Liposome nano particle based on folic acid targeting as well as preparation method and application of liposome nano particle

Abstract

The invention belongs to the technical field of nano-agents, and discloses a folic acid targeting-based liposome nano-particle as well as a preparation method and application of the folic acid targeting-based liposome nano-particle. The preparation method comprises the following steps: dissolving phospholipid, cholesterol, polyethylene glycol, folic acid modified polyethylene glycol and a fluorescent dye in a solvent, and carrying out rotary evaporation to form a uniform film; preparing nano ferroferric oxide into a hydrated solution; adding the hydration liquid into the thin film to carry out hydration treatment until no solid substance exists; and then adding microRNA (Ribonucleic Acid) to carry out RNA loading, so as to prepare the lipidosome nano particles. The liposome nanoparticles provided by the invention can integrate a plurality of functional substances into the same nano-carrier to realize the synergistic effect of multi-modal diagnosis and treatment, so that an integrated cancer diagnosis and treatment scheme is realized, the treatment effect is improved, and side effects are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of nanopharmaceuticals, and in particular relates to a liposome nanoparticle based on folic acid targeting, and a preparation method and application thereof. Background Art

[0002] With the continuous advancement of tumor treatment technology, the application of nanotechnology in cancer diagnosis and treatment has gradually attracted widespread attention. Nanoparticles have become ideal drug carriers and diagnosis and treatment platforms due to their unique physical and chemical properties, such as high surface area, adjustable particle size, and easy surface functionalization. In recent years, the application research of multifunctional nanoparticles in the field of integrated tumor diagnosis and treatment has made important progress. These nanoparticles can not only realize tumor imaging diagnosis, but also can be directly used for treatment, thereby greatly improving the accuracy and effectiveness of treatment.

[0003] Since folate receptors are often overexpressed on the surface of tumor cells, folic acid is widely used in targeted tumor therapy. By combining folic acid with nanoparticles, the enrichment effect of nanoparticles in tumor tissues can be enhanced, improving the specificity and effectiveness of treatment. Among them, nano-iron tetroxide (Fe3O4) is currently a hot topic of research due to its good magnetic properties and its ability to be used as a contrast agent for magnetic resonance imaging (MRI). At the same time, the application prospects of fluorescent dyes in photothermal therapy and fluorescence imaging are also very broad.

[0004] In addition, microRNA (miRNA), as an endogenous non-coding RNA, can regulate gene expression and participate in a variety of biological processes. MicroRNA-101-3p has been shown to inhibit cell proliferation and migration in a variety of tumors, and therefore has potential application value in tumor treatment. However, integrating these functional substances into the same nanocarrier to achieve synergistic effects of multimodal diagnosis and treatment still faces great challenges. The specific challenges are: (1) Stability of composite materials: It is a technical challenge to effectively combine nanomaterials with different functions and maintain their stability in the body. Composite materials need to remain physically and chemically stable in the in vivo environment to ensure their imaging and therapeutic effects. (2) Precise control of functionalization: Accurately combining folic acid, fluorescent dyes and miRNA-101-3p on nanocarriers requires precise control of the loading amount and release behavior of each component to ensure effectiveness and safety. (3) Distribution and elimination in the body: The distribution and elimination process of nanocarriers in the body may affect the therapeutic effect and side effects. For example, nanoparticles may accumulate in organs such as the liver and spleen, thereby affecting their targeting effect in tumors. (4) Coordination of imaging and treatment: The performance of nanocarriers in multimodal imaging (such as MRI and fluorescence imaging) needs to be coordinated with their therapeutic functions (such as photothermal therapy). The imaging and therapeutic effects of different modes often affect each other. (5) Optimization of treatment and imaging windows: Ensuring effective imaging during treatment and maintaining the therapeutic effect during imaging requires nanocarriers to have good functional stability.

