Vascular endothelium targeted bionic nano-particles as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of biological medicine, and relates to a vascular endothelium targeted bionic nanoparticle and a preparation method and application thereof.The preparation method of the bionic nanoparticle comprises the steps that 1, STM2457 is dissolved, NH2-MSN is added, the mixture is stirred in a dark place, and STMat MSN is obtained; (2) adding the STM (at) MSN and adamantane carboxylic acid into DMF (Dimethyl Formamide) to obtain ade-MSN; (3) adding the ade-MSN into a PBS (Phosphate Buffer Solution), adding beta-CD, and stirring, so as to obtain STM2457 (at) CD-ade-MSN; (4) mixing the liposome with the platelet membrane, and adding the product obtained in the step (3) to obtain STM2457 (at) CD-ade-MSN / PL; and (5) mixing the product in the step (4) with the reduced CD31 antibody to obtain the bionic nanoparticles. The vascular endothelium targeted bionic nanoparticles prepared by the invention can be used for preventing, relieving or / and treating cardiovascular toxicity caused by chemotherapeutic drugs.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and in particular relates to a bionic nanoparticle targeted at vascular endothelium, a preparation method and an application thereof. Background Art

[0002] Doxorubicin (DOX), as a representative of anthracycline chemotherapy drugs, remains a cornerstone drug for cancer treatment due to its broad-spectrum anticancer activity. However, its long-term use can cause severe cardiovascular toxicity, especially complications such as venous sclerosis, atherosclerosis, and myocardial infarction caused by vascular endothelial cell damage, which significantly affects the patient's survival prognosis.

[0003] DOX disrupts endothelial homeostasis through multiple mechanisms: activating the NF-κB pathway to inhibit eNOS function, leading to impaired vasodilation; inducing mitochondrial ROS accumulation, activating the p38 MAPK / p53 cascade and driving premature endothelial senescence; and inducing the ASAP phenotype, triggering an outburst of proinflammatory cytokines such as IL-6, exacerbating vascular inflammation. These processes synergistically disrupt vascular barrier function, forming a core mechanism of chemotherapy-induced cardiovascular toxicity.

[0004] Methyltransferase-Like 3 (METTL3) is a catalytic 6 A modified core enzyme plays an important role in cardiovascular disease. Studies have shown that METTL3 plays an important role in cardiovascular disease. 6 A modification regulates endothelial inflammation, aging and plaque development, and is one of the key regulatory targets of DOX vascular toxicity. Inhibiting its enzymatic activity can restore endothelial function, suggesting its potential as an intervention target.

[0005] However, m 6 A modification is widely present in various biological processes and plays an important role. Traditional small molecule inhibitors have difficulty achieving precise intervention due to poor targeting and low bioavailability. Therefore, it is challenging to achieve precise targeted intervention of vascular endothelial cells to minimize the impact on other normal tissues and organs. Summary of the Invention

[0006] In view of the problems and shortcomings in the prior art, the present invention provides a biomimetic nanoparticle targeting vascular endothelium, a preparation method and an application thereof.

[0007] Based on the above purpose, the present invention adopts the following technical solutions:

[0008] The first aspect of the present invention provides a method for preparing STM2457@CD-ade-MSN / PL nanoparticles, comprising the following steps:

[0009] (1) STM2457 was dissolved in a solvent to obtain an STM2457 solution, and amino-modified MSN was added to the STM2457 solution and stirred in the dark for 24 to 48 hours. The precipitate was collected by centrifugation and dried to obtain STM2457@NH2-MSN.

[0010] (2) STM2457@NH2-MSN and adamantane carboxylic acid were added to N,N-dimethylformamide (DMF) and stirred at room temperature to obtain ade-MSN;

[0011] (3) ade-MSN was added to PBS buffer, and then β-cyclodextrin (β-CD) was added to the PBS buffer, stirred at 30°C for 8 h, and the precipitate was collected by centrifugation. The precipitate was washed to remove free β-cyclodextrin to obtain STM2457@CD-ade-MSN;

[0012] (4) The liposomes are mixed with the platelet membrane to form a liposome-membrane mixture, the STM2457@CD-ade-MSN prepared in step (3) is added to the liposome-membrane mixture, ultrasonically coated, and the precipitate is collected by centrifugation. The precipitate is resuspended in PBS and freeze-dried to obtain STM2457@CD-ade-MSN / PL.

[0013] Preferably, the mass ratio of STM2457 to amino-modified MSN is 1:5.

[0014] Preferably, the amount ratio of STM2457@NH2-MSN to adamantane carboxylic acid is 100 mg:0.5 mmol, the mass ratio of β-cyclodextrin to ade-MSN is 2:1; the mass ratio of liposomes to platelet membranes is 1:1, and the mass ratio of STM2457@CD-ade-MSN to the liposome-membrane mixture is 1:10.

[0015] Preferably, the solvent in step (1) is a solution consisting of dimethyl sulfoxide (DMSO) and methanol in a volume ratio of 1:1.

[0016] Preferably, before coupling STM2457@NH2-MSN with adamantane carboxylic acid in step (2), the adamantane carboxylic acid is activated with EDC / NHS. The activation step is as follows: adamantane carboxylic acid, EDC, and NHS are added to a PBS buffer solution and stirred for reaction. After the reaction, the mixture is centrifuged to obtain a precipitate, which is then freeze-dried to obtain activated adamantane carboxylic acid. More preferably, the mass ratio of adamantane carboxylic acid, EDC, and NHS is 10:2.5:3.

[0017] Preferably, the stirring time in step (2) is 12 to 24 hours.

[0018] Preferably, the pH value of the PBS buffer in step (3) is 6.8-7.6.

[0019] Preferably, the freeze-drying process in step (4) requires adding a freeze-drying protectant to the suspension of the precipitate after resuspending it in PBS.

[0020] More preferably, the freeze-drying protective agent in step (4) is trehalose, and the mass ratio of trehalose to STM2457@CD-ade-MSN is 1:1.

