A magnetically guided interactive ultrasonic graded controlled release drug-loaded microsphere and its preparation method and application

Abstract

The present invention discloses a magnetically guided interactive ultrasonic graded controlled release drug-loaded microsphere and its preparation method and application. The microsphere is a core-shell sandwich composite structure, which consists of a magnetic array core, a functional multi-level chimeric drug-loaded sandwich layer and a shield shell. The magnetic array core responds to the magnetic field and has superparamagnetism; the functional multi-level chimeric drug-loaded sandwich layer is a three-layer polymer layer loaded with different functional drugs, which is degradable and stimuli-responsive, can be controlled to release rapidly under the action of an ultrasonic interactive magnetic field, and can be stably released in a natural non-human intervention environment, and can be used for the treatment of different stages of the disease; the shield shell is the protective outer layer of the microsphere, which can reduce the loss and deposition of the microsphere during transportation. The drug-loaded microspheres of the present invention have good stability, controllability, biocompatibility and targeting, can achieve precise transportation and controlled drug release through the combined application of magnetic field and ultrasound, improve drug efficacy, reduce toxic side effects, and have broad application prospects in the medical field.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a magnetically guided interactive ultrasonic graded controlled-release drug-loaded microsphere, and a preparation method and application thereof. Background Art

[0002] Normally, after taking a drug, only a small part of it is transported to the affected part through the blood circulation to produce therapeutic effects. Most of the drug is transported to various parts of the body and eventually excreted from the body through liver and kidney metabolism. Therefore, the actual amount of drug used by the patient must be much higher than the amount required to reach the affected part and actually treat the disease. Since all drugs are toxic, the part of the drug that is transported to other parts of the body may not only cause damage to the body's normal tissues and organs, but also increase the burden on the liver and kidneys and cause liver and kidney diseases. Such drug dosage forms also cause drug waste and increase patient expenses. Therefore, the development of the biodelivery system is of great significance for improving drug efficacy and reducing toxic side effects.

[0003] Drug-loaded microspheres have a good effect in drug delivery, reducing side effects and improving patients' quality of life, but there are still some problems:

[0004] (1) Mixing multiple drugs together in microspheres can cause interactions between the drugs, resulting in unstable drug efficacy;

[0005] (2) During the transportation process, microspheres may aggregate and deposit, which may affect the delivery of microspheres and even cause blood vessel blockage, endangering life safety. Microspheres may also be eroded by body fluids, causing degradation or destruction of the microspheres, and even causing the drug to be released before reaching the target site, reducing drug efficacy and increasing side effects.

[0006] (3) Microspheres are often targeted by surface modification and ligand binding, biorecognition molecules, and temperature or pH response properties. This single approach results in poor targeting, high waste, and high cost.

[0007] (4) The drug encapsulation rate in microspheres is low and easily degraded, the drug function is single, and the drug release mode is single and uncontrollable, which cannot meet the needs of disease treatment;

[0008] (5) Disease development requires many stages, but current microspheres directly release all drugs. When the disease develops to different stages, the microspheres need to be re-injected, which increases treatment costs and patient suffering.

[0009] Therefore, in order to solve the above clinical problems, we must overcome the following technical bottlenecks:

[0010] (1) Drugs in microspheres should avoid mutual reactions;

[0011] (2) The microspheres cannot aggregate during transport and are resistant to corrosion by body fluids;

[0012] (3) Microspheres should have good targeting to reduce losses;

[0013] (4) The drug encapsulation rate should be good and it should not degrade quickly. Instead, the degradation rate should be artificially controlled and self-degradable so that it can be adapted to different stages of disease development, thereby reducing patient expenses and treatment pain.

[0014] The existing patent CN 107982535 B discloses a targeted microwave controlled-release drug-loaded nano-microsphere and its preparation method and application. The patent is a typical core-shell structure, the outer shell is a phospholipid mixture modified with fucoidan, and the inner core is loaded with ionic liquids and chemotherapeutic drugs, with good biocompatibility and improved targeting. However, this microsphere has a single structure, low drug loading and a single type. If multiple drugs are loaded, drug interactions will inevitably occur, and the functional release of drugs cannot be controlled artificially. It is also very likely to be eroded by body fluids during the transportation of targeted sites, resulting in premature degradation. In addition, the effect of targeted treatment cannot be achieved at different stages of disease development, the drug release method is single, and there may be a risk of uncontrollable drug release.

[0015] There have been relevant studies on the targeted transport of magnetically guided microspheres to the target site. For example, patent CN 102579357 B discloses a magnetic composite drug-loaded microsphere and its preparation method. This patent is also a core-shell structure, which uses the inside of the microsphere to simultaneously coat magnetic nanoparticles and drugs to achieve targeted transport and drug sustained release performance. However, this structure also has problems such as a single structure and the drug is prone to mutual reaction. The drug can only be released slowly, and the drug release method cannot be selected in a targeted manner according to the development of the disease, and the scope of application is limited; at the same time, there is no protective structure on the surface of the microsphere, which will lead to reduced drug efficacy. Patent CN117503853 A discloses a magnetic nano drug-loaded microsphere and its preparation method and application. This patent is that the Puhuang microsphere is immersed in an aqueous solution containing ferric oxide nanoparticles to obtain magnetic nano drug-loaded microspheres through electrostatic action. The preparation process of this method is simple, easy to operate, and improves targeting to a certain extent. Then this structure is more single, the drug cannot meet the needs of clinical disease treatment, and the magnetic nanoparticles adsorbed on the surface of the microsphere may also fall off, so that the microspheres appear to aggregate, leading to blood vessel blockage and endangering the patient's life. Summary of the invention

[0016] One of the purposes of the present invention is to provide a magnetically guided interactive ultrasonic graded controlled release drug-loaded microsphere in order to solve the above technical problems. The main structure of the microsphere is a core-shell sandwich composite structure, which is composed of a magnetic array core, a functional multi-level chimeric drug-loaded sandwich layer and a shield shell from the inside to the outside; the magnetic array core is a three-dimensional solid matrix, occupying 20-25% of the volume of the microsphere; the functional multi-level chimeric drug-loaded sandwich layer is prepared by an electro-super spraying process, occupying 60-75% of the volume of the microsphere, and can be divided into a middle layer, a middle layer and a middle layer from the inside to the outside, each layer consisting of a degradable substance, magnetic nanoparticles and different functional drugs; the middle layer and the middle layer, and the middle layer and the middle layer are mutually matched through a ridge-like structure; the ridge-like structure is a quasi-sine curve structure of varying heights, prepared by an ultrasonic-vacuum rotation structuring technology; the shield shell is the outermost protective layer of the microsphere, occupying 5-15% of the volume of the microsphere, and contains anti-aggregation substances, collagen and magnetic nanoparticles;

[0017] In order to better realize the present invention, further, the functional medicine is divided into medicine for late stage, medicine for middle stage and medicine for acute stage; the late stage is the late stage of disease development, the middle stage is the middle stage of disease development, and the acute stage is the acute stage of disease development;

[0018] To better implement the present invention, further, the medicine for the late stage is present in the middle layer, the medicine for the middle stage is present in the middle layer, and the medicine for the acute stage is present in the middle layer;

[0019] To better implement the present invention, further, the height of the ridge-like structure is 40-60% of the height of the middle layer;

[0020] To better realize the present invention, further, the anti-aggregation substance is a compound that provides positive or negative charge to the microspheres, preferably one of polyethyleneimine, polyvinyl alcohol, polyacrylic acid, polydimethyldiazepine, and dodecyltrimethylammonium bromide.

