structured nanoparticles show typical CeO2 diffraction peaks ((111), (200), (220), (311)) and the Au (220) peak, further verifying its composite structure.
[0051] Raman spectroscopy (LabRAM HR Evolution) test Figure 1 As shown in Figure C, the F2g mode in the Au / CeO2 core-shell nanoparticles is at 465 cm -1 There is an obvious red shift at 600 cm -1 A new Au-O-Ce bond peak appears at , indicating that the introduction of Au changes the lattice environment of CeO2 and generates rich oxygen vacancies.
[0052] X-ray photoelectron spectroscopy (XPS, Thermo ESCALAB 250Xi) was used to analyze the Ce 3d valence state composition, such as Figure 1 As shown in D, Ce in Au / CeO2 3+ The ratio increased from 21.03% to 30.27%, which helped to improve its catalytic ability.
[0053] Step 2: Biomimetic enzyme activity detection
[0054] (2.1) Description of the catalytic mechanism of SOD-like enzymes: Figure 2 As shown in A, the reversible conversion between Ce(III) and Ce(IV) gives it SOD-like enzyme activity, which can catalyze the conversion of superoxide anion (·O2 - ) produces hydrogen peroxide (H2O2) and oxygen (O2).
[0055] (2.2) Determination of SOD-like enzyme activity by NBT method: Figure 2 B is the purple absorption curve of NBT reduction catalyzed by Au / CeO2 at different concentrations (25-400 μg / mL). As the concentration of Au / CeO2 increases, the absorption peak at 560 nm decreases significantly, indicating that O2 - It is gradually cleared and exhibits concentration-dependent SOD-like enzyme catalytic activity.
[0056] (2.3) Comparison of SOD activity of different materials: Figure 2 In C, Au / CeO2 has a better inhibitory effect on NBT reaction than CeO2, and the material concentration is 100μg / mL, indicating that the introduction of Au enhances the SOD enzyme-like properties of the material.
[0057] (2.4) Description of the catalytic mechanism of CAT-like enzymes: Figure 2 D in the figure indicates the decomposition reaction of Ce(III) / Ce(IV) to H2O2, that is, H2O2 is converted into water and oxygen.
[0058] (2.5) CAT-like kit to detect SOD-like enzyme activity: Figure 2 Figure E shows the absorption spectrum of Au / CeO2 core-shell structured nanoparticles for H2O2 decomposition at different concentrations (25-400 μg / mL). As the sample concentration increases, the absorbance in the 405-415 nm range gradually decreases, indicating that the residual amount of H2O2 decreases and the CAT-like enzyme activity increases.
[0059] (2.6) Comparison of CAT activity of different materials: Figure 2 Figure F shows that at a concentration of 100 μg / mL, Au / CeO2 is more effective than CeO2 in decomposing H2O2, with the lowest absorbance, further proving that Au enhances the CAT-like properties of the material.
[0060] Step 3: Surface modification and drug loading
[0061] (3.1) Optimization experiment of PEG-linked astrocyte homing peptide DAG: Figure 3 As shown in A, Au / CeO2 core-shell structured nanoparticles are prepared with NH2-PEG at different mass ratios. 2000 -Mal(Au / CeO2 and NH2-PEG 2000 The specific steps are as follows: Au / CeO2 (1 mg / mL) and different masses of NH2-PEG 2000 -Mal was stirred at room temperature for 2 h, and then centrifuged at 12000 rpm for 15 min to remove free NH2-PEG 2000 -Mal. Then, Au / CeO2 with different amounts of PEG modification was incubated with CTX cells at 37°C for 2 hours, and the average fluorescence intensity of fluorescently labeled nanoparticles was quantified by flow cytometry to analyze the differences in CTX cell uptake of nanoparticles in each group. The experimental results showed that when the mass ratio was 1:5, cellular uptake was significantly enhanced, and further increasing the NH2-PEG 2000 -Mal ratio cellular uptake was not significantly increased.
[0062] (3.2) DAG modification mechanism: Figure 3As shown in Figure B, compared with the unmodified (Au / CeO2) or the carrier modified with simply physically adsorbed astrocyte homing peptide DAG (DAG-PEG-Au / CeO2), the DAG-Mal-PEG-Au / CeO2 connected by covalent coupling showed the highest fluorescence intensity, indicating that it has the strongest targeting performance.
