A reactive oxygen species-responsive hydrogel coating for anti-vascular restenosis, its preparation method and application

Abstract

The present invention relates to the technical field of biomedical materials, and discloses a reactive oxygen species-responsive hydrogel coating for anti-vascular restenosis, its preparation method and application. The reactive oxygen species-responsive hydrogel coating is a hydrogel coating obtained by crosslinking a reactive oxygen species-responsive and scavenging polymer prodrug and dopamine-modified oxidized dextran. The hydrogel coating is transferred to the inner wall of the blood vessel along with the high-pressure balloon dilation, and responds to degradation under the stimulation of excessive reactive oxygen species in the diseased tissue, releasing antioxidant drugs, effectively scavenging local excessive reactive oxygen species, improving the inflammatory microenvironment, and thus inhibiting vascular restenosis.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical materials, and particularly relates to a reactive oxygen species-responsive hydrogel coating for anti-vascular restenosis, and a preparation method and application thereof. Background Art

[0002] Cardiovascular diseases (CVDs) have become the number one killer threatening human health. Percutaneous Coronary Intervention (PCI) has become the mainstream technology for treating cardiovascular diseases due to its characteristics of minimal trauma, less bleeding, and low complications. As an "interventional without implantation" innovative treatment plan, Drug-Coated Balloons (DCBs) have shown significant advantages in preventing in-stent restenosis and inhibiting acute thrombosis. DCBs can efficiently transfer anti-proliferative drugs to the vessel wall while dilating stenotic blood vessels, and do not leave permanent implants, thereby effectively inhibiting the proliferation and migration of local smooth muscle cells and delaying the occurrence of restenosis after surgery. Compared with traditional stent implantation, DCBs have multiple clinical advantages, including no in-vivo foreign body residue, no risk of in-stent thrombosis, shortening the time of dual antiplatelet therapy, reducing the bleeding risk, and having a wider scope of application. Therefore, DCBs are considered a key competitive technology in the medical device field and have great market potential.

[0003] However, the coating drugs of existing DCBs mainly include paclitaxel and rapamycin. For example, CN101496813A discloses a composition for treating vascular restenosis or other tissue hyperplasia and an application method thereof. The composition includes rapamycin, paclitaxel, and heparin. The application of the composition includes not only systemic administration but also local slow release of the drug into the diseased tissue. The composition can be applied to a stent or platform by a premixing / or multi-layer spraying method. It is first confirmed that the rapamycin + paclitaxel mixture and the rapamycin + paclitaxel + heparin mixture have a more significant inhibitory effect on vascular endothelial hyperplasia after stent implantation than any single drug use.

[0004] However, these two drugs still face significant limitations in clinical applications. Although paclitaxel has good anti-proliferative effects, its systemic toxicity is high and the coating particles are prone to shedding; rapamycin has low lipophilicity and slow tissue absorption. These problems greatly limit the clinical pharmacological applications and biological effects of such drugs, ultimately leading to the occurrence of vascular restenosis. There is an urgent need for new coating drugs to promote the clinical application of DCBs.

[0005] In vascular interventional therapy, the vascular intima is inevitably torn, triggering an inflammatory response and excessive healing, leading to negative vascular remodeling, smooth muscle cell proliferation and migration, and excessive neointimal hyperplasia. Oxidative stress and inflammatory responses are key early factors in this pathological process, and these responses are closely related to the excessive generation of reactive oxygen species (ROS) in the local microenvironment. Excessive reactive oxygen species not only trigger apoptosis and tissue damage but also inhibit the repair of vascular injury. Therefore, timely and effective regulation of the reactive oxygen species level in the wound microenvironment to keep it within the normal range is crucial for promoting neointimal regeneration and vascular repair.

[0006] The excessive generation of reactive oxygen species provides a precise drug delivery target for the treatment of inflammatory diseases. Reactive oxygen species-responsive and scavenging coating materials can not only achieve targeted drug delivery and controlled release but also inhibit inflammation and promote the rapid repair of damaged intima by scavenging reactive oxygen species. Borate ester bonds have been widely used in inflammatory targeting and remission therapy due to their responsiveness and consumption ability towards reactive oxygen species. Catechol-containing compounds have also been widely used in the fields of antioxidant, anti-inflammatory, and anti-infection in recent years due to their functional groups such as catechol and acrylic acid. Although these studies provide a theoretical basis for the development of novel reactive oxygen species-responsive materials, there is currently no application of reactive oxygen species-responsive hydrogel coatings in situ constructed based on borate esters and catechol-containing compounds for inhibiting restenosis.