[0021] The second object of the present invention is to provide a method for preparing magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres:

[0022] (1) Preparation of magnetic array core: The preparation of magnetic array core was carried out in a magnetic field environment. 10-20 g / mL of pectin and 10-20 g / mL of iron powder were added to sterile distilled water and homogenized under ultrasound to obtain solution M. After homogenization, 20-30 times the volume of solution M of 35% glycerol, 35% sesame oil and 1% sesame oil were added dropwise at a rate of 0.5-1.5 drops / second under 40-50°C water bath, 100-150 rpm stirring and 50-100w ultrasound. 30% of a composite oil phase containing 1-3% of an emulsifier organic solvent, and then continue stirring for 8-16 hours; then add glutaraldehyde ether solution under 40-50°C water bath, 150-200rpm stirring and 50-100w ultrasonic conditions, and then continue stirring at room temperature for 10-20 hours; after stirring, collect the precipitate and wash it with sterile distilled water, and after each washing, screen and collect it with a magnetic field, and finally suspend and dry it in a nitrogen flow at 40-50°C to obtain a magnetic array core;

[0023] To better realize the present invention, further, the mass ratio of pectin to iron powder is 1-2:1;

[0024] To better implement the present invention, further, the pH of the sterile distilled water is 7.4-7.6;

[0025] To better implement the present invention, further, the ultrasonic power is 50-150w, the homogenization speed is 5000-15000rpm, and the homogenization time is 1-5min;

[0026] To better realize the present invention, further, the amount of glutaraldehyde ether solution added is 10-20% of the amount of the composite oil phase added;

[0027] (2) Preparation of functional multi-level chimeric drug-loaded sandwich layer: After the drug to be used in the later stage is dissolved, it is added to an organic solvent containing degradable substance a and magnetic nanoparticles, and slowly stirred in a water bath combined with ultrasound to obtain solution N. Subsequently, under 8-12 kV electric field combined with ultrasound, solution N is sprayed onto the outer surface of the magnetic array core suspended in a three-dimensional nitrogen gas flow, and then ultrasonic vacuum treatment is performed, and the solution is dried in a nitrogen gas flow to obtain and collect quasi-particles n containing the middle layer; after the drug to be used in the later stage is dissolved, it is added to an organic solvent containing degradable substance b and magnetic nanoparticles, and slowly stirred in a water bath combined with ultrasound to obtain solution X. Under 8-12 kV electric field combined with ultrasound, solution X is sprayed onto the outer surface of quasi-particles n suspended in a three-dimensional nitrogen gas flow, and then ultrasonic vacuum treatment is performed, and the solution is dried in a nitrogen gas flow to obtain and collect quasi-particles x containing the middle second layer; after the drug to be used in the acute stage is dissolved, it is added to an organic solvent containing degradable substance c and magnetic nanoparticles, and slowly stirred in a water bath combined with ultrasound to obtain solution Y. Under a kV electric field combined with ultrasound, the solution Y is sprayed onto the outer surface of the quasi-particle x suspended in a three-dimensional nitrogen gas flow, and then subjected to ultrasonic vacuum treatment and dried in a nitrogen gas flow, to obtain and collect the quasi-particle y containing the middle three layers, i.e., the functional multi-level chimeric drug-loaded sandwich layer is prepared;

[0028] To better realize the present invention, further, the degradable substances a, b, and c are any three of polylactic acid, polylactic acid-polyglycolic acid copolymer, gelatin, polyhydroxybutyrate, polylactic acid-polyethylene glycol copolymer, polyurethane, polyhydroxyalkanoate, and chitosan, and the content of the three substances in their corresponding organic solvents is 40-60%;

[0029] To better realize the present invention, further, the content of the magnetic nanoparticles in the organic solvent is 0.5-1.5%;

[0030] To better implement the present invention, further, the water bath is combined with ultrasonic conditions, the water bath temperature is 40-50°C, and the ultrasonic power is 50-150w;

[0031] To better implement the present invention, further, the slow stirring speed is 50-150rpm;

[0032] To better implement the present invention, further, the drug content of solution N, solution X, and solution Y is 5-25%;

[0033] To better implement the present invention, further, the combined ultrasonic condition, the ultrasonic power is 10-200w;

[0034] To better implement the present invention, further, the ultrasonic vacuum treatment has an ultrasonic power of 10-200w and a treatment time of 10-60min;

[0035] (3) Preparation of shield shell: anti-aggregation substances, collagen and magnetic nanoparticles are added to an organic solution containing polylactic acid-glycolic acid copolymer, slowly stirred in a water bath combined with ultrasonic conditions, and then an acidic solution is added and mixed to obtain a solution Z; then, under an 8-12 kV electric field and a 10-200w ultrasonic environment, the solution Z is sprayed onto the outer surface of the quasi-particle y suspended in a three-dimensional nitrogen gas flow, and then ultrasonically vacuum treated and dried in a nitrogen gas flow to obtain and collect particles containing a shield shell, that is, magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres;

[0036] To better realize the present invention, further, the concentrations of the anti-aggregation substance, collagen and magnetic nanoparticles in the organic solution are 0.1-5%, 0.1-5% and 1-10%, respectively, and the concentration of the polylactic acid-glycolic acid copolymer in the organic solution is 1-25%;

[0037] To better implement the present invention, further, the water bath is combined with ultrasonic conditions, the water bath temperature is 40-50°C, and the ultrasonic power is 50-150w;

[0038] To better implement the present invention, further, the slow stirring speed is 50-150rpm;

[0039] To better implement the present invention, further, in the ultrasonic vacuum treatment, the ultrasonic power is 10-200w and the treatment time is 10-60min.

[0040] The components used in the present invention are all commercially available products, and their structures and compositions are known to those skilled in the art.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The preparation of the core of the microsphere magnetic array has always been carried out in a magnetic field environment, so that the arrangement of magnetic particles is consistent, and the superparamagnetism of the core is further improved through active screening by the magnetic field; the synergistic effect of the functional multi-level chimeric drug-loaded sandwich layer of the microsphere and the magnetic nanoparticles of the shield shell can significantly improve the targeting and control accuracy of the microsphere;

[0043] 2. Innovative electrospraying technology was developed to innovatively prepare a functional multi-level chimeric drug-loaded sandwich layer. Each layer is chimeric through a ridge-like structure, so that the layers are tightly combined and the types of drug release are properly connected. At the same time, the problem of mutual reaction between drugs and reduced efficacy is avoided. More importantly, the functional multi-level chimeric drug-loaded sandwich layer can be controlled to release rapidly under the interaction of ultrasonic magnetic field, and can be stably released in a natural non-human intervention environment. The reasonable allocation of functional drugs at different levels can achieve different drugs to treat different stages of the disease development and be used for the treatment of different stages of the disease. That is, the middle three layers can be used for anti-inflammatory and analgesic in the acute stage, the middle two layers can be used for promoting healing and treatment in the medium term, and the middle one layer can be used for promoting tissue recovery and preventing recurrence in the late stage;

[0044] 3. The microsphere shield shell can synergistically improve the targeting of the microspheres while avoiding the problem of premature degradation or destruction of the microspheres during treatment and transportation, and can also improve biocompatibility, prevent deposition, and improve dispersibility. In addition, after completing the protection of the microspheres, that is, after the microspheres reach the targeted position, the external ultrasonic power and alternating magnetic field can be artificially controlled to promote rapid disintegration, thereby exposing the functional multi-level chimeric drug-loaded sandwich layer to achieve the next step of treatment. Among them, the mechanism of rapid disintegration of the microsphere shield shell, the addition of magnetic nanoparticles can respond to the external environment, that is, magnetocaloric effect and vibration occur, accelerating the disintegration of the shield shell, and the addition of acidic substances can cause the pH of the surface of the microspheres to decrease when they come into contact with body fluids, and the ester bonds of PLGA will be protonated by the acid, making the oxygen atoms in the ester bonds easier to attack, thereby accelerating the degradation process.