[0021] Preferably, the preparation process of the amino-modified MSN in step (1) is as follows:

[0022] Combine 64 mL of water, 10.5 mL of ethanol (0.179 mol), and 10.4 mL of 25% hexadecyltrimethylammonium chloride (CTAC) solution (7.86 mmol). Stir at room temperature for 10 minutes to obtain a mixed solution. Add 4.1 mL of triethanolamine (TEA, 0.031 mol) to the mixed solution, adjust the pH to 11, heat to 85°C, and continue stirring for 10 minutes. To the mixed solution, 4.35 mL of tetraethoxysilane (TEOS) (19.5 mmol) was slowly added dropwise. The mixture was stirred vigorously at 65°C under nitrogen overnight to obtain a milky white particle suspension. The suspension was cooled to room temperature, and 351 mL of ethanol was added to precipitate the silica particles. The suspension was allowed to stand for 4 hours and then centrifuged at 10,000 rpm for 15 minutes. The precipitate was collected and placed in a mixture of methanol / hydrochloric acid (500:19 by volume) by waterbath sonication to remove the template agent CTAC. The mixture was stirred for 24 hours and then centrifuged at 10,000 rpm for 60 minutes. The precipitate was collected and washed three times with methanol and air-dried or dried at room temperature to obtain pure MSNs. 500 mg of MSNs were weighed and dispersed in 20 mL of methanol. 200 μL of 3-aminopropyltriethoxysilane (APTES) was then added. The mixture was stirred at 65°C, sealed, and washed and lyophilized to obtain amino-modified MSNs (NH2-MSNs).

[0023] Preferably, the specific process of liposome preparation in step (4) is as follows:

[0024] DSPE-PEG2000-Mal, lecithin, and cholesterol were dissolved in a chloroform / methanol mixture (volume ratio 4:1) at a mass ratio of 1:4:1, and the film was formed by rotary evaporation and hydrated with PBS at 50°C for 10 min. Probe sonication (150 W, 5 s on / off, 3 min) was performed to obtain uniform liposomes.

[0025] Preferably, the specific process of preparing the platelet membrane in step (4) is:

[0026] First, EDTA was added to the collected blood samples to a final concentration of 5 mM to prevent platelet aggregation. Next, the blood and plasma samples were centrifuged at 100 rcf for 20 minutes, and the platelet-rich plasma (PRP) layer was collected to separate red blood cells from white blood cells. The PRP was further centrifuged at 100 rcf for 20 minutes to remove residual blood cells. To prevent platelet activation, purified PRP was added to PBS buffer containing 1 mmol / L EDTA and 2 μmol / L prostaglandin E1 (PGE1). The platelets were then centrifuged at 800 rcf for 20 minutes to pellet the platelets. After removal of the supernatant, the pelleted platelets were resuspended in PBS containing 1 mmol / L EDTA and supplemented with protease inhibitors. The extracted platelets were frozen and thawed five times at -80°C and 37°C, centrifuged at 12,000 rcf for 20 minutes, and the supernatant discarded. The pelleted platelet membrane (PM) was obtained. The extracted platelet membranes were stored at -80°C.

[0027] Preferably, in step (4), the liposome-membrane mixture is prepared by mixing the liposomes with the platelet membranes, placing them in an ice bath and performing ultrasound to fully mix them, and then extruding them using a micro-extruder to obtain the liposome-membrane mixture.

[0028] The second aspect of the present invention provides STM2457@CD-ade-MSN / PL nanoparticles prepared using the method for preparing STM2457@CD-ade-MSN / PL nanoparticles according to any one of the first aspects of the present invention.

[0029] A third aspect of the present invention provides a method for preparing vascular endothelial-targeted biomimetic nanoparticles, comprising the following steps:

[0030] S1: adding CD31 antibody and tris(2-carboxyethyl)phosphine to PBS buffer, stirring to mix, and incubating at room temperature. After the incubation, a mixed solution is obtained, and the remaining tris(2-carboxyethyl)phosphine in the mixed solution is removed to obtain a reduced CD31 antibody;

[0031] S2: The STM2457@CD-ade-MSN / PL nanoparticles described in claim 5 are mixed with the reduced CD31 antibody prepared in step S1 in PBS buffer, and the mixture is stirred at room temperature in the dark. After the reaction is completed, the reaction solution is dialyzed. After dialysis, the dialyzed reaction solution is freeze-dried to obtain vascular endothelial-targeted biomimetic nanoparticles.

[0032] Preferably, the molar ratio of the CD31 antibody to tris(2-carboxyethyl)phosphine is 1:10; and the mass ratio of the STM2457@CD-ade-MSN / PL nanoparticles to the reduced CD31 antibody is 80:1.

[0033] Preferably, the pH value of the PBS buffer in step S1 is 6.8-7.6.

[0034] Preferably, the pH value of the PBS buffer in step S2 is 6.8-7.6, and the PBS solution contains 1 mM EDTA.

[0035] Preferably, the stirring reaction time in step S2 at room temperature in the dark is 8 to 12 hours.

[0036] Preferably, in step S1, a Zeba desalting column is used to remove the remaining tris(2-carboxyethyl)phosphine in the mixed solution, and the molecular weight cut-off of the Zeba desalting column is 7 KDa.

[0037] Preferably, the molecular weight cut-off of the dialysis in step S2 is 10 kDa.

[0038] Preferably, the freeze-drying treatment process in step S2 requires adding a freeze-drying protectant to the reaction solution after dialysis.

[0039] More preferably, the freeze-drying protective agent in step S2 is trehalose, and the mass ratio of trehalose to STM2457@CD-ade-MSN / PL is 1:1.

[0040] The fourth aspect of the present invention provides a vascular endothelium-targeted biomimetic nanoparticle prepared by the preparation method described in the third aspect.

[0041] The fifth aspect of the present invention provides the use of the STM2457@CD-ade-MSN / PL nanoparticles described in the second aspect in the preparation of a drug for preventing, alleviating or / and treating cardiovascular toxicity caused by chemotherapy drugs.

[0042] The sixth aspect of the present invention provides the use of the vascular endothelium-targeted biomimetic nanoparticles described in the fourth aspect in the preparation of a drug for preventing, alleviating or / and treating cardiovascular toxicity caused by chemotherapy drugs.

[0043] The seventh aspect of the present invention provides a drug for preventing, alleviating and / or treating cardiovascular toxicity caused by chemotherapy drugs, wherein the drug contains the STM2457@CD-ade-MSN / PL nanoparticles described in the second aspect or the endothelial-targeted biomimetic nanoparticles described in the fourth aspect.

[0044] Compared with the prior art, the present invention has the following positive and beneficial effects:

[0045] (1) The present invention uses the METTL3 inhibitor STM2457 to prepare STM2457@CD-ade-MSN / PL nanoparticles, which specifically inhibit the proliferation of vascular endothelial cells during chemotherapy. 6A epigenetic modification provides a new translational medicine strategy for the prevention and treatment of DOX chemotherapy-related vascular complications.

