Preparation method of nanoparticles, modification method of scaffold and scaffold

Abstract

The invention provides a preparation method of nanoparticles, a modification method of a scaffold and the scaffold, and the preparation method of the nanoparticles comprises the following steps: adding an isometric drug solution into a first solution, and carrying out ultrasonic oscillation; inserting an electrode into the first solution, and connecting the electrode with a positive electrode of a power supply, so that the medicine is combined with the adsorption body in the first solution to form an internal material of the nanoparticles; taking out the electrode, inserting into deionized water, oscillating and cleaning, and turning off the power supply; then changing an electrode interface, connecting an electrode loaded with the internal material with a negative electrode, placing the electrode in a second solution for reaction so as to wrap the external material on the outer side of the internal material to form nano particles, and oscillating the nano particles on the surface of the electrode into a deionized water solution; and then freeze-drying, and collecting the nanoparticles. The nanoparticles prepared by the preparation method of the drug-carrying nanoparticles can be attached to a stent, so that components in liquid are prevented from being attached and deposited on the surface of the stent.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a method for preparing nanoparticles, a method for modifying a stent, and a stent. Background Art

[0002] Stents are commonly used medical devices in various interventional surgeries, such as cardiac stents, vascular stents, urinary stents, etc. Although the manufacturing process and manufacturing materials of stents are constantly improving, there are still many clinical problems with existing stents. After the stent is implanted in the human body, substances in the liquid (urine, blood, etc.) flowing through the stent are easily deposited on the surface of the stent, thus affecting the normal use of the stent. Taking urinary stents as an example, urinary stents are prone to bacterial deposition and crusting when left in the urinary system for a long time, causing symptoms such as dysuria, urinary tract infection, urinary pain, irritation, etc. Therefore, it is necessary to modify the existing stents and find suitable modified materials to improve their surface properties and avoid or reduce the deposition of components in the liquid on the stent surface. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the present invention provides a method for preparing functional nanoparticles carrying drugs and ions, comprising the following steps:

[0004] An equal volume of drug solution is added to the first solution at a predetermined speed and ultrasonically vibrated; an electrode is inserted into the first solution and connected to the positive electrode of a power source, so that the drug is combined with the adsorbent in the first solution to form the internal material of the nanoparticles; the electrode is taken out and inserted into deionized water for vibration and cleaning, and then the power source is turned off;

[0005] Then, the electrode interface is changed, and the electrode carrying the above-mentioned internal material is connected to the negative electrode, and placed in a second solution for reaction to wrap the external material on the outside of the internal material to form nanoparticles. Then, the electrode is taken out and placed in deionized water, the power is turned off, and the nanoparticles on the surface of the electrode are ultrasonically shaken into the deionized water solution; then, the nanoparticles are freeze-dried and collected.

[0006] The nanoparticles prepared by the method for preparing drug-carrying nanoparticles of the present invention can be used as a modified material of the stent and attached to the stent. The nanoparticles can effectively prevent the components in the liquid from adhering to and depositing on the surface of the stent, thereby improving the performance of the stent.

[0007] Optionally, the first solution is a poly-lysine solution or a chitosan solution or a liposome solution or a glycosaminoglycan solution; the second solution is a copper chloride solution or a silver chloride solution or a mixed solution of copper chloride and silver chloride.

[0008] Optionally, the concentration of the drug solution is 1-10 mg / ml, the predetermined speed is 1-100 microliters / 0.1-10s / drop, the concentration of the first solution is 0.5-5 mg / ml, the ultrasonic oscillation time is 10 minutes, the voltage of the power supply is 1-10V, the time for adsorbing nanoparticles is 10 minutes, the concentration of the second solution is 1-10 mg / ml, the reaction time of the electrode in the second solution is 2 hours, and the temperature is 20°C.