[0045] 4. Preparation of functional multi-stage chimeric drug-loaded sandwich layer, spraying layer by layer by electric field combined with ultrasound, the semi-finished microspheres are always suspended in the three-dimensional nitrogen flow, this preparation method can make the functional drugs and other substances more evenly distributed on the surface of the microspheres, the particle size is more consistent, the drug encapsulation efficiency is higher, the nitrogen can protect the microspheres and drugs from oxidation or damage, so the finished product qualification rate is higher; on the other hand, the ultrasonic electric field effect can shorten the synthesis time and improve the sensitivity of practical application; proper vacuum treatment at room temperature immediately after spraying can form a ridge-like structure, making each layer structure more compact, increasing the stability of the microspheres and the drug embedding rate; adding a small amount of magnetic nanoparticles to each drug-loaded layer can not only synergistically improve the targeting of the microspheres, but also accelerate the release of drugs under the stimulation of magnetic field combined with ultrasound, so as to expand the scope of drug application;

[0046] 5. Staged treatment of diseases: When human intervention occurs, drugs are released on demand, and the magnetic field and ultrasound interactive response achieve specific rapid release, accurately control the release time and dosage of drugs, and synergize to improve the treatment effect. That is, different treatment cycles have different ultrasound magnetic field interaction frequencies, and the types and concentrations of drugs released are also different. In the acute phase, it can reduce inflammation and relieve pain, promote healing and treatment in the middle phase, and promote tissue recovery and prevent recurrence in the late phase. Under natural non-human intervention conditions, the microspheres will degrade layer by layer according to their self-degradation characteristics to release drugs slowly, so as to achieve staged treatment of specific functional drugs at different stages of disease development, and finally completely biodegrade.

[0047] In summary, the magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres of the present invention have significant innovation and practicality, and are expected to provide a new and effective means for the treatment of diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Schematic diagram of cross section of magnetically guided interactive ultrasonic step-by-step controlled release of drug-loaded microspheres

[0049] Figure 2 A magnified schematic diagram of the cross-section of the ridge-like structure of magnetically guided interactive ultrasound-guided controlled release drug-loaded microspheres

[0050] Figure 3 Schematic diagram of the production of multi-level structure spraying of magnetically guided interactive ultrasonic controlled release drug-loaded microspheres

[0051] Figure 4 Electron microscopic photo of magnetically guided interactive ultrasonic step-by-step controlled release drug-loaded microspheres

[0052] Figure 5 The results of the in vitro sustained release test of the drug

[0053] Figure 6 The results of drug release tests under magnetic field, ultrasound, and magnetic field combined with ultrasound

[0054] Figure 7 The results of the cavitation disintegration response test of the shield shell are shown in Figure 2.

[0055] Figure numerals: A, magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres, B, functional multi-stage chimeric drug-loaded sandwich layer, 1, shield shell, 2, middle third layer, 3, middle second layer, 4, middle first layer, 5, magnetic array core, 6, drugs for late stage, 7, drugs for mid-stage, 8, drugs for acute stage, 9, ridge-like structure, 10, three-dimensional motion nitrogen gas flow, 11, spraying trajectory, 12, solution to be sprayed, DETAILED DESCRIPTION

[0056] The technical scheme of the present invention is further described in detail below in conjunction with embodiments and comparative examples, but the present invention is not limited to these specific embodiments.

[0057] The following are examples and comparative examples.

[0058] Example 1

[0059] 15 g / mL pectin and 15 g / mL iron powder were added to sterile distilled water at a feed mass ratio of 1.5:1, and homogenized at 10000 rpm for 3 min under 100 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ether containing 2% sorbitan oleate with a volume 25 times that of solution M was added dropwise at a rate of 1 drop / second under 45° C. water bath, 100 rpm stirring and 75 W ultrasound, and then continued to stir for 12 h; then, 15% of the volume of the composite oil phase glutaraldehyde ether solution was added under 45° C. water bath, 175 rpm stirring and 75 W ultrasound, and then continued to stir at room temperature for 15 h; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 45° C. to obtain a magnetic array core 5;

[0060] 50% of the drug 6 erlotinib used in the later stage was dissolved and added to dichloromethane containing polylactic acid and 1.0% magnetic nanoparticles, and slowly stirred at 100 rpm for 30 minutes in a 45°C water bath combined with 100w ultrasound to obtain solution N. Subsequently, under 10kV electric field combined with 100w ultrasound, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10, and then vacuum treated with 100w ultrasound for 30 minutes, dried in a nitrogen gas flow, and quasi-particles n containing a middle layer 4 were prepared and collected; 50% of the drug 7 dexamethasone used in the mid-term was dissolved and added to dichloromethane containing polyhydroxybutyrate and 1.0% magnetic nanoparticles. The solution was then sprayed onto the outer surface of the quasi-particle n suspended in a three-dimensional nitrogen gas stream 10 under a 10 kV electric field and a 100 w ultrasonic environment, and then vacuum treated with 100 w ultrasonic waves for 30 min, and dried in a nitrogen gas stream to obtain and collect the quasi-particle x containing the middle second layer 3; 50% of the acute drug 8 ibuprofen was dissolved and added to ethanol containing gelatin and 1.0% magnetic nanoparticles, and then slowly stirred at 100 rpm for 30 min in a 45 ° C water bath combined with a 100 w ultrasonic environment to obtain a solution Y; Under a kV electric field combined with a 100W ultrasonic environment, the solution Y was sprayed onto the outer surface of the quasi-particle x suspended in a three-dimensional moving nitrogen gas flow 10, and then subjected to a 100W ultrasonic vacuum treatment for 30 minutes, and dried in a nitrogen gas flow, to obtain and collect the quasi-particle y containing the middle three layers 2, i.e., the preparation of the functional multi-level chimeric drug-loaded sandwich layer B was completed;

[0061] 2.5% polyethyleneimine, 2.5% collagen and 5% magnetic nanoparticles were added to a 50% ethanol solution containing 13% polylactic acid-glycolic acid copolymer, and slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100W ultrasonic conditions, and then 1M acetic acid solution was added and mixed to obtain solution Z; then, under a 10kV electric field and 100W ultrasonic environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional moving nitrogen gas flow 10, and then vacuum treated with 100W ultrasonic vacuum for 30 min, dried in a nitrogen gas flow, and particles containing a shield shell 1 were obtained and collected, namely, magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A were obtained.

[0062] Example 2

[0063] 20 g / mL of pectin and 20 g / mL of iron powder were added to sterile distilled water at a feed mass ratio of 2:1, and homogenized at 15000 rpm for 5 min under 150 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% acetone containing 3% sorbitol laurate, which was 30 times the volume of solution M, was added dropwise at a rate of 1.5 drops / second under 50° C. water bath, 150 rpm stirring and 100 W ultrasound, and then continued to stir for 16 hours; then, 20% of the volume of the composite oil phase glutaraldehyde ether solution was added under 50° C. water bath, 200 rpm stirring and 100 W ultrasound, and then continued to stir at room temperature for 20 hours; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 50° C. to obtain a magnetic array core 5;

[0064] 60% of the drug 6 erlotinib used in the later stage was dissolved and added to acetic acid containing chitosan and 1.5% magnetic nanoparticles, and slowly stirred at 150 rpm for 30 minutes in a 50°C water bath combined with 150W ultrasound to obtain solution N. Subsequently, under 12kV electric field combined with 200W ultrasound, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10, and then vacuum treated with 200W ultrasound for 60 minutes, dried in a nitrogen gas flow, and quasi-particles n containing a middle layer 4 were prepared and collected; 60% of the drug 7 dexamethasone used in the mid-term was dissolved and added to dichloromethane containing polylactic acid and 1.5% magnetic nanoparticles. In a 50°C water bath combined with 150W ultrasonic conditions, the solution was slowly stirred at 150rpm for 30min to obtain a solution X. In a 12kV electric field combined with a 200W ultrasonic environment, the solution X was sprayed onto the outer surface of the quasi-particle n suspended in a three-dimensional moving nitrogen gas flow 10, and then subjected to a 200W ultrasonic vacuum treatment for 60min, and dried in a nitrogen gas flow to obtain and collect the quasi-particle x containing the middle second layer 3; 60% of aspirin, a drug for the acute phase, was dissolved and added to chloroform containing polyhydroxyalkanoate and 1.5% of magnetic nanoparticles, and slowly stirred at 150rpm for 30min in a 50°C water bath combined with a 150W ultrasonic condition to obtain a solution Y. Under a kV electric field combined with a 200W ultrasonic environment, the solution Y was sprayed onto the outer surface of the quasi-particle x suspended in a three-dimensional moving nitrogen gas flow 10, and then subjected to a 200W ultrasonic vacuum treatment for 60 minutes, and dried in a nitrogen gas flow, to obtain and collect the quasi-particle y containing the middle three layers 2, i.e., the preparation of the functional multi-level chimeric drug-loaded sandwich layer B was completed;

[0065] 5% polyvinyl alcohol, 5% collagen and 10% magnetic nanoparticles were added to a 50% ethanol solution containing 25% polylactic acid-glycolic acid copolymer, and the mixture was slowly stirred at 150 rpm for 30 min in a 50°C water bath combined with 150W ultrasonic conditions. Then, 1M acetic acid solution was added and mixed to obtain solution Z. Subsequently, under a 12kV electric field and 200W ultrasonic environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional nitrogen gas flow 10, and then subjected to 200W ultrasonic vacuum treatment for 60 min and dried in a nitrogen gas flow to obtain and collect particles containing a shield shell 1, thereby obtaining magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A.

