Biomimetic nano-delivery system M@RCPDA nanoparticles for the treatment of idiopathic pulmonary fibrosis and preparation method thereof

Abstract

The present invention relates to a bionic nano delivery system M@RCPDA nanoparticle for treating idiopathic pulmonary fibrosis and a preparation method thereof, and belongs to the field of biomedical technology. The present invention synthesizes caffeine nanoparticles by alkaline oxidation method, drops rapamycin methanol solution to synthesize rapamycin caffeine polydopamine nanoparticles, adds macrophage membrane vesicle solution to mix, and repeatedly extrude with a liposome extruder to obtain M@RCPDA nanoparticles. The bionic nano delivery system M@RCPDA nanoparticles constructed by the present invention realize more efficient IPF targeted drug delivery, degrade deposited collagen, and restore the damaged lung tissue structure; develop macrophage bionic polydopamine nanoparticles M@RCPDA that jointly load RAPA and CA, and the combined administration of RAPA and CA is applied to the treatment of IPF and verifies the efficacy and potential synergistic effect of the combined application of the two, thereby improving the effect of the combined administration of RAPA and CA in treating IPF.

Description

Technical Field

[0001] The invention relates to a bionic nano delivery system M@RCPDA nanoparticle for treating idiopathic pulmonary fibrosis and a preparation method thereof, belonging to the technical field of biomedicine. Background Art

[0002] Idiopathic pulmonary fibrosis (IPF) has complex pathogenic factors and a short median survival. CA is an effective CTGF inhibitor and has been widely studied in liver fibrosis. It can inhibit CTGF expression in bleomycin-induced fibroblasts, but the effect of single CA treatment is not enough to reverse IPF; rapamycin (RAPA) is an autophagy activator and a mature anti-aging drug. It has shown the potential to reverse abnormal aging of fibroblasts and alleviate fibrosis in animal models, and has attracted great attention in fibrosis treatment research. However, in IPF-related studies, RAPA treatment has the shortcomings of single-target treatment. Although it inhibits fibroblast activation and proliferation in animal models, it fails to stop the progression of IPF. It is also accompanied by side effects such as systemic immunosuppression caused by long-term use.

[0003] Since the pathogenic mechanism of IPF involves complex interactions of signaling pathways, combined drug therapy has the potential to break through the dilemma of insufficient efficacy of RAPA. Due to the complex pathological environment of the lung physiological barrier and idiopathic pulmonary fibrosis, the drug concentration at the target site of traditional drugs or non-targeted preparations is low. The existing scheme can only target cardiac fibrosis and cannot achieve responsive release of drugs. A single drug cannot effectively treat pulmonary fibrosis. Therefore, achieving targeted drug delivery and controlled release in pulmonary fibrosis foci remains a key challenge in preclinical research. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a bionic nano-delivery system M@RCPDA nanoparticles for the treatment of idiopathic pulmonary fibrosis and a preparation method thereof. The bionic nano-delivery system is specifically a novel macrophage membrane bionic polydopamine nano-delivery system macrophage-modified polydopamine nanoparticles loaded with rapamycin and caffeine (M@RCPDA). The bionic nano-delivery system M@RCPDA carries and releases rapamycin (RAPA) and (CA) in the microenvironment rich in oxidative stress of IPF. Based on the inherent migration characteristics of macrophages and the oxidative stress-responsive release characteristics of polydopamine (PDA), M@RCPDA is targeted to accumulate in the IPF microenvironment dominated by oxidative stress and responsively releases the two drugs. The therapeutic effect of M@RCPDA on IPF is achieved based on the combined treatment of RAPA and CA. This dual-drug combined treatment strategy, through the potential synergistic effect of the two, ultimately provides a drug that can reverse IPF and expand the combined treatment of IPF.

[0005] The preparation method of the biomimetic nano-delivery system M@RCPDA nanoparticles for the treatment of idiopathic pulmonary fibrosis comprises the following specific steps:

[0006] (1) Synthesis of caffeine nanoparticles (CPDA) by alkaline oxidation method: dopamine hydrochloride (DA·HCl), caffeine (CA), and deionized water were mixed and stirred at room temperature for 0.5 h, and sodium hydroxide solution was slowly added. The mixture was stirred at 25-50 °C for 4-6 h to obtain caffeine nanoparticles (CPDA). The caffeine nanoparticles (CPDA) were centrifuged at 15000 rpm for 10 min, and the precipitate was resuspended in deionized water. The centrifugation was repeated until the supernatant was colorless. The precipitate was centrifuged at 4000 rpm for 5 min, and the supernatant was freeze-dried for storage.