[0009] Optionally, the size of the nanoparticles is adjusted by regulating the injection amount, injection speed and concentration of the first solution; the surface charge of the nanoparticles is adjusted by regulating the ratio of the internal material content to the external material content;

[0010] The injection volume of the first solution is 1 to 1000 microliters, the injection speed is 0.1s to 10s / drop, and the concentration of the first solution is 1 to 10mg / ml;

[0011] The electrical properties of the electrode that adsorbs the internal material are consistent with those of the first solution, and the electrical properties of the electrode that adsorbs the external material are opposite to those of the first solution. The electrode that adsorbs the external material regulates the amount of material attracted by the outer surface of the nano-ions by regulating the voltage range.

[0012] Optionally, the nanoparticles are spherical structures with a diameter of 50 to 500 nm, and the surface electrical properties of the nanoparticles are -30 to -5 mV;

[0013] The drug includes at least one of heparin, rapamycin, paclitaxel, asiatica glycoside, etc., and the external material includes at least one of copper ions and silver ions;

[0014] The content ratio of the drug to copper ions or silver ions or the mixed solution of copper ions and silver ions in the nanoparticles is 0.3:1-3:1, wherein the ratio of copper ions to silver ions is 0.5:1-2:1.

[0015] The present invention also provides a method for modifying a stent, comprising the following steps:

[0016] S1, after cleaning the stent, placing it in a third solution and reacting it at a predetermined temperature and time to form a connection layer on the surface of the stent, and then placing the stent in deionized water for ultrasonic cleaning and drying;

[0017] S2, placing the stent with the connecting layer in a fourth solution, and reacting it at a predetermined temperature and time to form a positively charged polymer capable of adsorbing nanoparticles on the outside of the connecting layer, and then placing the stent in deionized water for ultrasonic cleaning and drying;

[0018] S3, preparing drug-carrying nanoparticles according to the preparation method according to any one of claims 1 to 5;

[0019] S4, dissolving a predetermined amount of the nanoparticles prepared in S3 in deionized water to obtain a nanoparticle solution; placing the stent obtained in S2 in the nanoparticle solution, and reacting at a predetermined temperature and time, taking it out, ultrasonically cleaning it in deionized water, and placing it in the nanoparticle solution again, repeating the operation for at least 2 times, and drying it to obtain the stent loaded with nanoparticles.

[0020] The modification method of the stent of the present invention is suitable for surface modification of stents of various complex shapes. The negatively charged functional material is combined with the positively charged functional ion by utilizing the electrostatic force, and nanoparticles with an overall negative charge are obtained by controlling the content and ratio. Then, a high positive potential is loaded on the surface of the stent by polydopamine to realize the assembly of the stent and the nanoparticles. The modified stent can effectively avoid or reduce the adhesion and deposition of components in the liquid on the surface of the stent, thereby improving the performance of the stent.

[0021] Optionally, in S1, the third solution is a polydopamine solution, the stent is cleaned by ultrasound, the concentration of the polydopamine solution is 2 mg / ml, and the predetermined temperature and time are 20 to 40° C. for 6 to 12 hours;

[0022] In S2, the fourth solution is a poly-lysine solution, the concentration of the poly-lysine solution is 0.5-5 mg / ml; the predetermined temperature and time are 20-40° C. for 6-12 hours;

[0023] In S4, the concentration of the nanoparticle solution is 0.1-10 mg / ml, the predetermined temperature and time are 20-40° C. for reaction for 0.5-5 hours, the ultrasonic cleaning time in deionized water is 30 minutes, and the drying method is to place in a 40° C. oven for drying for 24 hours.

[0024] The present invention also provides a method for modifying a stent, comprising the following steps:

[0025] S1, after cleaning the stent, placing it in a mixed solution of the third solution and the fourth solution, and reacting them at a predetermined temperature and time, and then placing the stent in deionized water for ultrasonic cleaning and drying;

[0026] S2, preparing drug-carrying nanoparticles according to the preparation method according to any one of claims 1 to 5;

[0027] S3, dissolving a predetermined amount of the nanoparticles prepared in S2 in deionized water to obtain a nanoparticle solution; placing the stent obtained in S1 in the nanoparticle solution, and reacting at a predetermined temperature and time, taking it out, ultrasonically cleaning it in deionized water, and placing it in the nanoparticle solution again, after reciprocating the operation for at least 2 times, drying it to obtain the stent loaded with nanoparticles.

