Porous nano-composite repair membrane loaded with drug exosome as well as preparation method and application of porous nano-composite repair membrane
By using biological 3D printing technology to prepare porous nanocomposite repair membranes in skin wound dressings, using plant exosomes as carriers, the problems of drug sustained release and tissue regeneration in the existing technology are solved, and rapid repair and functional skin trauma are achieved The controlled release of drugs has anti-inflammatory and antioxidant properties, and improves the efficiency of plant resources.
Patent Information
- Application Number
- CN202411282153.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-13
- Publication Date
- 2024-12-17
AI Technical Summary
Existing skin wound dressings are difficult to achieve drug-sustaining and promoting tissue regeneration, and cannot effectively solve the problems of rapid repair of skin trauma and controlled release of functional drugs.
Porous nanocomposite repair membranes were prepared by biological 3D printing technology. By printing silk fibroin, chitosan and other materials into porous scaffolds, and using plant exosomes as carriers, the drugs were allowed to enter the exosomes through co-incubation method, combining with Anti-inflammatory and antioxidant properties, forming a porous nanocomposite repair membrane loaded with drugs.
It realizes the sustained release effect of the drug, promotes cell proliferation and migration, has anti-inflammatory and antioxidant characteristics, improves biocompatibility, achieves the purpose of wound healing, and reduces the preparation cost of animal exosomes and increases plants. Resource utilization rate.
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Figure CN119139547A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of biomedical materials, and specifically relates to a porous nanocomposite repair membrane loaded with drug exosomes, and a preparation method and application thereof. Background Art
[0002] Skin is the largest organ of human beings and a natural barrier against external stimuli. In daily life, it may be traumatized by accidents, diseases, physiological degeneration and other factors, which may affect the integrity of skin morphology or function, and thus affect its aesthetics or normal use of functions. In severe cases, it may even cause economic and psychological burdens on patients. With the improvement of people's living standards and the growing needs of life, people's pursuit of beauty is constantly improving. The healing of skin wounds is a dynamic and continuous physiological process, including hemostasis, inflammation, proliferation and remodeling (microscopic perspective). How to achieve rapid repair of skin wounds and controlled release of functional drugs has become a hot topic in the field of regenerative medicine.
[0003] Plant exosomes (PELNs) are a type of naturally occurring lipid bilayer extracellular vesicles used for the exchange of substances and information between plant cells. They are about 30-150nm in diameter and can be used to deliver a variety of components such as nucleic acids, proteins, lipids, and small molecule compounds. In recent years, compared with animal exosomes, PELNs have been highlighted mainly for their lower cost, low immunogenicity, flexible administration, greater stability, better tissue penetration, and high natural medicinal value. Their potential as drugs and drug carriers has been continuously explored, and eventually formed high-value-added pharmaceutical products, which have great development potential in future disease treatment methods.
[0004] Patent CN202410237709.7 discloses a bio-based hydrogel wound dressing and a preparation method thereof. The hydrogel wound dressing prepared by mixing tannic acid, chitosan quaternary ammonium salt solution and dialdehyde cellulose and chitosan solution by ultrasound has antibacterial and anti-inflammatory effects, but it fails to achieve sustained drug release. Patent CN202410048999.0 discloses a garlic exosome granule wound dressing and a preparation method thereof. The dressing is prepared by mixing garlic exosomes loaded with antibiotics and hydrogel, and fails to provide space to promote cell proliferation and migration. Therefore, it is urgent to develop a repair membrane to solve the problems of drug sustained release and tissue regeneration promotion of existing dressings. Summary of the invention
[0005] In order to overcome the shortcomings and deficiencies in the prior art, the primary purpose of the present invention is to provide a method for preparing a porous nanocomposite repair membrane loaded with drug exosomes. The porous nanocomposite repair membrane has a multi-scale nanostructured pore size, which is conducive to the release of drug-loaded exosomes and achieves the effect of sustained drug release; it also has the characteristics of anti-inflammatory, antioxidant, and cell regeneration promotion, good biocompatibility, and can provide space to promote cell proliferation and migration, thereby achieving the purpose of wound healing.
[0006] Another object of the present invention is to provide a porous nanocomposite repair membrane prepared by the above method. The method is prepared in a mild environment, uses widely available materials, is simple to operate, and improves the development and utilization rate of plant resources.
[0007] Another object of the present invention is to provide an application of the porous nanocomposite repair membrane.
