CN115554477A - Dexamethasone myocardial patch and preparation method thereof - Google Patents

Abstract

The invention discloses a preparation method of a dexamethasone myocardial patch, which is characterized in that Dexamethasone (DEX) is subjected to electrostatic spinning to prepare the DEX fiber myocardial patch, the thickness of the DEX fiber myocardial patch is 0.033-0.043mm, the air permeability is 14.36-68.10mm/s, the DEX fiber myocardial patch has better elastic deformation, and the strain can reach 227%. When 0.05g DEX is added into 10g of electrostatic spinning solution, the accumulated DEX release amount of the myocardial patch for 10 hours can reach more than 200 mu g, and the drug-loaded release effect can be controlled. The prepared dexamethasone myocardial patch has a 3D porous structure, excellent deformation and resilience, better drug-loaded release and electrical conductivity. Through conductive stimulation, the controllable release of DEX drugs can be effectively induced, and the micro-environment of myocardial infarction area inflammation can be effectively improved.

Description

Dexamethasone myocardial patch and preparation method thereof

technical field

The invention belongs to the technical field of preparation of functional nanometer membranes, and in particular relates to a dexamethasone myocardial patch and a preparation method thereof.

Background technique

Statistics from the World Health Organization show that about 30% of the world's 58 million deaths are caused by cardiovascular diseases, and myocardial infarction (MI) is one of the most common cardiovascular diseases. On the basis of coronary artery disease, the blood flow of coronary artery is suddenly reduced or terminated, causing severe and persistent acute ischemia in the corresponding myocardium, which eventually leads to ischemic necrosis of the myocardium. After the onset of the disease, it will be difficult for the patient's heart function to return to a normal level. According to the "China Cardiovascular Health and Disease Report 2019 Summary", since 2005, the mortality rate of patients with myocardial infarction in my country has generally shown a rapid growth trend. The current treatment methods for myocardial infarction mainly include drug therapy, angioplasty, interventional therapy of coronary artery bypass grafting, thrombolytic therapy and traditional Chinese medicine therapy, etc., but none of these treatments can repair the damaged myocardial tissue, and necrosis and fibrosis The heart muscle also does not return to normal, so none of these methods are effective in treating myocardial infarction. Heart transplantation is currently the most ideal treatment method, but its clinical application is also limited due to the shortage of donors and the immune rejection of allogeneic transplantation.

As the research progresses, the use of tissue engineering technology to construct myocardial patches will be a reliable treatment method. Tissue-engineered myocardial patches can limit ventricular remodeling, prevent dilatation, reduce infarct size, improve ventricular mechanical properties, and reduce apoptosis. It can not only treat myocardial infarction at the source, repair the damaged part of the heart, but also solve the problems caused by insufficient heart transplant donors and immune rejection.

An ideal myocardial patch should have the following characteristics: ① Good elasticity and certain mechanical strength to ensure that the scaffold material will not be damaged by the beating of the heart. ②It has good biocompatibility and does not cause inflammation, toxicity and immune rejection in the body. ③ It has good electrical conductivity, so that the myocardial patch can contract synchronously with the heart, and avoid serious arrhythmia after transplantation in the body.

Myocardial patch is mainly divided into non-carrier cardiac patch and carrier myocardial patch. The construction mainly uses polymer synthetic materials, decellularized natural matrix or extracellular matrix such as collagen as the scaffold material for the preparation of myocardial patches.

At present, the methods for preparing tissue-engineered myocardial patch scaffolds include bioprinting technology, decellularization method, molecular self-assembly and electrospinning technology, etc.

Electrospinning is a special fiber manufacturing process. The polymer solution or melt is placed under high-voltage static electricity of several thousand to tens of thousands of volts. The polymer droplet at the needle tip changes from a spherical shape to a conical shape under the action of an electric field force. Shape (that is, "Taylor cone"), when the electric field force is large enough, the polymer droplets overcome the surface tension to form an eruption stream, the solvent evaporates or solidifies during the eruption process, and finally falls on the receiving device, forming a diameter of Fibrous structures ranging from hundreds of nanometers to several micrometers.

Because electrospinning technology has strong controllability to material composition and size, and is simple and easy to master, electrospinning technology has become a common technology in tissue engineering. As a common technology for tissue engineering materials, electrospinning technology can synthesize microstructures similar to natural extracellular matrix, and can synthesize required porous and fiber diameter-controlled scaffolds by adjusting parameters such as solution concentration, flow rate, and jet height. And spinning out materials with ordered microstructures. Studies have shown that scaffolds loaded with nanofibers can promote the proliferation and differentiation of mesenchymal stem cells into the myocardium. At the same time, the phenotype of differentiated mesenchymal stem cells and the expression of cardiac markers are highly resonant, which has a positive effect on promoting myocardial functional reconstruction. There are also experimental results showing that the prepared nanofiber myocardial patch can improve cardiac function after myocardial infarction, increase the survival rate of adipose-derived mesenchymal stem cells, improve the therapeutic efficiency of stem cells, inhibit cell apoptosis, promote angiogenesis, and reduce scar area. In addition, as a carrier of adipose-derived mesenchymal stem cells, the prepared myocardial patch can also inhibit the ventricular remodeling of adipose-derived mesenchymal stem cells, and play a synergistic role in promoting myocardial repair.