[0007] (2) Synthesis of rapamycin caffeine polydopamine nanoparticles (RCPDA): Dissolve CPDA in deionized water, stir at 1000-1200 rpm, slowly drop rapamycin (RAPA) methanol solution with a concentration of 100-1000 μg / mL, continue stirring at room temperature until the methanol evaporates completely, then centrifuge to remove free RAPA to obtain RCPDA solution;

[0008] (3) Preparation of macrophage membrane vesicle solution from mouse mononuclear macrophage leukemia cells (RAW264.7): The macrophage membrane vesicle solution was prepared using mouse mononuclear macrophage leukemia cells by differential centrifugation;

[0009] (4) Preparation of M@RCPDA: Take the RCPDA solution synthesized in step (2) into a centrifuge tube, add the RAW264.7 macrophage membrane vesicle solution prepared in step (3), mix well, and use a liposome extruder with 400 nm and 200 nm polycarbonate microporous filter membranes to repeatedly extrude 5-10 times to obtain M@RCPDA nanoparticles.

[0010] Preferably, in step (1), the mass ratio of the amount of dopamine hydrochloride added to the amount of caffeine (CA) added is: 16-32:0.1-0.6; the mass volume ratio of the amount of dopamine hydrochloride added to the amount of deionized water added is 16-32:14, g / L; the concentration of sodium hydroxide is 64 μM, and the mass volume ratio of the amount of dopamine hydrochloride added to the amount of sodium hydroxide solution added is 16-32:2, g / L.

[0011] Preferably, in step (2), the mass volume ratio of CPDA to deionized water is 1:1, mg / mL.

[0012] Preferably, in step (2), the volume ratio of CPDA solution to RAPA methanol solution is 2:1, and the centrifugal speed is 4000 rpm.

[0013] Preferably, in step (4), the volume ratio of the RCPDA solution to the RAW264.7 macrophage membrane vesicle solution is 1-9:1.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The biomimetic nano-delivery system M@RCPDA nanoparticles constructed in the present invention achieves more efficient IPF targeted drug delivery, degrades deposited collagen, and restores the damaged lung tissue structure, thus demonstrating the potential for curing IPF.

[0016] (2) CA reduces the level of the key fibrosis factor TGF-β1 by inhibiting the overexpression of CTGF caused by RAPA treatment. The combined administration of RAPA and CA is used in the treatment of IPF to verify the efficacy and potential synergistic effect of the combined application of the two.

[0017] (3) Developed macrophage biomimetic polydopamine nanoparticles M@RCPDA that co-loaded RAPA and CA, creatively applied the inherent migration characteristics of CXCR4+ macrophages and the oxidative stress-responsive release characteristics of polydopamine (PDA), and in the process improved the traditional synthesis method of polydopamine to achieve the encapsulation of CA and RAPA, IPF targeting and responsive release. Ultimately, the effect of combined administration of RAPA and CA in the treatment of IPF was further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the polyacrylamide gel electrophoresis image of M@RCPDA;

[0019] Figure 2 Cumulative release curves of RAPA and CA in buffer systems containing or not containing 0.1 mM H2O2 (n = 3);

[0020] Figure 3 To study the lung targeting ability and biodistribution of M@RCPDA nanoparticles in vivo.

[0021] Figure 3 A is whole-body imaging at different time points after tail vein injection;

[0022] Figure 3 B is an in vitro fluorescence image of the main organs;

[0023] Figure 3 C is the in vitro fluorescence quantification of major organs (n=4);

[0024] Figure 4 The Masson staining images of the left posterior lobe lung tissue sections of each group of mice after drug administration, among which,

[0025] Figure 4 B is Figure 4 A detailed enlarged picture;

[0026] Figure 5 The Ashcroft score of lung tissue was obtained after administration.

[0027] Figure 6 is the lung collagen volume fraction of each group of mice after administration. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is described in detail below through specific implementation methods. It should be understood that the following specific implementation methods are only exemplary, and any changes or modifications should be within the scope of protection of the present invention as long as they do not deviate from the technical solution design of the present invention. The present invention is described in detail below in conjunction with examples.

