Liposome nanoparticle based on folic acid targeting and preparation method and application thereof
Technical Field
The invention belongs to the technical field of nano-medicament, and in particular relates to a liposome nanoparticle based on folic acid targeting, and a preparation method and application thereof.
Background
With the continuous progress of tumor treatment technology, the application of nanotechnology in cancer diagnosis and treatment has gradually attracted a great deal of attention. Nanoparticles become ideal drug carriers and diagnosis and treatment platforms due to their unique physicochemical properties, such as high surface area, adjustable particle size, easy surface functionalization, etc. In recent years, application research of multifunctional nano particles in the field of tumor diagnosis and treatment integration has been greatly advanced, and the nano particles not only can realize imaging diagnosis of tumors, but also can be directly used for treatment, so that the accuracy and effect of treatment are greatly improved.
Folic acid is widely used in targeted therapy of tumors, as the surface of tumor cells usually overexpresses the folate receptor. By combining folic acid with the nano particles, the enrichment effect of the nano particles in tumor tissues can be enhanced, and the specificity and effectiveness of treatment can be improved. Among them, nano ferroferric oxide (Fe 3O4) is a hot spot of current research due to its good magnetic properties and characteristics that can be used as a Magnetic Resonance Imaging (MRI) contrast agent. Meanwhile, the fluorescent dye has very broad application prospect in photothermal treatment and fluorescent imaging.
In addition, microRNA (miRNA), as an endogenous non-coding RNA, is capable of regulating gene expression and is involved in a variety of biological processes. microRNA-101-3p is proved to have the function of inhibiting cell proliferation and migration in various tumors, so that the microRNA-101-3p has potential application value in tumor treatment. However, integration of these functional substances into the same nanocarrier to achieve synergy of multimodal diagnosis and therapy is still facing significant challenges. The specific challenges are (1) the stability of the composite material, namely, the effective composition of the nano materials with different functions and the maintenance of the stability in vivo, are one technical problem. The composite material needs to remain physically and chemically stable in the in vivo environment to ensure its imaging and therapeutic effects. (2) And the functional precise control is that folic acid, fluorescent dye and miRNA-101-3p are accurately combined on the nano carrier, and the loading and release behaviors of each component need to be precisely controlled so as to ensure the effectiveness and the safety. (3) In vivo distribution and exclusion the in vivo distribution and exclusion process of nanocarriers may affect therapeutic effects and side effects. For example, nanoparticles may accumulate in organs such as the liver, spleen, etc., thereby affecting their targeting effect in tumors. (4) Coordination of imaging and therapy the performance of nanocarriers in multimodal imaging (e.g., MRI and fluorescence imaging) needs to be coordinated with their therapeutic functions (e.g., photothermal therapy). The imaging and therapeutic effects of the different modes tend to interact. (5) Optimizing the treatment and imaging window ensures effective imaging at the time of treatment and maintains the therapeutic effect at the time of imaging, which requires good functional stability of the nanocarriers.
Therefore, it is needed to provide a nanoparticle capable of integrating functional substances into the same nanocarrier so as to achieve an integrated cancer diagnosis and treatment scheme, improve the therapeutic effect and reduce the side effects.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems in the prior art described above. Therefore, the invention provides a liposome nanoparticle based on folic acid targeting, and a preparation method and application thereof. The liposome nanoparticle provided by the invention can integrate a plurality of functional substances into the same nano-carrier, realize the synergistic effect of multi-mode diagnosis and treatment, further realize an integrated cancer diagnosis and treatment scheme, improve the treatment effect and reduce the side effect.
The invention provides a preparation method of liposome nano particles based on folic acid targeting.
Specifically, the preparation method of the liposome nanoparticle based on folic acid targeting comprises the following steps:
dissolving phospholipid, cholesterol, polyethylene glycol, folic acid modified polyethylene glycol and fluorescent dye in a solvent, performing rotary evaporation to form a uniform film, preparing nano ferroferric oxide into hydration liquid, adding the hydration liquid into the film for hydration treatment until no solid matters exist, and then adding microRNA for RNA loading to prepare the folic acid targeting liposome nano particles.
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 effectiveness and safety of the liposome nanoparticle are ensured by precisely controlling the loading and release behavior of each component.