Myocardial injury is the impairment of cell function caused by myocardial cell ischemia and hypoxia. Myocardial infarction is a common cause of myocardial injury in coronary heart disease and the leading cause of heart disease morbidity and death worldwide. Early cardiac ischemia and hypoxia after myocardial infarction lead to apoptosis and necrosis of a large number of cells, and the loss of a large number of cardiomyocytes seriously affects cardiac remodeling after myocardial infarction and plays an important role in the recovery of cardiac function.

Glucocorticoid is an extremely important class of regulatory molecules in the body. It plays an important role in regulating the development, growth, metabolism and immune function of the body. It is the most important regulatory hormone for the body's stress response and is the most widely used clinically. And effective anti-inflammatory and immunosuppressant. In urgent or critical situations, glucocorticoids are often the first choice. Common clinical glucocorticoids include prednisone, methylprednisone, betamethasone, beclomethasone dipropionate, prednisolone, hydrocortisone, dexamethasone, etc. These glucocorticoid drugs have anti-inflammatory, anti-toxic, anti-allergic, anti-shock, non-specific immune suppression and antipyretic effects, and can prevent and prevent the occurrence of immune inflammatory reactions and pathological immune reactions. Almost all types of allergic diseases are effective. Among them, dexamethasone has pharmacological effects such as anti-inflammation, anti-endotoxin, immune suppression, anti-shock and enhancement of stress response, can inhibit hypoxia-ischemia, and has obvious curative effect and improvement effect on myocardial infarction.

Based on this, aiming at the key scientific issues of abnormal electrical signal conduction and inflammatory microenvironment in the myocardial infarction area, the present invention provides a dexamethasone fiber myocardial patch and its preparation method, which is expected to provide new ideas and new strategies for myocardial function reconstruction.

Contents of the invention

Aiming at the key scientific problems of abnormal electrical signal conduction and inflammatory microenvironment in the myocardial infarction area, the present invention provides a dexamethasone fiber myocardial patch and a preparation method thereof. The dexamethasone DEX fiber myocardial patch prepared by the method has controllable Thickness, air permeability, tensile stress, strain, resilience, drug release. DEX nanofibers can realize the effective delivery of drugs, overcome the defects of single drug mode, promote the therapeutic effect, enhance the functional recovery of the body, corresponding to the prepared myocardial patch, and have controllable deformation, resilience, conductivity, and breathability In the experiment, it can fit well on the pig heart and effectively promote the synchronous systolic and diastolic functions of the myocardium. DEX nanofiber myocardial patch has good resilience, and the rebound effect is good after repeated use; it has good electrical conductivity and electrical signal conduction, and the electrical signal conduction is normal under fixed deformation conditions; it has good anti-inflammatory and load-carrying properties. The drug release effect can induce the controllable release of the drug in the myocardial patch through conductive stimulation; the DEX myocardial patch of the present invention has a significant promoting effect on effectively improving the inflammatory microenvironment of the infarct area.

The technical scheme that the present invention adopts is as follows:

The preparation method of dexamethasone myocardial patch comprises the following steps: dissolving dexamethasone DEX in a spinning solution containing a conductive material and an elastomer material, heating and stirring at 40-60° C. for 2-3 hours to obtain a spinning solution, Wherein the mass concentration of DEX is 0.1-0.5%, and the DEX fiber membrane is obtained by electrospinning based on the spinning liquid, and the myocardial patch is obtained.

In the above technical scheme, further, the conductive material is selected from one or more of carbon black, carbon nanotubes, graphene, graphene oxide, reduced graphene oxide, polyaniline, polythiophene, polypyrrole, Mxene .

Further, the elastomer material is selected from one or more of styrene-based thermoplastic elastomers, thermoplastic polyolefin elastomers, polyurethane-based thermoplastic elastomers, and polyester-based thermoplastic elastomers.

Further, the mass concentration of the elastomer material in the spinning solution is not more than 5%, and the mass concentration of the conductive material is 0.01-0.03%.

Furthermore, the spinning solution with DEX needs to be ultrasonically treated and heated at 20-40°C for 60-120 minutes, so that DEX is uniformly dispersed in the spinning solution to facilitate spinning.

Further, the parameters of the electrospinning are: the receiving distance is 10-11cm, the liquid supply speed is 1.5-2mL/h, the drum speed is 200-300r/min, the spinning environment temperature is 30-40°C, the voltage The size is 12-15kV.

Furthermore, when 0.05 g of DEX is added to every 10 g of electrospinning solution, the accumulated DEX release amount of the myocardial patch can reach more than 200 μg in 10 h, which has a controllable drug-loaded release effect.

Further, the conductive material is preferably graphene oxide GO.

Further, the elastomer material is preferably polyurethane thermoplastic elastomer PU.

