Neutrophil-targeted delivery nanoparticles, methods of making and using the same

Abstract

The present application belongs to the technical field of targeted drug research and development, and particularly relates to a neutrophil-targeted delivery nanoparticle, a preparation method thereof and application thereof in postoperative treatment of tumors. The present application designs a neutrophil-targeted delivery nanoparticle which can target neutrophils in situ in blood, and can overcome the complicated neutrophil extraction, drug loading and reinfusion processes of non-in situ targeting. Meanwhile, the acute inflammatory environment of the postoperative site of tumors can recruit a large number of neutrophils to gather, which provides a strong guarantee for efficient targeted drug delivery. On this basis, the combined delivery of the chemotherapeutic drug doxorubicin and the STING agonist SR-717 can play a role in chemotherapy on one hand; on the other hand, the anti-tumor immune response activated by chemotherapy-induced ICD combined with the immune response activated by the STING agonist can effectively inhibit the postoperative recurrence and metastasis of tumors through the immunotherapy pathway.

Description

Technical Field

[0001] This invention belongs to the field of targeted drug development technology, specifically relating to a nanoparticle for targeted delivery via neutrophils, its preparation method, and its application in postoperative tumor treatment. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Chemotherapy is an important treatment for inhibiting postoperative recurrence and metastasis of tumors, but it still suffers from problems such as poor biocompatibility, poor targeting, and severe side effects. Therefore, there is an urgent need to develop a delivery strategy that can target the postoperative tumor site and increase the drug accumulation at the tumor site. Biofouling polymer modification, biomimetic techniques, and live cell hitchhiking are three common strategies to improve drug delivery efficiency. Among them, live cell hitchhiking has lower immunogenicity and biotoxicity, and has therefore gained popularity among researchers in recent years. Acute inflammation after tumor surgery is a prominent feature of the postoperative site, which can recruit a large number of neutrophils to the postoperative site. Therefore, neutrophils are an ideal tool for postoperative site drug delivery. In past studies, researchers have usually extracted neutrophils, loaded drug molecules in vitro, and then reinfused them into the body. However, this strategy has disadvantages such as difficulty in neutrophil isolation, short lifespan, and complex drug loading process. Compared with in vitro targeting strategies, in situ targeting of neutrophils in the blood can effectively avoid the above problems and is more promising.

[0004] While chemotherapy alone has shown some effectiveness in suppressing tumor recurrence and metastasis, it is often accompanied by problems such as drug resistance, leading to ultimately poor treatment outcomes. Immunotherapy, a novel cancer treatment approach developed in recent years, has demonstrated promising prospects in suppressing tumor recurrence and metastasis. Chemotherapy drugs delivered to the tumor site (such as doxorubicin DOX) can, on the one hand, enter the cell nucleus to directly kill tumor cells and inhibit tumor growth; on the other hand, they can induce immunogenic cell death (ICD), thereby activating an anti-tumor immune response. However, the anti-tumor immune response activated solely by ICD is insufficient to effectively suppress tumor recurrence and metastasis. Therefore, it is often combined with other adjuvants to further activate and amplify the anti-tumor immune response, achieving the ideal therapeutic effect of chemotherapy-immunotherapy combination therapy. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a neutrophil-targeted delivery nanoparticle and its preparation method. This invention can effectively encapsulate both hydrophilic and hydrophobic drugs, exhibiting good versatility and scalability; the prepared neutrophil-targeted delivery nanoparticle shows promising application prospects in postoperative tumor treatment.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing nanoparticles for targeted delivery via neutrophils, comprising the following steps:

[0008] Phospholipid molecules were formulated into a chloroform solution, rotary evaporated to form a membrane, dried, hydrated, dialyzed, and homogenized to obtain blank liposomes. Then, drug loading and purification were performed, and surface-targeting molecules were modified using avidin to finally obtain nanoparticles for neutrophil-targeted delivery.

[0009] In a second aspect, the present invention provides a neutrophil-targeted delivery nanoparticle, which is obtained by the preparation method of the neutrophil-targeted delivery nanoparticle as described in the first aspect.

[0010] Thirdly, the present invention provides the application of neutrophil-targeted delivery nanoparticles as described in the second aspect in the preparation of postoperative tumor treatment drugs.