[0046] (2) This invention prepares endothelial-targeted biomimetic nanoparticles (ETMNs) and precisely delivers the METTL3 inhibitor STM2457 via platelet membrane-fused liposomes and CD31 antibody modification. ETMN innovatively integrates biomimetic targeting with epigenetic regulation mechanisms: CD31 antibodies and platelet membranes are used to enhance endothelial targeting and increase drug accumulation in damaged blood vessels; and DOX-induced endothelial senescence and inflammatory activation are blocked by inhibiting METTL3 enzyme activity, thereby synergistically alleviating vascular damage during chemotherapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the synthetic design of ETMN;

[0048] Figure 2 Figures 2 and 3 are the morphological potential characterization images of ETMN and MSN, where A is the TEM image of MSN; B is the TEM image of ETMN; C is the AFM image of ETMN; D is the DLS particle size image of ETMN and MSN; E is the Zeta potential image of ETMN and MSN; F is the image of MSN and ETMN after PBS precipitation for 30 minutes;

[0049] Figure 3 Figure 1 is the physical and chemical characterization diagram of ETMN, where A is TGA thermal gravimetric analysis; B is BET test; C is platelet membrane verification; D is FTIR Fourier transform infrared spectroscopy;

[0050] Figure 4 Figure 1 shows the in vitro and targeted studies of ETMN, where A is the hemolysis test; B is the CCK-8 cell viability test; C is the ETMN sustained-release effect evaluation; and D is the ETMN targeted evaluation.

[0051] Figure 5 Figure 4 is a biosafety evaluation chart, where A is a HE staining chart of various mouse tissues and organs (scale bar: 100 μm); BE are mouse blood biochemical tests, where B is the mouse alanine aminotransferase (ALT) test result chart; C is the UREA test result chart; D is the CREA test result chart; E is the mouse aspartate aminotransferase (AST) test result chart, a liver function indicator; statistical data are expressed as mean ± standard deviation (n = 6); ns indicates no statistically significant difference;

[0052] Figure 6 Schematic diagram of the drug treatment process of mice in the Vehicle group, DOX group, DOX+CM group, DOX+STM2457 group, and DOX+ETMN group;

[0053] Figure 7Figure 3 shows that ETMN nanoparticles improved DOX-induced vascular aging and atherosclerosis; A is a representative figure showing the gross morphology of the aortic arch; B is a representative figure showing the gross SA-β-gal staining of mouse blood vessels; C is a statistical analysis figure showing the gross SA-β-gal staining of mouse blood vessels; D is a representative figure showing the overall ORO staining of mouse aorta; E is a quantitative statistical analysis figure showing the overall ORO staining of mouse aorta; statistical data are expressed as mean ± standard deviation (n = 6), and ** represents P value < 0.01. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below through examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not intended to limit the present invention.

[0055] Example 1: Preparation of STM2457@CD-ade-MSN / PL nanoparticles

[0056] A method for preparing STM2457@CD-ade-MSN / PL nanoparticles, comprising the following steps:

[0057] (1) STM2457 was dissolved in a solvent consisting of DMSO and methanol in a volume ratio of 1:1, and amino-modified MSN (NH2-MSN) was added. The mixture was stirred in the dark for 48 h, centrifuged at 12,000 rpm for 15 min, and the precipitate was collected and dried to obtain STM2457@NH2-MSN (denoted as STM@MSN). The mass ratio of STM2457 to NH2-MSN was 1:5.

[0058] (2) Adamantane carboxylic acid (ade-COOH) (50 mg) was stirred with EDC (12.5 mg) and NHS (15 mg) in PBS for 15 minutes for activation. The precipitate was then centrifuged and freeze-dried to obtain activated adamantane carboxylic acid. STM2457@NH2-MSN (100 mg) and activated adamantane carboxylic acid (ade-COOH, 0.5 mmol) were then added to DMF for coupling and stirred at room temperature for 24 hours to obtain ade-MSN.

[0059] (3) ade-MSN was added to PBS buffer at pH 7.4, β-CD was added, and the mixture was stirred at 30°C for 8 h. The mixture was centrifuged at 10,000 rpm for 10 min, and the precipitate was collected. The precipitate was washed to remove free β-CD to obtain STM2457@CD-ade-MSN, where the mass ratio of β-CD to ade-MSN was 2:1.

[0060] (4) Liposomes and platelet membranes were mixed in a mass ratio of 1:1 and then mixed by probe ultrasound (200W, 5s pulse / 5s interval, total duration 2min) to obtain a mixture. The mixture was passed through Avanti The mixture was extruded by a Mini-Extruder, first through a polycarbonate membrane (pore size 400 nm), and then through a polycarbonate membrane (pore size 200 nm) to obtain a liposome-membrane mixture, and the STM2457@CD-ade-MSN prepared in step (3) was added to the liposome-membrane mixture. Probe ultrasound (100 W, intermittent mode) promoted the coating, and the precipitate was collected after centrifugation at 10,000 rpm for 10 min. After the precipitate was resuspended in PBS, trehalose, a freeze-drying protective agent, was added to the suspension of the precipitate resuspended in PBS, and freeze-dried to obtain STM2457@CD-ade-MSN / PL, wherein the mass ratio of STM2457@CD-ade-MSN to the liposome-membrane mixture was 1:10, and the mass ratio of trehalose to STM2457@CD-ade-MSN was 1:1.

[0061] The specific process for synthesizing amino-modified MSN (NH2-MSN) is as follows: 64 mL of water, 10.5 mL of ethanol (0.179 mol), and 10.4 mL of 25% hexadecyltrimethylammonium chloride (CTAC) solution (7.86 mmol) were mixed and stirred at room temperature for 10 minutes to obtain a mixed solution. 4.1 mL of triethanolamine (TEA, 0.031 mol) was added to the mixed solution, the pH of the solution was adjusted to 11, and the solution was heated to 85°C and stirred for 10 minutes. 4.35 mL of tetraethoxysilane (TEOS) (19.5 mmol) was slowly added dropwise to the solution, and the mixture was stirred vigorously overnight at 65°C under nitrogen to obtain a milky white particle suspension. The suspension was then cooled to room temperature, and 351 mL of ethanol was added to precipitate the silica particles. The suspension was allowed to stand for 4 hours and centrifuged at 10,000 rpm for 15 minutes. The precipitate was collected and placed in a mixture of methanol / hydrochloric acid (500:19 by volume) by waterbath sonication to remove the template agent CTAC. The mixture was stirred for 24 hours and then centrifuged at 10,000 rpm for 60 minutes. The precipitate was collected and washed three times with methanol and air-dried or dried at room temperature to obtain pure MSNs. 500 mg of MSNs were weighed and dispersed in 20 mL of methanol. 200 μL of 3-aminopropyltriethoxysilane (APTES) was then added. The mixture was stirred and sealed at 65°C overnight. The mixture was washed and freeze-dried to obtain NH2-MSNs.