[0066] Example 3

[0067] 10 g / mL of pectin and 10 g / mL of iron powder were added to sterile distilled water at a feed mass ratio of 1:1, and homogenized at 5000 rpm for 1 min under 50 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ethanol containing 1% sodium dodecyl sulfate, which was 20 times the volume of solution M, was added dropwise at a rate of 0.5 drops / second under 40° C. water bath, 100 rpm stirring and 50 W ultrasound conditions, and then continued to stir for 8 hours; then, 10% of the volume of the composite oil phase glutaraldehyde ether solution was added under 40° C. water bath, 150 rpm stirring and 50 W ultrasound conditions, and then continued to stir at room temperature for 10 hours; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 40° C. to obtain a magnetic array core 5;

[0068] 40% of the drug 6 erlotinib for the later stage was dissolved and added into dichloromethane containing polyurethane and 0.5% magnetic nanoparticles, and slowly stirred at 50 rpm for 30 min in a 40°C water bath combined with 50W ultrasound to obtain solution N. Subsequently, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10 under 8kV electric field combined with 10W ultrasound, and then vacuum treated with 10W ultrasound for 10 min, and dried in a nitrogen gas flow to obtain and collect quasi-particles n containing a middle layer 4. 40% of the drug 7 dexamethasone for the mid-stage was dissolved and added into acetic acid containing chitosan and 0.5% magnetic nanoparticles, and slowly stirred at 50 rpm for 30 min in a 40°C water bath combined with 50W ultrasound to obtain solution X. kV electric field combined with 10w ultrasonic environment, spray solution X onto the outer surface of quasi-particle n suspended in three-dimensional nitrogen gas flow 10, then 10w ultrasonic vacuum treatment for 10min, dry in nitrogen gas flow, obtain and collect quasi-particle x containing middle two layers 3; 40% of the drug 8 ibuprofen used in the acute phase was dissolved and added to chloroform containing polylactic acid-polyglycolic acid copolymer and 0.5% magnetic nanoparticles, and slowly stirred at 50rpm for 30min in a 40℃ water bath combined with 50w ultrasonic conditions to obtain solution Y, and spray solution Y onto the outer surface of quasi-particle x suspended in three-dimensional nitrogen gas flow 10 under 8 kV electric field combined with 10w ultrasonic environment, then 10w ultrasonic vacuum treatment for 10min, dry in nitrogen gas flow, obtain and collect quasi-particle y containing middle three layers 2, that is, the preparation of functional multi-stage chimeric drug-loaded sandwich layer B is completed;

[0069] 0.1% polyacrylic acid, 0.1% collagen and 1% magnetic nanoparticles were added to a 50% ethanol solution containing 1% polylactic acid-glycolic acid copolymer, and the mixture was slowly stirred at 50 rpm for 30 min in a 40°C water bath combined with 50W ultrasonic conditions. Then, 1M acetic acid solution was added and mixed to obtain solution Z. Subsequently, under an 8kV electric field and 10W ultrasonic environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional nitrogen gas flow 10, and then subjected to 10W ultrasonic vacuum treatment for 10 min and dried in a nitrogen gas flow to obtain and collect particles containing a shield shell 1, thereby obtaining magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A.

[0070] Example 4

[0071] 15 g / mL of pectin and 15 g / mL of iron powder were added to sterile distilled water at a feed mass ratio of 1.5:1, and homogenized at 10000 rpm for 5 min under 150 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ethanol containing 3% polysorbate 20, which was 25 times the volume of solution M, was added dropwise at a rate of 1.5 drops / second under 45° C. water bath, 100 rpm stirring and 100 W ultrasound conditions, and then continued to stir for 8 hours; then, 20% of the volume of the composite oil phase glutaraldehyde ether solution was added under 45° C. water bath, 175 rpm stirring and 75 W ultrasound conditions, and then continued to stir at room temperature for 10 hours; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 45° C. to obtain a magnetic array core 5;

[0072] 60% of the drug 6 erlotinib used in the later stage was dissolved and added to ethanol containing gelatin and 0.5% magnetic nanoparticles, and slowly stirred at 100 rpm for 30 minutes in a 45°C water bath combined with 100w ultrasound to obtain solution N. Subsequently, under 12 kV electric field combined with 200w ultrasound, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10, and then vacuum treated with 10w ultrasound for 10 minutes and dried in a nitrogen gas flow to obtain and collect quasi-particles n containing a middle layer 4. 40% of the drug 7 dexamethasone used in the middle stage was dissolved and added to chloroform containing polylactic acid-polyethylene glycol copolymer and 1.5% magnetic nanoparticles, and slowly stirred at 100 rpm for 30 minutes in a 45°C water bath combined with 100w ultrasound to obtain solution N. Solution X, under a 10 kV electric field combined with a 150 w ultrasonic environment, spray solution X onto the outer surface of quasi-particle n suspended in a three-dimensional moving nitrogen gas flow 10, then treat with a 150 w ultrasonic vacuum for 30 min, and dry in a nitrogen gas flow to obtain and collect quasi-particle x containing a middle second layer 3; 50% of the drug 8 prednisone used in the acute phase is dissolved and added to acetic acid containing chitosan and 1.0% magnetic nanoparticles, and slowly stirred at 50 rpm for 30 min in a 50 ° C water bath combined with a 150 w ultrasonic condition to obtain solution Y, under a 12 kV electric field combined with a 200 w ultrasonic environment, spray solution Y onto the outer surface of quasi-particle x suspended in a three-dimensional moving nitrogen gas flow 10, then treat with a 100 w ultrasonic vacuum for 30 min, and dry in a nitrogen gas flow to obtain and collect quasi-particle y containing a middle third layer 2, that is, the preparation of the functional multi-level chimeric drug-loaded sandwich layer B is completed;

[0073] 2.5% polydimethyldiazepine, 0.1% collagen and 10% magnetic nanoparticles were added to a 50% ethanol solution containing 25% polylactic acid-glycolic acid copolymer, and slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100W ultrasonic conditions, and then 1M acetic acid solution was added and mixed to obtain solution Z; then, under a 12 kV electric field and 200W ultrasonic environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional moving nitrogen gas flow 10, and then vacuum treated with 150W ultrasound for 30 min, dried in a nitrogen gas flow, and particles containing a shield shell 1 were obtained and collected, namely, magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A were obtained.