[0011] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0012] 1. This invention fully utilizes the inflammatory environment at the tumor postoperative site and the anti-inflammatory properties of neutrophils to develop a nano-delivery system that leverages neutrophils to improve the efficiency of targeted drug delivery at the postoperative site.

[0013] 2. This invention develops a loading strategy for directly targeting neutrophils in the blood. Compared with the traditional in vitro loading and reinfusion strategy, this strategy can effectively avoid complex steps such as neutrophil separation and drug loading, and can also overcome the disadvantage of short in vitro lifespan of neutrophils, making it more practical.

[0014] 3. This invention achieves combined chemotherapy-immunotherapy for tumors by delivering chemotherapy drugs and STING agonists at the postoperative site of tumor surgery, which can effectively inhibit postoperative recurrence and metastasis of tumors. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 This is a schematic diagram of the structure of TLipD in Example 1 and TLipS in Example 2;

[0017] Figure 2 (a) shows the particle size distribution of LipD, TLipD, LipS and TLipS obtained by dynamic light scattering; (b) shows the Zeta potential of LipD, TLipD, LipS and TLipS; (c) shows the cryo-transmission electron microscopy characterization of TLipD; (d) shows the cryo-transmission electron microscopy characterization of TLipS.

[0018] Figure 3 (a) shows the confocal microscopy results of LipD and TLipD after co-incubation with neutrophils; (b) shows the flow cytometry results of LipD and TLipD after co-incubation with neutrophils for 1 h and 4 h; (c) shows the statistical graph of the average fluorescence intensity of LipD and TLipD after co-incubation with neutrophils for 1 h and 4 h.

[0019] Figure 4 (a) shows the enrichment of LipICG and TLipICG in tumor tissue at different time points after tail vein injection; (b) shows the statistical graph of the average fluorescence intensity of LipICG and TLipICG in tumor tissue at different time points.

[0020] Figure 5 (a) shows the cell viability of TLipD, TLipS, and TLipDS; (b) shows the cell live / dead staining results of TLipD, TLipS, and TLipDS.

[0021] Figure 6 (a) shows the CRT staining results of cells in PBS (control group), TLipD, TLipS, and TLipDS; (b) shows the statistical graph of the average fluorescence intensity of CRT in PBS (control group), TLipD, TLipS, and TLipDS; (c) shows the statistical results of HMGB1 release in PBS (control group), TLipD, TLipS, and TLipDS.

[0022] Figure 7 (a) shows the DC maturation results of the PBS (control group), TLipD, TLipS, and TLipDS groups; (b) shows the IL-6 release results of the PBS (control group), TLipD, TLipS, and TLipDS groups; (c) shows the TNF-α release results of the PBS (control group), TLipD, TLipS, and TLipDS groups.

[0023] Figure 8(a) shows the results of tumor treatment after surgery in mice in the PBS, TLipD, TLipS, LipDS and TLipDS groups; (b) shows the statistical graph of tumor quality after surgery in mice in the PBS, TLipD, TLipS, LipDS and TLipDS groups.

[0024] Figure 9 (a) shows the establishment of the lung metastasis model and the lung metastasis inhibition pattern; (b) shows the lung metastasis status of the PBS, TLipD, TLipS, LipDS and TLipDS groups; (c) shows lung sections and H&E staining images of the PBS, TLipD, TLipS, LipDS and TLipDS groups; (d) shows the lung metastasis count statistics of the PBS, TLipD, TLipS, LipDS and TLipDS groups; (e) shows the mouse survival curves of the PBS, TLipD, TLipS, LipDS and TLipDS groups. Detailed Implementation

[0025] A first specific embodiment of the present invention provides a method for preparing nanoparticles for targeted delivery via neutrophils, comprising the following steps:

[0026] Phospholipid molecules were formulated into a chloroform solution, rotary evaporated to form a membrane, dried, hydrated, dialyzed, and homogenized to obtain blank liposomes. Then, drug loading and purification were performed, and surface-targeting molecules were modified using avidin to finally obtain nanoparticles for neutrophil-targeted delivery.

[0027] In one or more embodiments of this implementation, the phospholipid molecules include hydrogenated soybean lecithin, cholesterol, and 1,2-distearyl-sn-glycerol-3-phosphate ethanolamine-poly(ethylene glycol)-biotin; the molar ratio of hydrogenated soybean lecithin, cholesterol, and 1,2-distearyl-sn-glycerol-3-phosphate ethanolamine-poly(ethylene glycol)-biotin is 55-59:35-40:1-10.