[0062] The specific process of liposome preparation was as follows: DSPE-PEG2000-Mal, phosphatidylcholine and cholesterol were dissolved in chloroform / methanol (volume ratio 4:1) at a mass ratio of 1:4:1, and the film was formed by rotary evaporation, hydrated with PBS at 50°C for 10 min, and probe sonicated (150 W, 5 s on / off, 3 min) to obtain uniform liposomes.

[0063] The specific process of platelet membrane preparation: First, EDTA is added to the collected blood sample to a final concentration of 5mM to prevent platelet aggregation. Next, the blood and plasma samples are centrifuged at 100rcf for 20 minutes, and the upper platelet-rich plasma (PRP) is taken to separate red blood cells and white blood cells. The PRP is further centrifuged at 100rcf for 20 minutes to remove residual blood cells. To avoid platelet activation, purified PRP is added to PBS buffer containing 1mmol / L EDTA and 2μmol / L prostaglandin E1 (PGE1), followed by centrifugation at 800rcf for 20 minutes to induce platelet precipitation. After removing the supernatant, the precipitated platelets are resuspended in a PBS solution containing 1mmol / L EDTA and protease inhibitors are added. The extracted platelets were frozen and thawed five times at -80°C and 37°C, centrifuged at 12,000 rcf for 20 minutes, and the supernatant was discarded. The lower precipitate was the platelet membrane (PM). The extracted platelet membrane was stored at -80°C.

[0064] Example 2: Preparation of endothelial-targeted biomimetic nanoparticles

[0065] A method for preparing biomimetic nanoparticles targeting vascular endothelium (eg Figure 1 The specific steps are as follows:

[0066] S1: Add 0.37 nmol of CD31 antibody (1 mg / mL) and 3.7 nmol of tris(2-carboxyethyl)phosphine to a pH 7.4 PBS buffer, stir and mix, and incubate at room temperature for 1 h to reduce disulfide bonds to generate free sulfhydryl groups. After the incubation, the remaining tris(2-carboxyethyl)phosphine in the mixture is removed using a Zeba desalting column (molecular weight cutoff 7 kDa) to obtain the reduced CD31 antibody;

[0067] S2: The STM2457@CD-ade-MSN / PL nanoparticles prepared in Example 1 were mixed with the reduced CD31 antibody prepared in step S1 in a PBS buffer solution (containing 1 mM EDTA) at pH 7.0, and the mixture was stirred in the dark at room temperature for 12 h. After the reaction, the reaction solution was dialyzed (molecular weight cutoff 10 kDa) to remove unbound antibodies and other small molecules. The lyophilization protectant trehalose was added to the dialyzed reaction solution to obtain endothelial-targeted biomimetic nanoparticles (denoted as ETMN); wherein the mass ratio of STM2457@CD-ade-MSN / PL nanoparticles to reduced CD31 antibodies was 80:1, and the mass ratio of trehalose to STM2457@CD-ade-MSN / PL was 1:1.

[0068] Comparative Example 1: Preparation of CD-ade-MSN Material

[0069] A CD-ade-MSN material is prepared by stirring adamantane carboxylic acid (ade-COOH) (50 mg) with EDC (12.5 mg) and NHS (15 mg) in PBS for 15 minutes for activation. The precipitate is then centrifuged and freeze-dried to obtain the activated adamantane carboxylic acid. NH2-MSN (100 mg) is then coupled with the activated adamantane carboxylic acid (ade-COOH, 0.5 mmol) in DMF and stirred at room temperature for 24 hours to obtain ade-MSN. The ade-MSN is then dispersed in PBS (pH 7.4), and excess β-CD is added. The mixture is stirred at 30°C for 8 hours. The mixture is then centrifuged at 10,000 rpm for 10 minutes and washed to remove free β-CD, yielding the CD-ade-MSN material (denoted as CM). The molar ratio of β-CD to ade-MSN is 2:1.

[0070] Example 3: Characterization Test

[0071] 1. The encapsulation efficiency (EE) and drug loading efficiency (LE) of the STM@MSN prepared in step (1) of Example 1 were measured:

[0072] STM2457 was dissolved in a solution consisting of DMSO and methanol in a volume ratio of 1:1, and amino-modified MSN (NH2-MSN) was added and stirred in the dark for 48 hours. The mass ratio of STM2457 to NH2-MSN was 1:5. After the reaction, the reaction solution was centrifuged at 12,000 rpm for 15 minutes. The supernatant was collected and the absorbance of the supernatant was measured using a UV absorption spectrophotometer. The STM2457 content in the supernatant was calculated based on the standard curve formula of the relationship between STM2457 and absorbance. The encapsulation efficiency (EE) and drug loading efficiency (LE) of STM@MSN can be calculated by the following formula:

[0073] Encapsulation efficiency (EE) = (weight of encapsulated drug / total weight of input drug) × 100%,

[0074] Drug loading efficiency (LE) = (weight of loaded drug / total weight of drug and nanoparticles) × 100%,

[0075] The total weight of the drug input is 100 mg; the weight of the encapsulated drug = the total weight of the drug input - the weight of STM2457 in the supernatant, 85.3 mg; the weight of the loaded drug = the total weight of the drug input - the weight of STM2457 in the supernatant, 85.3 mg; the total weight of the drug and nanoparticles = the freeze-dried precipitate, 400 mg.

[0076] Calculations show that the encapsulation efficiency EE is approximately 85.3% and the drug loading efficiency LE is approximately 21.3%.

[0077] 2. Morphological characterization of ETMN

[0078] The microscopic morphology of ETMN was tested, and the morphology and particle size distribution were determined by transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic light scattering (DLS). Figure 2 As shown. TEM shows the morphology of MSN and ETMN ( Figure 2 A-2B), under the microscope, MSNs are uniformly dispersed, and most of the particles are small. The internal porous structure is clearly visible at around 20nm, indicating that the high specific surface area characteristics of MSNs contribute to the efficient loading and sustained release of drugs. ETMNs appear as uniformly distributed monodispersed spherical nanoparticles with a diameter of about 70 to 100nm. The outer light gray halo in the figure is a coated fusion membrane structure, and the outer membrane encapsulation is continuous and complete. DLS characterization of the particle size of MSN and ETMN ( Figure 2 D), which is basically consistent with the particle size characterized by the dynamic light scattering nanoparticle size analyzer. The results show that the average particle size of ETMN is 78.42±12.63nm, which is larger than that of unmodified MSN (21.70±2.87nm), suggesting that the surface functionalization process leads to an increase in its particle size and that the liposome fusion membrane may encapsulate multiple MSN particles. Atomic force microscopy (AFM) shows that the diameter of a single ETMN particle is 50-100nm, which is basically consistent with the DLS results ( Figure 2 C), ETMN particles are evenly distributed, with slight aggregation (bright yellow clumps) in some areas, which may be caused by hydrophobic interactions during the biomimetic membrane fusion process.