[0029] Example 1

[0030] Preparation method of biomimetic nano-delivery system M@RCPDA nanoparticles for the treatment of idiopathic pulmonary fibrosis:

[0031] (1) Synthesis of caffeine nanoparticles (CPDA) by alkaline oxidation method: 16 mg of dopamine hydrochloride (DA·HCl), 100 μg of caffeine (CA), and 14 mL of deionized water were mixed and stirred at room temperature for 0.5 h, and 2 mL of 64 μM sodium hydroxide solution was slowly added. The mixture was stirred at 50 °C for 4 h to obtain caffeine nanoparticles (CPDA). The caffeine nanoparticles (CPDA) were centrifuged at 15,000 rpm for 10 min, the precipitate was resuspended in deionized water, and the centrifugation was repeated until the supernatant was colorless. The precipitate was centrifuged at 4,000 rpm for 5 min, and the supernatant was freeze-dried for storage;

[0032] (2) Synthesis of rapamycin caffeine polydopamine nanoparticles (RCPDA): CPDA was dissolved in deionized water to a concentration of 1 mg / mL. The mixture was stirred at 1000 rpm and slowly dripped with rapamycin (RAPA) methanol solution (100 μg / mL) at a volume ratio of 2:1. The mixture was stirred continuously at room temperature until the methanol was completely evaporated. The free RAPA was then removed by centrifugation at 4000 rpm to obtain the RCPDA solution.

[0033] (3) Preparation of RAW264.7 macrophage membrane vesicle solution: The macrophage membrane vesicle solution was prepared by differential centrifugation.

[0034] (4) Preparation of M@RCPDA: The RCPDA solution synthesized in step (2) was placed in a centrifuge tube, and the RAW264.7 macrophage membrane vesicle solution prepared in step (3) was added thereto. The RCPDA solution and the RAW264.7 macrophage membrane vesicle solution were mixed at a volume ratio of 1:1, and then the mixture was extruded 10 times using a liposome extruder with 400 nm and 200 nm polycarbonate microporous membranes, respectively, to obtain M@RCPDA nanoparticles.

[0035] Example 2

[0036] Preparation method of biomimetic nano-delivery system M@RCPDA nanoparticles for the treatment of idiopathic pulmonary fibrosis:

[0037] (1) Synthesis of caffeine nanoparticles (CPDA) by alkaline oxidation method: 24 mg of dopamine hydrochloride (DA·HCl), 400 μg of caffeine (CA), and 14 mL of deionized water were mixed and stirred at room temperature for 0.5 h, and 2 mL of 64 μM sodium hydroxide solution was slowly added. The mixture was stirred at 50 °C for 5 h to obtain caffeine nanoparticles (CPDA). The caffeine nanoparticles (CPDA) were centrifuged at 15,000 rpm for 10 min, the precipitate was resuspended in deionized water, and the centrifugation was repeated until the supernatant was colorless. The precipitate was centrifuged at 4,000 rpm for 5 min, and the supernatant was freeze-dried for storage;

[0038] (2) Synthesis of rapamycin caffeine polydopamine nanoparticles (RCPDA): CPDA was dissolved in deionized water to a concentration of 1 mg / mL. The mixture was stirred at 1000 rpm and slowly dripped with rapamycin (RAPA) methanol solution (500 μg / mL) at a volume ratio of 2:1. The mixture was stirred continuously at room temperature until the methanol was completely evaporated. The free RAPA was then removed by centrifugation at 4000 rpm to obtain the RCPDA solution.

[0039] (3) Preparation of RAW264.7 macrophage membrane vesicle solution: The macrophage membrane vesicle solution was prepared by differential centrifugation.

[0040] (4) Preparation of M@RCPDA: The RCPDA solution synthesized in step (2) was placed in a centrifuge tube, and the RAW264.7 macrophage membrane vesicle solution prepared in step (3) was added thereto. The RCPDA solution and the RAW264.7 macrophage membrane vesicle solution were mixed at a volume ratio of 2:1, and then extruded five times using a liposome extruder with 400 nm and 200 nm polycarbonate microporous membranes to obtain M@RCPDA nanoparticles.