[0005] Therefore, there is an urgent need to provide a nanoparticle that can integrate functional substances into the same nanocarrier in order to achieve an integrated cancer diagnosis and treatment plan, improve the treatment effect and reduce side effects. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes a liposome nanoparticle based on folic acid targeting and a preparation method and application thereof. The liposome nanoparticle provided by the present invention can integrate multiple functional substances into the same nanocarrier to achieve the synergistic effect of multimodal diagnosis and treatment, thereby realizing an integrated cancer diagnosis and treatment plan, improving the treatment effect and reducing side effects.

[0007] The invention provides a method for preparing liposome nanoparticles based on folic acid targeting.

[0008] Specifically, a method for preparing folic acid-targeted liposome nanoparticles comprises the following steps:

[0009] Phospholipids, cholesterol, polyethylene glycol, polyethylene glycol modified with folic acid, and fluorescent dye are dissolved in a solvent and rotary evaporated to form a uniform film; nano-ferroferric oxide is made into a hydration liquid; the hydration liquid is added into the film for hydration treatment until no solid matter is left; microRNA is then added for RNA loading to obtain liposome nanoparticles based on folic acid targeting.

[0010] Preferably, the mass ratio of the phospholipid, the cholesterol, the polyethylene glycol, and the folic acid-modified polyethylene glycol is (50-60): (30-40): (8-10): (0.5-2). Further preferably, the mass ratio of the phospholipid, the cholesterol, the polyethylene glycol, and the folic acid-modified polyethylene glycol is (52-56): (32-40): (8-10): (0.5-1.5). The loading amount and release behavior of each component are precisely controlled to ensure the effectiveness and safety of the liposome nanoparticles.

[0011] Preferably, the phospholipid comprises at least one of phosphatidylcholine and phosphatidylinositol.

[0012] Preferably, the fluorescent dye includes at least one of IR-780, IR-1061, and IR-820. Further preferably, the fluorescent dye is IR-780. The absorption wavelength of IR-780 is quite different from that of ferroferric oxide, and IR-780 has no magnetic resonance signal, which can well avoid the interference of other components during treatment and improve the coordination of imaging and treatment.

[0013] Preferably, the mass of the fluorescent dye accounts for 1%-10% of the total mass of the phospholipid, the cholesterol, the folate-modified polyethylene glycol, the polyethylene glycol, the microRNA, and the nano-ferroferric oxide; further preferably, the mass of the fluorescent dye accounts for 3%-7% of the total mass of the phospholipid, the cholesterol, the folate-modified polyethylene glycol, the polyethylene glycol, the microRNA, and the nano-ferroferric oxide.

[0014] Preferably, the solvent includes at least one of chloroform, dichloromethane and anhydrous ethanol.

[0015] Preferably, the mass ratio of the total mass of the phospholipid, the cholesterol, the polyethylene glycol, the folic acid-modified polyethylene glycol and the fluorescent dye to the solvent is 1:250-300.

[0016] Preferably, the rotary evaporation process is: rotary evaporation at 35-45° C. and vacuum 90-110 mbar for 30-60 minutes until a uniform film is formed.

[0017] Preferably, the preparation process of the hydration liquid is: adding the nano-ferroferric oxide solution to water in a volume ratio of 1:(90-110), ultrasonically mixing for 8-12 minutes to prepare the hydration liquid. The mass fraction of the nano-ferroferric oxide solution is 15%-25%, preferably 20%.

[0018] Preferably, the hydration process is to perform ultrasonic treatment at 55-65° C. for 5-10 minutes until no solid matter is left.

[0019] Preferably, the microRNA includes microRNA-101-3p.

[0020] Preferably, the RNA loading process is to absorb the microRNA storage solution and add it into the hydrated system, and place it on a shaker at 2-4° C. for 10-14 hours.

[0021] In the above preparation process, lecithin self-assembles into a bilayer membrane structure to form the main framework of the liposome. The solvent is used to dissolve the phospholipids to facilitate their uniform distribution during the synthesis process; and by evaporating the organic solvent, the phospholipids will be deposited as a film, ready for the next step of hydration. During the film hydration process, water or buffer solution is used to re-expand the phospholipid film to form liposome vesicles. After hydration, the phospholipid bilayer self-assembles into a closed vesicle structure, enclosing the aqueous drug inside to form liposomes. Nano-iron tetroxide is loaded into liposomes as a drug or active ingredient for delivery through liposomes. Folic acid is used to functionalize the surface of liposomes to enhance their targeting, stability or biocompatibility. Polyethylene glycol can increase the stability of liposomes and prevent them from aggregating or degrading during storage or in vivo environments.