Preferably, the phospholipid comprises at least one of lecithin and phosphatidylinositol.
Preferably, the fluorescent dye comprises at least one of IR-780, IR-1061, IR-820. Further preferably, the fluorescent dye is IR-780. The difference of absorption wavelengths of the IR-780 and the ferroferric oxide is large, and the IR-780 has no magnetic resonance signal, so that the interference of other components during treatment can be well avoided, and the coordination of imaging and treatment is improved.
Preferably, the mass of the fluorescent dye accounts for 1-10% of the total mass of the phospholipid, the cholesterol, the folic acid modified polyethylene glycol, the microRNA and the nano ferroferric oxide, and further preferably, the mass of the fluorescent dye accounts for 3-7% of the total mass of the phospholipid, the cholesterol, the folic acid modified polyethylene glycol, the microRNA and the nano ferroferric oxide.
Preferably, the solvent comprises at least one of chloroform, dichloromethane and absolute ethanol.
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.
Preferably, the rotary evaporation is carried out by rotary evaporation at 35-45℃under vacuum of 90-110mbar for 30-60 minutes until a uniform film is formed.
Preferably, the hydration liquid is prepared by adding nano ferroferric oxide solution (90-110 vol.%) into water, and ultrasonic mixing for 8-12 min. The mass fraction of the nano ferroferric oxide solution is 15% -25%, preferably 20%.
Preferably, the hydration treatment is carried out for 5-10 minutes at 55-65 ℃ until no solids are present.
Preferably, the microRNA comprises microRNA-101-3p.
Preferably, the RNA loading process is to suck microRNA storage solution, add the microRNA storage solution into a hydrated system and place the microRNA storage solution on a 2-4 ℃ shaker for 10-14 hours.
In the preparation process, lecithin self-assembles into a double-layer membrane structure, a main framework solvent for forming liposome is used for dissolving the phospholipid, so that the phospholipid is uniformly distributed in the synthesis process, and the phospholipid is deposited into a thin film by evaporating an organic solvent to prepare for the next hydration. During membrane hydration, water or buffer solution is used to re-expand the phospholipid membrane to form liposome vesicles. After hydration, the phospholipid bilayer self-assembles into a closed vesicle structure, which seals the internal aqueous phase medicament to form a liposome. The nano-ferroferric oxide is loaded into liposomes as a drug or active ingredient for delivery through the liposomes. Folic acid is used to functionalize the liposome surface to enhance its targeting, stability or biocompatibility. Polyethylene glycol can increase the stability of the liposome and prevent it from aggregating or degrading in storage or in vivo environments.
The invention also provides a liposome nanoparticle based on folic acid targeting.
The liposome nanoparticle based on folic acid targeting is prepared by the preparation method, and comprises a lipid bilayer of inner core nano ferroferric oxide, a fluorescent dye positioned inside the lipid bilayer, PEG embedded in the lipid bilayer, folic acid modified PEG and microRNA adsorbed outside the lipid bilayer.
The invention also provides application of the liposome nanoparticle based on folic acid targeting.
In particular to application of the liposome nano-particles based on folic acid targeting in preparing tumor therapeutic drugs.
The invention also provides a medicine for treating tumors.
In particular to a drug for treating tumors, which comprises liposome nano particles based on folic acid targeting.
The liposome nanoparticle based on folic acid targeting provided by the invention utilizes a multiple drug loading mode of a liposome nanometer drug loading system to embed folic acid modified polyethylene glycol and fluorescent dye into a lipid bilayer, loads nano ferroferric oxide into a hydrophilic core, and adsorbs microRNA outside the liposome. According to the invention, the characteristics of multiple drug carrying sites of the liposome are utilized to determine the optimal composite drug carrying mode of Fe 3O4 and fluorescent dye according to different solubilities, the obtained liposome nano particles have strong photo-thermal stability and functional stability, and because the difference of absorption wavelengths of ferroferric oxide and IR-780 is large, the IR-780 has no magnetic resonance signal, the interference of other components during treatment can be well avoided, the dual-mode imaging and treatment are realized, and the compatibility of imaging and treatment is strong. The invention utilizes folic acid to modify the surface of the nanoparticle, improves the targeting property of the liposome nanoparticle to tumor cells, and reduces the adhesion to normal tissues.