[0041] Example 3

[0042] Preparation method of biomimetic nano-delivery system M@RCPDA nanoparticles for the treatment of idiopathic pulmonary fibrosis:

[0043] (1) Synthesis of caffeine nanoparticles (CPDA) by alkaline oxidation method: 24 mg of dopamine hydrochloride (DA·HCl), 600 μg of caffeine (CA), and 14 mL of deionized water were mixed and stirred at room temperature for 0.5 h, and 2 mL of 64 μM sodium hydroxide solution was slowly added. The mixture was stirred at 25 °C for 6 h to obtain caffeine nanoparticles (CPDA). The caffeine nanoparticles (CPDA) were centrifuged at 15,000 rpm for 10 min, the precipitate was resuspended in deionized water, and the centrifugation was repeated until the supernatant was colorless. The precipitate was centrifuged at 4,000 rpm for 5 min, and the supernatant was freeze-dried for storage;

[0044] (2) Synthesis of rapamycin caffeine polydopamine nanoparticles (RCPDA): CPDA was dissolved in deionized water to a concentration of 1 mg / mL. The mixture was stirred at 1200 rpm and slowly dripped with rapamycin (RAPA) methanol solution (1000 μg / mL) at a volume ratio of 2:1. The mixture was stirred continuously at room temperature until the methanol was completely evaporated. The free RAPA was then removed by centrifugation at 4000 rpm to obtain the RCPDA solution.

[0045] (3) Preparation of RAW264.7 macrophage membrane vesicle solution: The macrophage membrane vesicle solution was prepared by differential centrifugation.

[0046] (4) Preparation of M@RCPDA: The RCPDA solution synthesized in step (2) was placed in a centrifuge tube, and the RAW264.7 macrophage membrane vesicle solution prepared in step (3) was added thereto. The RCPDA solution and the RAW264.7 macrophage membrane vesicle solution were mixed at a volume ratio of 9:1, and then extruded eight times using a liposome extruder with 400 nm and 200 nm polycarbonate microporous membranes to obtain M@RCPDA nanoparticles.

[0047] Test Example 1

[0048] Complete inheritance of membrane protein components of M@RCPDA

[0049] like Figure 1 As shown, the SDS-PAGE image shows that there is no protein component on the surface of RCPDA before cell membrane modification, while the protein bands of M@RCPDA surface membrane protein are similar to those of macrophage membrane protein, proving that almost all protein components of the macrophage membrane are completely inherited on the M@RCPDA nanoparticles. The M@RCPDA protein band is lighter, which may be due to the loss when passing through the filter membrane during the preparation process.

[0050] Test Example 2

[0051] M@RCPDA nanoparticles release CA and RAPA in response to H2O2 concentrations in oxidative stress environment of pulmonary fibrosis

[0052] The results of in vitro release experiments showed that M@RCPDA nanoparticles released CA and RAPA in response to H2O2 at the oxidative stress concentration of pulmonary fibrosis. This preliminarily proves that M@RCPDA nanoparticles can increase the drug concentration in pulmonary fibrosis tissue and reduce the drug concentration in normal tissue, thereby improving the IPF treatment effect of dual-drug combination therapy.

[0053] like Figure 2 As shown in the figure, consistent with the long in vivo clearance time of polydopamine nanoparticles, M@RCPDA nanoparticles released slowly in an environment without hydrogen peroxide (H2O2) (PBS solution containing 0.5% Tween 80, pH 7.4). Within 48 hours of the dosing interval, the cumulative release rate of CA was 13.3±0.9%, and the cumulative release rate of RAPA was 15.5±0.9%, ensuring the stability of the nanoparticles before reaching the target site. In the release medium simulating the pulmonary fibrosis environment (PBS solution containing 0.1 mM H2O2 and 0.5% Tween 80, pH 7.4), the cumulative release rate of CA of M@RCPDA nanoparticles within 48 hours was 86.7±3.6%, and the cumulative release rate of RAPA was 94.4±2.5%.

[0054] Test Example 3

[0055] Real-time in vivo imaging and drug distribution in isolated organs of IPF mice

[0056] In order to evaluate the lung fibrosis targeting efficiency of M@RCPDA and further explain the effect of macrophage membrane modification on the biodistribution of nanoparticles, a fluorescence distribution experiment was performed using a small animal in vivo imaging analyzer. The groups were set up: DiR-CPDA and DiR-M@CPDA, which were injected into the tail vein of pulmonary fibrosis model mice, and the in vivo imaging system was used to observe and quantify the fluorescence distribution.