[0074] Example 5

[0075] 20 g / mL of pectin and 10 g / mL of iron powder were added to sterile distilled water at a feed mass ratio of 1:1, and homogenized at 15000 rpm for 1 min under 50 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ethanol containing 2% polysorbate 80, which was 20 times the volume of solution M, was added dropwise at a rate of 0.5 drops / second under 50° C. water bath, 150 rpm stirring and 50 W ultrasound, and then continued to stir for 12 hours; then, 10% of the volume of the composite oil phase glutaraldehyde ether solution was added under 50° C. water bath, 175 rpm stirring and 75 W ultrasound, and then continued to stir at room temperature for 20 hours; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 40° C. to obtain a magnetic array core 5;

[0076] 50% of the drug 6 erlotinib used in the later stage was dissolved and added to chloroform containing polylactic acid-polyglycolic acid copolymer and 1.0% magnetic nanoparticles, and slowly stirred at 150 rpm for 30 min in a 45°C water bath combined with 100W ultrasound to obtain solution N. Subsequently, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional moving nitrogen gas flow 10 under a 12 kV electric field combined with 10W ultrasound, and then vacuum treated with 200W ultrasound for 30 min and dried in a nitrogen gas flow to obtain and collect quasi-particles n containing a middle layer 4. 40% of the drug 7 dexamethasone used in the mid-stage was dissolved and added to ethanol containing gelatin and 1.5% magnetic nanoparticles, and slowly stirred at 150rpm for 30 min in a 40°C water bath combined with 50W ultrasound to obtain solution X. Under a V electric field combined with a 150W ultrasonic environment, the solution X was sprayed onto the outer surface of the quasi-particle n suspended in a three-dimensional nitrogen gas flow 10, and then subjected to a 150W ultrasonic vacuum treatment for 30 minutes, and dried in a nitrogen gas flow, to obtain and collect the quasi-particle x containing the middle second layer 3; 60% of the drug 8 cephalosporin used in the acute phase was dissolved and added to chloroform containing polyhydroxybutyrate and 0.5% magnetic nanoparticles, and slowly stirred at 50 rpm for 30 minutes in a 40°C water bath combined with a 50W ultrasonic condition to obtain a solution Y, and under a 10 kV electric field combined with a 200W ultrasonic environment, the solution Y was sprayed onto the outer surface of the quasi-particle x suspended in a three-dimensional nitrogen gas flow 10, and then subjected to a 100W ultrasonic vacuum treatment for 60 minutes, and dried in a nitrogen gas flow, to obtain and collect the quasi-particle y containing the middle third layer 2, that is, the preparation of the functional multi-stage chimeric drug-loaded sandwich layer B was completed;

[0077] 5% dodecyltrimethylammonium bromide, 2.5% collagen and 10% magnetic nanoparticles were added to a 50% ethanol solution containing 13% polylactic acid-glycolic acid copolymer, and the mixture was slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 150W ultrasound. Then, 1M acetic acid solution was added and mixed to obtain solution Z. Subsequently, under a 12 kV electric field and 100W ultrasound environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional moving nitrogen gas flow 10, and then subjected to 200W ultrasonic vacuum treatment for 30 min and dried in a nitrogen gas flow to obtain and collect particles containing a shield shell 1, namely, magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A.

[0078] Comparative Example 1

[0079] 15 g / mL pectin and 15 g / mL iron powder were added to sterile distilled water at a feed mass ratio of 1.5:1, and homogenized at 10000 rpm for 3 min under 100 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ether containing 2% sorbitan oleate with a volume 25 times that of solution M was added dropwise at a rate of 1 drop / second under 45° C. water bath, 100 rpm stirring and 75 W ultrasound, and then continued to stir for 12 h; then, 15% of the volume of the composite oil phase glutaraldehyde ether solution was added under 45° C. water bath, 175 rpm stirring and 75 W ultrasound, and then continued to stir at room temperature for 15 h; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 45° C. to obtain a magnetic array core 5;

[0080] 50% of drug 6 erlotinib for the late stage, 50% of drug 7 dexamethasone for the mid-stage, and 50% of drug 8 ibuprofen for the acute stage were dissolved and added into dichloromethane containing polylactic acid and 1.0% magnetic nanoparticles, and slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100W ultrasound to obtain solution N, and then sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional moving nitrogen gas stream 10 under a 10kV electric field combined with 100W ultrasound, and then vacuum treated with 100W ultrasound for 30 min, dried in a nitrogen gas stream, and quasi-particles n containing a mixture of multiple drugs were obtained and collected;

[0081] 2.5% polyethyleneimine, 2.5% collagen and 5% magnetic nanoparticles were added to a 50% ethanol solution containing 13% polylactic acid-glycolic acid copolymer, and slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100W ultrasonic conditions, and then 1M acetic acid solution was added and mixed to obtain solution Z; then, under a 10kV electric field and 100W ultrasonic environment, solution Z was sprayed onto the outer surface of quasi-particles n suspended in a three-dimensional moving nitrogen gas flow 10, and then vacuum treated with 100W ultrasonic vacuum for 30 min, dried in a nitrogen gas flow, and particles containing a shield shell 1 were obtained and collected, namely, magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A were obtained.

[0082] Comparative Example 2

[0083] 15 g / mL pectin and 15 g / mL iron powder were added to sterile distilled water at a feed mass ratio of 1.5:1, and homogenized at 10000 rpm for 3 min under 100 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ether containing 2% sorbitan oleate with a volume 25 times that of solution M was added dropwise at a rate of 1 drop / second under 45° C. water bath, 100 rpm stirring and 75 W ultrasound, and then continued to stir for 12 h; then, 15% of the volume of the composite oil phase glutaraldehyde ether solution was added under 45° C. water bath, 175 rpm stirring and 75 W ultrasound, and then continued to stir at room temperature for 15 h; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 45° C. to obtain a magnetic array core 5;

[0084] 50% of the drug 6 erlotinib used in the later stage was dissolved and added to dichloromethane containing polylactic acid, and slowly stirred at 100 rpm for 30 minutes in a 45°C water bath combined with 100w ultrasound to obtain solution N. Subsequently, under 10kV electric field combined with 100w ultrasound, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10, and then vacuum treated with 100w ultrasound for 30 minutes, dried in a nitrogen gas flow, and quasi-particles n containing a middle layer 4 were prepared and collected; 50% of the drug 7 dexamethasone used in the middle stage was dissolved and added to chloroform containing polyhydroxybutyrate. , slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100w ultrasound to obtain solution X, sprayed onto the outer surface of quasi-particle n suspended in a three-dimensional nitrogen gas flow 10 under a 10kV electric field combined with a 100w ultrasound environment, then subjected to a 100w ultrasound vacuum treatment for 30 min, and dried in a nitrogen gas flow to obtain and collect quasi-particle x containing a middle second layer 3; 50% of the acute phase drug 8 ibuprofen was dissolved and added to ethanol containing gelatin, slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with a 100w ultrasound to obtain solution Y, sprayed onto the outer surface of quasi-particle x suspended in a three-dimensional nitrogen gas flow 10 under a 10 kV electric field combined with a 100w ultrasound environment, then subjected to a 100w ultrasound vacuum treatment for 30 min, and dried in a nitrogen gas flow to obtain and collect quasi-particle y containing a middle third layer 2, i.e., the preparation of the functional multi-stage chimeric drug-loaded sandwich layer B was completed;

[0085] 2.5% polyethyleneimine and 2.5% collagen were added to a 50% ethanol solution containing 13% polylactic acid-glycolic acid copolymer, and the mixture was slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100W ultrasound. Then, 1M acetic acid solution was added and mixed to obtain solution Z. Subsequently, under a 10kV electric field and 100W ultrasound environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional nitrogen gas flow 10, and then subjected to 100W ultrasonic vacuum treatment for 30 min and dried in a nitrogen gas flow to obtain and collect particles containing a shield shell 1, thereby obtaining magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A.