Owing to adopting above-mentioned technical scheme, have following beneficial effect:

Myocardial patches prepared by DEX can achieve controllable DEX fiber membrane thickness, air permeability, tensile stress, strain, resilience, and drug-loaded release, and have controllable deformation, resilience, electrical conductivity, air permeability, and mechanical properties. and drug-loaded release, it can fit well on the pig heart, and can effectively promote the synchronous systolic and diastolic functions of the myocardium. The DEX nanofiber myocardial patch has good resilience, and the rebound effect is good after repeated use. It has good electrical conductivity and electrical signal conduction, and under the condition of fixed deformation, the electrical signal conduction is normal. It has good anti-inflammatory and controllable drug-loaded release effects.

According to a specific example of the present invention, the specific properties of the myocardial patch prepared by the present invention are as follows: the thickness of the nanofiber membrane is 0.033-0.043mm, the air permeability of the nanofiber membrane is 14.36-68.10mm/s, and the tensile strength of the 0.1% DEX membrane The tensile stress is 306473Pa and the strain is 48%; the tensile stress of 0.3% DEX film is 288173Pa and the strain is 122%; the tensile stress of 0.5% DEX film is 966326Pa and the strain is 227%. From the release curve slopes of drug-loaded at various concentrations, the release slope was the largest in the first 8 hours. After heating in a water bath at 37°C for 10 hours, the cumulative release amount of 0.5% DEX loaded with drug reached more than 200 μg, which had a good drug-loaded release effect. And through conductive stimulation, the controlled release of drugs can be induced, which can significantly promote the effective improvement of the inflammatory microenvironment in the infarct area.

Description of drawings

Below in conjunction with accompanying table and accompanying drawing, the present invention will be further described:

Fig. 1 is the resilience test of the DEX myocardial patch that embodiment 3 makes;

Fig. 2 is the electric signal of the DEX myocardial patch that embodiment 3 makes when stretching 20%;

Figure 3 is the standard curve of DEX;

Fig. 4 is that the DEX cardiac muscle patch that embodiment 3 makes is fitted on the pig heart;

detailed description

The technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific examples.

The preparation method of the dexamethasone myocardial patch of the present invention comprises the steps of: dissolving dexamethasone DEX in a spinning solution containing a conductive material and an elastomer material, heating and stirring at 40-60°C for 2-3h, and obtaining a spinning solution The silk solution, wherein the mass concentration of DEX is 0.1-0.5%, and the DEX fiber membrane is obtained by electrospinning based on the spinning solution, and the myocardial patch is obtained.

In the preparation method of the dexamethasone myocardial patch, regulating the concentration and dispersion of DEX is an important condition for forming a good spinning solution, and regulating the mass concentration of DEX to 0.1-0.5% requires ultrasonic treatment, and ultrasonic treatment at 20-40°C for 60- 120min, so that DEX is uniformly dispersed in the spinning solution to facilitate spinning. Adding too high a concentration of DEX will lead to a decrease in the mechanical properties of the fiber membrane, making it difficult to form the fiber, and it is impossible to prepare a DEX fiber membrane with a good shape. In addition, conductive materials need to be added to the DEX spinning solution. The DEX fiber membrane without conductors has no conductive function, cannot effectively promote electrical signal conduction, and cannot play the role of myocardial function reconstruction; DEX spinning solution also needs to add Elastomer material, DEX fiber membrane without elastomer, does not have good elastic deformation, is easy to be brittle, and is easy to break during stretching, which does not meet the multiple systolic and diastolic functions of myocardial function. In addition, in order to make the prepared DEX myocardial patch not only have controllable deformation, resilience, electrical conductivity and other properties, but also better obtain a fibrous membrane myocardial patch with excellent air permeability And mechanical properties, improve the synergistic function of DEX myocardial patch, the concentration of the suitable elastomeric material in the described DEX fiber patch should not exceed 5%, the conductive material concentration is preferably 0.01-0.03%, exceeding this range will lead to fiber formation Difficulty, beading, non-integrity of fibrous membrane morphology, thus hindering the application of myocardial patch. Through the optimization and regulation of the concentration of the conductor and the elastomer material, and the synergistic effect, the DEX fiber membrane can be prepared, thus endowing it with excellent comprehensive properties.

In addition, in order to form a good DEX myocardial patch, the spinning conditions are also very critical. Adjust the receiving distance to 10-11cm, the liquid supply speed to 1.5-2mL/h, the drum speed to 200-300r/min, the spinning ambient temperature to 30-40°C, and the voltage to 12-15kV. By coordinating the spinning parameters, the DEX fiber membrane can be prepared smoothly. The electrospinning parameters are the result of comprehensive control, combined with the fiber formation conditions and membrane morphology, can effectively prepare a complete DEX nanofiber membrane.

In the method of the present invention, the conductive material can be one or more of carbon black, carbon nanotubes, graphene, graphene oxide, reduced graphene oxide, polyaniline, polythiophene, polypyrrole, Mxene, preferably Graphene oxide GO; the elastic material can be one or more of styrene-based thermoplastic elastomers, thermoplastic polyolefin elastomers, polyurethane-based thermoplastic elastomers, and polyester-based thermoplastic elastomers, preferably polyurethane PU.