[0007] Therefore, the development of hydrogel coatings with reactive oxygen species-responsive and scavenging capabilities can provide potential solutions to the clinical problem of restenosis. Summary of the Invention

[0008] In view of the clinical problem of restenosis, the present invention provides a reactive oxygen species-responsive hydrogel coating for anti-restenosis. This hydrogel coating is transferred to the inner wall of the blood vessel along with the high-pressure balloon dilation and degrades responsively under the stimulation of excessive reactive oxygen species in the diseased tissue, releasing antioxidant drugs to effectively scavenge local excessive reactive oxygen species, improve the inflammatory microenvironment, and thus inhibit restenosis.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A reactive oxygen species-responsive hydrogel coating for anti-restenosis, wherein the reactive oxygen species-responsive hydrogel coating is a hydrogel coating crosslinked by a reactive oxygen species-responsive and scavenging polymer prodrug and dopamine-modified oxidized dextran;

[0011] The structural formula I of the reactive oxygen species-responsive and scavenging polymer prodrug is as follows:

[0012] (I)

[0013] Wherein R 1 is H, , , , , , , , , any one of; R 2 is a polycation;

[0014] The polycation includes one or more of poly-L-lysine, polyethyleneimine, polyaminoamine, polyamino co-ester, polyacrylamine, polyquaternary ammonium salt polymer, polymethacrylate;

[0015] The structural formula II of the dopamine-modified oxidized dextran is as follows:

[0016] (II)

[0017] Wherein n is a natural number from 50 to 500.

[0018] In the present invention, the reactive oxygen species-responsive and scavenging polymer prodrug is a polycation grafted with carboxyphenylboronic acid ester of a catechol compound. The dopamine-modified oxidized dextran contains an imine bond, and a hydrogel coating is formed by crosslinking through a Schiff base reaction between the two. Among them, the imine bond and the boronic acid ester bond have good reactive oxygen species responsiveness and break under the trigger of high reactive oxygen species in inflammatory tissues, capable of releasing phenolic drugs and scavenging local excessive reactive oxygen species to exert anti-inflammatory and antioxidant functions. At the same time, dopamine modification can enhance the transfer and adhesion of the coating to the vascular inner wall, improve the drug delivery efficiency and prolong its residence time. The hydrogel coating is biodegradable, has good biocompatibility, can relieve high oxidative stress and inflammatory reactions, and promote the rapid repair of the vascular endothelium, thereby effectively inhibiting post-interventional vascular restenosis.

[0019] The reaction formula for the degradation of the reactive oxygen species-responsive and scavenging polymer prodrug is as follows:

[0020]

[0021] The mass ratio of the reactive oxygen species-responsive and scavenging polymer prodrug to the dopamine-modified oxidized dextran is 1:1 - 1:6, preferably 1:2. At this ratio, the hydrogel has better gel-forming properties.

[0022] The preparation of the reactive oxygen species-responsive hydrogel coating includes the steps of: spraying a reactive oxygen species-responsive and scavenging polymer prodrug and dopamine-modified oxidized dextran on the surface of a substrate by ultrasonic atomization, and subjecting it to self-crosslinking to obtain the reactive oxygen species-responsive hydrogel coating. The hydrogel coating is prepared by ultrasonic atomization spraying technology, which has a simple process and mild conditions, and can uniformly and efficiently coat functional components on the surface of cardiovascular implantable devices.

[0023] The preparation process of the reactive oxygen species-responsive and scavenging polymer prodrug includes the steps of:

[0024] Step 1: React a catechol compound shown by formula M1 and 4-carboxyphenylboronic acid in an anhydrous solvent to obtain a catechol carboxyphenylboronate shown by formula M2;

[0025]

[0026] Step 2: Dissolve the catechol carboxyphenylboronate shown by formula M2 in a mixed solvent of an organic solvent and water, add EDC and NHS and mix them, then add an aqueous solution of a polycation and react. After adjusting with an inorganic base, dialysis is carried out to obtain the reactive oxygen species-responsive and scavenging polymer prodrug. The reaction formula is as follows:

[0027]

[0028] In Step 1, the molar ratio of M1 to 4-carboxyphenylboronic acid is 0.5:1 - 0.9:1, preferably 0.9:1;

[0029] The solvent in Step 1 includes any one or more of N,N-dimethylformamide, dimethyl sulfoxide, dichloromethane, chloroform, toluene or dioxane;

[0030] In Step 1, the reaction temperature is 60 - 120 °C and the reaction time is 4 - 24 h;

[0031] Preferably, after removing the solvent by rotary evaporation for the product of Step 1, the product is dissolved in ethyl acetate and recrystallized to purify the product.