[0008] The purpose of the present invention is achieved through the following technical solutions:
[0009] In the first aspect, the present invention claims protection for a method for preparing a porous nano-composite repair membrane loaded with drug exosomes, firstly, a bio-based polymer gel is low-temperature printed by a biological 3D printer, and a porous scaffold is obtained after fixation, freeze-drying and sterilization; then, exosomes are extracted from plants by centrifugation combined with a qEV column, and drug-co-incubation treatment is performed to obtain drug-loaded plant exosomes; then, the porous scaffold is immersed in a solution containing drug-loaded plant exosomes, excess liquid on the surface of the scaffold is removed, and then a layer of dense membrane is attached to obtain a porous nano-composite repair membrane loaded with drug exosomes.
[0010] As a further optimization of the above preparation method, the preparation method of the porous scaffold is as follows: first, silk fibroin and chitosan are compounded in a certain proportion by a blending method, and then an appropriate amount of polydimethylsiloxane and carbomer are added after stirring to obtain a biological 3D printing ink; then a biological 3D printer is used to perform low-temperature printing, fixation, freeze-drying, and sterilization to obtain a porous scaffold.
[0011] The ratio of silk fibroin to chitosan is 1:9-5:5; the mass concentration of polydimethylsiloxane is 3-8wt%; the mass concentration of carbomer is 0.1-3wt%; the printing parameters of the biological 3D printer are: printing speed: 7-11mm / s, air pressure: 0.45-0.6MPa, spacing: 1.4-1.8mm, and printing temperature is -10-10°C.
[0012] The fixing method comprises dissolving an appropriate amount of calcium chloride and genipin in water to prepare a fixing solution, then immersing the printed stent in the fixing solution, taking it out after fixing, washing it with water, and removing excess fixing solution on the surface of the stent, wherein the mass concentration of calcium chloride is 3-10wt%, the mass concentration of genipin is 0.3-2wt%, the fixing time is 1.5-3h, and the washing method is immersing in water for 20min / time, 3 times; the sterilization is one or more of ultraviolet sterilization, radiation sterilization, ozone sterilization or ethylene oxide sterilization.
[0013] As a further optimization of the above preparation method, the plant is one or more of ginger, garlic, ginseng, aloe, wheat, tomato, grapefruit or lemon; the centrifugation method is one or more of low-temperature ultracentrifugation and sucrose density gradient centrifugation; the drug is one or more of curcumin, vitamin E, paclitaxel, and doxorubicin; the ratio of the co-incubated drug to plant exosomes is 1:10-1:30 (g / g), and the co-incubation time is 1-5h; the concentration of the drug-loaded plant exosome solution is 10-30wt%; the time for the stent to be immersed in the drug-loaded plant exosome solution is 3-120min; the dense membrane is one or more of polylactic acid, polycaprolactone, polyurethane, and polyacrylonitrile.
[0014] In a second aspect, the present invention also seeks to protect the porous nanocomposite repair membrane loaded with drug exosomes prepared by the above-mentioned preparation method.
[0015] In a third aspect, the present invention further requests protection for the use of the porous nanocomposite repair membrane loaded with drug exosomes in the field of biomedical materials or tissue engineering technology.
[0016] Compared with the prior art, the present invention has the following beneficial effects:
[0017] The porous nanocomposite repair membrane prepared by the present invention uses a porous scaffold as a "climbing frame" for cell proliferation and migration, uses drug-loaded plant exosomes as "nutrients", and chemically cross-links silk fibroin, chitosan and genipin, with a stable structure and certain mechanical strength. The drug is allowed to enter the plant exosomes through the co-incubation method, which improves the dispersibility and utilization rate of the drug in the porous scaffold.
[0018] 1. The present invention uses plant exosomes as drug-carrying matrices, which reduces the preparation cost of animal exosomes, while improving the utilization rate of insoluble or poorly soluble drugs, increasing the added value of plant active ingredients, and providing a new way to develop and utilize plant resources.
[0019] 2. The porous nanocomposite repair membrane of the present invention has multi-sized nanostructured pores, which is conducive to the release of drug-loaded plant exosomes, achieving the effect of sustained drug release; the mechanical strength of the porous scaffold can provide space to promote cell proliferation and migration at the wound.
[0020] 3. The porous nanocomposite repair membrane of the present invention has the characteristics of anti-inflammatory, anti-oxidation, promoting cell regeneration, etc., and has good biocompatibility, thereby achieving the purpose of wound healing. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a process flow chart of the preparation method of the present invention.