[0079] 3. Potential of ETMN

[0080] MSN and ETMN were dispersed in ultrapure water to prepare a suspension with a concentration of 0.1 mg / mL. Ultrasonic treatment was performed for 5 minutes to eliminate agglomerates and ensure uniform dispersion of particles. The Zeta potential of the particles was measured using a dynamic light scattering (DLS) and potentiometric analysis. The test temperature was set at 25°C, the equilibrium time was 120 seconds, and each sample was measured three times to obtain the average value. The test results are shown in Figure 2. Figure 2 E. The larger the absolute value of the zeta potential, the higher the particle surface charge density, the stronger the electrostatic repulsion, and the better the system stability. ETMN has a larger absolute value of the zeta potential and better stability.

[0081] 4. Stability characterization of ETMN

[0082] MSN and ETMN were dissolved in PBS at a concentration of 1 mg / mL, and allowed to stand at room temperature for 30 minutes to observe the precipitation. Figure 2 F, Compared with MSN, ETMN has better dispersibility and solution stability.

[0083] 5. Thermogravimetric analysis of ETMN

[0084] The thermal stability and composition of ETMN were analyzed by thermogravimetric analysis (TGA). Figure 3 As shown in A. The thermogravimetric curve shows that the weight of ETMN decreases continuously with increasing temperature from the initial weight of 5000 μg ( Figure 3 A) , with a final residue of approximately 940 μg (18.8%), indicating partial decomposition of the material at high temperature, leaving behind stable components. During the low-temperature phase, the sample lost 7.2% weight (TG dropped from 100% to 92.8%), corresponding to the evaporation of adsorbed water or residual solvent. During the main decomposition phase (224°C), a significant weight loss of 27.5% (TG dropped from 92.8% to 65.3%) was observed, resulting from the release of the drug STM2457 and the destruction of the cyclodextrin-adamantane gating structure. The high-temperature residue (18.8%) contained a stable MSN support (SiO2), indicating that its framework maintained integrity at high temperatures.

[0085] 6. Specific surface area and pore size analysis of ETMN (BET)

[0086] The specific surface area parameters of ETMN and MSN were determined by nitrogen adsorption-desorption (BET) method. Figure 3 As shown in B. From the nitrogen adsorption-desorption isotherm ( Figure 3 B) It can be seen that the isotherm belongs to type IV isotherm, and the H2b type adsorption hysteresis loop appears, which corresponds to the capillary condensation phenomenon that occurs in the porous structure of MSN adsorption. The specific surface area is calculated according to the BET equation. The BET specific surface area of ​​MSN is 454.86m 2 / g, and the BJH pore size is 2-4 nm. After drug loading, the BET specific surface area of ​​ETMN is reduced to 227.67 m 2 This decrease may be due to the encapsulation of STM2457 occupying the pores of MSNs, thereby reducing the specific surface area, which confirms that STM2457 is successfully loaded into MSNs.

[0087] 7. ETMN platelet membrane coating verification

[0088] The platelet membrane coating of ETMN was confirmed by Coomassie brilliant blue stained gel electrophoresis. At the same time, for comparison, Platelet (platelet), PM (platelet membrane), ETMN (targeted nanoparticles) and MSN (bare silicon nanoparticles) were measured. The results are shown in Figure 2. Figure 3 As shown in Figure C, the protein band distribution of Platelet (platelet), PM (platelet membrane), ETMN (targeted nanoparticles) and MSN (bare silicon nanoparticles) was compared, confirming that the platelet membrane was successfully coated on the surface of ETMN. The band distribution of ETMN and PM was similar, indicating that the integrity of membrane proteins was preserved. Western blot showed that the key platelet-specific membrane protein CD41 (GPIIb / IIIa receptor) was visible in the ETMN group ( Figure 3 C), indicating successful integration of platelet membrane components onto the nanoparticle surface.

[0089] 8. Infrared characterization of ETMN

[0090] Fourier transform infrared spectroscopy was used to characterize ETMN and evaluate its special spectral absorption. At the same time, for comparison, the infrared spectra of MSN and CD-ade-MSN were also tested. The results are as follows Figure 3 As shown in D, in the infrared spectrum of MSN mesoporous silicon, 3346 cm -1 The peak at 1075 cm-1 is attributed to the stretching vibration of hydroxyl groups, mainly from the hydroxyl groups and silanol groups adsorbed in the mesoporous silica voids of MSN. -1 , 799cm -1 and 473cm -1 These are typical characteristic peaks of MSN mesoporous silicon, which are respectively attributed to the asymmetric stretching vibration peak of Si-O-Si skeleton, the symmetric stretching vibration peak and the Si-OH stretching vibration peak of silanol group. After loading cyclodextrin and adamantane, CD-ade-MSN has a peak at 3346 cm -1 The OH stretching vibration peak red-shifted and broadened to 3287 cm -1 , indicating that the addition of cyclodextrin promotes the formation of intermolecular hydrogen bonds. Since cyclodextrin is rich in hydroxyl groups, these hydroxyl groups are adsorbed on MSN by intermolecular hydrogen bonds. -1The absorption peak of ETMN is also attributed to the OH bending vibration peak of hydroxyl group. After loading STM2457, ETMN has a peak at 3287cm -1 The absorption peak is blue-shifted to 3375 cm -1 This is because after the introduction of STM2457, the material is rich in unassociated NH groups, 1686cm -1 The absorption peak that appears is attributed to the C=O stretching vibration peak of the amide group in STM2457, and is also superimposed with the C=N stretching vibration peak at 1533 cm -1 The broad peak at 1173 cm is attributed to the NH bending vibration peak and the superposition peak of the C=C stretching vibration peak in the nitrogen-containing ring. -1 The new absorption peak is attributed to the CN stretching vibration peak. The shift and change of the infrared spectrum absorption peak indicate that the modification of MSN mesoporous silica is successful and reveal that its adsorption mainly relies on hydrogen bonding interaction.