[0028] The present invention also provides a stent prepared according to the modification method of the present invention, comprising: a stent body, a connection layer covered on the surface of the stent body, a polymer covered on the outside of the connection layer, and the polymer is a positively charged polymer or a negatively charged polymer; a nanoparticle arrangement layer covered on the outside of the polymer, the polarity of the polymer is opposite to the polarity of the nanoparticle arrangement layer, the nanoparticles in the nanoparticle arrangement layer include an internal material and an external material adsorbed on the internal material by electrostatics, one of the internal material and the external material includes a drug, and the other includes ions adsorbed by electrostatics.

[0029] Optionally, the stent is a urinary tract stent, a cardiac stent, a peripheral vascular stent, a biliary stent, a tracheal stent or an esophageal stent; and the connecting layer is a polydopamine coating;

[0030] The nanoparticles are positively charged polymers or negatively charged polymers having amino groups and carboxyl groups, the drugs include at least one of heparin, rapamycin, paclitaxel, and asiatica glycoside, and the ions include at least one of copper ions and silver ions.

[0031] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0033] Figure 1 It is a schematic diagram of the process of the modification method of the stent in one embodiment of the present invention. DETAILED DESCRIPTION

[0034] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0035] This embodiment provides a method for preparing drug-carrying nanoparticles, and the prepared nanoparticles can be attached to a stent to avoid or reduce the deposition of components in a liquid on the surface of the stent.

[0036] Specifically, the preparation method of nanoparticles includes the following steps: adding an equal volume of drug solution to a first solution at a predetermined speed and performing ultrasonic oscillation; inserting an electrode into the first solution and connecting it to the positive electrode of a power supply so that the drug combines with the adsorbent in the first solution to form the internal material of the nanoparticle; taking out the electrode and inserting it into deionized water for oscillation and cleaning, and then turning off the power supply; then changing the electrode interface, connecting the electrode carrying the above-mentioned internal material to the negative electrode, placing it in a second solution for reaction, so as to wrap the external material outside the internal material to form nanoparticles, then taking out the electrode and placing it in deionized water, turning off the power supply, and ultrasonically oscillating the nanoparticles on the surface of the electrode into the deionized water solution; then freeze-drying and collecting the nanoparticles. The prepared nanoparticles are an embedded body structure, including internal materials and external materials. Among them, the electrical properties of the electrode that adsorbs the internal material are consistent with the electrical properties of the first solution, and the electrical properties of the electrode that adsorbs the external material are opposite to the electrical properties of the first solution. The electrode that adsorbs the external material regulates the amount of material attracted by the outer surface of the nanoparticle by regulating the voltage range.

[0037] In some embodiments, the first solution is a poly-lysine solution or a chitosan solution or a liposome solution or a glycosaminoglycan solution; the second solution is a cupric chloride solution or a silver chloride solution or a mixed solution of cupric chloride and silver chloride. Those skilled in the art can also select different specific types of the first solution and the second solution as needed.

[0038] Specifically, the concentration of the drug solution is 1-10 mg / ml, the predetermined speed is 1-100 microliters / 0.1-10s / drop, the concentration of the first solution is 0.5-5 mg / ml, the ultrasonic oscillation time is 10 minutes, the voltage of the power supply is 1-10V, the adsorption time of the nanoparticles is 10 minutes, the concentration of the second solution is 1-10 mg / ml, the electrode reacts in the second solution for 2 hours, and the temperature is 20° C. It is understandable that those skilled in the art can make appropriate adjustments based on this data to meet different needs. For example, each of the above parameters can fluctuate within a range of 10%.

[0039] Further, the size of the nanoparticles is adjusted by regulating the injection amount, injection speed and concentration of the first solution; the surface charge of the nanoparticles is adjusted by regulating the ratio of the internal material content to the external material content; for example, the injection amount of the first solution is 1 to 1000 microliters, the injection speed is 0.1s to 10s / drop, and the concentration of the first solution is 1 to 10mg / ml. It is understood that those skilled in the art can make appropriate adjustments based on this data to meet different needs, for example, each of the above parameters can fluctuate within a range of 10%.