According to a kind of specific example of the present invention, the preparation of dexamethasone myocardial patch and application, test are specifically as follows:

(1) The DEX myocardial patch was prepared with the elastomer material polyurethane (PU), the conductor material graphene oxide (GO), and dexamethasone (DEX) as raw materials. PU has high elasticity and biocompatibility, so it is selected as the main material of myocardial patch scaffold; appropriate amount of GO can improve the mechanical properties, hydrophilicity, and cytocompatibility of nanofibers, and can also provide certain electrical conductivity. DEX is an anti-inflammatory drug commonly used in the treatment of myocardial infarction, which can play an anti-inflammatory effect on infarcted myocardial tissue and improve inflammation. The concentration of PU used is not more than 5%, the concentration of GO is 0.01-0.03%, and the concentration of DEX is 0.1-0.5%.

(2) Add GO and PU successively to the DEX spinning solution, put the stirring bottle into an ultrasonic cleaner at 20-40°C for 60-120min, so that GO is completely dispersed in the solution. After ultrasonication, take out the glass stirring bottle, then weigh the target mass of anti-inflammatory drug into the glass stirring bottle, and finally add PU. Put it into a digital display temperature-controlled heating stirrer, heat and stir at 40-60°C for 2-3 hours, and finally stir on a dual-row magnetic stirrer at room temperature for 8-12 hours to prepare 10 g of uniform spinning solution.

(3) Turn on the power of the electrospinning machine, turn on the "light", "fan" and "heating" on the control touch panel, and the electrospinning machine will perform lighting, exhaust and heating at this time. Roll a layer of tinfoil on the right roller and wait for the electrospinning machine to heat up to 30-40°C.

(4) After testing the viscosity and conductivity of the prepared spinning solution, draw 8ml of the spinning solution with a 10mL disposable sterile syringe. Install the syringe on the slide, clamp the positive pole (red wire) of the high-voltage power supply to the needle, move it so that the receiving distance is 10-11cm, and set the liquid supply speed and slide speed to 1.5-2mL on the touch panel /h, adjust the drum speed to 200-300r/min. Manually supply liquid in the liquid supply interface to move the squeeze wrench to the micro-end of the syringe, manually press the right button to push the syringe slowly, and observe whether the spinning solution is pushed out smoothly.

(5) Close the hatch, turn on the high-voltage power switch, press the high-voltage reset button, and adjust the voltage to 12-15kV through the knob. When the spinning is completed, after turning off the high-voltage power supply, it is necessary to wait for a period of time to conduct the residual charge of the equipment away before collecting the prepared nanofiber membrane.

(6) This test requires the use of NDJ-5S microcomputer digital display viscometer. The instrument is equipped with 4 gears of speed and 4 rotors. Check the range table. Considering the range and the size of the container, choose No. 3 rotor and 60 rpm /min speed (full scale is 2000mPa·s). Install the selected rotor on the viscometer, place a glass stirring bottle with spinning solution under the rotor, rotate the lifting hand wheel, and adjust the height so that the bottom of the rotor is submerged in the spinning solution. Turn on the machine and press the "OK" button to set the default rotor speed to 40-60 rpm. Finally, press the "OK" button again, and the viscometer starts to measure. When the viscosity measurement value is stable, the viscometer stops measuring and records the data at this time. Finally press the "RESET" key and "OK" key to measure again.

(7) Turn on the power, press the "switch" button to start the DDS-307A conductivity meter. Put the conductivity electrode into the spinning solution, and place it still after the spinning solution completely covers the conductivity electrode. The conductivity value on the display continues to rise. When the conductivity value remains unchanged, record the conductivity value of the spinning solution at this time. Each group was tested three times and the data was recorded.

(8) First turn on the power of YG(B)141D digital fabric thickness meter, select 200mm ² presser foot area and 200cN pressure, and put 200cN weight on the presser foot. Then adjust to zero. When the presser foot falls and touches the reference plate, press the adjustment button, repeat the zero adjustment for many times, and start the test after the zero adjustment is stable. Set the test mode and time to continuous and 10s. Clean the reference plate, put the nanofiber film sample on the reference plate, press the start button to start the test, read when the reading indicator light is on, record the reading at this time as the thickness of the nanofiber film, and test each group of samples three times.

(9) The instrument required for the tensile test of the nanofiber membrane is the LES-G1 tensile testing machine (Japan Kado Technology Co., Ltd.). Before starting the test, sample preparation is carried out first, and a nanofiber membrane of 0.5cm*4cm is cut. Wrap it with a stretch frame. According to the type of sensor above the tensile testing machine, align the pointer of Force Transducer to type A on the setting panel. Set the stretching method at the bottom right of the panel to select the STD standard stretching method. Adjust the zero adjustment knob "ZERO ADJ" (to the right is "+") on the machine, and adjust CH1 and CH2 to the appropriate initial volume. After completing all the settings and clamping the sample on the instrument, click "Record Start", press "SINGLE" on the panel, and the tensile testing machine starts to stretch. After the nanofiber membrane breaks, press "stop recording", and then press "RES" on the panel to test the next set of samples. Save the test file after all tests are done. The measuring range is 2*10 during the test. The strain-stress calculation formula is as follows:

Strain = CH1*250%

Stress (F)＝CH2*range*10-3*9.8/10N

Fiber cross-sectional area (S) = sample width * sample thickness m ²

Stress＝F/SPa

(10) Use a 250g small weight to test the resilience of the nanofibers. Cut out nanofiber membranes of 1cm*4cm and 5cm*8cm respectively. Hang a weight weighing 250g on a 1cm*4cm sample to observe the weight-carrying capacity of the fiber membrane and the morphological integrity after the load is removed.