[0063] (3.3) Confocal microscopy imaging: Figure 3 Figure C shows the uptake of nanoparticles by CTX cells at different astrocyte homing peptide DAG modification ratios. Specifically: Given that astrocyte homing peptide DAG can be attached to the Au / CeO2 surface through electrostatic and covalent interactions, it is speculated that when the amount of astrocyte homing peptide DAG added is higher than that of NH2-PEG 2000 -Mal (molar ratio), it is expected to further enhance the targeting effect of astrocyte homing peptide DAG. 2000 Optimal cellular uptake was achieved when the molar ratio of -Mal to the astrocyte homing peptide DAG was 5:8, presumably indicating that DAG-modifiable sites had reached saturation at this point.
[0064] (3.4) Construction and characterization of DACe@ET: The Michael addition reaction combined with electrostatic adsorption strategy was used to achieve targeted modification of the Au / CeO2 carrier with the astrocyte homing peptide DAG. At the same time, the surface pores of Au / CeO2 and van der Waals forces were used to achieve efficient loading of ET-18-OCH3. Specifically, the astrocyte homing peptide DAG (0.5 mM) and ET-18-OCH3 (6 μM) were added to the NH2-PEG 2000 -Mal-modified Au / CeO2 solution (0.5 mg / mL) was stirred at room temperature for 4 h. Subsequently, the mixture was centrifuged (12000 rpm, 30 min) to remove unbound free substances. Figure 4 A in the figure shows that the characteristic absorption peak of ET-18-OCH3 appears at 260nm in DACe@ET through UV-visible spectrum comparison, indicating that the drug has been successfully loaded.
[0065] (3.5) Changes in particle size distribution: Figure 4 As shown in Figure B, after Au / CeO2 was modified with targeting peptide and loaded with drug, the hydrated particle size was 76.6±2.8nm.
[0066] (3.6) Zeta potential change: Figure 4 C in the figure shows that the zeta potential of DACe@ET is -0.08±0.08 mV.
[0067] Example 2: In vitro and in vivo application experiments using the DACe@ET nanomedicine obtained in Example 1
[0068] Part I: Cell-level experiments
[0069] (1) In vitro hemolysis experiment: After collecting whole blood from ICR mice by cardiac puncture, add an appropriate amount of PBS and mix thoroughly. Centrifuge at 2000 rpm for 5 min at 4°C. Repeat this process 3 times to efficiently separate and obtain red blood cells. Then, add PBS solution containing 2% (v / v) red blood cells to DACe@ET, Au / CeO2, CeO2, H2O (positive control), and PBS (negative control) solutions, incubate at 37°C for 4 h, and then centrifuge. Collect the supernatant and measure its absorbance at 570 nm using an enzyme-labeled instrument to calculate the hemolysis rate. Figure 5 As shown, the supernatants of the DACe@ET, Au / CeO2, and CeO2 groups were transparent, and the hemolysis rates were all below 5%. However, the hemolysis rate of DACe@ET was further reduced to 1.03±0.59%. This phenomenon may be attributed to the increase in the thickness of the hydration layer on the Au / CeO2 surface after the targeting peptide was modified, forming a certain steric hindrance effect, which effectively reduced the nonspecific interaction between the Au / CeO2 and the cell membrane, and ultimately improved its compatibility in the blood environment.