[0086] Comparative Example 3

[0087] 15 g / mL pectin and 15 g / mL iron powder were added to sterile distilled water at a feed mass ratio of 1.5:1, and homogenized at 10000 rpm for 3 min under 100 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ether containing 2% sorbitan oleate with a volume 25 times that of solution M was added dropwise at a rate of 1 drop / second under 45° C. water bath, 100 rpm stirring and 75 W ultrasound, and then continued to stir for 12 h; then, 15% of the volume of the composite oil phase glutaraldehyde ether solution was added under 45° C. water bath, 175 rpm stirring and 75 W ultrasound, and then continued to stir at room temperature for 15 h; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 45° C. to obtain a magnetic array core 5;

[0088] 50% of the drug 6 erlotinib used in the later stage was dissolved and added to dichloromethane containing polylactic acid and 1.0% magnetic nanoparticles, and slowly stirred at 100 rpm for 30 minutes in a 45°C water bath combined with 100w ultrasound to obtain solution N. Subsequently, under 10kV electric field combined with 100w ultrasound, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10, and then vacuum treated with 100w ultrasound for 30 minutes, dried in a nitrogen gas flow, and quasi-particles n containing a middle layer 4 were prepared and collected; 50% of the drug 7 dexamethasone used in the mid-term was dissolved and added to dichloromethane containing polyhydroxybutyrate and 1.0% magnetic nanoparticles. The mixture was slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100W ultrasound to obtain a solution X. The solution X was sprayed onto the outer surface of the quasi-particle n suspended in a three-dimensional nitrogen gas flow 10 under a 10 kV electric field combined with a 100W ultrasound environment, and then vacuum treated with 100W ultrasound for 30 min, and dried in a nitrogen gas flow to obtain and collect the quasi-particle x containing the second middle layer 3. 50% of the drug 8 ibuprofen used in the acute phase was dissolved and added to ethanol containing gelatin and 1.0% magnetic nanoparticles. The mixture was slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with a 100W ultrasound environment to obtain a solution Y. The solution Y was sprayed onto the outer surface of the quasi-particle x suspended in a three-dimensional nitrogen gas flow 10 under a 10 kV electric field combined with a 100W ultrasound environment, and then vacuum treated with 100W ultrasound for 30 min, and dried in a nitrogen gas flow to obtain and collect the quasi-particle y containing the third middle layer 2. The microspheres prepared at this moment were used as the final microspheres.

[0089] Comparative Example 4

[0090] 15 g / mL pectin and 15 g / mL iron powder were added to sterile distilled water at a feed mass ratio of 1.5:1, and homogenized at 10000 rpm for 3 min under 100 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ether containing 2% sorbitan oleate with a volume 25 times that of solution M was added dropwise at a rate of 1 drop / second under 45° C. water bath, 100 rpm stirring and 75 W ultrasound, and then continued to stir for 12 h; then, 15% of the volume of the composite oil phase glutaraldehyde ether solution was added under 45° C. water bath, 175 rpm stirring and 75 W ultrasound, and then continued to stir at room temperature for 15 h; after stirring, the precipitate was collected and washed with sterile distilled water, and finally suspended and dried in a nitrogen flow at 45° C. to obtain a magnetic array core 5;

[0091] 50% of the drug 6 erlotinib used in the later stage was dissolved and added to dichloromethane containing polylactic acid and 1.0% magnetic nanoparticles, and slowly stirred at 100 rpm for 30 minutes in a 45°C water bath combined with 100w ultrasound to obtain solution N. Subsequently, under 10kV electric field combined with 100w ultrasound, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10, and then vacuum treated with 100w ultrasound for 30 minutes, dried in a nitrogen gas flow, and quasi-particles n containing a middle layer 4 were prepared and collected; 50% of the drug 7 dexamethasone used in the mid-term was dissolved and added to dichloromethane containing polyhydroxybutyrate and 1.0% magnetic nanoparticles. The solution was then sprayed onto the outer surface of the quasi-particle n suspended in a three-dimensional nitrogen gas stream 10 under a 10 kV electric field and a 100 w ultrasonic environment, and then vacuum treated with 100 w ultrasonic waves for 30 min, and dried in a nitrogen gas stream to obtain and collect the quasi-particle x containing the middle second layer 3; 50% of the acute drug 8 ibuprofen was dissolved and added to ethanol containing gelatin and 1.0% magnetic nanoparticles, and then slowly stirred at 100 rpm for 30 min in a 45 ° C water bath combined with a 100 w ultrasonic environment to obtain a solution Y; Under a kV electric field combined with a 100W ultrasonic environment, the solution Y was sprayed onto the outer surface of the quasi-particle x suspended in a three-dimensional moving nitrogen gas flow 10, and then subjected to a 100W ultrasonic vacuum treatment for 30 minutes, and dried in a nitrogen gas flow, to obtain and collect the quasi-particle y containing the middle three layers 2, i.e., the preparation of the functional multi-level chimeric drug-loaded sandwich layer B was completed;

[0092] 2.5% polyethyleneimine, 2.5% collagen and 5% magnetic nanoparticles were added to a 50% ethanol solution containing 13% polylactic acid-glycolic acid copolymer, and slowly stirred at 100 rpm for 30 min in a 45°C water bath combined with 100W ultrasonic conditions, and then 1M acetic acid solution was added and mixed to obtain solution Z; then, under a 10kV electric field and 100W ultrasonic environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional moving nitrogen gas flow 10, and then vacuum treated with 100W ultrasonic vacuum for 30 min, dried in a nitrogen gas flow, and particles containing a shield shell 1 were obtained and collected, namely, magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A were obtained.

[0093] Comparative Example 5

[0094] 5 g / mL pectin and 5 g / mL iron powder were added to sterile distilled water at a feed mass ratio of 0.5:1, and homogenized at 5000 rpm for 1 min under 10 W ultrasound to obtain solution M; after homogenization, a composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% ether containing 2% sorbitan oleate, which was 15 times the volume of solution M, was added dropwise at a rate of 1 drop / second under 25° C. water bath, 100 rpm stirring and 25 W ultrasound conditions, and then continued to stir for 3 hours; then, 15% of the volume of the composite oil phase glutaraldehyde ether solution was added under 25° C. water bath, 175 rpm stirring and 15 W ultrasound conditions, and then continued to stir at room temperature for 15 hours; after stirring, the precipitate was collected and washed with sterile distilled water, and after each washing, it was screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 45° C. to obtain a magnetic array core 5;

[0095] 50% of the drug 6 erlotinib used in the later stage was dissolved and added to dichloromethane containing polylactic acid and 1.0% magnetic nanoparticles, and slowly stirred at 10 rpm for 30 minutes in a 25°C water bath combined with 10w ultrasound to obtain solution N. Subsequently, under 2kV electric field combined with 10w ultrasound, solution N was sprayed onto the outer surface of the magnetic array core 5 suspended in a three-dimensional nitrogen gas flow 10, and then vacuum treated with 10w ultrasound for 30 minutes, dried in a nitrogen gas flow, and quasi-particles n containing a middle layer 4 were prepared and collected; 50% of the drug 7 dexamethasone used in the mid-term was dissolved and added to dichloromethane containing polyhydroxybutyrate and 1.0% magnetic nanoparticles. The particles were slowly stirred at 10 rpm for 30 min in a 25°C water bath combined with 10w ultrasound to obtain solution X, which was sprayed onto the outer surface of quasi-particle n suspended in a three-dimensional nitrogen gas flow 10 under a 2kV electric field combined with a 10w ultrasound environment, and then vacuum treated with 100w ultrasound for 30 min, and dried in a nitrogen gas flow to obtain and collect quasi-particle x containing the middle second layer 3; 50% of the drug 8 ibuprofen used in the acute phase was dissolved and added to ethanol containing gelatin and 1.0% magnetic nanoparticles, and slowly stirred at 10 rpm for 30 min in a 25°C water bath combined with a 10w ultrasound to obtain solution Y, which was sprayed onto the outer surface of quasi-particle x suspended in a three-dimensional nitrogen gas flow 10 under a 2 kV electric field combined with a 10w ultrasound environment, and then vacuum treated with 100w ultrasound for 30 min, and dried in a nitrogen gas flow to obtain and collect quasi-particle y containing the middle third layer 2, that is, the preparation of the functional multi-stage chimeric drug-loaded sandwich layer B was completed;

[0096] 2.5% polyethyleneimine, 2.5% collagen and 5% magnetic nanoparticles were added to a 50% ethanol solution containing 1% polylactic acid-glycolic acid copolymer, and the mixture was slowly stirred at 10 rpm for 30 min in a 25°C water bath combined with 10W ultrasonic conditions. Then, 0.1M acetic acid solution was added and mixed to obtain solution Z. Subsequently, under a 2kV electric field and 10W ultrasonic environment, solution Z was sprayed onto the outer surface of quasi-particles y suspended in a three-dimensional moving nitrogen gas flow 10, and then subjected to 100W ultrasonic vacuum treatment for 30 min and dried in a nitrogen gas flow to obtain and collect particles containing a shield shell 1, thereby obtaining magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres A.