[0032] In Step 2, the molar ratio of M2 to the polycation is 100:1 - 10:1, preferably 80:1;

[0033] The organic solvent in Step 2 includes any one or more of dimethyl sulfoxide, dichloromethane, chloroform, methanol, ethanol, N,N-dimethylformamide, tetrahydrofuran.

[0034] The molar ratio of the charged EDC and NHS is 1:1 - 1.2:1, preferably 1.2:1; The molar ratio of EDC and M2 is 1.1:1 - 1.5:1;

[0035] The volume ratio of the organic solvent to water in the mixed solvent is 2:1 - 8:1, preferably 4:1, which enables good solubility of the feedstock and more complete reaction.

[0036] The polycation includes one or more of poly-L-lysine, polyethyleneimine, polymethacrylate, and polyamine dendrimer, preferably polyethyleneimine; the polycation provides abundant amino groups. On the one hand, it serves as a macromolecular backbone to graft M2 to achieve antioxidant effect; on the other hand, it uses the Schiff base reaction between its amino groups and the aldehyde groups of oxidized dextran to form a hydrogel coating.

[0037] The catechol compounds represented by the formula M1 include one or more of caffeic acid, hydroxytyrosol, norepinephrine, epinephrine, quercetin, catechin, and procyanidin.

[0038] In step 2, the reaction temperature is room temperature and the reaction time is 12 - 24 h.

[0039] The pH of the polycation aqueous solution is 5.0 - 6.0; after the reaction, an inorganic base is used to adjust the pH to 7.0 - 7.2.

[0040] The preparation process of the dopamine-modified oxidized dextran includes the steps of: oxidizing dextran with sodium periodate to obtain oxidized dextran, adding dopamine hydrochloride to the oxidized dextran aqueous solution for reaction, dialyzing and freeze-drying to obtain the dopamine-modified oxidized dextran.

[0041] The molecular weight of the dextran is 10k - 100 kDa, preferably 40 kDa; the molecular weight affects the viscosity. If the viscosity is too high, spraying is difficult and it is hard to prepare.

[0042] The molar ratio of the polymerization unit number of the dextran to sodium periodate is 10:1 - 1:2, preferably 2:1; the oxidation reaction temperature is room temperature and the reaction time is 4 - 24 h.

[0043] The molar ratio of the polymerization unit number of the dextran to the feeding amount of dopamine hydrochloride is 10:1 - 2:1, preferably 3:1.

[0044] The reaction temperature of dopamine hydrochloride and oxidized dextran is room temperature and the reaction time is 6 - 24 h.

[0045] The present invention also provides a preparation method of the active oxygen-responsive hydrogel coating for anti-vascular restenosis, including the steps of: spraying the active oxygen-responsive and scavenging polymer precursor aqueous solution and the dopamine-modified oxidized dextran aqueous solution on the surface of the substrate by ultrasonic atomization respectively, and obtaining the active oxygen-responsive hydrogel coating through self-crosslinking.

[0046] Through the ultrasonic atomization spraying technique, a Schiff base reaction occurs between the reactive oxygen-responsive and scavenging polymer prodrug and dopamine-modified oxidized dextran on the substrate surface to obtain a hydrogel crosslinked network. This preparation method has a simple process and mild conditions, enabling the functional components to be uniformly and efficiently coated on the surface of cardiovascular implantable and interventional devices.

[0047] The mass fraction of the aqueous solution of the reactive oxygen-responsive and scavenging polymer prodrug is 0.1 wt% - 10 wt%, preferably 2 wt%.

[0048] The mass fraction of the aqueous solution of dopamine-modified oxidized dextran is 0.4 wt% - 40 wt%, preferably 4 wt%. If the dextran content is too high, the viscosity is too large and the spraying is not smooth; if the content is too low, the Schiff base reaction is weak, it is not easy to crosslink into a film, and at the same time the loading amount is low, and the expected effect is poor.