(11) Use the YG461E fabric breather to test the air permeability of the nanofiber membrane, turn on the power and air source switches of the fabric breather, and connect it to the computer. Cut out a 6cm*6cm nanofiber membrane (the minimum size must be at least 20% larger than the clamping head used to ensure that the clamping head can fully clamp the sample), and the sampling should be representative. Fit the appropriate gripping head and place the specimen flat on the test bench. Open the software for testing air permeability on the computer, set the parameters in the setting interface, and start the test after completion, and test each group of samples three times. Test parameters: GB-T5453:1997, orifice plate number 3, sample pressure difference 100Pa, sample area 20cm ² .

(12) Cut out a 3cm*1cm nanofiber membrane, and clamp the two ends of the nanofiber membrane with the two ends of the red and black test leads of the DM3068 digital multimeter. Start the DM3068 digital multimeter, connect the computer USB, open the UtraSensor ForDM3000 Serious software on the computer, click "Connect" to connect the software to the instrument, and create a new sensor project. The conductive signal of the nanofiber membrane was tested in real time when it was tiled, stretched by 10%, and stretched by 20%, and the test time was 10 minutes.

(13) Prepare 5 μg/ml, 10 μg/ml, 15 μg/ml, 20 μg/ml, 25 μg/ml of dexamethasone/phosphate buffered saline (MP/PBS) respectively, and stir at room temperature on a dual column magnetic stirrer to make DEX was fully dissolved in PBS solution. Turn on the UV spectrophotometer, wait for the machine to warm up for 20-30 minutes, and start testing. Turn the knob to adjust the wavelength to 250nm, select a quartz cuvette, and drop DEX/PBS into the quartz cuvette to test the absorbance of DEX at this time. The standard curves of MP, HC and DEX were made by Origin software and analyzed to obtain their linear equations.

(14) Take 0.01g of DEX nanofiber membrane, soak it in a glass bottle with 10ml of PBS solution, put them into a three-water tank with digital display and temperature control, and heat them in a water bath at 37°C. The absorbance test was carried out at the time points of 1h, 2h, 3h, 4h, 5h, 6h, 8h, 10h, 12h, 20h, and 24h. Take out 4ml of the solution and drop it into a quartz cuvette, and use a UV spectrophotometer to measure the absorbance of the drug-loaded nanofiber membrane in the PBS solution at the corresponding time point. After the test, an equal amount of PBS solution needs to be added to the glass bottle. Calculate the drug-loaded concentration corresponding to each time point according to the drug-loaded standard curve, and calculate the cumulative release result of DEX.

(15) In order to characterize the use of the myocardial patch, the nanofibrous membrane was attached to the pig heart for testing. Purchase a fresh pig heart, clean its surface, cut out a 0.5% DEX nanofiber membrane loaded with drugs with a size of 4cm*4cm, and attach it to the pig heart. Use a syringe to inflate and inhale the heart of the pig to simulate the diastolic and systolic movements of the heart, and observe the adhesion and overall effect of the cardiac-nanofiber patch.

(16) A hydrogen balloon was used to simulate the heart, and a 4cm*4cm drug-loaded 0.5% DEX nanofiber membrane was adhered to the inflated balloon, and air was continuously injected into the balloon to observe the detachment of the nanofiber membrane.

(17) Soak the pig heart-nanofiber patch in PBS solution and DMEM medium for 1 hour respectively, and observe the overall effect.

Example 1

(1) The PU concentration used is 5%, the GO concentration is 0.03%, the Dex concentration is 0.1%, the DMF used is 4.72-4.74g, and the THF is 4.72-4.74g.

(2) Take a clean glass stirring bottle, put a magnetic stirrer in the stirring bottle, weigh the target mass of DMF, THF solution and GO into the stirring bottle with an electronic balance, then add PU, put the stirring bottle into the ultrasonic Sonication was carried out at 20°C for 60 min in a cleaner to completely disperse GO in the solution. After ultrasonication, take out the glass stirring bottle, then weigh the target mass of anti-inflammatory drug into the glass stirring bottle, and finally add PU. Put it into a digital display temperature-controlled heating stirrer, heat and stir at 60°C for 3 hours, and finally stir for 12 hours at room temperature on a double row magnetic stirrer to prepare 10 g of uniform spinning solution.

(3) Turn on the power of the electrospinning machine, turn on the "light", "fan" and "heating" on the control touch panel, and the electrospinning machine will perform lighting, exhaust and heating at this time. Roll a layer of tinfoil on the right roller and wait for the electrospinning machine to heat up to 40°C.