[0091] Example 4: ETMN in vitro studies

[0092] 1. Hemolysis test of ETMN

[0093] Fresh blood samples were collected in EDTA-free centrifuge tubes and centrifuged (1,500 rpm, 10 min). The red blood cells were washed with PBS to obtain a cell density of approximately 5.0 × 10 9 Different concentrations of ETMN (25, 50, 100, 200, and 500 μg / mL) were added to red blood cells to form a mixture. Ultrapure water and PBS were used as positive and negative controls, respectively, to control the hemolytic effect of ETMN. After 30 minutes, the mixture was centrifuged at 1,500 rpm for 10 minutes to pellet the red blood cells. Finally, the absorbance (A) at 578 nm was recorded using a microplate reader, and the percentage of hemolysis was calculated. The percentage of hemolysis of RBCs was calculated according to the following formula:

[0094]

[0095] Hemolysis test showed that compared with the positive group (H2O group), ETMN showed superior blood compatibility in the range of 25-500 μg / mL ( Figure 4 A) Even at high concentrations (500 μg / mL), ETMN showed no significant hemolytic activity, indicating its suitability for intravenous or systemic administration.

[0096] 2. Cell activity and proliferation ability:

[0097] HUVEC cells were cultured in 96-well plates at 37°C in an incubator with 5% CO2 and 95% humidity. The cells were seeded at a density of 8,000 cells per well and allowed to adhere for 12 hours. Complete culture medium and ETMN were then mixed at concentrations of 0, 10, 20, 40, 80, 160, 200, 250, 300, 350, and 400 μg / mL and added to the 96-well plates for incubation for 24 hours. The initial culture medium was discarded, and the cells were gently rinsed once or twice with PBS. The proliferation capacity of HUVEC in each group was quantitatively analyzed using the CCK-8 assay. A CCK-8 working solution was prepared at a ratio of 1:10 (volume ratio) between CCK-8 and culture medium. 100 μL of CCK-8 working solution was added to each well and incubated at 37°C for 1 hour. Finally, absorbance at 450 nm was measured using a GF-M3000 microplate reader. The cell viability was calculated based on the absorbance using the following formula:

[0098]

[0099] As: absorbance of experimental wells (containing cells, culture medium, CCK-8 solution, and drug solution);

[0100] Ac: absorbance of control well (containing cells, culture medium, and CCK-8 solution, but no drug);

[0101] Ab: absorbance of blank wells (containing culture medium and CCK-8 solution, but not cells or drugs).

[0102] CCK-8 cell viability assay showed that when ETMN was ≤ 200 μg / mL, ETMN had no significant toxicity to vascular endothelial cells (viability > 90%), while at 300 μg / mL, ETMN had significant toxicity ( Figure 4 B), may be due to the aggregation or dissolution of nanoparticles at high concentrations to release drugs leading to cell stress.

[0103] 3. Sustained-release effect of ETMN

[0104] In order to verify that ETMN has the property of slowly releasing STM2457, ETMN and the control group STM@MSN (the substance prepared in step (1) of Example 1) were dispersed in PBS buffer (pH 7.4) at 1 mg / mL, and ultrasonically treated for 5 minutes to ensure uniform dispersion to prepare two nanoparticle solutions. The two nanoparticle solutions were respectively loaded into dialysis bags with a molecular retention rate of 8-14 kDa and immersed in 50 mL PBS. Samples were taken at predetermined times of 0, 0.25, 0.5, 1, 2, 4, 6, 8, 12, 24, 36, and 48 hours, with 1 mL of dialysate taken each time and supplemented with an equal volume of fresh medium. The dialysate was centrifuged (12,000 rpm, 10 minutes), and the absorbance was measured at the maximum absorption wavelength of STM2457 (260 nm). The concentration was calculated using the standard curve. The results are shown in Figure 2. Figure 4 As shown in C.

[0105] By comparing the drug release effects of ETMN and the control group STM@MSN, it can be found that the drug release rate of STM@MSN is significantly accelerated, indicating that the ETMN constructed in this study meets the design requirements of sustained release ( Figure 4 C).

[0106] Example 5: In vivo distribution study and biosafety assessment of ETMN

[0107] (1) Targeted verification of ETMN

[0108] To verify the vascular targeting ability of ETMN nanoparticles, Cy5.5-NHS ester was covalently modified on the surface of ETMN using the amino coupling method. Cy5.5 fluorescently labeled ETMN was prepared using this method, recorded as Cy5.5-ETMN. At the same time, a control group of Cy5.5 fluorescently labeled CM was set up, recorded as Cy5.5-CM, and the targeting efficiency of Cy5.5-ETMN was evaluated using the small animal in vivo imaging technology (In Vivo Imaging System, IVIS) system.

[0109] C57BL / 6 mice were selected and divided into a Cy5.5-ETMN experimental group, a Cy5.5-CM non-targeted control group, and a Vehicle group, with 6 mice in each group.

[0110] The treatment method of the Cy5.5-ETMN experimental group was as follows: Cy5.5-ETMN (dissolved in PBS and stored in the dark) was injected into the tail vein (10 mg / kg). At 2 hours, 8 hours, and 12 hours, the aorta of the anesthetized mice was isolated and the fluorescence signal was collected.

[0111] The treatment method of the Cy5.5-CM non-targeted control group was as follows: Cy5.5-CM (dissolved in PBS and stored in the dark) was injected into the tail vein (10 mg / kg). At 2 hours, 8 hours, and 12 hours, the aorta of anesthetized mice was isolated and the fluorescence signal was collected.

[0112] The Vehicle group was treated by tail vein injection of PBS. At 2 hours, 8 hours, and 12 hours, the mice were anesthetized and the aorta was isolated for fluorescence signal acquisition.

[0113] The fluorescence distribution of the Cy5.5-ETMN experimental group, Cy5.5-CM non-targeted control group and Vehicle group was dynamically monitored at 2h, 8h and 12h after tail vein injection. Figure 4 As shown in D.

[0114] Figure 4 D shows that compared with the control group, Cy 5.5-CM, the Cy5.5 fluorescence signal of Cy 5.5-ETMN in the mouse aorta was significantly enhanced, and the signal intensity gradually accumulated over time (2 hours, 8 hours, and 12 hours). This result indicates that ETMN has successfully achieved efficient enrichment in the vascular endothelium through surface antibody targeted modification and platelet membrane coating to prolong circulation time.

[0115] (2) Biosafety Assessment of ETMN

[0116] 1. HE staining of mouse tissues and organs

[0117] To evaluate the biosafety of ETMN in vivo, normal C57BL / 6 mice were divided into a vehicle group and an ETMN group, with 6 mice in each group.

[0118] The mice in the Vehicle group were injected with PBS into the tail vein once every 2 days for 8 weeks.