[0022] The present invention also provides a liposome nanoparticle based on folic acid targeting.

[0023] Specifically, a liposome nanoparticle based on folic acid targeting is prepared by the above preparation method; it includes an inner core nano-iron tetroxide, a lipid bilayer covering the inner core nano-iron tetroxide, a fluorescent dye located inside the lipid bilayer, PEG, folic acid-modified PEG embedded in the lipid bilayer, and microRNA adsorbed on the outside of the lipid bilayer.

[0024] The present invention also provides the application of the above-mentioned liposome nanoparticles based on folic acid targeting.

[0025] Specifically, the above-mentioned folic acid-targeted liposome nanoparticles are used in the preparation of tumor therapeutic drugs.

[0026] The invention also provides a medicine for treating tumors.

[0027] Specifically, a drug for treating tumors comprises the above-mentioned liposome nanoparticles based on folic acid targeting.

[0028] The liposome nanoparticles based on folic acid targeting provided by the present invention utilize the multiple drug loading methods of the liposome nano drug loading system to embed folic acid-modified polyethylene glycol and fluorescent dyes into the lipid bilayer, load nano ferroferric oxide into the hydrophilic core, and adsorb microRNA onto the outside of the liposome. The present invention utilizes the characteristics of the multiple drug loading sites of the liposome to determine the optimal composite drug loading method for Fe3O4 and fluorescent dyes according to the different solubility, and the obtained liposome nanoparticles have strong photothermal stability and functional stability; and because the absorption wavelength difference between ferroferric oxide and IR-780 is large, IR-780 has no magnetic resonance signal, and can well avoid the interference of other components during treatment, realize dual-modal imaging and treatment, and the coordination of imaging and treatment is strong. The present invention utilizes folic acid to modify the surface of the nanoparticles, improves the targeting of liposome nanoparticles to tumor cells, and reduces the attachment to normal tissues.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) Multifunctional diagnosis and treatment integration: The present invention integrates folic acid, fluorescent dye, nano-ferroferric oxide and microRNA into a nanoparticle carrier to achieve multimodal diagnosis and treatment integration of tumors. The liposome nanoparticles not only have the characteristics of strong targeting, good imaging effect and high treatment efficiency, but also can effectively treat tumors through photothermal effect and gene regulation.

[0031] (2) Enhanced targeting: Folic acid-modified liposome nanoparticles can specifically recognize and bind to folate receptors on the surface of tumor cells, thereby improving the enrichment effect of liposome nanoparticles in tumor tissues, thereby enhancing the targeting of treatment and reducing side effects on normal tissues.

[0032] (3) Synergistic therapeutic effect: By combining photothermal therapy, magnetic resonance imaging and gene regulation, the liposome nanoparticles of the present invention can produce a synergistic effect in tumor treatment, which not only improves the overall effect of tumor treatment, but also reduces the side effects that may be caused by a single treatment method.

[0033] (4) Innovative design: The liposome nanoparticles provided by the present invention are uniquely designed, integrating multiple functions in one, and improving the specificity of treatment through the targeting effect of folic acid. This innovative design can overcome the shortcomings of the existing technology and has broad application prospects in the field of tumor treatment.