[0028] In one or more embodiments of this implementation, the rotary evaporation temperature is 40-60℃ and the time is 20-40 min; the drying is vacuum drying and the drying time is 12-24 h.

[0029] In one or more embodiments of this implementation, the hydration medium includes an aqueous solution of ammonium sulfate with a concentration of 0.2-0.4M, a hydration temperature of 50-70°C, and a hydration time of 20-40 minutes.

[0030] In one or more embodiments of this implementation, the dialysate includes a PBS buffer solution, and the dialysate time is 6-18 hours.

[0031] In one or more embodiments of this implementation, the homogenization pressure is 10,000-20,000 kpsi, and the number of homogenization cycles is 4-8.

[0032] In one or more embodiments of this implementation, the drug comprises doxorubicin or the STING agonist SR-717, and the mass of the drug is 10-20% of the mass of the blank liposome.

[0033] In one or more embodiments of this implementation, the purification is carried out by high-speed centrifugation at a speed of 40,000-60,000 g for 30-60 min.

[0034] In one or more embodiments of this implementation, the surface-targeting molecule includes an anti-Ly6G antibody, the avidin includes avidin, the avidin mass is 5-15% of the liposome mass, and the antibody mass is 20-30% of the avidin mass.

[0035] In a second embodiment of the present invention, a neutrophil-targeted delivery nanoparticle is obtained by the preparation method of the neutrophil-targeted delivery nanoparticle as described in the first embodiment.

[0036] The third embodiment of the present invention is the application of neutrophil-targeted delivery nanoparticles, as described in the second embodiment, in the preparation of postoperative tumor treatment drugs.

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0038] Abbreviations for terms:

[0039] Tumor immunogenic death, abbreviated as ICD;

[0040] Soy hydrogenated lecithin, abbreviated as HSPC;

[0041] Cholesterol, abbreviated as Chol;

[0042] 1,2-Distearyl-sn-glycerol-3-phosphate ethanolamine-poly(ethylene glycol)-biotin, abbreviated as: DSPE-PEG2000-Biotin;

[0043] Doxorubicin, abbreviated as DOX;

[0044] Phosphate buffer solution, abbreviated as PBS;

[0045] Interferon gene stimulating factor, abbreviated as STING;

[0046] Doxorubicin-loaded non-targeted liposome nanoparticles, abbreviated as LipD;

[0047] SR-717-loaded non-targeted liposome nanoparticles, abbreviated as LipS;

[0048] Doxorubicin-loaded neutrophil-targeting liposome nanoparticles, abbreviated as TLipD;

[0049] SR-717 loaded with neutrophil-targeting liposome nanoparticles, abbreviated as: TLipS;

[0050] Cryo-transmission electron microscopy, abbreviated as cryo-TEM.

[0051] Example 1

[0052] Preparation of LipD and TLIPD particles

[0053] Weigh out HSPC (75 mg), Chol (25 mg), and DSPE-PEG2000-Biotin (27 mg) respectively, and dissolve them thoroughly in 20 mL of chloroform. Remove the chloroform by rotary evaporation at 50 °C, forming a complete phospholipid molecular film on the flask wall. Dry under vacuum at room temperature for 12 h. Add 10 mL of ammonium sulfate solution (0.3 M) and hydrate at 60 °C for 30 min. Then homogenize by high pressure 4-8 times and dialyze in PBS buffer (10 mM, pH 7.4) for 24 h. Weigh out DOX (15 mg), dissolve it in 2 mL of pure water, and add it to the dialyzed blank liposome solution. Hydrate at 60 °C for 40 min. Then centrifuge at high speed (50000 g, 40 min) to remove unencapsulated DOX, obtaining LipD.

[0054] Take 10 mg of LipD particles, add 1 mg of avidin, react overnight at 4°C, and centrifuge to remove unreacted avidin. Take 0.2 mg of anti-Ly6G antibody, add it to the purified liposome nanoparticles, react overnight at 4°C, and purify by high-speed centrifugation to obtain TLipD.