Compared with the prior art, the invention has the beneficial effects that:
(1) The multifunctional diagnosis and treatment integrated method realizes the multi-mode diagnosis and treatment integrated of tumors by integrating folic acid, fluorescent dye, nano ferroferric oxide and microRNA into one nanoparticle carrier. The liposome nanoparticle not only has the characteristics of strong targeting, good imaging effect and high treatment efficiency, but also can be used for effectively treating tumors through the photothermal effect and the gene regulation and control effect.
(2) The targeting enhancement is that the folic acid modified liposome nano particles can specifically identify and bind to the folic acid receptor on the surface of tumor cells, and the enrichment effect of the liposome nano particles in tumor tissues is improved, thereby enhancing the targeting of treatment and reducing the side effect on normal tissues.
(3) The liposome nanoparticle can generate a synergistic effect in tumor treatment by combining photothermal therapy, magnetic resonance imaging and gene regulation, so that the overall effect of tumor treatment is improved, and side effects possibly caused by a single treatment means are reduced.
(4) The liposome nanoparticle provided by the invention has unique design, integrates multiple functions, and improves the specificity of treatment through the targeting effect of folic acid. The innovative design can overcome the defects of the prior art, and has wide application prospect in the field of tumor treatment.
(5) Safety and biocompatibility by optimizing the synthesis method of the nano particles, the invention ensures the safety and biocompatibility of the prepared liposome nano particles and reduces the potential toxicity and immunoreaction risk of the nano material in organisms. The liposome nanoparticle based on folic acid targeting provided by the invention has the innovation and practicality in the field of tumor diagnosis and treatment integration, and provides a novel efficient and low-toxicity method for cancer treatment.
Drawings
FIG. 1 is a schematic diagram of the structure of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticle;
FIG. 2 is a transmission electron microscope image of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles;
FIG. 3 is a zeta potential profile of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles;
FIG. 4 is a graph showing the nanoparticle size distribution of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles;
FIG. 5 is a macroscopic view of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles;
FIG. 6 is a photo-thermal stability profile of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles;
FIG. 7 is a graph showing absorbance measurements of FA-Lipo-Fe 3O4 -Mir101@IR780 liposomal nanoparticles and other particles;
FIG. 8 shows the experimental effect of the magnetic distribution of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles;
FIG. 9 is a graph of photothermal effects of different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticle (drug) at 0.6W/cm 2 laser power;
FIG. 10 is a graph showing the photothermal effects of different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles (drug) at 1.1W/cm 2 laser power;
FIG. 11 is a graph showing the photothermal effects of different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles (drug) at 1.7W/cm 2 laser power;
FIG. 12 shows tumor cell viability at different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposomal nanoparticles (drug);
FIG. 13 shows tumor cell inhibition at different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticle (drug).
Detailed Description
In order to make the technical solutions of the present invention more apparent to those skilled in the art, the following examples will be presented. It should be noted that the following examples do not limit the scope of the invention.
The starting materials, reagents or apparatus used in the following examples are all available from conventional commercial sources or may be obtained by methods known in the art unless otherwise specified.
Examples
A preparation method of liposome nano-particles based on folic acid targeting comprises the following steps:
(1) Dosing and dissolution
Lecithin, cholesterol, polyethylene glycol, folic acid modified polyethylene glycol (commercially available from Shanghai Bos Biotechnology Co., ltd.) were added to the vessel at a mass ratio of 54:36:9:1, and then IR-780 was added at a total mass of 5%. Adding chloroform according to the solid-liquid mass ratio of 1:280, and carrying out ultrasonic treatment by using a 100W probe type ultrasonic crusher until the chloroform is completely dissolved to obtain the to-be-steamed liquid.
(2) Rotary evaporation
The to-be-spun solution was transferred to a 500mL spherical evaporation bottle. Rotary evaporation at 40 ℃ under vacuum at 100mbar until a uniform film formed.
(3) Hydration
Adding the nano ferroferric oxide solution (10-50 nm, mass fraction is 20%) into ultrapure water according to a volume ratio of 1:99, and carrying out ultrasonic mixing for 10 minutes to prepare hydration liquid. Hydration liquid was added to the film and hydrated at 60 ℃. Ultrasonic treatment is carried out until no solid matters exist, and the solid matters are transferred into a light-proof centrifuge tube to be fixed to 10mL.