[0034] (5) Safety and biocompatibility: By optimizing the synthesis method of nanoparticles, the present invention ensures the safety and biocompatibility of the prepared liposome nanoparticles, and reduces the potential toxicity and immune response risks of nanomaterials in vivo. The folic acid-targeted liposome nanoparticles provided by the present invention are innovative and practical in the field of integrated tumor diagnosis and treatment, and provide a new method for cancer treatment with high efficiency and low toxicity. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles;

[0036] Figure 2 This is the transmission electron microscopy image of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles;

[0037] Figure 3 This is the zeta potential distribution diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles;

[0038] Figure 4 The nanoparticle size distribution diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles;

[0039] Figure 5 This is the naked eye observation picture of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles;

[0040] Figure 6 This is the photothermal stability diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles;

[0041] Figure 7 This is the absorbance test diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles and other particles;

[0042] Figure 8 This is the experimental result of magnetic distribution of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles;

[0043] Fig. 9 Different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drugs) at 0.6W / cm 2 Photothermal effect diagram under laser power;

[0044] Fig.10Different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drugs) at 1.1W / cm 2 Photothermal effect diagram under laser power;

[0045] Fig.11 Different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drugs) at 1.7W / cm 2 Photothermal effect diagram under laser power;

[0046] Fig.12 is the survival rate of tumor cells under different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drug);

[0047] Fig.13 The tumor cell inhibition rate under different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drug). DETAILED DESCRIPTION

[0048] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0049] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0050] Example

[0051] A method for preparing folic acid-targeted liposome nanoparticles comprises the following steps:

[0052] (1) Ingredients and dissolution

[0053] Lecithin, cholesterol, polyethylene glycol, and folic acid-modified polyethylene glycol (purchased from Shanghai Pengshuo Biotechnology Co., Ltd.) were added to the container at a mass ratio of 54:36:9:1, and IR-780 was added at a total mass ratio of 5%. Chloroform was added at a solid: liquid mass ratio of 1:280, and ultrasonic treatment was performed with a 100W probe-type ultrasonic crusher until it was completely dissolved to obtain a liquid to be evaporated.

[0054] (2) Rotary evaporation

[0055] Transfer the liquid to be rotary evaporated into a 500 mL spherical evaporating flask and rotary evaporate at 40°C and vacuum 100 mbar until a uniform film is formed.

[0056] (3) Hydration

[0057] Add nano-ferroferric oxide solution (10-50nm, mass fraction 20%) to ultrapure water at a volume ratio of 1:99, and mix by ultrasonic for 10 minutes to prepare a hydration solution. Add the hydration solution to the film and hydrate at 60°C. Ultrasonicate until there is no solid matter, and transfer to a light-proof centrifuge tube and adjust the volume to 10mL.

[0058] (4) RNA loading

[0059] 50 μL of mir101-3p (microRNA) storage solution was added to the centrifuge tube in step (3). The tube was placed on a shaker at 4°C for 12 hours to obtain FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles.

[0060] Product effect testing

[0061] (1) Morphological characterization of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles.

[0062] Figure 1 Schematic diagram of the structure of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles. Figure 1 As shown, in the liposome nanoparticles, the inner core is loaded with hydrophilic nano-ferroferric oxide, IR-780 is located in the lipid bilayer formed by lipids, PEG and folic acid (FA)-modified PEG are embedded in the lipid bilayer and expose the modified active targeting sites, and microRNA is adsorbed on the outside of the lipid bilayer.

[0063] The negative staining electron microscope was used to take pictures of liposomes: the liposome samples were stained on a carbon film copper grid by the negative staining method, and then the morphology and distribution images of the liposomes were taken using a transmission electron microscope (TEM) to observe their morphology and structural characteristics. Figure 2 This is the transmission electron microscopy image of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles. Figure 2 It can be seen that under the electron microscope, the liposomes appear uniformly round, and the lipid bilayer and the internal hydrophilic core can be seen.

[0064] Measuring Nanoparticle Potential: Nanoparticles are suspended in an aqueous medium and their surface potential (zeta potential) is measured using electrophoretic light scattering to assess the surface charge properties and stability of the particles. Figure 3 The zeta potential distribution diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles is shown in Figure 1. Figure 3 It can be seen that the liposome potential is around -30mv, which has good stability.

[0065] Particle size distribution test: The liposome nanoparticles are dispersed in a suitable solution, and the Brownian motion of the particles in the solution is measured using a dynamic light scattering (DLS) instrument, and the average particle size and distribution of the liposome nanoparticles are calculated. Figure 4 The particle size distribution diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles is shown in Figure 2. Figure 4 It can be seen that the size of the liposome nanoparticles is around 100 nm, which is a very ideal size.