[0022] Figure 2 This is an electron microscope image of the porous scaffold prepared in Example 1.
[0023] Figure 3 These are electron micrographs of plant exosomes before and after drug loading obtained in Example 1; in the figure, (a) is an electron micrograph of plant exosomes, and (b) is an electron micrograph of drug-loaded plant exosomes. DETAILED DESCRIPTION
[0024] The content of the present invention is further described below in conjunction with specific examples, but it should not be construed as limiting the present invention. If not specifically indicated, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.
[0025] Example 1
[0026] 1. Silk fibroin and chitosan are mixed with 4wt% polydimethylsiloxane and 0.5wt% carbomer in a ratio of 2:8 to obtain 20wt% biological 3D printing ink; then a biological 3D printer is used for low-temperature printing according to the following parameters: printing speed is 10mm / s, air pressure is 0.6MPa, spacing is 1.49mm, and printing temperature is 10°C to obtain a three-dimensional scaffold; the three-dimensional scaffold printed above is immersed in a fixing solution for 2h, wherein the fixing solution contains 6wt% calcium chloride and 1wt% genipin, and after the fixation is completed, it is taken out and immersed in water for 20min, which is carried out 3 times in total. After the cleaning is completed, the three-dimensional scaffold is placed in a freeze dryer for freeze drying, and then irradiated and sterilized with 25-40kGy to obtain a porous scaffold.
[0027] 2. Wash fresh tomatoes with deionized water and grind them with a peeling machine. Then centrifuge the tomato juice at 1000 rpm for 10 min, 5000 rpm for 20 min, and 10000 rpm for 30 min to remove large particle impurities and broken cell fragments in the tomato juice. Then centrifuge the supernatant at 150000 rpm for 1.5 h at 4 ° C to remove large molecular proteins and soluble impurities in the supernatant. The obtained precipitate was resuspended with PBS solution; finally, it was purified with a qEV column to obtain tomato exosomes; the tomato exosomes prepared above were diluted to 300 μg / mL with PBS, and paclitaxel and tomato exosomes were co-incubated for 4 h at a ratio of 1:10 (g / g) to obtain paclitaxel-loaded tomato exosomes, which were prepared into a 30 wt% paclitaxel-loaded tomato exosome solution with PBS.
[0028] 3. Soak the porous scaffold obtained in step 1 in the paclitaxel-loaded tomato exosome solution obtained in step 2 for 60 minutes, remove the excess liquid on the surface of the scaffold, and then attach a layer of polycaprolactone film to obtain a porous nanocomposite repair membrane loaded with paclitaxel tomato exosomes.
[0029] Figure 2 This is an electron microscope image of the porous scaffold prepared in Example 1. Figure 2 It can be seen that the pore structure of the porous scaffold is multi-scale, which is conducive to the release of drug-loaded plant exosomes and achieves the effect of sustained drug release; the mechanical strength of the porous scaffold provides a suitable growth space for cell growth in the wound. Figure 3 The electron micrographs of plant exosomes before and after drug loading prepared in Example 1 are shown in Figure 1, wherein (a) is an electron micrograph of plant exosomes, and (b) is an electron micrograph of drug-loaded plant exosomes. Figure 3 It can be seen that the size of the plant exosomes becomes larger after drug loading, indicating that the drug enters the plant exosomes.
[0030] Example 2
[0031] 1. Silk fibroin and chitosan are mixed with 4wt% polydimethylsiloxane and 0.5wt% carbomer in a ratio of 2:8 to obtain 20wt% biological 3D printing ink; then a biological 3D printer is used for low-temperature printing according to the following parameters: printing speed is 10mm / s, air pressure is 0.6MPa, spacing is 1.49mm, and printing temperature is 10°C to obtain a three-dimensional scaffold; the three-dimensional scaffold printed above is immersed in a fixing solution for 2h, wherein the fixing solution contains 6wt% calcium chloride and 1wt% genipin, and after the fixation is completed, it is taken out and immersed in water for 20min, which is carried out 3 times in total. After the cleaning is completed, the three-dimensional scaffold is placed in a freeze dryer for freeze drying, and then irradiated and sterilized with 25-40kGy to obtain a porous scaffold.