[0049] The mass ratio of the reactive oxygen-responsive and scavenging polymer prodrug to dopamine-modified oxidized dextran is 1:1 - 1:6, preferably 1:2.

[0050] The ultrasonic atomization spraying rate is 2 - 20 μL per minute, preferably 10 μL per minute; the thickness of the hydrogel coating is 2 - 20 μm, preferably 5 - 10 μm. The spraying speed affects the coating morphology and crosslinked structure; the coating thickness corresponds to the drug loading amount, and the thicker the coating, the relatively better the anti-restenosis effect.

[0051] The substrate includes one or more of polyethylene terephthalate, polydimethylsiloxane, polyurethane, high-density polyethylene, polyamide, polytetrafluoroethylene, polyvinyl chloride, acrylate, etc., preferably polyethylene terephthalate.

[0052] The present invention also provides the application of the reactive oxygen-responsive hydrogel coating for anti-vascular restenosis in the preparation of medical materials for anti-vascular restenosis.

[0053] In the hydrogel coating of the present invention at the vascular lesion site, the coating degrades under the stimulation of reactive oxygen, releases phenolic compounds, eliminates local excessive reactive oxygen, improves the inflammatory microenvironment, promotes the repair of the endothelium and delays the process of vascular restenosis. This coating has biodegradability and can achieve the controlled and long-term release of drugs, improving the bioavailability of drugs.

[0054] For example, when preparing a balloon material, the coating is applied to the surface of the balloon; the balloon catheter material includes one or more of polyvinyl chloride, polyethylene, polyurethane, polyethylene terephthalate, nylon, polyether block amide, preferably polyether block amide; the inner diameter of the balloon catheter is 1.0 - 5.0 mm, preferably 1.25 - 1.5 mm; the length of the balloon catheter is 10 - 30 mm, preferably 15 - 25 mm.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] (1) The present invention applies the reactive oxygen species-responsive hydrogel platform to the design of the vascular balloon coating, realizing the controllable, on-demand and long-acting release of drugs, effectively reducing or avoiding the toxic and side effects of drugs, and significantly improving the bioavailability of drugs, thereby expecting to achieve better therapeutic effects.

[0057] (2) In the present invention, a hydrogel cross-linking network is formed by chemically cross-linking polymer prodrugs and modified dextran. The prepared hydrogel coating can rapidly respond and degrade under high levels of reactive oxygen species expression, release antioxidant drugs, eliminate excessive reactive oxygen species, and further improve the local inflammatory microenvironment and delay the process of vascular restenosis. At the same time, the introduction of dopamine enhances the transfer and adhesion ability of the coating on the vascular inner wall, further improving the drug delivery efficiency and prolonging its residence time.

[0058] (3) The hydrogel coating of the present invention can form a gel in situ, and the chemical cross-linking is relatively firm, reducing the possible loss of drugs during balloon delivery. By adjusting the functional components and ratios, the drug loading, mechanical properties and drug release rate of the coating can be precisely controlled. In addition, the ultrasonic atomization spraying process is adopted, which has the advantages of simple operation, strong repeatability and high controllability, ensuring the uniformity and consistency of the coating. Description of the Drawings

[0059] Figure 1 1H NMR spectrum of the reactive oxygen species-responsive and scavenging polymer prodrug PEI-CBEC prepared in Example 1.

[0060] Figure 2 1H NMR spectrum of dopamine-modified oxidized dextran OD-PDA prepared in Example 1.

[0061] Figure 3 Appearance diagrams of reactive oxygen species-responsive hydrogels with different mass ratios of PEI-CBEC to OD-PDA prepared in Example 1.

[0062] Figure 4 Reactive oxygen species-responsive degradation curve of the reactive oxygen species-responsive hydrogel coating prepared in Example 1.

[0063] Figure 5 Reactive oxygen species scavenging ability curve of the reactive oxygen species-responsive hydrogel coating prepared in Example 2.

[0064] Figure 6 Inhibition of reactive oxygen species in cells on the surface of the reactive oxygen species-responsive hydrogel coating prepared in Example 3.

[0065] Figure 7In [a], a is the apparent diagram of the reactive oxygen-responsive hydrogel coating prepared in Example 4, and b in Figure 7 is the microscopic diagram of the reactive oxygen-responsive hydrogel coating prepared in Example 4.

[0066] Figure 8 It shows the transfer of the reactive oxygen-responsive hydrogel coating prepared in Example 4 to the inner wall of the rat carotid artery.