[0055] Example 2

[0056] Preparation of LipS and TLIPS particles

[0057] Weigh out HSPC (75 mg), Chol (15 mg), DSPE-PEG2000-Biotin (27 mg), and SR-717 (15 mg) separately and add them to a mixed solution of 15 mL chloroform and 15 mL methanol, dissolving thoroughly. Remove chloroform by rotary evaporation at 50 °C, forming a complete phospholipid molecular film on the flask wall. Dry under vacuum at room temperature for 12 h. Add 10 mL of PBS buffer solution (10 mM, pH 7.4) and hydrate at 60 °C for 30 min. Then homogenize 4-8 times under high pressure and centrifuge at high speed (50000 g, 40 min) to remove unencapsulated SR-717, obtaining LipS.

[0058] Take 10 mg of LipS particles, add 1 mg of avidin, react overnight at 4°C, and centrifuge to remove unreacted avidin. Take 0.2 mg of anti-Ly6G antibody, add it to the purified liposome nanoparticles, react overnight at 4°C, and purify by high-speed centrifugation to obtain TLipS.

[0059] Experimental Example 1

[0060] LipD, TLipD, LipS, and TLipS characterization

[0061] The structural diagrams of TLipD and TLipS are shown below. Figure 1 As shown. First, dynamic light scattering technique was used to characterize the four particle sizes obtained. For example... Figure 2 As shown in a, the sizes of all four particles are around 150 nm, and the modification with the targeting molecule has no significant effect on the particle size. The Zeta potentials of the four particles were then characterized, as shown in Figure a. Figure 2 As shown in b, the Zeta potentials of LipD and TLipD are around -18 mV, while that of LipS is around -14 mV. After modification with the targeting molecule, the potential drops to around -20 mV. The morphology of the liposome nanoparticles was further characterized using cryo-TEM. Figure 2 c and Figure 2 As can be seen from 'd', the prepared liposomes have a spherical structure with a size of approximately 120 nm. The size obtained from dynamic light scattering is slightly larger than that obtained from electron microscopy, which is due to the hydration of PEG molecules on the liposome surface. In addition, doxorubicin formed rod-shaped crystals within the liposomes.

[0062] Experimental Example 2

[0063] In vitro cell targeting

[0064] Mouse neutrophils were extracted from blood using a mouse peripheral blood neutrophil extraction kit. The neutrophils were then co-incubated with TLipD and LipD, respectively. Neutrophils were labeled with Ly6G-FITC antibody, and the nuclei were labeled with Hoechst. Figure 3 As shown in Figure a, confocal microscopy revealed that the DOX signal in neutrophils was significantly higher than that in other white blood cells in the TLipD group. In the LipD group, the DOX signal in other white blood cells was higher than that in neutrophils. To further quantitatively evaluate the targeting of liposomal nanomedicines, neutrophils were co-incubated with TLipD and LipD for 1 h and 4 h, respectively, to remove unbound nanomedicines, followed by quantitative characterization by flow cytometry. The flow cytometry results showed that the fluorescence signal of the targeted liposomal nanomedicine was higher than that of the non-targeted group, and the interaction became increasingly stronger with prolonged exposure time. Figure 3 (b, c) The results of laser confocal microscopy and flow cytometry, respectively, demonstrated the good targeting ability of TLipD to neutrophils from both qualitative and quantitative perspectives.

[0065] Experimental Example 3

[0066] Postoperative targeted therapy for tumors in vivo

[0067] Preparation of LipICG and TLIPICG particles

[0068] Weigh out HSPC (75 mg), Chol (15 mg), DSPE-PEG2000-Biotin (27 mg), and ICG (0.1 mg) separately and add them to a mixture of 15 mL chloroform and 15 mL methanol, dissolving thoroughly. Remove chloroform by rotary evaporation at 50 °C, forming a complete phospholipid molecular film on the flask wall. Dry under vacuum at room temperature for 12 h. Add 10 mL of PBS buffer solution (10 mM, pH 7.4) and hydrate at 60 °C for 30 min. Then homogenize 4-8 times under high pressure and centrifuge at high speed (50000 g, 40 min) to remove unencapsulated ICG, obtaining LipICG.

[0069] Take 10 mg of LipICG particles, add 1 mg of avidin, react overnight at 4°C, and centrifuge to remove unreacted avidin. Take 0.2 mg of anti-Ly6G antibody, add it to the purified liposome nanoparticles, react overnight at 4°C, and purify by high-speed centrifugation to obtain TLipICG.