[0032] 2. Wash fresh tomatoes with deionized water and grind them with a peeling machine. Then centrifuge the tomato juice at 1000 rpm for 10 min, 5000 rpm for 20 min, and 10000 rpm for 30 min to remove large particle impurities and broken cell fragments in the tomato juice. Then centrifuge the supernatant at 150000 rpm for 1.5 h at 4 ° C to remove large molecular proteins and soluble impurities in the supernatant. The obtained precipitate was resuspended with PBS solution; finally, it was purified with a qEV column to obtain tomato exosomes; the tomato exosomes prepared above were diluted to 300 μg / mL with PBS, and paclitaxel and tomato exosomes were co-incubated for 4 h at a ratio of 1:30 (g / g) to obtain paclitaxel-loaded tomato exosomes, which were prepared into a 10 wt% paclitaxel-loaded tomato exosome solution with PBS.
[0033] 3. Soak the porous scaffold obtained in step 1 in the paclitaxel-loaded tomato exosome solution obtained in step 2 for 60 minutes, remove the excess liquid on the surface of the scaffold, and then attach a layer of polycaprolactone film to obtain a porous nanocomposite repair membrane loaded with paclitaxel tomato exosomes.
[0034] Example 3
[0035] 1. Silk fibroin and chitosan are mixed with 4wt% polydimethylsiloxane and 0.5wt% carbomer in a ratio of 2:8 to obtain 20wt% biological 3D printing ink; then a biological 3D printer is used for low-temperature printing according to the following parameters: printing speed is 10mm / s, air pressure is 0.6MPa, spacing is 1.49mm, and printing temperature is 10°C to obtain a three-dimensional scaffold; the three-dimensional scaffold printed above is immersed in a fixing solution for 2h, wherein the fixing solution contains 6wt% calcium chloride and 1wt% genipin, and after the fixation is completed, it is taken out and immersed in water for 20min, which is carried out 3 times in total. After the cleaning is completed, the three-dimensional scaffold is placed in a freeze dryer for freeze drying, and then irradiated and sterilized with 25-40kGy to obtain a porous scaffold.
[0036] 2. Wash the fresh ginger with deionized water and grind it with a peeling machine. Then, centrifuge the ginger juice at 1000 rpm for 10 min, 5000 rpm for 20 min, and 10000 rpm for 30 min to remove large particle impurities and broken cell fragments in the ginger juice. Then, centrifuge the supernatant at 150000 rpm for 1.5 h at 4 ° C to remove large molecular proteins and soluble impurities in the supernatant. The obtained precipitate was resuspended with PBS solution; finally, it was purified with a qEV column to obtain ginger exosomes; the ginger exosomes prepared above were diluted to 300 μg / mL with PBS, and doxorubicin and ginger exosomes were co-incubated for 4 h at a ratio of 1:10 (g / g) to obtain doxorubicin-loaded ginger exosomes, which were prepared into a 30 wt% doxorubicin-loaded ginger exosome solution with PBS.
[0037] 3. Soak the porous scaffold obtained in step 1 in the doxorubicin-loaded ginger exosome solution obtained in step 2 for 60 minutes, remove the excess liquid on the surface of the scaffold, and then attach a layer of polycaprolactone film to obtain a porous nanocomposite repair membrane loaded with doxorubicin-loaded ginger exosomes.
[0038] Example 4
[0039] 1. Silk fibroin and chitosan are mixed with 4wt% polydimethylsiloxane and 0.5wt% carbomer in a ratio of 2:8 to obtain 20wt% biological 3D printing ink; then a biological 3D printer is used for low-temperature printing according to the following parameters: printing speed is 10mm / s, air pressure is 0.6MPa, spacing is 1.49mm, and printing temperature is 10°C to obtain a three-dimensional scaffold; the three-dimensional scaffold printed above is immersed in a fixing solution for 2h, wherein the fixing solution contains 6wt% calcium chloride and 1wt% genipin, and after the fixation is completed, it is taken out and immersed in water for 20min, which is carried out 3 times in total. After the cleaning is completed, the three-dimensional scaffold is placed in a freeze dryer for freeze drying, and then irradiated and sterilized with 25-40kGy to obtain a porous scaffold.
[0040] 2. Wash fresh aloe vera with deionized water and grind it with a peeling machine. Then centrifuge the aloe juice at 1000 rpm for 10 min, 5000 rpm for 20 min, and 10000 rpm for 30 min to remove large particle impurities and broken cell fragments in the aloe juice. Then centrifuge the supernatant at 150000 rpm for 1.5 h at 4 ° C to remove large molecular proteins and soluble impurities in the supernatant. The obtained precipitate was resuspended with PBS solution; finally, it was purified with a qEV column to obtain aloe exosomes; the aloe exosomes prepared above were diluted to 300 μg / mL with PBS, and curcumin and aloe exosomes were co-incubated for 4 h at a ratio of 1:10 (g / g) to obtain curcumin-loaded aloe exosomes, which were prepared into a 30 wt% curcumin-loaded aloe exosome solution with PBS.