[0057] like Figure 3As shown in the figure, compared with the unmodified DiR-CPDA, the macrophage membrane-modified DiR-M@CPDA reduced the accumulation of DiR-M@CPDA in the liver and increased the accumulation in the lungs at different time periods after administration: 1, 2, 4, 6, 12, and 24 hours. In order to further observe the fluorescence distribution of the preparation in various organs after administration, the mice were immediately killed after 24 hours of filming, and the main organs (heart, liver, spleen, lung, and kidney) were removed for quantitative fluorescence intensity of the main organs in the ex vivo imaging experiment. Corresponding to the in vivo fluorescence distribution, the quantitative results of fluorescence intensity of each organ in vitro also showed that compared with the DiR-@RCPDA group, the fluorescence intensity of the lungs in the modified DiR-M@RCPDA group increased (the fluorescence intensity of the lungs was 5.3 times higher than that of the unmodified nanoparticle group), and it was found that the distribution of the drug in the liver was significantly less than that of the unmodified DiR-CPDA group. Therefore, based on the above results. Combined with the results of in vivo imaging experiments, it can be shown that the preparation has good lung targeting ability, and macrophage membrane modification can greatly increase the distribution of nanoparticles in the lungs while reducing drug distribution in other organs, especially the liver.

[0058] The results of the in vivo biodistribution experiment combined with the results of the in vitro release experiment show that M@RCPDA nanoparticles can specifically target the lungs. M@RCPDA nanoparticles specifically target the lungs and respond to the high concentration of hydrogen peroxide in the pulmonary fibrosis environment to release drugs, thereby increasing the drug concentration in the fibrosis lesions and reducing the distribution of drugs in normal organ tissues. Therefore, it can be expected that the lung targeting ability of M@RCPDA nanoparticles and the oxidative stress response release are conducive to improving the treatment of pulmonary fibrosis and reducing the systemic side effects of drugs, especially the potential systemic immunosuppression risk of rapamycin.

[0059] Test Example 4

[0060] Masson staining sections were used to evaluate the lung collagen deposition and lung tissue structure recovery of mice in each group after drug administration. The experimental groups were bleomycin + PBS solution (BLM + PBS), bleomycin + free caffeine (BLM + free CA), bleomycin + free rapamycin (BLM + free RAPA), bleomycin + free combination drug (BLM + free combo), bleomycin + RCPDA nanoparticles (BLM + RCPDA), bleomycin + M@RCPDA nanoparticles (BLM + M@RCPDA), and healthy control group (Control). The results are shown in Figure 4As shown in A and B, after the experiment, the untreated control group (BLM+PBS) still had a large amount of lung consolidation and blue collagen deposition, as well as large areas of alveolar thickening and fusion. In comparison, the dual-drug treatment in the BLM+free combo group reduced the area of ​​blue collagen deposition (pulmonary fibrosis foci) in the mouse lung tissue, reduced lung septal thickening and cell aggregation, and restored the lung tissue structure. This reduced the lesions in the mouse lung tissue, reduced collagen production, and degraded collagen deposition, thus enhancing the therapeutic effect of IPF.

[0061] In addition, compared with other treatment groups, the lung tissue lesions of mice in the preparation group were alleviated, collagen production was reduced, and collagen deposition was degraded, approaching the level of healthy mice. The specific results are as follows: Figure 5 and Figure 6 As shown in the figure, compared with other treatment groups, the blue collagen deposition in the preparation (BLM+M@RCPDA) group was reduced, there was no lung consolidation area, and the alveolar structure was slightly thickened, indicating that M@RCPDA significantly reduced fibrosis and promoted the recovery of lung tissue structure. This shows that the preparation M@RCPDA modified with macrophage membrane can better reduce collagen deposition and restore lung structure.

[0062] Test Example 5

[0063] Quantitative analysis of collagen evaluation indicators such as CVF, α-SMA, HYP, etc.

[0064] To further quantify collagen deposition and pathological changes in lung tissue, the blue collagen area was separated and the CVF of mice was calculated by Masson staining section analysis. Figure 6 The results showed that compared with the dual-drug combination treatment group and the unmodified dual-drug nanoparticle treatment group, the CVF of the BLM+M@RCPDA group was significantly reduced, indicating that the M@RCPDA modified with macrophage membrane significantly reduced the collagen deposition area and normalized the lung tissue structure; the CVF% of the BLM+CA group and the BLM+RAPA group was higher than that of the BLM+free combo group (P<0.01), which shows that the dual-drug combination treatment can significantly reduce collagen deposition compared with single drug treatment.