[0040] In some embodiments, the nanoparticles are spherical structures with a diameter of 50 to 500 nm, and the surface electrical properties of the nanoparticles are -30 to -5 mV; the drug includes at least one of heparin, rapamycin, paclitaxel, and asiaticoside, and the external material includes at least one of copper ions and silver ions; the ratio of the drug to copper ions or silver ions or the mixed solution of copper ions and silver ions in the nanoparticles is 0.3:1 to 3:1, wherein the ratio of copper ions to silver ions is 0.5:1 to 2:1. It is understood that those skilled in the art can make appropriate adjustments based on this data to meet different needs, for example, each of the above parameters can fluctuate within a range of 10%.

[0041] This embodiment also provides a method for modifying a stent, which can be a urinary tract stent, a cardiac stent, a vascular stent, or other implantable implants in a human or animal body. The purpose of the modification includes but is not limited to preventing or reducing the adhesion and deposition of components in the liquid on the stent surface.

[0042] Specifically, see Figure 1 , the modification method of the scaffold mainly includes the following steps:

[0043] S1, after cleaning the stent, placing it in a third solution and reacting it at a predetermined temperature and time to form a connecting layer on the surface of the stent, and then placing the stent in deionized water for ultrasonic cleaning and drying; a polydopamine coating is formed on the surface of the stent after treatment, so that it can be combined with the high-potential polymer through functional groups.

[0044] S2, placing the above-mentioned stent with a connecting layer in a fourth solution, and reacting it at a predetermined temperature and time to form a positively charged polymer capable of adsorbing nanoparticles on the outside of the connecting layer, and then placing the stent in deionized water for ultrasonic cleaning and drying; the treated stent forms a high-potential positively charged polymer layer on the outside of the polydopamine coating.

[0045] S3, preparing drug-carrying nanoparticles. Specifically, the drug-carrying nanoparticles may be prepared according to the preparation method of any of the above embodiments.

[0046] S4, dissolving a predetermined amount of the nanoparticles prepared in S3 in deionized water to obtain a nanoparticle solution; placing the stent obtained in S2 in the nanoparticle solution, and reacting at a predetermined temperature and time, taking it out, ultrasonically cleaning it in deionized water, and placing it in the nanoparticle solution again, repeating the operation for at least 2 times, and drying it to obtain the stent loaded with nanoparticles.

[0047] The stent obtained by the above method can avoid or reduce the adhesion and deposition of components in the liquid on the stent surface.

[0048] In some embodiments, in S1, the third solution is a polydopamine solution, the stent can be cleaned by ultrasound, the concentration of the polydopamine solution is 2 mg / ml, and the predetermined temperature and time are 20-40°C for 6-12 hours; in S2, the fourth solution is a polylysine solution, the concentration of the polylysine solution is 0.5-5 mg / ml, and the predetermined temperature and time are 20-40°C for 6-12 hours. It is understandable that those skilled in the art can make appropriate adjustments based on this data to meet different needs. For example, each of the above parameters can fluctuate within a range of 10%.

[0049] Further, in S4, the concentration of the nanoparticle solution is 0.1-10 mg / ml, the predetermined temperature and time are 20-40° C. for 0.5-5 hours, the ultrasonic cleaning time in deionized water is 30 minutes, and the drying method is to place in a 40° C. oven for 24 hours. It is understood that those skilled in the art can make appropriate adjustments based on this data to meet different needs, for example, each of the above parameters can fluctuate within a range of 10%.

[0050] In some embodiments, the stent loaded with poly-lysine-drug-copper nanoparticles is obtained by drying.

[0051] This embodiment also provides a method for modifying a stent. The main difference between this method and the above embodiments is that the third solution and the fourth solution are blended and prepared as a single-layer coating on the surface of the stent. For example, the polydopamine solution is blended with a high-potential positively charged polymer as a single-layer coating on the surface of the stent. Various temperature parameters, time parameters, concentration parameters, etc. in this method can be based on the above embodiments. Specifically, the modification method of the stent mainly includes the following steps:

[0052] S1, after cleaning the stent, placing it in a mixed solution of a third solution and a fourth solution, and reacting them at a predetermined temperature and time, and then placing the stent in deionized water for ultrasonic cleaning and drying; wherein the third solution can be a polydopamine solution, and the fourth solution can be a polylysine solution.