(4) After testing the viscosity and conductivity of the prepared spinning solution, draw 8ml of the spinning solution with a 10mL disposable sterile syringe. Install the syringe on the slide, clamp the positive pole (red wire) of the high-voltage power supply to the needle, move it so that the receiving distance is 11cm, set the liquid supply speed and the slide speed to 1.5mL/h on the touch panel, respectively, Adjust the drum speed to 300r/min. Manually supply liquid in the liquid supply interface to move the squeeze wrench to the micro-end of the syringe, manually press the right button to push the syringe slowly, and observe whether the spinning solution is pushed out smoothly.

(5) Close the hatch, turn on the high-voltage power switch, press the high-voltage reset button, and adjust the voltage to 15kV through the knob. When the spinning is completed, after turning off the high-voltage power supply, it is necessary to wait for a period of time to conduct the residual charge of the equipment away before collecting the prepared nanofiber membrane.

Example 2

(1) The PU concentration used is 5%, the GO concentration is 0.03%, the Dex concentration is 0.3%, the DMF used is 4.72-4.74g, and the THF is 4.72-4.74g.

(2) Take a clean glass stirring bottle, put a magnetic stirrer in the stirring bottle, weigh the target mass of DMF, THF solution and GO into the stirring bottle with an electronic balance, then add PU, put the stirring bottle into the ultrasonic Sonication was carried out at 20°C for 60 min in a cleaner to completely disperse GO in the solution. After ultrasonication, take out the glass stirring bottle, then weigh the target mass of anti-inflammatory drug into the glass stirring bottle, and finally add PU. Put it into a digital display temperature-controlled heating stirrer, heat and stir at 60°C for 3 hours, and finally stir for 12 hours at room temperature on a double row magnetic stirrer to prepare 10 g of uniform spinning solution.

(3) Turn on the power of the electrospinning machine, turn on the "light", "fan" and "heating" on the control touch panel, and the electrospinning machine will perform lighting, exhaust and heating at this time. Roll a layer of tinfoil on the right roller and wait for the electrospinning machine to heat up to 40°C.

(4) After testing the viscosity and conductivity of the prepared spinning solution, draw 8ml of the spinning solution with a 10mL disposable sterile syringe. Install the syringe on the slide, clamp the positive pole (red wire) of the high-voltage power supply to the needle, move it so that the receiving distance is 11cm, set the liquid supply speed and the slide speed to 1.5mL/h on the touch panel, respectively, Adjust the drum speed to 300r/min. Manually supply liquid in the liquid supply interface to move the squeeze wrench to the micro-end of the syringe, manually press the right button to push the syringe slowly, and observe whether the spinning solution is pushed out smoothly.

(5) Close the hatch, turn on the high-voltage power switch, press the high-voltage reset button, and adjust the voltage to 15kV through the knob. When the spinning is completed, after turning off the high-voltage power supply, it is necessary to wait for a period of time to conduct the residual charge of the equipment away before collecting the prepared nanofiber membrane.

Example 3

(1) The PU concentration used is 5%, the GO concentration is 0.03%, the Dex concentration is 0.5%, the DMF used is 4.72-4.74g, and the THF is 4.72-4.74g.

(2) Take a clean glass stirring bottle, put a magnetic stirrer in the stirring bottle, weigh the target mass of DMF, THF solution and GO into the stirring bottle with an electronic balance, then add PU, put the stirring bottle into the ultrasonic Sonication was carried out at 20°C for 60 min in a cleaner to completely disperse GO in the solution. After ultrasonication, take out the glass stirring bottle, then weigh the target mass of anti-inflammatory drug into the glass stirring bottle, and finally add PU. Put it into a digital display temperature-controlled heating stirrer, heat and stir at 60°C for 3 hours, and finally stir for 12 hours at room temperature on a double row magnetic stirrer to prepare 10 g of uniform spinning solution.

(3) Turn on the power of the electrospinning machine, turn on the "light", "fan" and "heating" on the control touch panel, and the electrospinning machine will perform lighting, exhaust and heating at this time. Roll a layer of tinfoil on the right roller and wait for the electrospinning machine to heat up to 40°C.

(4) After testing the viscosity and conductivity of the prepared spinning solution, draw 8ml of the spinning solution with a 10mL disposable sterile syringe. Install the syringe on the slide, clamp the positive pole (red wire) of the high-voltage power supply to the needle, move it so that the receiving distance is 11cm, set the liquid supply speed and the slide speed to 1.5mL/h on the touch panel, respectively, Adjust the drum speed to 300r/min. Manually supply liquid in the liquid supply interface to move the squeeze wrench to the micro-end of the syringe, manually press the right button to push the syringe slowly, and observe whether the spinning solution is pushed out smoothly.

(5) Close the hatch, turn on the high-voltage power switch, press the high-voltage reset button, and adjust the voltage to 15kV through the knob. When the spinning is completed, after turning off the high-voltage power supply, it is necessary to wait for a period of time to conduct the residual charge of the equipment away before collecting the prepared nanofiber membrane.

Example 4

(1) The PU concentration used is 5%, the Dex concentration is 0.5%, the DMF used is 4.72-4.74g, and the THF is 4.72-4.74g.