[0065] The changes in tissue pathological structure were expressed using the Ashcroft score, such as Figure 5 As shown, the Ashcroft score of the BLM+free combo group was significantly reduced compared with the single drug treatment group, indicating that the dual-drug combination treatment significantly normalized the lung tissue structure. Compared with the dual-drug combination treatment group, the Ashcroft score of the preparation (BLM+M@RCPDA) group was significantly reduced (P<0.0001). The Ashcroft score of the BLM+RCPDA group was significantly different from that of the unmodified dual-drug nanoparticle (BLM+RCPDA) treatment group (P<0.0001).

[0066] comprehensive Figure 4 , Figure 5 , Figure 6 The results showed that the quantitative results were consistent with the results directly shown in the slices. M@RCPDA significantly reduced fibrosis foci, reduced alveolar thickening and fusion, and promoted the recovery of lung structure. This further demonstrated that macrophage membrane-modified M@RCPDA can significantly reduce collagen deposition and restore lung tissue structure.

[0067] After confirming that M@RCPDA can significantly reduce collagen deposition, it is necessary to further quantify the level of collagen secretion, so the results of α-SMA immunohistochemical staining were quantified. Figure 3 As shown, although there was a significant difference in α-SMA in the BLM+M@RCPDA group compared with the healthy control group (P<0.05), and the collagen secretion in the BLM+M@RCPDA group had not yet returned to normal levels, the α-SMA content in the BLM+M@RCPDA group was significantly reduced compared with the other treatment groups.

Claims

1. A method for preparing a biomimetic nano-delivery system M@RCPDA nanoparticle for the treatment of idiopathic pulmonary fibrosis, characterized in that: The steps of the preparation method are as follows: (1) Synthesis of caffeine nanoparticles (CPDA) by alkaline oxidation method: dopamine hydrochloride (DA·HCl), caffeine (CA), and deionized water were mixed and stirred at room temperature for 0.5 h, and sodium hydroxide solution was slowly added. The mixture was stirred at 25-50 °C for 4-6 h to obtain caffeine nanoparticles (CPDA). The mixture was centrifuged at 15,000 rpm for 10 min, and the precipitate was resuspended in deionized water. The centrifugation was repeated until the supernatant was colorless. The precipitate was centrifuged at 4,000 rpm for 5 min, and the supernatant was freeze-dried for storage. (2) Synthesis of rapamycin caffeine polydopamine nanoparticles (RCPDA): Dissolve CPDA in deionized water, stir at 1000-1200 rpm, slowly drop rapamycin (RAPA) methanol solution with a concentration of 100-1000 μg / mL, continue stirring at room temperature until the methanol evaporates completely, then centrifuge to remove free RAPA to obtain RCPDA solution; (3) Preparation of macrophage membrane vesicle solution from mouse mononuclear macrophage leukemia cells (RAW264.7): The macrophage membrane vesicle solution was prepared using mouse mononuclear macrophage leukemia cells by differential centrifugation; (4) Preparation of M@RCPDA: Take the RCPDA solution synthesized in step (2) into a centrifuge tube, add the RAW264.7 macrophage membrane vesicle solution prepared in step (3), mix well, and use a liposome extruder with 400 nm and 200 nm polycarbonate microporous filter membranes to repeatedly extrude 5-10 times to obtain M@RCPDA nanoparticles.

2. The preparation method according to claim 1, characterized in that: In the step (1), the mass ratio of the amount of dopamine hydrochloride added to the amount of caffeine (CA) added is: 16-32:0.1-0.

6.

3. The preparation method according to claim 1, characterized in that: The mass volume ratio of the added amount of dopamine hydrochloride to the added amount of deionized water is 16-32:14, g / L.

4. The preparation method according to claim 1, characterized in that The concentration of sodium hydroxide was 64 μM, and the mass volume ratio of the added amount of dopamine hydrochloride to the added amount of sodium hydroxide solution was 16-32:2, g / L.

5. The preparation method according to claim 1, characterized in that: In the step (2), the mass volume ratio of CPDA to deionized water is 1:1, mg / mL.

6. The preparation method according to claim 1, characterized in that: In the step (2), the volume ratio of the CPDA solution to the RAPA methanol solution is 2:

1.

7. The preparation method according to claim 1, characterized in that The centrifugal speed in step (2) is 4000 rpm.

8. The preparation method according to claim 1, characterized in that: In the step (4), the volume ratio of the RCPDA solution to the RAW264.7 macrophage membrane vesicle solution is 1-9:

1. 9 . The biomimetic nano delivery system M@RCPDA nanoparticles for treating idiopathic pulmonary fibrosis obtained by the preparation method according to any one of claims 1 to 8 .

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