(4) RNA loading
Mu.L of mir101-3p (microRNA) stock solution is pipetted into the centrifuge tube of step (3). Placing on a 4 ℃ shaking table for 12 hours to obtain the FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nano particles.
Product effect test
(1) Morphological characterization of FA-Lipo-Fe 3O4 -Mir101@IR780 liposomal nanoparticles.
FIG. 1 is a schematic structural diagram of an FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticle, wherein in the liposome nanoparticle, hydrophilic nano ferroferric oxide is loaded on an inner core, IR-780 is positioned in a lipid bilayer formed by lipid, PEG and Folic Acid (FA) -modified PEG is embedded in the lipid bilayer and a modified active targeting point is exposed, and microRNA is adsorbed outside the lipid bilayer.
And (3) taking a liposome picture by adopting a negative staining method and an electron microscope (TEM), namely carrying out staining treatment on a liposome sample on a carbon film copper net by adopting the negative staining method, and then taking morphology and distribution images of the liposome by adopting a Transmission Electron Microscope (TEM) to observe morphology and structural characteristics of the liposome. FIG. 2 is a transmission electron microscope image of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles, and as can be seen from FIG. 2, the liposome presents a uniform circular shape under electron microscope, and a lipid bilayer and an inner hydrophilic core can be seen.
Nanoparticle potential was measured by suspending the nanoparticles in an aqueous medium and measuring their surface potential (zeta potential) using electrophoretic light scattering to evaluate the surface charge properties and stability of the particles. FIG. 3 shows the zeta potential distribution diagram of the FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nano-particles, and as can be seen from FIG. 3, the liposome potential is about-30 mv, and the liposome nano-particles have better stability.
Particle size distribution test Liposome nanoparticles were dispersed in a suitable solution, brownian movement of the particles in the solution was measured using a dynamic light scattering instrument (DLS), and the average particle size of the liposome nanoparticles and their distribution were calculated. FIG. 4 shows the particle size distribution diagram of the FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles, and as can be seen from FIG. 4, the liposome nanoparticles have a size of about 100nm and a very ideal size.
(2) Physicochemical properties of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles.
Fig. 5 is a macroscopic view of the FA-Lipo-Fe 3O4 -mir101@ir780 liposome nanoparticle, and as can be seen from fig. 5, the prepared liposome nanoparticle solution is clear, demonstrating good liposome nanoparticle uniformity.
The photo-thermal stability of the nanoparticle was measured by circularly irradiating the nanoparticle solution three times with a laser at a power of 1.1W using an 800nm laser, restarting after cooling to room temperature each time, recording the temperature change every 30 seconds, and evaluating the photo-thermal stability. Fig. 6 is a photo-thermal stability diagram of the FA-Lipo-Fe 3O4 -mir101@ir780 liposome nanoparticle, and as can be seen from fig. 6, the temperature rising performance of the liposome nanoparticle does not change significantly after multiple heating, which indicates that the liposome nanoparticle has good photo-thermal stability.
The absorption peaks of the nanoparticles were measured by scanning the absorption spectra of the Fe 3O4 solution, the IR-780 solution, the FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticle solution by an ultraviolet-visible spectrophotometer, and determining the maximum absorption peak at a specific wavelength to analyze the optical characteristics thereof. FIG. 7 is a graph showing absorbance measurements of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles and other particles, wherein the liposome nanoparticles have absorption peaks in the two-component absorption regions at the same time, indicating successful loading of each component.
(3) Magnetic distribution effect of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles.