[0070] To further demonstrate the in vivo postoperative targeting performance of TLipD, a melanoma postoperative model was established in C57 mice. Four hours postoperatively, TLipICG and LipICG were injected via the tail vein, and their accumulation at the tumor site was observed using small animal in vivo imaging. Figure 4 The α-image results show that the fluorescence signal intensity of the targeted group was higher than that of the non-targeted group at all time points. This indicates that the targeted nanoparticles have good targeting ability to the tumor postoperative site. Furthermore, as... Figure 4 As shown in b, for the non-targeted nanoparticles, the fluorescence intensity at the tumor site gradually decreased after 12 hours. The fluorescence intensity of the targeted nanoparticles remained constant, indicating that the targeted nanoparticles have a long-term accumulation characteristic at the tumor site, which is of great significance for inhibiting tumor recurrence.

[0071] Experiment Example 4

[0072] In vitro cytotoxicity

[0073] The cytotoxicity of neutrophil-targeting liposome nanoparticles was evaluated using an MTT assay. Figure 5 As shown in Figure 'a', SR-717 did not have a significant killing effect on tumor cells; at 20 μg / mL, the cell viability remained above 95%. TLipD, on the other hand, showed a significant killing effect on melanoma cells, with an IC50 of 8.8 μg / mL. The cytotoxicity of the combined treatment group (TLipDS) was essentially the same as that of the TLipD group alone. Cell viability staining experiments further validated these results; compared to the PBS and TLipDS groups, the experimental group containing DOX showed a significant cell death signal. Figure 5 (b)

[0074] Experimental Example 5

[0075] Cellular immunogenic death

[0076] While DOX enters the cell nucleus to kill tumor cells and exert its chemotherapeutic effect, it can also induce the production of ICDs, thereby activating an anti-tumor immune response. During ICD production, CRT proteins are specifically expressed on the cell membrane surface. Anti-CRT-FITC antibodies are used to label the CRTs on the cell surface, such as... Figure 6 As shown in a, the confocal results indicate that the DOX treatment group exhibited significant green fluorescence, while the PBS and TLIPS groups showed no significant fluorescence. Figure 6 As shown in b, the flow cytometry quantitative characterization results showed that the CRT fluorescence signal intensity in the DOX-containing treatment group was approximately 1.3 times that of the PBS and TLipS groups, while there was no significant difference between the TLipD and TLipDS groups. The ICD phenomenon is accompanied by the release of HMGB1; therefore, the released HMGB1 was quantitatively measured using an ELISA kit. Figure 6As shown in c, there was no significant difference between the TLipD and TLipDS groups, and the difference was approximately twice that of the PBS combined with the TLipS group. The results of CRT and HMGB1 both indicate that the DOX-containing treatment group can effectively induce ICD, which provides a good foundation for subsequent specific immunotherapy.

[0077] Experimental Example 6

[0078] DC cell activation

[0079] To investigate the activation of dendritic cells (DCs), progenitor DCs were extracted from mouse bone marrow, stimulated for 7 days, and then co-incubated with tumor cell culture supernatant. The surface of the DCs was then labeled with CD11c, CD80, and CD86. Figure 7 As shown in Figure a, flow cytometry analysis results indicate that the TLipDS group exhibited the highest degree of DC maturation. Compared to the PBS group, both the TLipD and TLipS groups demonstrated some degree of DC activation. This suggests that DOX-induced ICD-produced substances such as CRT and HMGB1 effectively promote DC maturation, and SR-717 can also promote DC maturation by activating the STING pathway within DC cells. Figure 7 b in Figure 7 As shown in c, the ELISA results show that the marker factors IL-6 and TNF-α released during DC cell maturation are consistent with the trend of DC maturation, further illustrating that DC cells can be effectively activated through the ICD and STING pathways, thereby activating related T cells and improving the efficacy of tumor immunotherapy.

[0080] Experimental Example 7

[0081] Postoperative recurrence prevention

[0082] A post-operative melanoma model was established in C57 mice, and the mice were injected with PBS, TLipD, TLipS, LipDS, and TLipDS, respectively. Figure 8 As shown in Figure a, the tumor growth curves in mice show that the TLipDS group effectively inhibited melanoma recurrence compared to the LipDS group. This is mainly because the modification of the targeting molecule can increase the accumulation and retention time of the drug at the tumor site, thus exhibiting a good anti-recurrence effect. Both the TLIPS and TLipD groups showed some inhibitory effects in the early stages, but the inhibitory effect of the TLIPS group was significantly weaker than that of the TLID group in the later stages. After treatment, the recurrent tumors were weighed, as shown in Figure a. Figure 8As shown in b, the TLipDS group had the smallest tumor mass, which is consistent with the tumor volume data. The overall treatment results demonstrate that chemotherapy combined with ICD-induced immunotherapy plays a crucial role in the overall relapse prevention process, with SR717 amplifying the signal and enhancing the effect of tumor immunotherapy.