[0041] 3. Soak the porous scaffold obtained in step 1 in the curcumin-loaded aloe exosome solution obtained in step 2 for 60 minutes, remove the excess liquid on the surface of the scaffold, and then attach a layer of polycaprolactone film to obtain a porous nanocomposite repair membrane loaded with curcumin aloe exosomes.
[0042] Comparative Example 1
[0043] Silk fibroin and chitosan were mixed with 4wt% polydimethylsiloxane and 0.5wt% carbomer in a ratio of 2:8 to obtain 20wt% biological 3D printing ink; then a biological 3D printer was used for low-temperature printing according to the following parameters: printing speed of 10mm / s, air pressure of 0.6MPa, spacing of 1.49mm, printing temperature of 10°C to obtain a three-dimensional scaffold; the three-dimensional scaffold printed above was immersed in a fixing solution for 2h, wherein the fixing solution contained 6wt% calcium chloride and 1wt% genipin, and after the fixation, it was taken out and immersed in water for 20min, which was carried out 3 times in total. After the cleaning, the three-dimensional scaffold was placed in a freeze dryer for freeze drying, and then sterilized by irradiation of 25-40kGy, and then a layer of polycaprolactone film was attached to obtain a porous scaffold.
[0044] Comparative Example 2
[0045] 1. Mix silk fibroin and chitosan in a ratio of 2:8, with 4wt% polydimethylsiloxane and 0.5wt% carbomer, let stand, apply, put it in a freeze dryer for freeze drying, and then sterilize it by irradiation at 25-40kGy to obtain a composite gel film.
[0046] 2. Wash fresh tomatoes with deionized water and grind them with a peeling machine. Then centrifuge the tomato juice at 1000 rpm for 10 min, 5000 rpm for 20 min, and 10000 rpm for 30 min to remove large particle impurities and broken cell fragments in the tomato juice. Then centrifuge the supernatant at 150000 rpm for 1.5 h at 4 ° C to remove large molecular proteins and soluble impurities in the supernatant. The obtained precipitate was resuspended with PBS solution; finally, it was purified with a qEV column to obtain tomato exosomes; the tomato exosomes prepared above were diluted to 300 μg / mL with PBS, and paclitaxel and tomato exosomes were co-incubated for 4 h at a ratio of 1:10 (g / g) to obtain paclitaxel-loaded tomato exosomes, which were prepared into a 30 wt% paclitaxel-loaded tomato exosome solution with PBS.
[0047] 3. Soak the composite gel membrane obtained in step 1 in the paclitaxel-loaded tomato exosome solution obtained in step 2 for 60 minutes, remove the excess liquid on the surface of the stent, and then attach a layer of polycaprolactone film to obtain a porous nanocomposite gel membrane loaded with paclitaxel tomato exosomes.
[0048] The porous nanocomposite repair membranes prepared in Examples 1-4, the porous scaffolds prepared in Comparative Example 1, and the composite membranes prepared in Comparative Example 2 were subjected to an in vitro cell proliferation test (CCK-8 method). The performance of the samples obtained in the above implementation methods is shown in Table 1.
[0049] Table 1 Cell proliferation performance of the porous nanocomposite repair membrane prepared in Examples 1-2, the porous scaffold of Comparative Example 1, and the composite membrane prepared in Comparative Example 2. Name / Serial Number Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 CCK-8 results 95.6％ 86.2％ 94.3％ 96.2％ 70.9％ 80.3％
[0050] Table 1 shows the cell proliferation performance of the porous nano-composite repair membranes prepared in Examples 1-2, the porous scaffolds of Comparative Example 1, and the composite membranes prepared in Comparative Example 2. As can be seen from Table 1, the relative cell viability of the porous nano-composite repair membrane prepared in Example 1 is higher than that of Comparative Example 1, indicating that the paclitaxel-loaded tomato exosomes have a good effect in promoting cell regeneration. The porous nano-composite repair membrane prepared in Example 2 is higher than that in Comparative Example 2. This is because the multi-scale nanostructure pore size and cross-linking agent fixation in the porous nano-composite repair membrane make the architecture stable and can provide space to promote cell proliferation and migration. The porous nano-composite repair membrane of the present invention is added with drug-loaded plant exosomes, which have the characteristics of anti-inflammatory, anti-oxidation, and promoting cell regeneration, which is helpful for wound healing and achieves the purpose of wound repair.