[0066] (2) Physical and chemical properties of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles.

[0067] Figure 5 This is the naked eye observation picture of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles. Figure 5 It can be observed that the prepared liposome nanoparticle solution is clear, demonstrating that the liposome nanoparticles have good uniformity.

[0068] Measurement of the photothermal stability of nanoparticles: The nanoparticle solution was irradiated three times with an 800 nm laser at a power of 1.1 W, and the irradiation was restarted each time after cooling to room temperature. The temperature change was recorded every 30 seconds to evaluate its photothermal stability. Figure 6 The photothermal stability diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles is shown in Figure 1. Figure 6 It can be seen that the heating performance of liposome nanoparticles does not change significantly after multiple heating, indicating that they have good photothermal stability.

[0069] Measuring the absorption peak of nanoparticles: The absorption spectra of Fe3O4 solution, IR-780 solution, and FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticle solution were scanned by UV-visible spectrophotometer to determine the maximum absorption peak at a specific wavelength to analyze its optical properties. Figure 7 This is the absorbance test diagram of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles and other particles; the liposome nanoparticles have absorption peaks in the absorption regions of both components, indicating that each component has been successfully loaded.

[0070] (3) Magnetic distribution effect of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles.

[0071] Cell inoculation will be performed, HepG2 cells will be inoculated in a 10cm culture dish at an appropriate density, and cultured in culture medium to 80%-90% confluence. For magnetic treatment, a ring magnet is placed at the bottom of the culture dish to ensure that the magnetic field is evenly distributed. Finally, liposome nanoparticles (drugs) are added for treatment: a drug solution containing magnetic liposome nanoparticles is added to the culture dish to ensure that the liposome nanoparticles (drugs) cover the cells and are affected by the magnetic field. The cells are incubated at 37°C and 5% CO2 for 24 hours, and crystal violet staining is performed after the incubation to observe the magnetic distribution effect of liposome nanoparticles (drugs). The specific process is as follows: After incubating the liposome nanoparticles (drugs) for 24 hours, the culture medium is discarded, and the surface of the culture dish is gently rinsed with PBS buffer, and repeated several times until no color residue of the liposome nanoparticles (drugs) can be seen in the culture dish. Then use 4% paraformaldehyde to fix the cells for 10 minutes, and then rinse again with PBS. Then add 1% crystal violet staining solution to the culture dish and stain for 10-15 minutes to stain the cells. The culture dish was rinsed with tap water or PBS to remove excess crystal violet staining solution until the staining solution stopped flowing out. Finally, the cell distribution and survival were observed and recorded under a microscope, with special attention paid to the cell survival in the area where the liposome nanoparticles (drugs) were distributed. Figure 8 This is the experimental result of magnetic distribution of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles, where: Figure 8 Middle A shows that nanoparticles are added to a culture dish with a magnet attached below for cell culture; Figure 8 Middle B shows that after the magnet is removed, the nanoparticles are found to aggregate along the magnetic field lines of the magnet; Figure 8 Middle C shows that after discarding the culture medium and washing with PBS several times, the nanoparticles still exist, indicating that they have been taken up by cells in large quantities; Figure 8 Middle D shows that after crystal violet staining, obvious tumor cell death can be seen in the area where the magnetic field lines of the magnet are distributed.

[0072] (4) Photothermal effects of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles at different concentrations and powers.

[0073] Liposome nanoparticles were prepared into solutions of different concentrations (10, 30, 50 μg / mL) and exposed to 0.6, 1.1, and 1.7 W / cm 2 Irradiate under laser power, record temperature changes every 30 seconds, and evaluate the photothermal effect. Figure 9-11 Different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drugs) at 0.6W, 1.1W and 1.7W / cm 2 Photothermal effect diagram under laser power, by Figure 9-11It can be seen that the heating effect of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drugs) is significantly improved with the increase of concentration and laser power, and its photothermal effect is excellent.

[0074] (5) In vivo anti-tumor efficacy of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles.