[0067] Figure 9 It shows the effect of the reactive oxygen-responsive hydrogel coating prepared in Example 5 on inhibiting reactive oxygen at the interventional site of the rat abdominal aorta. Detailed implementation manners

[0068] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Those skilled in the art who make modifications or equivalent replacements on the basis of understanding the technical solutions of the present invention, without departing from the spirit and scope of the technical solutions of the present invention, shall all be covered within the protection scope of the present invention.

[0069] The raw materials used in the following detailed implementation manners are all purchased from the market.

[0070] Example 1

[0071] (I) Preparation of reactive oxygen-responsive and scavenging polymer prodrugs:

[0072] Step 1-1: Dissolve ethyl caffeate (EC) (1.87 g, 9 mmol) and 4-carboxyphenylboronic acid (CBA) (1.38 g, 10 mmol) in 10 mL of N,N-dimethylformamide (DMF), stir at 100 °C for 8 hours, and the solution gradually becomes clear and dark green. After the reaction is completed, remove the solvent by rotary evaporation, add 5 mL of pre-cooled ethyl acetate to dissolve the concentrate, and perform overnight recrystallization at -20 °C. Collect the precipitated white solid and dry it under vacuum to obtain the intermediate 4-carboxyphenylboronic acid ethyl caffeate (CBEC);

[0073] Step 1-2: Adjust the pH of the aqueous solution of polyethyleneimine (PEI) (1.0 g, 0.04 mmol) to 5.0. Then dissolve the CBEC (1.196 g, 3.20 mmol) prepared in Step 1-1 in a mixture of dimethyl sulfoxide (8 mL) and water (2 mL), and stir at room temperature for 30 minutes to release heat. Subsequently, add EDC (0.669 g, 3.49 mmol) and NHS (0.368 g, 3.20 mmol) to the mixture, continue stirring for 2 hours, and then add this mixture to the PEI solution. After reacting for 24 hours, dialyze and freeze-dry to finally obtain polyethyleneimine modified with 4-carboxyphenylboronic acid caffeic acid ethyl ester (PEI-CBEC), and its structural formula is as follows:

[0074]

[0075] Figure 1 1H NMR spectrum of PEI-CBEC. It can be seen from the peak positions that it is successfully synthesized.

[0076] (II) Preparation of dopamine-modified oxidized dextran:

[0077] Step 2-1: At room temperature, slowly drop an aqueous solution of sodium periodate (6.34 g, 29.6 mmol) into an aqueous solution of dextran (10.0 g, 61.7 mmol, molecular weight 40 kDa), stir and react for 6 hours, then add 20 mL of ethylene glycol and continue stirring for 2 hours to neutralize the unreacted sodium periodate, dialyze and freeze-dry to obtain oxidized dextran (OD);

[0078] Step 2-2: Dissolve the OD (5.6 g, 34.6 mmol) prepared in Step 2-1 in 100 mL of distilled water with pH 7.4, then add dopamine hydrochloride (2.1 g, 11.1 mmol), and stir at room temperature for 12 hours. After the reaction, dialyze and freeze-dry to obtain dopamine-modified oxidized dextran (OD-PDA), and its structural formula is as follows, where n is 200:

[0079]

[0080] Figure 2 1H NMR spectrum of the above-prepared OD-PDA. It can be seen from the peak positions that it is successfully synthesized.

[0081] (III) Exploration of the ratio between PEI-CBEC and OD-PDA hydrogel

[0082] Dissolve PEI-CBEC and OD-PDA separately in distilled water (the mass concentration of PEI-CBEC is 2 wt%, and the mass concentration of OD-PDA is 4 wt%). According to different mass ratios (2:1, 1:4, 1:2, 1:1), mix them quickly and evenly, and let it stand for 10 min. Then invert it and observe the gel flow situation.

[0083] Figure 3 This is a gel photo of PEI-CBEC@OD-PDA. The experimental results show that when the mass ratio of PEI-CBEC / OD-PDA is 1:2, the cross-linked hydrogel is more uniform and stable.

[0084] (IV) Preparation of reactive oxygen species-responsive hydrogel coating:

[0085] Dissolve PEI-CBEC and OD-PDA separately in distilled water (the mass concentration of PEI-CBEC is 2 wt%, and the mass concentration of OD-PDA is 4 wt%). The mass ratio of PEI-CBEC to OD-PDA is 1:2. Through the double-headed ultrasonic atomization spraying technology (the spraying rate is set at 10 μL per minute, and the spraying thickness is 5 μm), uniformly coat it on the surface of pre-cleaned, sterilized, and expanded polyethylene terephthalate (PET), and quickly cross-link to form a hydrogel coating PEI-CBEC@OD-PDA.