[0083] Experimental Example 8

[0084] Postoperative prevention of metastasis

[0085] To further evaluate the application of the prepared neutral particle-targeting nanomedicine in inhibiting tumor metastasis, such as... Figure 9 As shown in 'a', a lung metastasis model was established after tumor surgery. Ten days after model establishment, the mice were euthanized and dissected. The dissected lungs were photographed, as shown... Figure 9 As shown in b, it can be seen that the PBS group had significantly more black lung metastases than the other treatment groups. No obvious metastases were observed in the TLipDS group. Subsequently, lung sections of the mice were prepared and stained with H&E, as shown... Figure 9 As shown in c, the H&E full scan results clearly show that the proportion of tumor tissue in the PBS, TLipS, TLipD, and LipDS groups is much larger than that in the TLipDS group. Figure 9 As shown in d, the number of lung metastases in the TLipDS group was significantly less than in other groups, which is consistent with the results of H&E. The survival rate of the mice was also monitored; after 18 days, as... Figure 9 In the study, all mice in the e and PBS groups died, while the survival rates in the TLipS, TLipD, and LipDS groups were 40%, 60%, and 60%, respectively, with the TLipDS group having a 100% survival rate. This indicates that targeted combination therapy has a good effect on preventing postoperative recurrence and metastasis of melanoma and can effectively prolong the survival of mice.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of making a neutrophil-engrafting, targeted delivery nanoparticle, comprising, The method comprises the following steps: The phospholipid molecules are prepared into a chloroform solution, and are spin-evaporated into a film and dried, and then are hydrated, dialyzed, homogenized to obtain blank liposomes, and then are drug-loaded and purified, and are modified with avidin to obtain the neutrophil-targeted delivery nanoparticles; The phospholipid molecules comprise soybean hydrogenated lecithin, cholesterol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-biotin; the molar ratio of the soybean hydrogenated lecithin, cholesterol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-biotin is 55-59:35-40:1-10; The surface targeting molecule is an anti-Ly6G antibody, and the avidin is avidin.

2. The preparation method of nanoparticles for neutrophil-targeted delivery as described in claim 1, characterized in that, The spin-evaporation temperature is 40-60 DEG C, and the time is 20-40 min; the drying is vacuum drying, and the drying time is 12-24 h.

3. The preparation method of nanoparticles for neutrophil-targeted delivery as described in claim 1, characterized in that, The hydration medium comprises an ammonium sulfate aqueous solution, the concentration is 0.2-0.4 M, the hydration temperature is 50-70 DEG C, and the hydration time is 20-40 min; Or, the dialysis liquid comprises a PBS buffer solution, and the dialysis time is 6-18 h.

4. The preparation method of nanoparticles for neutrophil-targeted delivery as described in claim 1, characterized in that, The homogenization pressure is 10000-20000 kpsi, and the homogenization times are 4-8 times.

5. The preparation method of nanoparticles for neutrophil-targeted delivery as described in claim 1, characterized in that, The drug comprises doxorubicin or a STING agonist SR-717, and the mass of the drug is 10-20 % of the mass of the blank liposomes.

6. The preparation method of nanoparticles for neutrophil-targeted delivery as described in claim 1, characterized in that, The purification is high-speed centrifugation, the speed is 40000-60000 g, and the time is 30-60 min.

7. The preparation method of nanoparticles for neutrophil-targeted delivery as described in claim 1, characterized in that, The mass of the avidin is 5-15 % of the mass of the liposomes, and the mass of the antibody is 20-30 % of the mass of the avidin.

8. A neutrophil-engrafting, targeted delivery nanoparticle, comprising: The neutrophil-targeted delivery nanoparticles are obtained by the preparation method of any one of claims 1-7.

9. The neutrophil-targeted delivery nanoparticles of claim 8 in the preparation of a postoperative tumor treatment drug.

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