[0070] (2) Antioxidant capacity assessment: 30 μM Aβ was used 25-35 and 100μM FeSO4 (abbreviated as: Aβ 25-35 +Fe 2+ ) to construct a cell efficacy model. In order to evaluate the content of intracellular reactive oxygen species (ROS), the experiment selected 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) as the detection probe. This compound has no fluorescence properties in the unoxidized state. When reacting with intracellular ROS, it can be converted into 2',7'-dichlorofluorescein (DCF) with a strong fluorescence signal. By measuring the changes in the fluorescence intensity of DCF, the degree of cellular oxidative stress can be quantitatively analyzed. The specific steps are as follows: 4 hours after the cell efficacy model was constructed, each group (Control, Aβ 25-35 +Fe 2+, CeO2, ET-18-OCH3, Au / CeO2, DACe@ET) and CTX cells were co-incubated for 24 hours, the drug solution was discarded, serum-free DMEM containing DCFH-DA (10 μM) was added and incubated for another 30 minutes, the cells were digested and the fluorescence intensity was tested using flow cytometry to observe the differences in the ROS scavenging ability of different intervention groups. Then, a cell efficacy model was constructed and drug treatment was performed using the same method. After 24 hours of drug intervention, the drug-containing culture medium in the culture dish was discarded, and the cells were gently rinsed with PBS buffer. Subsequently, RIPA lysis buffer containing 1% phosphatase inhibitors and 1% protease inhibitors was added for lysis, and the supernatant after lysis was collected for subsequent analysis. The total protein concentration of the sample was determined by the BCA method, and the operation was performed according to the instructions of the kit to further detect oxidative stress-related biomarkers such as SOD and MDA in the supernatant to evaluate the oxidative stress status of the cells. As Figure 6 As shown, Figure 6 The A in the figure shows that Aβ 25-35 +Fe 2+ The cellular ROS levels in the treatment group were significantly increased, while the DACe@ET group significantly reduced ROS generation, returning it to near normal levels (the control group value was 1.00, and the DACe@ET group value was 1.08); Figure 6 DACe@ET treatment in Figure B restored the total SOD activity and MDA level of cells to normal levels. These data indicate that DACe@ET can effectively alleviate oxidative stress.
[0071] Part II: Animal Efficacy Experiments
[0072] (1) Model selection: 3×Tg transgenic mice (129-Tg (AβPPSwe, tauP301L) 1Lfa / Psen1 tm1Mpm / Mmjax), and wild-type mice were C57BL / 6 female mice of the same age and background.
[0073] (2) Dosage frequency: DACe@ET, Au / CeO2, and CeO2 were all administered via tail vein injection (dose: 2 mg / mL) once every 3 days for a total of 9 treatments.
[0074] (3) Brain iron deposition detection: To detect the iron deposition in brain tissue, Perl's Prussian blue staining method was used for analysis. First, the brain tissue sections were placed in a 3% H2O2 solution and incubated at room temperature for 10 minutes to fully remove the endogenous peroxidase activity. Subsequently, they were transferred to a freshly prepared Prussian blue working solution (mixed by equal volumes of 5% hydrochloric acid and 5% potassium ferrocyanide) and incubated at room temperature for 30 minutes in the dark to complete the staining. After staining, the sections were rinsed three times with PBS solution, each lasting 5 minutes. Afterwards, a diaminobenzidine colorimetric solution was used for color development for 30 minutes in the dark, and the cell nuclei were counterstained with hematoxylin to enhance the contrast of the tissue structure. Figure 7 As shown, compared with wild-type mice (WT), the CAA model group showed obvious brown color, indicating a large amount of iron deposition; the CeO2 and Au / CeO2 treatment groups were alleviated to a certain extent, while the DACe@ET treatment group had significantly reduced brain tissue iron staining, close to the WT level, indicating that it has excellent brain iron homeostasis regulation ability.
[0075] The above description of the embodiments is intended to facilitate understanding and use of the present invention by those skilled in the art. Those skilled in the art will readily be able to make various modifications to these embodiments and apply the general principles described herein to other embodiments without resorting to creative effort. Therefore, the present invention is not limited to the above-described embodiments. Any improvements or modifications made by those skilled in the art based on the principles of the present invention that do not depart from the scope of the present invention should be considered within the scope of protection of the present invention.