[0119] The mice in the ETMN group were treated with ETMN (50 mg / kg, dissolved in PBS) injected into the tail vein once every 2 days for 8 weeks.

[0120] ETMN (50 mg / kg, dissolved in PBS) at a dose five times that of the experimental group was injected through the tail vein. The experiment adopted an 8-week continuous administration schedule. After the administration, the experimental animals were anesthetized with isoflurane and then killed.

[0121] For tissue and organ sampling, cardiac perfusion was performed and lung, spleen, heart, liver, and kidney tissues were collected for HE staining. The HE staining steps are as follows:

[0122] (1) Frozen sections were air-dried at room temperature for 3 h and hydrated for 10 min.

[0123] (2) Soak in hematoxylin solution for 5 minutes, then rinse with tap water for 6 minutes;

[0124] (3) Differentiate with 1% hydrochloric acid alcohol for 3 seconds and rinse with tap water for 2 minutes;

[0125] (4) Place the sections in Tris (pH 8.8) to blue for 3 seconds, then rinse with tap water;

[0126] (5) Soak the slices in eosin dye for 5 min and wash the slice surface with PBS;

[0127] (6) The dehydration steps are as follows:

[0128] Soak in 90% ethanol for 1 min;

[0129] Soak in anhydrous ethanol I for 5 min;

[0130] Soak in fresh anhydrous ethanol II for 5 minutes;

[0131] (7) The transparent steps are as follows:

[0132] Soak in clearing agent I for 5 minutes;

[0133] Soak in new clearing agent II for 5 minutes;

[0134] (8) Use a fully automatic sealing machine to seal the slides;

[0135] (9) Observe and take pictures under the microscope.

[0136] The results of HE staining experiments are as follows Figure 5 As shown in A, in the hematoxylin-eosin (HE)-stained sections of the heart, lungs, spleen, liver, and kidneys, the tissue morphology and structure were intact, the cells were arranged in an orderly manner, and no obvious pathological changes such as congestion, edema, necrosis, and inflammatory infiltration were observed ( Figure 5 A), Experimental results show that ETMN has good biocompatibility in vivo.

[0137] 2. Mouse blood biochemical test

[0138] To evaluate the biosafety of ETMN in vivo, normal C57BL / 6 mice were divided into Vehicle group, DOX group, DOX+CM group, DOX+STM2457 group, and DOX+ETMN group, with 6 mice in each group.

[0139] The mice in the Vehicle group were injected with PBS into the tail vein once every 2 days for 8 weeks.

[0140] The mice in the DOX group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and PBS injected into the tail vein once every 2 days for 8 weeks.

[0141] Mice in the DOX+CM group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and CM (50 mg / kg, dissolved in PBS) injected into the tail vein once every 2 days for 8 weeks.

[0142] Mice in the DOX+STM2457 group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and STM2457 (50 mg / kg, dissolved in PBS) injected into the tail vein once every 2 days for 8 weeks.

[0143] Mice in the DOX+ETMN group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and ETMN (50 mg / kg, dissolved in PBS) injected into the tail vein once every 2 days for 8 weeks.

[0144] The study employed an 8-week continuous dosing regimen. Following the end of dosing, the animals were anesthetized with sodium pentobarbital. Subsequently, 400 μL of whole blood was collected via abdominal aorta blood sampling. After 30 minutes of rest at room temperature, the blood was centrifuged at 3,500 rcf for 10 minutes to separate the serum samples, which were then measured using an automated biochemical analyzer.

[0145] Blood biochemical tests showed that the liver function indicators aspartate aminotransferase (AST), alanine aminotransferase (ALT), renal function indicators urea (UREA), creatinine (CREA) in each group were within the normal reference range, and no abnormalities were found ( Figure 5 B-5E). Experimental results show that ETMN has good biocompatibility in vivo.

[0146] (III) ETMN improves DOX-induced vascular aging and atherosclerosis

[0147] (1) Experimental animals:

[0148] C57BL / 6J mice and Apoe - / - Mice were purchased from Spav. In accordance with the "3R" ethical guidelines, experimental animals were housed in an SPF-grade barrier environment, maintaining constant temperature and humidity (22 ± 1°C, 50 ± 5% relative humidity) with a 12-hour light-dark cycle. Sterile bedding was regularly changed according to standard operating procedures, and ample sterilized feed and drinking water were provided. All procedures were in accordance with the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health.

[0149] (2) Experimental groups and treatment methods:

[0150] ApoE at 5 weeks of age - / - The mice were divided into vehicle group, DOX group, DOX+CM group, DOX+STM2457 group, and DOX+ETMN group, with 12 mice in each group. The treatment of each group was as follows (see Figure 6 ):

[0151] The mice in the Vehicle group were treated with PBS via tail vein injection once every two days for eight weeks.

[0152] The mice in the DOX group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and PBS injected into the tail vein once every 2 days for 8 weeks.

[0153] Mice in the DOX+CM group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and CM (10 mg / kg, dissolved in PBS) injected into the tail vein once every 2 days for 8 weeks.

[0154] Mice in the DOX+STM2457 group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and STM2457 (10 mg / kg, dissolved in PBS) injected into the tail vein once every 2 days for 8 weeks.

[0155] Mice in the DOX+ETMN group were treated with DOX (5 mg / kg) injected into the tail vein once a week for 4 weeks and ETMN (10 mg / kg, dissolved in PBS) injected into the tail vein once every 2 days for 8 weeks.

[0156] ApoE at 5 weeks of age - / - Mice were fed a high-fat diet purchased from Nantong Trophy Feed Technology Co., Ltd. and maintained on a normal diet until week 13. Starting from week 5 of the experiment, they were intravenously injected with DOX (5 mg / kg) weekly for 4 weeks. Starting from week 4 of the experiment, they were intravenously injected with ETMN, STM2457, and CM weekly at a dose of 10 mg / kg each.

[0157] (3) The operation process of whole-body ORO staining of aorta is as follows:

[0158] Take 13-week-old mice, anesthetize them and perform surgery under a stereomicroscope to separate the entire length of the aorta. Use ophthalmic scissors to make a longitudinal cut along the long axis of the blood vessel, and then gently wash the blood vessel sample with ddH2O. During the experiment, the sample was briefly placed in an isopropanol solution, then transferred to Oil Red O staining solution, and incubated in the dark at a constant temperature of 37°C for 1 hour (the staining time can be appropriately extended according to experimental requirements). After staining is completed, the sample is immersed in 60% isopropanol solution again for differentiation until the vascular endothelium is successfully stained with plaques, and there is no obvious red residue in the plaque-free area. After termination of differentiation, the blood vessel sample is thoroughly rinsed with ddH2O. Finally, the blood vessel sample is flattened on a black background slide with a ruler and photographed and recorded.