(2) Take a clean glass stirring bottle, put a magnetic stirrer in the stirring bottle, weigh the DMF and THF solutions of the target quality with an electronic balance, add them to the stirring bottle, then add PU, and put the stirring bottle into the ultrasonic cleaner Sonicate at 20°C for 60min. After ultrasonication, take out the glass stirring bottle, then weigh the target mass of anti-inflammatory drug into the glass stirring bottle, and finally add PU. Put it into a digital display temperature-controlled heating stirrer, heat and stir at 60°C for 3 hours, and finally stir for 12 hours at room temperature on a double row magnetic stirrer to prepare 10 g of uniform spinning solution.

(3) Turn on the power of the electrospinning machine, turn on the "light", "fan" and "heating" on the control touch panel, and the electrospinning machine will perform lighting, exhaust and heating at this time. Roll a layer of tinfoil on the right roller and wait for the electrospinning machine to heat up to 40°C.

(4) After testing the viscosity and conductivity of the prepared spinning solution, draw 8ml of the spinning solution with a 10mL disposable sterile syringe. Install the syringe on the slide, clamp the positive pole (red wire) of the high-voltage power supply to the needle, move it so that the receiving distance is 11cm, set the liquid supply speed and the slide speed to 1.5mL/h on the touch panel, respectively, Adjust the drum speed to 300r/min. Manually supply liquid in the liquid supply interface to move the squeeze wrench to the micro-end of the syringe, manually press the right button to push the syringe slowly, and observe whether the spinning solution is pushed out smoothly.

(5) Close the hatch, turn on the high-voltage power switch, press the high-voltage reset button, and adjust the voltage to 15kV through the knob. When the spinning is completed, after turning off the high-voltage power supply, it is necessary to wait for a period of time to conduct the residual charge of the equipment away before collecting the prepared nanofiber membrane.

Example 5

(1) The PU concentration used is 5%, the GO concentration is 0.03%, the DMF used is 4.72-4.74g, and the THF is 4.72-4.74g.

(2) Take a clean glass stirring bottle, put a magnetic stirrer in the stirring bottle, weigh the target mass of DMF, THF solution and GO into the stirring bottle with an electronic balance, then add PU, put the stirring bottle into the ultrasonic Sonication was carried out at 20°C for 60 min in a cleaner to completely disperse GO in the solution. After ultrasonication, take out the glass stirring bottle, and finally add PU. Put it into a digital display temperature-controlled heating stirrer, heat and stir at 60°C for 3 hours, and finally stir for 12 hours at room temperature on a double row magnetic stirrer to prepare 10 g of uniform spinning solution.

(3) Turn on the power of the electrospinning machine, turn on the "light", "fan" and "heating" on the control touch panel, and the electrospinning machine will perform lighting, exhaust and heating at this time. Roll a layer of tinfoil on the right roller and wait for the electrospinning machine to heat up to 40°C.

(4) After testing the viscosity and conductivity of the prepared spinning solution, draw 8ml of the spinning solution with a 10mL disposable sterile syringe. Install the syringe on the slide, clamp the positive pole (red wire) of the high-voltage power supply to the needle, move it so that the receiving distance is 11cm, set the liquid supply speed and the slide speed to 1.5mL/h on the touch panel, respectively, Adjust the drum speed to 300r/min. Manually supply liquid in the liquid supply interface to move the squeeze wrench to the micro-end of the syringe, manually press the right button to push the syringe slowly, and observe whether the spinning solution is pushed out smoothly.

(5) Close the hatch, turn on the high-voltage power switch, press the high-voltage reset button, and adjust the voltage to 15kV through the knob. When the spinning is completed, after turning off the high-voltage power supply, it is necessary to wait for a period of time to conduct the residual charge of the equipment away before collecting the prepared nanofiber membrane.

Example 6

(1) The concentration of PU used is 5%, the DMF used is 4.72-4.74g, and the THF is 4.72-4.74g.

(2) Take a clean glass stirring bottle, put a magnetic stirrer in the stirring bottle, weigh the DMF and THF solutions of the target quality with an electronic balance, add them to the stirring bottle, then add PU, and put the stirring bottle into the ultrasonic cleaner Sonicate at 20°C for 60min. After ultrasonication, the glass stirring bottle was taken out, and 10 g of uniform spinning solution was prepared.

(3) Turn on the power of the electrospinning machine, turn on the "light", "fan" and "heating" on the control touch panel, and the electrospinning machine will perform lighting, exhaust and heating at this time. Roll a layer of tinfoil on the right roller and wait for the electrospinning machine to heat up to 40°C.

(4) After testing the viscosity and conductivity of the prepared spinning solution, draw 8ml of the spinning solution with a 10mL disposable sterile syringe. Install the syringe on the slide, clamp the positive pole (red wire) of the high-voltage power supply to the needle, move it so that the receiving distance is 11cm, set the liquid supply speed and the slide speed to 1.5mL/h on the touch panel, respectively, Adjust the drum speed to 300r/min. Manually supply liquid in the liquid supply interface to move the squeeze wrench to the micro-end of the syringe, manually press the right button to push the syringe slowly, and observe whether the spinning solution is pushed out smoothly.

(5) Close the hatch, turn on the high-voltage power switch, press the high-voltage reset button, and adjust the voltage to 15kV through the knob. When the spinning is completed, after turning off the high-voltage power supply, it is necessary to wait for a period of time to conduct the residual charge of the equipment away before collecting the prepared nanofiber membrane.