[0086] Immerse the prepared coatings in PBS buffer (pH 7.4, 0.1 M) containing 1 mM and 10 mM H 2 O 2 respectively, and incubate them with shaking at 37 °C and 50 rpm / min. Use PBS without H 2 O 2 as the negative control. Take 100 μL of samples at different time points (0 min, 10 min, 20 min, 40 min, 60 min, 120 min), and supplement the same amount of PBS. Use an enzyme-labeled instrument to detect the absorbance at 280 nm, and quantify the release amount of the degradation product according to the standard curve, and calculate the cumulative release rate of the drug.

[0087] Figure 4 This is the ROS-responsive degradation and drug release experiment of the PEI-CBEC@OD-PDA coating under the condition of without / with hydrogen peroxide (H 2 O 2 ). The experimental results prove that under the condition of high levels of reactive oxygen species (1 mM and 10 mM H 2 O 2 ) in the simulated inflammatory tissue, this coating can be quickly degraded and release phenolic compounds. And with the increase of H 2 O 2With the increase in concentration, both the drug release rate and the cumulative release amount increased significantly, indicating that the coating has a significant responsiveness to high ROS.

[0088] Example 2

[0089] The preparation process of the reactive oxygen species-responsive scavenging polymer prodrug and dopamine-modified oxidized dextran was as in Example 1. Preparation of the reactive oxygen species-responsive hydrogel coating:

[0090] Dissolve PEI-CBEC and OD-PDA in distilled water respectively. The mass concentration of PEI-CBEC is 4 wt%, and the mass concentration of OD-PDA is 8 wt%. The mass ratio of PEI-CBEC to OD-PDA is 1:2. Using a dual-head ultrasonic atomization spraying technique (spraying rate set at 20 μL per minute, spraying thickness of 10 μm), uniformly coat it on the pre-cleaned and sterilized PET surface, and quickly crosslink to form a hydrogel coating.

[0091] Coating materials with areas of 0.25 mm 2 , 0.5 mm 2 , 1.0 mm 2 , 2.0 mm 2 , 3.0 mm 2 were placed in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) ethanol solution with a final concentration of 0.1 mM and incubated at 37°C in the dark for 30 minutes. The absorbance at 517 nm was measured using an enzyme-linked immunosorbent assay (ELISA) reader, and the absorbance of the sample solution (A 样品 ) and the pure DPPH ethanol solution (A 对照 ) was compared. The calculation formula for the DPPH radical scavenging rate is:

[0092] .

[0093] Figure 5 Shows the scavenging ability of the hydrogel coating for reactive oxygen species radicals. The results show that the hydrogel coating has a significant radical scavenging ability, and with the increase in the coating area, the scavenging efficiency also increases accordingly. More gel crosslinking makes the coating more stable. And within the same time, a larger amount of spraying theoretically results in a higher scavenging rate.

[0094] Example 3

[0095] The preparation process of the reactive oxygen species-responsive scavenging polymer prodrug and dopamine-modified oxidized dextran was as in Example 1. Preparation of the reactive oxygen species-responsive hydrogel coating:

[0096] Dissolve PEI-CBEC and OD-PDA in distilled water respectively. The concentration of PEI-CBEC is 2 wt% by mass, the mass concentration of OD-PDA is 4 wt%, and the mass ratio of PEI-CBEC to OD-PDA is 1:2. Coat it on the pre-cleaned and sterilized PET surface by double-headed ultrasonic atomization spraying technology (the spraying rate is set at 10 μL per minute, and the spraying thickness is 10 μm), and quickly crosslink to form a hydrogel coating.

[0097] First, human umbilical vein endothelial cells (HUVECs) were stimulated with lipopolysaccharide LPS (1 μg / mL) and cultured overnight. Then, inoculate at 5×10 4 cells / cm 2 on the surface of bare PET and the surface of the PEI-CBEC@OD-PDA coating. Unstimulated HUVECs were used as the normal control group. After culturing for 24 hours, use DHE dye (diluted 1:1000 in serum-free medium) to stain in the dark at 37 °C for 40 minutes, and use a fluorescence microscope to observe the cell fluorescence intensity of different groups. Quantitatively analyze the DHE fluorescence intensity to evaluate the amount of ROS generated.