[0159] (4) Aorta β-GAL staining

[0160] According to the instructions for the Beyotime β-galactosidase staining kit (C0602), the staining solution was prepared and preheated in a 37°C constant temperature water bath in the dark. Thirteen-week-old mice were anesthetized and surgically isolated under a stereomicroscope along the entire length of the aorta. The vessels were longitudinally incised along their long axis using ophthalmic scissors, and the vascular specimens were gently rinsed with ddH2O. Fresh vessel specimens were morphologically trimmed, washed with PBS, and fixed with fixative at 4°C for 8 hours. The vessel surface was then washed with PBS, and the staining solution was added. The vessels were then transferred to 37°C in the dark overnight.

[0161] The results are as follows Figure 7 As shown. Compared with the vehicle group, the aortic arch lesions in the DOX group and the DOX+CM control group were similar, with extensive lipid plaque deposition (yellow area). The plaques were diffusely distributed, involving the aortic arch and branch vessels. Compared with the slightly reduced lesion severity in the DOX+STM2457 group, the aortic arch lesions in the DOX+ETMN group were significantly improved, with only sporadic lipid deposition on the surface ( Figure 7 A) SA-β-gal staining of the aorta of mice showed that DOX treatment led to a significant increase in the SA-β-gal positive area of ​​the aorta endothelium, while the positive area in the DOX+ETMN group was significantly decreased ( Figure 7 B-7C). ORO staining of mouse aorta showed ( Figure 7 DOX treatment significantly exacerbated aortic lesion formation, indicating that DOX induced significant vascular damage. In contrast, the DOX+ETMN group exhibited a significant protective effect. Statistical analysis showed that the lesion area was reduced to approximately 20% compared to the DOX-treated group, and the efficacy was significantly superior to the DOX+STM2457 group. However, there was no significant difference between the DOX+CM group and the DOX group, indicating that the nanoparticle carrier itself had no protective effect.

[0162] These results suggest that, compared to the free METTL3 inhibitor STM2457, ETMN has a significant therapeutic effect in slowing plaque formation and delaying AS progression, validating the unique advantage of ETMN nanoparticles through a dual strategy of targeted delivery and controlled release.

Claims

1. A method for preparing STM2457@CD-ade-MSN / PL nanoparticles, characterized in that: The following steps are involved: (1) STM2457 was dissolved in a solvent to obtain an STM2457 solution, and amino-modified MSN was added to the STM2457 solution and stirred in the dark for 24 to 48 hours. The precipitate was collected by centrifugation and dried to obtain STM2457@NH2-MSN. (2) STM2457@NH2-MSN and adamantane carboxylic acid were added to N,N-dimethylformamide and stirred at room temperature to obtain ade-MSN; (3) ade-MSN was added to PBS buffer, and then β-cyclodextrin was added to the PBS buffer, stirred at 30°C for 8 h, and the precipitate was collected by centrifugation. The precipitate was washed to remove free β-cyclodextrin to obtain STM2457@CD-ade-MSN; (4) The liposomes are mixed with the platelet membrane to form a liposome-membrane mixture, the STM2457@CD-ade-MSN prepared in step (3) is added to the liposome-membrane mixture, ultrasonically coated, and the precipitate is collected by centrifugation. The precipitate is resuspended in PBS and freeze-dried to obtain STM2457@CD-ade-MSN / PL.

2. The method for preparing STM2457@CD-ade-MSN / PL nanoparticles according to claim 1, characterized in that: The mass ratio of the STM2457 to the amino-modified MSN is 1:

5.

3. The method for preparing STM2457@CD-ade-MSN / PL nanoparticles according to claim 1 or 2, characterized in that: The dosage ratio of STM2457@NH2-MSN to adamantane carboxylic acid is 100 mg:0.5 mmol; the mass ratio of β-cyclodextrin to ade-MSN is 2:1; the mass ratio of liposomes to platelet membranes is 1:1, and the mass ratio of STM2457@CD-ade-MSN to the liposome-membrane mixture is 1:

10.

4. The method for preparing STM2457@CD-ade-MSN / PL nanoparticles according to claim 1, characterized in that: Step (2) Before coupling STM2457@NH2-MSN with adamantane carboxylic acid, the adamantane carboxylic acid needs to be activated with EDC / NHS. The specific operation of the activation treatment is as follows: adamantane carboxylic acid, EDC, and NHS are added to PBS buffer and stirred for reaction. After the reaction, the precipitate is centrifuged and freeze-dried to obtain activated adamantane carboxylic acid.

5. STM2457@CD-ade-MSN / PL nanoparticles prepared by the method for preparing STM2457@CD-ade-MSN / PL nanoparticles according to any one of claims 1 to 4.

6. A method for preparing vascular endothelial-targeted biomimetic nanoparticles, characterized in that: The following steps are involved: S1: adding CD31 antibody and tris(2-carboxyethyl)phosphine to PBS buffer, stirring to mix, and incubating at room temperature. After the incubation, a mixed solution is obtained, and the remaining tris(2-carboxyethyl)phosphine in the mixed solution is removed to obtain a reduced CD31 antibody; S2: The STM2457@CD-ade-MSN / PL nanoparticles described in claim 5 are mixed with the reduced CD31 antibody prepared in step S1 in PBS buffer, and the mixture is stirred at room temperature in the dark. After the reaction is completed, the reaction solution is dialyzed. After dialysis, the dialyzed reaction solution is freeze-dried to obtain vascular endothelial-targeted biomimetic nanoparticles.

7. The method for preparing vascular endothelial-targeted biomimetic nanoparticles according to claim 6, characterized in that: The molar ratio of the CD31 antibody to tris(2-carboxyethyl)phosphine was 1:10; the mass ratio of the STM2457@CD-ade-MSN / PL nanoparticles to the reduced CD31 antibody was 80:

1.

8. A biomimetic nanoparticle targeted to vascular endothelium prepared by the preparation method according to claim 6 or 7.

9. Use of the STM2457@CD-ade-MSN / PL nanoparticles according to claim 5 or the endothelium-targeted biomimetic nanoparticles according to claim 8 in the preparation of a drug for preventing, alleviating, or / and treating cardiovascular toxicity caused by chemotherapy drugs.

10. A drug for preventing, alleviating and / or treating cardiovascular toxicity caused by chemotherapy drugs, characterized in that: The drug contains the STM2457@CD-ade-MSN / PL nanoparticles according to claim 5 or the vascular endothelial-targeted biomimetic nanoparticles according to claim 8.

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