[0053] S2, preparing drug-carrying nanoparticles. Specifically, the drug-carrying nanoparticles may be prepared according to the preparation method of any of the above embodiments.

[0054] S3, dissolving a predetermined amount of the nanoparticles collected in S2 in deionized water to obtain a nanoparticle solution; placing the stent obtained in S1 in the nanoparticle solution, and reacting at a predetermined temperature and time, taking it out, ultrasonically cleaning it in deionized water, and placing it in the nanoparticle solution again, after reciprocating the operation for at least 2 times, drying it to obtain the stent loaded with nanoparticles.

[0055] A detailed method for modifying a stent is described below, specifically a method for modifying a urinary tract stent carrying a sustained-release coating.

[0056] S1, the ureteral stent was ultrasonically cleaned, placed in a 2 mg / ml polydopamine solution, reacted at 20°C for 12 hours, ultrasonically cleaned in deionized water and dried.

[0057] S2, placing the above scaffold in a 3 mg / ml poly-lysine solution, reacting at 20° C. for 12 hours, ultrasonically cleaning in deionized water and drying.

[0058] S3, add an equal volume of 5mg / ml heparin solution to a 1mg / ml poly-lysine solution at a rate of 10 microliters / 1s / drop. After ultrasonic oscillation for 10 minutes, insert the electrode into the above solution, connect it to the positive pole of the power supply, set the voltage to 5V, adsorb the nanoparticles for 10 minutes, take out the electrode, insert it into deionized water for oscillation and cleaning, and then turn off the power. Then change the electrode interface, connect the electrode to the negative pole, place it in a 2mg / ml copper chloride solution, react at 20℃ for 2 hours, take out the electrode and place it in deionized water. Turn off the power, and ultrasonically oscillate the nanoparticles on the electrode surface into the solution. Then freeze-dry and collect the nanoparticles.

[0059] S4, take a certain amount of the nanoparticles collected in S3 and dissolve them in deionized water to obtain a nanoparticle solution with a concentration of 1 mg / ml. Place the stent obtained in S2 in the solution, react at 20°C for 2 hours, take it out and ultrasonically clean it in deionized water for 30 minutes, then place it in the nanoparticle solution again, repeat the operation 3 times, place it in a 40°C oven, and dry it for 24 hours to obtain a ureteral stent loaded with poly-lysine-heparin-copper nanoparticles.

[0060] An embodiment of the present invention further provides a stent prepared according to any of the above-mentioned modification methods, the stent mainly comprising: a stent body, a connecting layer covered on the surface of the stent body, a polymer covered on the outside of the connecting layer, the polymer being a positively charged polymer or a negatively charged polymer; a nanoparticle arrangement layer covered on the outside of the polymer, the polarity of the polymer being opposite to the polarity of the nanoparticle arrangement layer, the nanoparticles in the nanoparticle arrangement layer comprising an internal material and an external material electrostatically adsorbed on the internal material, one of the internal material and the external material comprising a drug, and the other comprising ions electrostatically adsorbed.

[0061] The polymer on the outside of the connecting layer can be a positively charged polymer with amino, carboxyl and other groups, such as polylysine, chitosan, ethylene glycol dimethacrylate, polyethyleneimine, etc., or a negatively charged polymer with amino, carboxyl and other groups, such as liposomes, glycosaminoglycans, etc.

[0062] Since the polarity of the polymer is opposite to that of the nanoparticle arrangement layer, the two can be attracted to each other by electrostatic attraction. If the polymer is positively charged, the nanoparticle is negatively charged; if the polymer is negatively charged, the nanoparticle is positively charged. The nanoparticle can also be a polymer.