[0098] Figure 6 It shows that the ROS probe (DHE) is used to evaluate the antioxidant ability of the coating. The results show that compared with the inflammatory group, the coating treatment group significantly reduces the generation of intracellular reactive oxygen species and is close to the reactive oxygen species expression level of normal cells. The thicker the coating thickness, the relatively better the inhibitory effect on intracellular reactive oxygen species.

[0099] Example 4

[0100] The preparation process of the reactive oxygen species-responsive and scavenging polymer prodrug and dopamine-modified oxidized dextran is as in Example 1. Preparation of the reactive oxygen species-responsive hydrogel coating:

[0101] Dissolve PEI-CBEC and OD-PDA in distilled water respectively. The mass concentration of PEI-CBEC is 2 wt%, the mass concentration of OD-PDA is 4 wt%, and the mass ratio of PEI-CBEC to OD-PDA is 1:2. Coat it on the surface of a pre-cleaned, sterilized and expanded balloon by double-headed ultrasonic atomization spraying technology (the spraying rate is set at 15 μL per minute, and the spraying thickness is 8 μm) (the balloon catheter material is polyether block amide, the catheter inner diameter is 1.25 mm, and the length is 15 mm), and quickly crosslink to form a hydrogel coating.

[0102] Figure 7 It shows the apparent and microscopic images of the hydrogel coating, indicating that the coating is evenly distributed on the balloon surface and has good loading. Figure 8The transfer of the coating to the inner wall of the blood vessel was demonstrated. A rat common carotid artery injury model was used in the experiment. A balloon coated with the PEI-CBEC@OD-PDA coating was inserted into the aorta through an incision. After inflation at a pressure of 8 atm for 1 minute, the balloon was deflated and removed. The coating conditions of the artery and the balloon before and after intervention were observed through a fluorescence imaging system. The results showed that the coating exhibited good transfer and adhesion properties during balloon dilation.

[0103] Example 5

[0104] The preparation process of the reactive oxygen species-responsive scavenging polymer prodrug and dopamine-modified oxidized dextran was as in Example 1. Preparation of the reactive oxygen species-responsive hydrogel coating:

[0105] PEI-CBEC and OD-PDA were separately dissolved in distilled water. The mass concentration of PEI-CBEC was 2 wt%, the mass concentration of OD-PDA was 4 wt%, and the mass ratio of PEI-CBEC to OD-PDA was 1:2. Through a dual-head ultrasonic atomization spraying technique (spraying rate set at 5 μL per minute and spraying thickness of 3 μm), it was coated on the surface of a pre-cleaned, sterilized, and dilated balloon (the balloon catheter material was polyether block amide, the balloon inner diameter was 1.5 mm, and the catheter length was 15 mm) to rapidly form a hydrogel coating.

[0106] An experiment was carried out using a rat abdominal aorta injury model. A balloon coated with the PEI-CBEC@OD-PDA coating was used to dilate the stenotic blood vessel. Three days after the operation, the ROS level in the abdominal aorta in vivo was detected by intraperitoneal injection of the L-012 chemical probe. Figure 9 The effect of the hydrogel coating on the postoperative reactive oxygen species level was demonstrated. The experimental results showed that compared with the untreated injury group, the coating group effectively reduced the postoperative reactive oxygen species expression and was close to the reactive oxygen species level of normal rats.

Claims

1. An active oxygen responsive hydrogel coating for preventing vascular restenosis, characterized in that: The active oxygen responsive hydrogel coating is a hydrogel coating obtained by cross-linking an active oxygen responsive-scavenging polymer prodrug and dopamine-modified oxidized dextran; The structural formula I of the active oxygen responsive-scavenging polymer prodrug is as follows: （I）； Where R1 is H, , , , , , , , , Any of; The structural formula II of the dopamine-modified oxidized dextran is as follows: (II); Where n is a natural number between 50 and 500; The preparation process of the active oxygen responsive-scavenging polymer prodrug comprises the steps of: Step 1, reacting a catechol compound as shown in formula M1 and 4-carboxyphenylboronic acid in an anhydrous solvent to obtain catechol carboxyphenylboronic acid ester as shown in formula M2; ； Step 2, dissolving catechol carboxyl phenyl borate represented by formula M2 in a mixed solvent of an organic solvent and water, adding EDC and NHS to mix, then adding a polycation aqueous solution to react, adjusting with an inorganic base and dialyzing to obtain the active oxygen response-scavenging polymer prodrug; The polycation includes one or more of poly-L-lysine, polyethyleneimine, and polyaminoamine; The preparation of the active oxygen responsive hydrogel coating comprises the steps of: spraying active oxygen responsive-scavenging polymer prodrug and dopamine-modified oxidized dextran on the surface of a substrate by ultrasonic atomization, and obtaining the active oxygen responsive hydrogel coating by self-crosslinking.