[0097] The magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres A of the above-mentioned embodiments and comparative examples were subjected to morphology and surface characteristics, drug loading test, in vitro non-human intervention drug release test, in vitro human intervention drug release test, simulated body fluid anti-deposition and anti-aggregation test and biocompatibility test. The specific test methods are as follows:

[0098] 1. Morphology and surface characteristics

[0099] The measurements were carried out using a scanning electron microscope (SEM).

[0100] 2. Drug loading test

[0101] The drug erlotinib was used as the detection object and high performance liquid chromatography (HPLC) was used for determination.

[0102] 3. In vitro non-human intervention drug release test / in vitro non-human intervention functional multi-stage chimeric drug-loaded sandwich layer B degradation test

[0103] Taking the drug erlotinib as the test object, the microspheres sustained-released the drug in a simulated in vivo environment and the dialysis bag method was used for measurement.

[0104] 4. In vitro artificial intervention drug release test / in vitro artificial functional multi-stage chimeric drug-loaded sandwich layer B degradation test

[0105] Taking the drug erlotinib as the test object, ultrasound, magnetic field, and magnetic field combined with ultrasound were used to act on the microspheres in a simulated in vivo environment, and the dialysis bag method was used for measurement.

[0106] 5. Targeted sports research

[0107] To simulate the in vivo environment, a specific magnetic field was used to make the microspheres move in the simulated body fluid, observe whether the microspheres were deposited and aggregated, and evaluate the magnetic field responsiveness of the microspheres.

[0108] 6. Biocompatibility test

[0109] The MTT method was used for determination.

[0110] 7. Study on cavitation disintegration response of shield shell

[0111] In order to simulate the in vivo environment, the test subjects of Example 1 and Comparative Example 3 were tested under two environments, namely, ultrasound combined with an alternating magnetic field and no external stimulation. The drug ibuprofen was used as the test object and the HPLC method was used for determination.

[0112] The test results of some performance tests of the embodiments and comparative examples are shown in Table 1:

[0113] Table 1 Performance test results of magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres embodiment and comparative example

[0114]

[0115] Combined with Table 1, Figure 4 , Figure 5 and Figure 6It can be seen that the magnetically guided interactive ultrasonic graded controlled-release drug-loaded microspheres A designed in the present invention have an ideal drug loading capacity and good magnetic field responsiveness; the drug is slowly released for a longer time without human intervention, and the protection of the shield shell makes the microspheres more stable during transportation, will not degrade prematurely, and will not deposit and aggregate, and have good biocompatibility; when human intervention occurs, the combination of ultrasound and magnetic field technology can controllably and quickly disintegrate the shield shell and release the drug in a timely manner.

[0116] In Comparative Example 1, the magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres A do not have a functional multi-level chimeric drug-loaded sandwich structure B, and multiple drugs are not isolated from each other but directly mixed together, resulting in drug interactions, reduced efficacy, and low drug encapsulation efficiency.

[0117] In comparative example 2, the magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres A only have a magnetic array core 5, but no magnetic nanoparticles are added to each layer, resulting in no synergistic effect, poor targeting, and a large loss of drugs during transportation.

[0118] In comparative example 3, the magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres A are not protected by the shield shell 1, and are degraded prematurely during transportation, resulting in premature release of the drug, a short sustained release time, poor biocompatibility, and easy deposition and aggregation.

[0119] In Comparative Example 4, the magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres A were not prepared and screened under a magnetic field environment, resulting in low targeting, poor superparamagnetism, poor biocompatibility, and easy deposition and aggregation.

[0120] In Comparative Example 5, the preparation process parameters of magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres A are not suitable, so the drug loading is low, the sustained release and rapid release are not ideal, deposition and aggregation are prone to occur, and the biocompatibility is poor.

[0121] The results show that the magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres A designed in the present invention have good properties and clinical application value.

[0122] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention can be made, and any changes that can be thought of by those skilled in the art should be within the scope of protection of the present invention.

Claims

1. A magnetically guided interactive ultrasonic graded controlled release drug-loaded microsphere, characterized in that: The main structure of the microsphere is a core-shell sandwich composite structure, which is composed of a magnetic array core, a functional multi-level chimeric drug-loaded sandwich layer and a shield shell from the inside to the outside; the magnetic array core is a three-dimensional solid matrix, occupying 20-25% of the volume of the microsphere; the functional multi-level chimeric drug-loaded sandwich layer is prepared by an electrospraying process, occupying 60-75% of the volume of the microsphere, and can be divided into a middle layer, a middle layer and a middle layer from the inside to the outside, each layer consisting of a degradable substance, magnetic nanoparticles and different functional drugs; the middle layer and the middle layer, and the middle layer and the middle layer are mutually matched through a ridge-like structure; the ridge-like structure is a quasi-sine curve structure of varying heights, prepared by an ultrasonic-vacuum rotation structuring technology; the shield shell is the outermost protective layer of the microsphere, occupying 5-15% of the volume of the microsphere, and containing anti-aggregation substances, collagen and magnetic nanoparticles; The preparation method comprises the following steps: (1) Preparation of magnetic array core: The preparation of magnetic array core was carried out in a magnetic field environment; 10-20 g / mL of pectin and 10-20 g / mL of iron powder were added to sterile distilled water with a pH of 7.4-7.6 in a mass ratio of 1-2:1, and homogenized at 5000-15000 rpm for 1-5 min under 50-150 W ultrasound to obtain solution M; after homogenization, 20-30 times the volume of solution M was added dropwise at a rate of 0.5-1.5 drops / second under 40-50 ° C water bath, 100-150 rpm stirring and 50-100 W ultrasound. A composite oil phase consisting of 35% glycerol, 35% sesame oil and 30% organic solvent containing 1-3% emulsifier is added, and then stirring is continued for 8-16 hours; then, glutaraldehyde ether solution is added under 40-50°C water bath, 150-200rpm stirring and 50-100w ultrasonic conditions, and the added amount is 10-20% of the amount of the composite oil phase, and then stirring is continued at room temperature for 10-20 hours; after stirring, the precipitate is collected and washed with sterile distilled water, and after each washing, it is screened and collected using a magnetic field, and finally suspended and dried in a nitrogen flow at 40-50°C to obtain a magnetic array core; (2) Preparation of functional multi-stage chimeric drug-loaded sandwich layer: The drug to be used in the later stage is dissolved and added to an organic solvent containing 40-60% of degradable substance a and 0.5-1.5% of magnetic nanoparticles. The solution N is slowly stirred at 50-150 rpm in a 40-50°C water bath combined with 50-150W ultrasound to obtain a solution N containing 5-25% of the drug. The solution is then heated for 8-12 hours. kV electric field combined with 10-200w ultrasonic conditions, spray solution N onto the outer surface of the magnetic array core suspended in a three-dimensional nitrogen gas flow, then perform 10-200w ultrasonic vacuum treatment for 10-60min, dry in a nitrogen gas flow, obtain and collect quasi-particles n containing a middle layer; dissolve the drug for the middle stage and add it to an organic solvent containing 40-60% of a degradable substance b and 0.5-1.5% of magnetic nanoparticles, slowly stir at 50-150rpm in a 40-50℃ water bath combined with 50-150w ultrasonic conditions to obtain a solution X containing 5-25% of the drug, and dry it in a nitrogen gas flow for 8-12 kV electric field combined with 10-200w ultrasonic environment, spraying solution X onto the outer surface of quasi-particle n suspended in a three-dimensional moving nitrogen gas flow, then 10-200w ultrasonic vacuum treatment for 10-60min, drying in a nitrogen gas flow, preparing and collecting quasi-particle x containing the middle two layers; dissolving the drug for the acute phase and adding it to an organic solvent containing 40-60% of a degradable substance c and 0.5-1.5% of magnetic nanoparticles, slowly stirring at 50-150rpm in a 40-50°C water bath combined with 50-150w ultrasonic conditions to obtain a solution Y containing 5-25% of the drug, spraying solution Y onto the outer surface of quasi-particle x suspended in a three-dimensional moving nitrogen gas flow under an 8-12 kV electric field combined with 10-200w ultrasonic environment, then 10-200w ultrasonic vacuum treatment for 10-60min, drying in a nitrogen gas flow, preparing and collecting quasi-particle y containing the middle three layers, that is, the preparation of the functional multi-stage chimeric drug-loaded sandwich layer is completed; The degradable substances a, b, and c are any three of polylactic acid, polylactic acid-polyglycolic acid copolymer, gelatin, polyhydroxybutyrate, polylactic acid-polyethylene glycol copolymer, polyurethane, polyhydroxyalkanoate, and chitosan; (3) Preparation of shield shell: Add anti-aggregation substance, collagen and magnetic nanoparticles to an organic solution containing 1-25% polylactic acid-glycolic acid copolymer, slowly stir at 50-150 rpm in a 40-50°C water bath combined with 50-150w ultrasonic conditions, then add acidic solution and mix well to obtain solution Z; then, under an 8-12 kV electric field and 10-200w ultrasonic environment, spray solution Z onto the outer surface of quasi-particles y suspended in a three-dimensional moving nitrogen gas flow, then perform 10-200w ultrasonic vacuum treatment for 10-60min, dry in a nitrogen gas flow, obtain and collect particles containing shield shells, and obtain magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres; The anti-coagulation substance is one of polyethyleneimine, polyvinyl alcohol, polyacrylic acid, and polydimethyldiazacyclohexine dodecyltrimethyl bromide; The concentrations of the anti-aggregation substance, collagen and magnetic nanoparticles in the organic solution are 0.1-5%, 0.1-5% and 1-10% respectively.