[0063] In some embodiments, the stent is a urinary tract stent, a cardiac stent, a peripheral vascular stent, a biliary stent, a tracheal stent or an esophageal stent, the connecting layer is a polydopamine coating, and the nanoparticles are positively charged polymers with amino and carboxyl groups, such as polylysine, chitosan, ethylene glycol dimethacrylate, polyethyleneimine, etc., or negatively charged polymers with amino and carboxyl groups, such as liposomes, glycosaminoglycans, etc. The nanoparticles can be the same material as the polymer on the outside of the connecting layer, or they can be different materials.

[0064] The nanoparticles may be an embedding body, the drug includes at least one of heparin and rapamycin, paclitaxel, and asiaticoside, and the ions include at least one of copper ions and silver ions. For example, the embedding body may include heparin, rapamycin, paclitaxel, asiaticoside, etc., and the embedding body may attract copper ions or silver ions to form nanoparticles; or the embedding body may include copper ions or silver ions, and the embedding body may attract heparin, rapamycin, paclitaxel, asiaticoside, etc. to form nanoparticles.

[0065] The above method of this embodiment is applicable to the surface modification of various complex-shaped stents. By utilizing the electrostatic force, the negatively charged functional material is combined with the positively charged functional ion, and by controlling the content and ratio, nanoparticles with a negative overall charge are obtained. Then, a high positive potential is loaded on the stent surface by polydopamine to achieve the assembly of the stent and the nanoparticles. The modified stent can avoid or reduce the adhesion and deposition of the components in the liquid on the stent surface.

[0066] In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise clearly defined. In the present invention, unless otherwise clearly defined and defined, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or integrated; it can be a mechanical connection, or an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0067] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0068] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0069] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A method for preparing drug-carrying nanoparticles, It is characterized in that The following steps are involved: Adding an equal volume of the drug solution into the first solution at a predetermined speed and performing ultrasonic vibration; Inserting an electrode into the first solution and connecting it to the positive electrode of a power source, so that the drug is combined with the adsorbent in the first solution to form the internal material of the nanoparticles; taking out the electrode and inserting it into deionized water for shaking and cleaning, and then turning off the power source; Then, the electrode interface is changed, and the electrode carrying the above-mentioned internal material is connected to the negative electrode, and placed in a second solution for reaction to wrap the external material on the outside of the internal material to form nanoparticles. Then, the electrode is taken out and placed in deionized water, the power is turned off, and the nanoparticles on the surface of the electrode are ultrasonically shaken into the deionized water solution; then, the nanoparticles are freeze-dried and collected.

2. The preparation method according to claim 1, It is characterized in that The first solution is a poly-lysine solution or a chitosan solution or a liposome solution or a glycosaminoglycan solution; the second solution is a copper chloride solution or a silver chloride solution or a mixed solution of copper chloride and silver chloride.

3. The preparation method according to claim 1 or 2, It is characterized in that The concentration of the drug solution is 1-10 mg / ml, the predetermined speed is 1-100 microliters / 0.1-10s / drop, the concentration of the first solution is 0.5-5 mg / ml, the time of the ultrasonic oscillation is 10 minutes, the voltage of the power supply is 1-10V, the time of adsorbing nanoparticles is 10 minutes, the concentration of the second solution is 1-10 mg / ml, the time for the electrode to react in the second solution is 2 hours, and the temperature is 20°C.

4. The preparation method according to claim 1, It is characterized in that The size of the nanoparticles is adjusted by regulating the injection amount, injection speed and concentration of the first solution; the surface charge of the nanoparticles is adjusted by regulating the ratio of the internal material content to the external material content; The injection volume of the first solution is 1 to 1000 microliters, the injection speed is 0.1s to 10s / drop, and the concentration of the first solution is 1 to 10mg / ml; The electrical properties of the electrode that adsorbs the internal material are consistent with those of the first solution, and the electrical properties of the electrode that adsorbs the external material are opposite to those of the first solution. The electrode that adsorbs the external material regulates the amount of material attracted by the outer surface of the nano-ions by regulating the voltage range.