2. The active oxygen responsive hydrogel coating for preventing vascular restenosis according to claim 1, characterized in that: The mass ratio of the active oxygen responsive-scavenging polymer prodrug to the dopamine-modified oxidized dextran is 1:1-1:

6.

3. The active oxygen responsive hydrogel coating for preventing vascular restenosis according to claim 1, characterized in that: In step 1, the molar ratio of M1 to 4-carboxyphenylboronic acid is 0.5:1-0.9:1; In step 1, the solvent includes any one or more of N,N-dimethylformamide, dimethyl sulfoxide, dichloromethane, chloroform, toluene or dioxane; In step 1, the reaction temperature is 60-120°C and the reaction time is 4-24h; In step 2, the molar ratio of M2 to polycation is 100:1-10:1; In step 2, the organic solvent includes any one or more of dimethyl sulfoxide, dichloromethane, chloroform, methanol, ethanol, N,N-dimethylformamide, and tetrahydrofuran; The molar ratio of EDC to NHS is 1:1-1.2:1; the molar ratio of EDC to M2 is 1.1:1-1.5:1; The volume ratio of the organic solvent to water in the mixed solvent is 2:1-8:1; The polycation includes one or more of poly-L-lysine, polyethyleneimine, and polyaminoamine; In step 2, the reaction temperature is room temperature and the reaction time is 12-24h; The pH of the polycation aqueous solution is 5.0-6.0; after the reaction is completed, the inorganic base is used to adjust the pH to 7.0-7.

2.

4. The active oxygen responsive hydrogel coating for preventing vascular restenosis according to claim 1, characterized in that: The preparation process of the dopamine-modified oxidized dextran comprises the steps of: oxidizing dextran with sodium periodate to obtain oxidized dextran, adding dopamine hydrochloride to an aqueous solution of oxidized dextran for reaction, dialyzing and freeze-drying to obtain the dopamine-modified oxidized dextran.

5. The active oxygen responsive hydrogel coating for preventing vascular restenosis according to claim 4, characterized in that: The molecular weight of the dextran is 10k-100kDa; The molar ratio of the number of polymerization units of the dextran to sodium periodate is 10:1-1:2; the temperature of the oxidation reaction is room temperature, and the reaction time is 4-24 hours; The molar ratio of the number of polymerization units of the dextran to dopamine hydrochloride is 10:1-2:1; The reaction temperature of dopamine hydrochloride and oxidized dextran is room temperature, and the reaction time is 6-24h.

6. The method for preparing the active oxygen responsive hydrogel coating for preventing vascular restenosis according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: spraying an aqueous solution of active oxygen responsive-scavenging polymer prodrugs and an aqueous solution of dopamine-modified oxidized dextran on the surface of a substrate respectively by ultrasonic atomization, and obtaining the active oxygen responsive hydrogel coating by self-crosslinking.

7. The method for preparing the active oxygen responsive hydrogel coating for preventing vascular restenosis according to claim 6, characterized in that: The mass fraction of the active oxygen responsive-scavenging polymer prodrug aqueous solution is 0.1 wt%-10 wt%; The mass fraction of the dopamine-modified oxidized dextran aqueous solution is 0.4 wt%-40 wt%; The mass ratio of the active oxygen responsive-scavenging polymer prodrug to dopamine-modified oxidized dextran is 1:1-1:6; The ultrasonic atomization spraying rate is 2-20 μL per minute; the thickness of the hydrogel coating is 2-20 μm; The substrate includes one or more of polyethylene terephthalate, polydimethylsiloxane, polyurethane, high-density polyethylene, polyamide, polytetrafluoroethylene, and polyvinyl chloride.

8. Use of the active oxygen responsive hydrogel coating for preventing vascular restenosis according to any one of claims 1 to 5 in preparing medical materials for preventing vascular restenosis.

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