Cell seeding will be performed and HepG2 cells will be seeded at the appropriate density in 10cm dishes and cultured in medium to 80% -90% confluency. In the magnetic treatment, a ring magnet is placed at the bottom of the culture dish to ensure the even distribution of the magnetic field. And finally, adding liposome nano particles (medicines) for treatment, namely adding a medicine solution containing the magnetic liposome nano particles into a culture dish, and ensuring that the liposome nano particles (medicines) cover cells and are influenced by a magnetic field. Cells were incubated at 37 ℃ in 5% CO2 for 24 hours, and after the incubation was completed, crystal violet staining was performed to observe the magnetic distribution effect of liposome nanoparticles (drugs). The specific procedure is as follows, after 24 hours incubation of the liposome nanoparticle (drug), the culture medium is discarded, the surface of the culture dish is gently rinsed with PBS buffer solution, and the procedure is repeated for a plurality of times until no color residue of the liposome nanoparticle (drug) is seen in the culture dish. Cells were then fixed with 4% paraformaldehyde for 10 min and then rinsed again with PBS. Then 1% crystal violet staining solution is added into a culture dish for staining for 10-15 minutes, so that cells are stained. And washing the culture dish with tap water or PBS to remove the excessive crystal violet staining solution until the staining solution is no longer flowing out. Finally, the cell distribution and survival were observed and recorded under a microscope, with particular attention to the cell survival of the liposome nanoparticle (drug) distribution region. FIG. 8 shows the experimental effect of magnetic distribution of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles, wherein in FIG. 8A, nanoparticles are added into a culture dish with a magnet adhered below for cell culture, in FIG. 8B, the nanoparticles are found to gather along magnetic lines of force of the magnet after the magnet is removed, in FIG. 8C, the culture medium is discarded and the nanoparticles are washed repeatedly by using pbs, which indicates that the nanoparticles are taken in a large amount by cells, in FIG. 8D, the tumor cell death in the region with the magnetic lines of force distribution of the magnet is obvious after crystal violet staining is shown.
(4) FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles with different concentrations and different power photo-thermal effects.
Liposome nanoparticles were configured as solutions of different concentrations (10, 30, 50. Mu.g/mL) and irradiated at laser powers of 0.6, 1.1, 1.7W/cm 2, respectively, with temperature changes recorded every 30s, and the photothermal effect was evaluated. Fig. 9-11 are graphs of photo-thermal effects of the FA-Lipo-Fe 3O4 -mir101@ir780 liposome nanoparticle (drug) with different concentrations at laser powers of 0.6W, 1.1W and 1.7W/cm 2, and as shown in fig. 9-11, the heating effect of the FA-Lipo-Fe 3O4 -mir101@ir780 liposome nanoparticle (drug) is remarkably improved along with the increase of the concentration and the laser power, and the photo-thermal effect is excellent.
(5) FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticle in vivo tumor inhibiting effect.
The in vivo tumor inhibition effect of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticle is tested by a. Inoculating HepG2 tumor cells in 96-well plates at a proper density, and inoculating 100 μl of cell suspension in culture medium per well to make each well contain about 8000 cells. The 96-well plates were placed in an incubator at 37 ℃ with 5% co until the cells grew adherent in the wells and reached a suitable state (typically about 24 hours). b. The nanoparticle drug was diluted according to a concentration gradient of 10, 20, 30, 50, 100 μg/mL. One set was formulated for each concentration. c. The medium was removed from the 96-well plate, and 100 μl of drug solution at different concentrations was added to each well to set a blank control group (without drug) and a negative control group (without cells). The 96-well plate was then returned to the incubator and incubation was continued for 24 hours. After d.24 hours, 10. Mu.L of CCK-8 reagent (cell count kit) was added to each well and gently mixed. Incubation in the incubator was continued for 1-4 hours until the liquid color in the wells changed significantly (from yellow to orange-red). e. The absorbance (OD value) of each well was measured at a wavelength of 450nm using an enzyme-labeled instrument, and the data was recorded. f. From the measured absorbance (OD value), the cell proliferation inhibition rate at each concentration was calculated. The calculation formula of the inhibition rate is as follows:
Survival (%) =1-inhibition (%).
G. The anti-tumor effect of the drug was evaluated by statistical analysis of the inhibition rate of different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposomal nanoparticle (drug) treatment groups, and a dose-response curve was drawn.
FIG. 12 shows the tumor cell viability at different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles (drug), and FIG. 13 shows the tumor cell inhibition at different concentrations of FA-Lipo-Fe 3O4 -Mir101@IR780 liposome nanoparticles (drug). As can be seen from fig. 12 and 13, the survival rate of tumor cells was significantly decreased with increasing drug concentration, and the drug had good antitumor effect.
The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.