Target-drug self-adaptive transition cross-linking self-assembly nano platform as well as preparation method and application of target-drug self-adaptive transition cross-linking self-assembly nano platform

Abstract

The invention belongs to the field of drug delivery system construction, and particularly relates to a target-drug self-adaptive transformation cross-linking self-assembly nano platform as well as a preparation method and application of the target-drug self-adaptive transformation cross-linking self-assembly nano platform. The doxorubicin is creatively taken as a carrier and a targeting ligand for oral delivery of the doxorubicin, so that the specific targeting and treatment effects of a tumor part are realized. The doxorubicin hydrochloride is subjected to stable self-assembly by virtue of disulfide bond crosslinking through a specific crosslinking material, a hydrophilic end sugar ring of the doxorubicin hydrochloride is anchored on the surface of a nanoparticle, and an intestinal epithelial cell barrier and a blood brain barrier are crossed by recognizing SGLT1 and OCTN2 which are highly expressed on a top side membrane of an intestinal epithelial cell, GLUT2 on a substrate side and GLUT1 on the surfaces of brain microvascular endothelial cells and glioma cells. The nanoparticles not only significantly improve the oral bioavailability of adriamycin, but also have an efficient accumulation effect in the brain, further break disulfide bonds and release adriamycin in a high-GSH environment, and achieve a safe and efficient anti-tumor effect.

Description

Technical Field

[0002] This invention relates to the field of drug delivery technology, and in particular to a target-drug adaptive transformation cross-linking self-assembly nanoplatform, its preparation method, and its application. Background Technology

[0003] Oral nanomedicine therapy for glioma faces multiple delivery challenges. First, due to the unique physiological characteristics of the gastrointestinal tract, such as enzyme barriers, intestinal epithelial cell barriers, and mucus layers, nanomedicines must overcome these limitations to enter the systemic bloodstream. Second, the blood-brain barrier prevents 99% of administered small and large molecule drugs from entering the system. Finally, the drugs have poor targeting specificity to tumor cells, resulting in extremely low drug uptake rates by tumor cells.

[0004] Currently, the construction of oral nanomedicine delivery systems is not yet perfect. Whether targeting a single or multiple transporters, complex chemical modifications are usually required to attach the transporter ligands to the surface of the nanocarrier. In particular, the construction of multi-transporter targeted drug delivery systems typically involves modifying the nanoparticle surface with multiple ligands. The use of large amounts of carrier materials not only results in low drug loading but also poses potential toxic side effects with long-term application. Furthermore, due to chemical steric hindrance, the co-modification efficiency of multiple ligands is low, making it difficult to achieve ideal multi-target delivery. Therefore, constructing a simple and efficient multi-transporter oral targeted nanomedicine delivery system is crucial for the safe and effective treatment of gliomas. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a "target-drug" adaptive cross-linking self-assembly nanoplatform, its preparation method, and its applications. This invention creatively uses the hydrophilic end of doxorubicin as a targeting ligand. The long carbon chains formed by the oxidative cross-linking agent "bind" the hydrophobic segment of doxorubicin, thereby stabilizing the nanoparticle structure formed by the self-assembly of doxorubicin. This platform can generate positively charged nanoparticles through self-assembly and can stably encapsulate carboplatin or irinotecan hydrochloride within the nanoplatform. Studies have shown that this platform can efficiently penetrate mucus to reach the surface of intestinal epithelial cells, targeting sodium-glucose cotransporter 1 (SGLT1), organic cation / carnitine transporter 2 (OCTN2), and glucose transporter 2 (GLUT2) expressed by intestinal epithelial cells, improving oral drug absorption. Furthermore, by targeting glucose transporter 1 (GLUT1) on the surface of brain microvascular endothelial cells and glioma cells, it enhances the drug's ability to cross the blood-brain barrier.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for preparing a target-drug adaptive cross-linking self-assembly nanoplatform, which is carried out by nanoprecipitation. The process of the self-assembly method is as follows: the drug and the cross-linking agent are added dropwise to a solvent, and then the thiol group of the cross-linking agent undergoes a redox reaction by contacting oxygen in the air. The flexible long carbon chain formed by continuous cross-linking "binds" the hydrophobic end of doxorubicin, and exposes its hydrophilic sugar ring as a target structure on the surface of the nanoparticle drug delivery system.

[0007] Specifically, the following steps are included: (1) Weigh the drug and dissolve it in an organic solvent to obtain a drug solution; the drug contains at least doxorubicin; (2) Weigh the crosslinking agent and dissolve it in methanol to obtain a crosslinking agent solution. The crosslinking agent has a six-carbon chain with a thiol group at each end in its molecular structure, and also contains an ether bond in its structure. (3) Mix the drug solution with the cross-linking agent solution, add the mixed liquid dropwise to ultrapure water and stir in an open container to obtain the final product.

[0008] Alternatively, doxorubicin may also be available in its hydrochloride form, namely doxorubicin hydrochloride.