Claims
1. A method for preparing DACe@ET nanomedicine, characterized in that: The following steps are involved: Step 1, synthesizing gold nanoparticles: adding a pre-cooled sodium borohydride solution to a mixed solution of tetrachloroauric acid and hexadecyltrimethylammonium bromide and stirring at room temperature. After the reaction is complete, the gold nanoparticles are collected by centrifugation and further purified to obtain the target product, and the product is lyophilized to obtain a powder sample; Step 2, synthesizing gold / cerium dioxide core-shell structured nanoparticles: adding a hexadecyltrimethylammonium bromide solution to the solution of gold nanoparticles prepared in step 1, stirring at room temperature, then sequentially adding an EDTA-NH3 solution and a cerium nitrate solution, continuing to stir, and finally placing the mixture in an oil bath for reaction. After the reaction is complete, the resulting product is centrifuged and the gold / cerium dioxide is resuspended to obtain gold / cerium dioxide core-shell structured nanoparticles; Step 3, modification with aminopolyethylene glycol maleimide and astrocyte homing peptide DAG: The gold / cerium dioxide core-shell structured nanoparticles prepared in step 2 are resuspended in deionized water, and then aminopolyethylene glycol maleimide is added. After magnetic stirring at room temperature, unbound aminopolyethylene glycol maleimide is removed by centrifugation. Then, astrocyte homing peptide DAG is added to the system, and stirring is continued at room temperature to achieve covalent coupling of the peptide molecules; Step 4, preparation of DACe@ET nanodrug: ET-18-OCH3 was added to the product described in step 3, and stirred at room temperature. Subsequently, the mixture was centrifuged to remove unbound free substances to obtain DACe@ET nanodrug.
2. The preparation method according to claim 1, characterized in that In step 1, the concentration of the sodium borohydride solution is 8-15 mM, and the concentration of cetyltrimethylammonium bromide is 0.1-0.3 M; and / or, The concentration of the sodium borohydride solution is 8-12 mM; and / or, In step 1, the sodium borohydride solution is added to a mixed solution of tetrachloroauric acid and hexadecyltrimethylammonium bromide, and the stirring time is 1-3 hours; and / or, In step 1, after the reaction is completed, the centrifugal speed is 7000-9000 rpm and the time is 10-20 min.
3. The preparation method according to claim 1, characterized in that In step 2, the concentration of the cetyltrimethylammonium bromide solution is 0.02-0.03M, the concentration of the EDTA-NH3 solution is 0.1-0.2M, and the concentration of the cerium nitrate solution is 0.1-0.2M; and / or, In step 2, the EDTA-NH3 is purchased from Fuzhou Aisizhi Biotechnology Co., Ltd.; and / or, In step 2, the gold nanoparticle solution is prepared by resuspending gold nanoparticle powder in 6-9 mL of deionized water.
4. The preparation method according to claim 1, characterized in that In step 2, the hexadecyltrimethylammonium bromide solution and the gold nanoparticle solution are stirred at room temperature for 25-35 minutes.
5. The preparation method according to claim 1, characterized in that In step 2, the EDTA-NH3 solution and the cerium nitrate solution are added and the stirring time is continued for 10-20 minutes; and / or, In step 2, the reaction time of the oil bath is 4-6 hours; and / or, In step 2, the centrifugal speed is 9000-11000 rpm, and the time is 20-40 min.
6. The preparation method according to claim 1, characterized in that In step 3, the concentration of the gold / cerium dioxide resuspended is 0.5-2 mg / mL, and then the surface is modified with amino polyethylene glycol maleimide, and the mass ratio of gold / cerium dioxide to amino polyethylene glycol maleimide is 1:1-1:20; and / or, The aminopolyethylene glycol maleimide was purchased from Avituo Pharmaceutical Technology Co., Ltd.
7. The preparation method according to claim 1, characterized in that In step 3, the amount of the astrocyte homing peptide DAG is such that the molar ratio of the aminopolyethylene glycol maleimide to the astrocyte homing peptide DAG is 5:5-5:10; and / or, In step 3, the astrocyte homing peptide DAG is DAGRKQKC, purchased from Hangzhou Zhongpeptide Biochemical Co., Ltd.; and / or, In step 3, the magnetic stirring time is 1.5-2.5h; and / or, In step 3, the stirring time is 3-5 hours; and / or, In step 4, the stirring time at room temperature is 3-5 hours; and / or, In step 4, the ET-18-OCH3 is purchased from MCE MedChemExpress; and / or, In step 4, the concentration of ET-18-OCH3 is 2-10 μM; and / or, In step 4, the centrifugal speed is 11000-13000 rpm, and the time is 25-35 min.
8. The DACe@ET nanomedicine obtained by the preparation method according to any one of claims 1 to 7.
9. Use of the DACe@ET nanomedicine according to claim 8 in the treatment of cerebral amyloid angiopathy, wherein the use is a non-diagnostic method or a non-therapeutic method.
10. The use according to claim 9, characterized in that: The DACe@ET nanomedicine regulates redox balance and reduces brain iron deposition.