[0051] The exosomes with four different drug loading concentrations were subjected to in vitro cell proliferation test (CCK-8 method) and drug loading test, and the results are shown in Table 2.
[0052] Table 2 shows the cell proliferation performance and drug loading performance of tomato exosomes with four different paclitaxel concentrations.
[0053] Table 2 shows the cell proliferation performance and drug loading performance of tomato exosomes with 4 different paclitaxel concentrations. As shown in Table 2, when the ratio of paclitaxel to exosomes is greater than 1:10, the cytotoxicity of paclitaxel-loaded tomato exosomes is within an acceptable range, that is, the biocompatibility is good and it is beneficial to promote cell regeneration. As can be seen from Table 2, as the number of exosomes increases, the drug loading of exosomes decreases, that is, the effective ingredients decrease, thereby affecting the sustained release effect of paclitaxel drugs; and when the drug loading of exosomes is too much, it will produce certain toxicity to cells and affect cell proliferation.
[0054] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.
Claims
1. A method for preparing a porous nanocomposite repair membrane loaded with drug exosomes, characterized in that: The porous nanocomposite repair membrane is prepared by firstly printing a bio-based polymer gel at low temperature using a biological 3D printer, and then obtaining a porous scaffold after fixation, freeze drying and sterilization. Then, exosomes are extracted from plants by a centrifugation method combined with a qEV column, and drug-co-incubation treatment is performed to obtain drug-loaded plant exosomes. Then, the porous scaffold is immersed in a solution containing drug-loaded plant exosomes, excess liquid on the surface of the scaffold is removed, and then a layer of dense membrane is attached to obtain a porous nanocomposite repair membrane loaded with drug exosomes.
2. The preparation method according to claim 1, characterized in that: The preparation method of the porous scaffold is as follows: first, silk fibroin and chitosan are compounded in proportion by a blending method, polydimethylsiloxane and carbomer are added after stirring evenly to obtain biological 3D printing ink; then, a biological 3D printer is used to perform low-temperature printing, fixation, freeze-drying, and sterilization to obtain a porous scaffold.
3. The preparation method according to claim 2, characterized in that: The ratio of silk fibroin to chitosan is 1:9-5:5; the mass concentration of polydimethylsiloxane is 3-8wt%; the mass concentration of carbomer is 0.1-3wt%; the printing parameters of the biological 3D printer are: printing speed: 7-11mm / s, air pressure: 0.45-0.6MPa, spacing: 1.4-1.8mm, and printing temperature is -10-10°C.
4. The preparation method according to claim 2, characterized in that: The fixing method is as follows: calcium chloride and genipin are dissolved in water to prepare a fixing solution, and then the printed stent is immersed in the fixing solution. After the fixing is completed, the stent is taken out and washed with water to remove excess fixing solution on the surface of the stent; wherein the mass concentration of calcium chloride is 3-10wt%, the mass concentration of genipin is 0.3-2wt%, the fixing time is 1.5-3h, and the washing method is immersing in water for 20min / time, 3 times.
5. The preparation method according to claim 2, characterized in that: The sterilization treatment is one or more of ultraviolet sterilization, radiation sterilization, ozone sterilization or ethylene oxide sterilization.
6. The preparation method according to claim 1, characterized in that: The plant is one or more of ginger, garlic, ginseng, aloe, wheat, tomato, grapefruit or lemon; the centrifugation method is one or more of low-temperature ultracentrifugation and sucrose density gradient centrifugation; the drug is one or more of curcumin, vitamin E, paclitaxel, and doxorubicin; in the co-incubation treatment, the mass ratio of the drug to the plant exosomes is 1:10-1:30, and the co-incubation time is 1-5h.
7. The preparation method according to claim 1, characterized in that: The concentration of the drug-loaded plant exosome solution is 10-30wt%; the time for the stent to be immersed in the drug-loaded plant exosome solution is 3-120min; and the dense membrane is one or more of polylactic acid, polycaprolactone, polyurethane, and polyacrylonitrile.
8. A porous nanocomposite repair membrane loaded with drug exosomes prepared according to the preparation method according to any one of claims 1 to 7.
9. Use of the porous nanocomposite repair membrane loaded with drug exosomes according to claim 8 in the field of biomedical materials or tissue engineering technology.