[0075] The in vivo anti-tumor efficacy of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles was tested. The specific process was as follows: a. HepG2 tumor cells were seeded in a 96-well plate at an appropriate density, and each well was inoculated with 100 μL of cell suspension in culture medium, so that each well contained about 8,000 cells. The 96-well plate was placed in an incubator at 37°C and 5% CO until the cells grew adherently in the well and reached a suitable state (usually about 24 hours). b. The nanoparticle drug was diluted according to a concentration gradient of 10, 20, 30, 50, and 100 μg / mL. One group was prepared for each concentration. c. The culture medium in the 96-well plate was removed, and 100 μL of drug solution of different concentrations was added to each well, and a blank control group (without drug) and a negative control group (without cells) were set up. Then the 96-well plate was returned to the incubator and cultured for another 24 hours. d. After 24 hours, 10 μL of CCK-8 reagent (cell counting kit) was added to each well and gently mixed. Continue to incubate in the incubator for 1-4 hours until the color of the liquid in the well changes significantly (from yellow to orange-red). e. Use an ELISA reader to measure the absorbance (OD value) of each well at a wavelength of 450nm and record the data. f. Based on the measured absorbance (OD value), calculate the cell proliferation inhibition rate at each concentration. The calculation formula for the inhibition rate is:

[0076]

[0077] Survival rate (%) = 1 - inhibition rate (%).

[0078] g. By performing statistical analysis on the inhibition rates of the groups treated with different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drug), the anti-tumor effect of the drug was evaluated and a dose-effect curve was drawn.

[0079] Fig.12 is the survival rate of tumor cells under different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drug); Fig.13 The inhibition rate of tumor cells under different concentrations of FA-Lipo-Fe3O4-Mir101@IR780 liposome nanoparticles (drugs). Fig.12 , Fig.13It can be seen that with the increase of drug concentration, the survival rate of tumor cells decreases significantly, and the drug has a good anti-tumor effect.

[0080] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing liposome nanoparticles, characterized in that: The following steps are involved: Phospholipids, cholesterol, polyethylene glycol, polyethylene glycol modified with folic acid, and fluorescent dye are dissolved in a solvent and rotary evaporated to form a uniform film; nano-ferroferric oxide is made into a hydration liquid; the hydration liquid is added into the film for hydration treatment until no solid matter is left; microRNA is then added for RNA loading to obtain liposome nanoparticles based on folic acid targeting.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the phospholipid, the cholesterol, the polyethylene glycol, and the folic acid-modified polyethylene glycol is (50-60): (30-40): (8-10): (0.5-2).

3. The preparation method according to claim 1 or 2, characterized in that: The fluorescent dye includes at least one of IR-780, IR-1061, and IR-820.

4. The preparation method according to claim 1 or 2, characterized in that: The solvent includes at least one of chloroform, dichloromethane and anhydrous ethanol.

5. The preparation method according to claim 4, characterized in that: The mass ratio of the total mass of the phospholipid, the cholesterol, the polyethylene glycol, the folic acid-modified polyethylene glycol and the fluorescent dye to the solvent is 1:250-300.

6. The preparation method according to claim 1 or 2, characterized in that: The rotary evaporation process is: rotary evaporation at 35-45° C. and vacuum 90-110 mbar for 30-60 minutes until a uniform film is formed.

7. The preparation method according to claim 1 or 2, characterized in that: The RNA loading process is to absorb the microRNA storage solution and add it into the hydrated system, and place it on a shaker at 2-4° C. for 10-14 hours.

8. A liposome nanoparticle, characterized in that: Prepared by the preparation method described in any one of claims 1 to 7; The invention comprises inner core nano-ferroferric oxide, a lipid bilayer covering the inner core nano-ferroferric oxide, a fluorescent dye located inside the lipid bilayer, PEG and folic acid-modified PEG embedded in the lipid bilayer, and microRNA adsorbed on the outside of the lipid bilayer.

9. Use of the folic acid-targeted liposome nanoparticles according to claim 8 in the preparation of tumor therapeutic drugs.

10. A drug for treating tumors, characterized in that: The folic acid-targeted liposome nanoparticles according to claim 8.

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