2. The magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres according to claim 1, characterized in that: The functional medicines are divided into medicines for the late stage, medicines for the middle stage and medicines for the acute stage; the medicines for the late stage are present in the middle layer, the medicines for the middle stage are present in the middle layer, and the medicines for the acute stage are present in the middle layer.

3. The magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres according to claim 1, characterized in that: The height of the ridge-like structure is 40-60% of the height of the middle layer.

4. The magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres according to claim 1, characterized in that: The anti-aggregation substance is one of polyethyleneimine, polyvinyl alcohol, polyacrylic acid, and polydimethyldiazepine dodecyltrimethyl bromide.

5. A method for preparing magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: (1) Preparation of magnetic array core: The preparation of magnetic array core was carried out in a magnetic field environment. 10-20 g / mL of pectin and 10-20 g / mL of iron powder were added to sterile distilled water and homogenized under ultrasound to obtain solution M. After homogenization, 20-30 times the volume of solution M of 35% glycerol, 35% sesame oil and 1% sesame oil were added dropwise at a rate of 0.5-1.5 drops / second under 40-50°C water bath, 100-150 rpm stirring and 50-100w ultrasound. 30% of a composite oil phase containing 1-3% of an emulsifier organic solvent, and then continue stirring for 8-16 hours; then add glutaraldehyde ether solution under 40-50°C water bath, 150-200rpm stirring and 50-100w ultrasonic conditions, and then continue stirring at room temperature for 10-20 hours; after stirring, collect the precipitate and wash it with sterile distilled water, and after each washing, screen and collect it with a magnetic field, and finally suspend and dry it in a nitrogen flow at 40-50°C to obtain a magnetic array core; (2) Preparation of functional multi-stage chimeric drug-loaded sandwich layer: The drug for the later stage is dissolved and added to an organic solvent containing degradable substance a and magnetic nanoparticles, and slowly stirred in a water bath combined with ultrasound to obtain solution N. Subsequently, under 8-12 kV electric field combined with ultrasound, solution N is sprayed onto the outer surface of the magnetic array core suspended in a three-dimensional nitrogen gas flow, and then ultrasonic vacuum treatment is performed, and the solution is dried in a nitrogen gas flow to obtain and collect quasi-particles n containing the middle layer; the drug for the mid-stage is dissolved and added to an organic solvent containing degradable substance b and magnetic nanoparticles, and slowly stirred in a water bath combined with ultrasound to obtain solution X. Under 8-12 kV electric field combined with ultrasound, solution X is sprayed onto the outer surface of quasi-particles n suspended in a three-dimensional nitrogen gas flow, and then ultrasonic vacuum treatment is performed, and the solution is dried in a nitrogen gas flow to obtain and collect quasi-particles x containing the middle second layer; the drug for the acute stage is dissolved and added to an organic solvent containing degradable substance c and magnetic nanoparticles, and slowly stirred in a water bath combined with ultrasound to obtain solution Y. Under a kV electric field combined with ultrasound, the solution Y is sprayed onto the outer surface of the quasi-particle x suspended in a three-dimensional nitrogen gas flow, and then subjected to ultrasonic vacuum treatment and dried in a nitrogen gas flow, to obtain and collect the quasi-particle y containing the middle three layers, i.e., the functional multi-level chimeric drug-loaded sandwich layer is prepared; (3) Preparation of shield shell: Add anti-aggregation substances, collagen and magnetic nanoparticles to an organic solution containing polylactic acid-glycolic acid copolymer, slowly stir under water bath combined with ultrasonic conditions, then add acidic solution and mix well to obtain solution Z; then, under 8-12 kV electric field and 10-200w ultrasonic environment, spray solution Z onto the outer surface of quasi-particles y suspended in a three-dimensional moving nitrogen gas flow, then ultrasonically vacuum treat and dry in a nitrogen gas flow to obtain and collect particles containing a shield shell, i.e., obtain magnetically conductive interactive ultrasonic graded controlled release drug-loaded microspheres.

6. The method for preparing magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres according to claim 5, characterized in that: In step (1), the mass ratio of pectin to iron powder is 1-2:1; the pH value of sterile distilled water is 7.4-7.6; the ultrasonic power is 50-150w, the homogenization speed is 5000-15000rpm, and the homogenization time is 1-5min; and the amount of glutaraldehyde ether solution added is 10-20% of the amount of the composite oil phase added.

7. The method for preparing magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres according to claim 5, characterized in that: In step (2), the degradable substances a, b, and c are any three of polylactic acid, polylactic acid-polyglycolic acid copolymer, gelatin, polyhydroxybutyrate, polylactic acid-polyethylene glycol copolymer, polyurethane, polyhydroxyalkanoate, and chitosan, and the content of the three substances in their corresponding organic solvents is 40-60%; the content of the magnetic nanoparticles in the organic solvent is 0.5-1.5%; the water bath combined with ultrasonic conditions, the water bath temperature is 40-50°C, the ultrasonic power is 50-150w; the slow stirring speed is 50-150rpm; the drug content of solution N, solution X, and solution Y is 5-25%; the combined ultrasonic condition, the ultrasonic power is 10-200w; the ultrasonic vacuum treatment, the ultrasonic power is 10-200w, and the treatment time is 10-60min.

8. The method for preparing magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres according to claim 5, characterized in that: In step (3), the concentrations of the anti-aggregation substance, collagen and magnetic nanoparticles in the organic solution are 0.1-5%, 0.1-5% and 1-10% respectively, and the concentration of the polylactic acid-glycolic acid copolymer in the organic solution is 1-25%; the water bath combined with ultrasonic conditions, the water bath temperature is 40-50°C, the ultrasonic power is 50-150w; the slow stirring speed is 50-150rpm; the ultrasonic vacuum treatment, the ultrasonic power is 10-200w, and the treatment time is 10-60min.

9. Use of the magnetically guided interactive ultrasonic graded controlled release drug-loaded microspheres as claimed in claim 1 in the preparation of drug delivery and tumor treatment products.

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