In the following form:

Table 1 is the solute quality, solvent situation of embodiment 1,2,3

Table 2 is the viscosity of the spinning solution of embodiment 1,2,3

Table 3 is the conductivity of the spinning solution of embodiment 1,2,3

Table 4 is the thickness of different drug-loaded electrospun nanofiber membranes

Table 5 is the air permeability of electrospun nanofiber membranes with different components

Table 6 is the absorbance of adding drug-loaded DEX

Table 1. Experimental grouping

Table 2. Viscosities of spinning solutions with different mass percentages (unit: mPa s)

Table 3. Conductivity of spinning solutions with different mass percentages (unit: μs/cm)

Table 4. Thickness of different drug-loaded electrospun nanofiber membranes (unit: mm)

Table 5. Air permeability of electrospun nanofiber membranes with different components (unit: mm/s)

Table 6. Absorbance of drug-loaded DEX added

Can know by above-mentioned embodiment 1,2,3, the thickness of DEX nanofiber membrane is 0.033-0.043mm, the air permeability of nanofiber membrane is 14.36-68.10mm/s, the tensile stress of 0.1% DEX membrane is 306473Pa, strain The tensile stress of the 0.3% DEX film is 288173Pa, and the strain is 122%; the tensile stress of the 0.5% DEX film is 966326Pa, and the strain is 227%. The prepared nanofibrous film has good deformation and resilience .

It can be known from the above Examples 1, 2, and 3 that, from the slopes of the release curves of drug-loaded at various concentrations, the release slope in the first 8 hours is the largest, indicating that the drug-loaded release rate is very fast and the release amount is large. Prolonged, the curve gradually stabilized, the drug-loaded release rate gradually slowed down, and the release amount gradually decreased. Observing the cumulative release curve of 0.5% drug-loaded drug, it was found that after heating in a water bath at 37°C for 10 hours, the cumulative release amount of 0.5% DEX loaded with drug reached more than 200 μg, which has a good drug-loaded release effect. However, in Examples 4, 5, and 6, no conductive GO, DEX, and only PU nanofibrous membranes were added, which did not have the electrical conductivity, elasticity, and drug-loaded release functions of the myocardial patch, and did not have the conditions for myocardial function reconstruction.

The dexamethasone myocardial patch prepared by the method of the invention has a 3D porous structure, excellent deformation and resilience, good drug loading and release, and electrical conductivity. The controllable release of DEX drugs can be effectively induced through conductive stimulation, which can significantly promote the effective improvement of the inflammatory microenvironment in the myocardial infarction area.

Claims (10)

1. The preparation method of dexamethasone myocardial patch, is characterized in that, comprises the following steps: dissolving dexamethasone DEX in the spinning solution containing conductive material and elastomeric material, heating and stirring at 40-60°C for 2-3h , to obtain a spinning solution, wherein the mass concentration of DEX is 0.1-0.5%, based on the spinning solution, electrospinning is used to obtain a DEX fiber membrane to obtain a myocardial patch. 2. the preparation method of dexamethasone myocardial patch according to claim 1, is characterized in that, described conductive material is selected from carbon black, carbon nanotube, graphene, graphene oxide, reduced graphene oxide, polyaniline , polythiophene, polypyrrole, and one or more of Mxene. 3. the preparation method of dexamethasone myocardial patch according to claim 1, is characterized in that, described elastomer material is selected from styrene thermoplastic elastomer, thermoplastic polyolefin elastomer, polyurethane thermoplastic elastomer, poly One or more of ester thermoplastic elastomers. 4. the preparation method of dexamethasone myocardial patch according to claim 1 is characterized in that, in the described spinning solution, the mass concentration of elastomeric material is no more than 5%, and the mass concentration of conductive material is 0.01-0.03% . 5. the preparation method of dexamethasone myocardial patch according to claim 1 is characterized in that, the spinning liquid that adds DEX needs ultrasonic treatment to heat again, and ultrasonic 60-120min is made DEX in spinning at 20-40 ℃. Evenly dispersed in the silk liquid to facilitate spinning. 6. the preparation method of dexamethasone myocardial patch according to claim 1, is characterized in that, the parameter of described electrospinning is: receiving distance is 10-11cm, and liquid supply speed is 1.5-2mL/h, The drum speed is 200-300r/min, the spinning ambient temperature is 30-40°C, and the voltage is 12-15kV. 7. the preparation method of dexamethasone myocardial patch according to claim 1 is characterized in that, when adding 0.05g DEX in every 10g electrospinning solution, the accumulative DEX discharge amount of described myocardial patch 10h can reach More than 200μg, it has a controllable drug-loaded release effect. 8. the preparation method of dexamethasone myocardial patch according to claim 1, is characterized in that, described conductive material is preferably graphene oxide GO. 9. The preparation method of dexamethasone cardiac muscle patch according to claim 1, is characterized in that, described elastomer material is preferably polyurethane thermoplastic elastomer PU. 10. A myocardial patch, characterized in that it is prepared by the method according to any one of claims 1-9.

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