5. The preparation method according to claim 1, It is characterized in that The nanoparticles are spherical structures with a diameter of 50 to 500 nm, and the surface electrical properties of the nanoparticles are -30 to -5 mV; The drug includes at least one of heparin, rapamycin, paclitaxel, and asiaticaside, and the external material includes at least one of copper ions and silver ions; The content ratio of the drug to copper ions or silver ions or the mixed solution of copper ions and silver ions in the nanoparticles is 0.3:1-3:1, wherein the ratio of copper ions to silver ions is 0.5:1-2:

1.

6. A method for modifying a scaffold, It is characterized in that The following steps are involved: S1, after cleaning the stent, placing it in a third solution and reacting it at a predetermined temperature and time to form a connection layer on the surface of the stent, and then placing the stent in deionized water for ultrasonic cleaning and drying; S2, placing the stent with the connecting layer in a fourth solution and reacting it at a predetermined temperature and time to form a polymer capable of adsorbing nanoparticles on the outside of the connecting layer, and then placing the stent in deionized water for ultrasonic cleaning and drying; S3, preparing drug-carrying nanoparticles according to the preparation method according to any one of claims 1 to 5; S4, dissolving a predetermined amount of the nanoparticles prepared in S3 in deionized water to obtain a nanoparticle solution; placing the stent obtained in S2 in the nanoparticle solution, and reacting at a predetermined temperature and time, taking it out, ultrasonically cleaning it in deionized water, and placing it in the nanoparticle solution again, repeating the operation for at least 2 times, and drying it to obtain the stent loaded with nanoparticles.

7. The method for modifying a stent according to claim 6, It is characterized in that In S1, the third solution is a polydopamine solution, and the stent is cleaned by ultrasound. The concentration of the polydopamine solution is 2 mg / ml, and the predetermined temperature and time are 20 to 40° C. for 6 to 12 hours. In S2, the fourth solution is a poly-lysine solution, the concentration of the poly-lysine solution is 0.5-5 mg / ml; the predetermined temperature and time are 20-40° C. for 6-12 hours; In S4, the concentration of the nanoparticle solution is 0.1-10 mg / ml, the predetermined temperature and time are 20-40° C. for reaction for 0.5-5 hours, the ultrasonic cleaning time in deionized water is 30 minutes, and the drying method is to place in a 40° C. oven for drying for 24 hours.

8. A method for modifying a scaffold, It is characterized in that The following steps are involved: S1, after cleaning the stent, placing it in a mixed solution of the third solution and the fourth solution, and reacting them at a predetermined temperature and time, and then placing the stent in deionized water for ultrasonic cleaning and drying; S2, preparing drug-carrying nanoparticles according to the preparation method according to any one of claims 1 to 5; S3, dissolving a predetermined amount of the nanoparticles prepared in S2 in deionized water to obtain a nanoparticle solution; placing the stent obtained in S1 in the nanoparticle solution, and reacting at a predetermined temperature and time, taking it out, ultrasonically cleaning it in deionized water, and placing it in the nanoparticle solution again, after reciprocating the operation for at least 2 times, drying it to obtain the stent loaded with nanoparticles.

9. A stent prepared by the modification method according to any one of claims 6 to 8, It is characterized in that include: A stent body, wherein the surface of the stent body is covered with a connecting layer, the outer side of the connecting layer is covered with a polymer, and the polymer is a positively charged polymer or a negatively charged polymer; the outer side of the polymer is covered with a nanoparticle arrangement layer, the polarity of the polymer is opposite to the polarity of the nanoparticle arrangement layer, and the nanoparticles in the nanoparticle arrangement layer include an internal material and an external material adsorbed on the internal material by electrostatics, one of the internal material and the external material includes a drug, and the other includes ions adsorbed by electrostatics.

10. The bracket according to claim 9, It is characterized in that The stent is a urinary tract stent, a cardiac stent, a peripheral vascular stent, a biliary stent, a tracheal stent or an esophageal stent; the connecting layer is a polydopamine coating; The nanoparticles are positively charged polymers or negatively charged polymers having amino groups and carboxyl groups, the drugs include at least one of heparin, rapamycin, paclitaxel, and asiatica glycoside, and the ions include at least one of copper ions and silver ions.

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