[0009] Analysis of the structure of doxorubicin revealed that it consists of a hydrophobic anthraquinone ring and a hydrophilic sugar ring. The sugar ring is a β-configuration epoxide hexacyclic ring with a C2 hydroxyl group, very similar to the structure of β-pyranose glucose. While substitution of the C4 and C6 hydroxyl groups in pyranose glucose with methyl groups does not affect its recognition of glucose transporters, the unmodified C2 group, located in an equatorial position, is crucial for glucose binding and transport. On the other hand, the C3 hydroxyl group in the sugar ring of doxorubicin is substituted with a primary amino group. Small molecules with amino groups, such as norepinephrine, carnitine, and histamine, can be transported via organic cation transporters on the apical side of intestinal epithelial cells. Therefore, doxorubicin possesses the key characteristics of both β-pyranose glucose and OCTN2 in substrate recognition.

[0010] The present invention discloses a method for preparing a target-drug adaptive cross-linking self-assembly nanoplatform. Firstly, doxorubicin itself is amphiphilic and can self-assemble into nanoparticles in water. The cross-linking agent undergoes a redox reaction upon contact with air, resulting in intermolecular cross-linking to form long carbon chains containing disulfide bonds. Based on the principle of "like dissolves like," the hydrophobic segment of doxorubicin is "bound," while the hydrophilic sugar ring of doxorubicin acts as a targeting ligand exposed on the nanoparticle surface. The synthesis process is mild and simple, making it suitable for the preparation and application of dual-target nanocarriers.

[0011] Furthermore, in step (1), the drug also includes an anti-tumor drug.

[0012] Furthermore, the antitumor drug is one or more of carboplatin and irinotecan hydrochloride.

[0013] Furthermore, the molar ratio of doxorubicin to carboplatin is 1:0.1~2; the molar ratio of doxorubicin to irinotecan hydrochloride is 1:0.1~2.

[0014] Further, in step (1), the organic solvent is one or more of acetonitrile, methanol, ethanol, and dimethyl sulfoxide; the volume of the organic solvent used is 100 ~ 1000 µL.

[0015] Further, in step (2), the crosslinking agent is 2,2'-(1,2-ethylenedioxy)diethylthiol; and the organic solvent is methanol.

[0016] Furthermore, the molar ratio of doxorubicin to crosslinking agent is 1:0.5~3, preferably 1:1.5.

[0017] In this invention, 2,2'-(1,2-ethylenedioxydioxo)diethylthiol is a six-carbon chain with a thiol group (-SH) at each end of the molecule, exhibiting good biocompatibility, while the ether bonds in its structure endow it with a certain degree of flexibility. As an oxidation-responsive chemical bond, the disulfide bond breaks under oxidative conditions, ultimately forming hydrophilic sulfones or sulfoxides. Therefore, the self-crosslinking of 2,2'-(1,2-ethylenedioxydioxo)diethylthiol is expected to act as a "surface molecular rope" to "bind" the nanoparticles formed by the self-assembly of doxorubicin, stabilizing their nanoparticle structure and exposing the hydrophilic ends of doxorubicin on the nanoparticle surface. Simultaneously, its disulfide bonds can be oxidized and broken in the high-glutathione environment within brain tumor cells, generating hydrophilic sulfones or sulfoxides, thereby specifically releasing doxorubicin.

[0018] Furthermore, in step (3), the temperature during stirring and mixing is room temperature to 45°C, and the time is 20 to 30 hours.

[0019] In a second aspect, the present invention provides a "target-drug" adaptive transformation crosslinking self-assembly nanoplatform prepared by any of the above methods.

[0020] In the aforementioned "target-drug" adaptive transformation cross-linking self-assembly nanoplatform, the hydrophilic end of doxorubicin is exposed on the surface of the nanoparticles, achieving an anti-tumor effect by overcoming dual barriers.

[0021] The self-assembled "target-drug" adaptive cross-linking self-assembled nanoplatform of this invention is a nanoparticle drug delivery system with the hydrophilic end of doxorubicin on the outside, the hydrophobic end on the inside, and the encapsulated drug inside. It has good mucus penetration ability and can recognize SGLT1, OCTN2 and GLUT2 highly expressed on the intestinal epithelial cell membrane, and GLUT1 highly expressed on the surface of brain microvascular endothelial cells and glial cells, thereby mediating nanoparticle entry into cells, enhancing cellular uptake, improving oral absorption, brain accumulation capacity and anti-tumor effect of the drug.

[0022] In a third aspect, this invention provides the application of the aforementioned "target-drug" adaptive transformation crosslinking self-assembly nanoplatform in the preparation of oral antitumor drugs. This system can be formulated with pharmaceutically acceptable excipients into pharmaceutically acceptable dosage forms such as emulsions, polymeric solutions, drops, powders, tablets, and capsules.

[0023] The beneficial effects of this invention include at least the following: (1) The "target-drug" adaptive cross-linking self-assembly nanoplatform provided by this invention utilizes the hydrophilic sugar ring of doxorubicin on the surface of the nanocarrier to recognize sodium-glucose cotransporter 1 (SGLT1) and organic cation / carnitine transporter 2 (OCTN2) highly expressed on the apical membrane of intestinal epithelial cells, mediating the entry of nanoparticles into cells. It has good targeting efficiency and improves cellular uptake. Experiments have confirmed that the above-mentioned carrier can dual-target the receptors on the surface of intestinal epithelial cells, effectively improving cellular uptake.

[0024] (2) The "target-drug" adaptive cross-linking self-assembly nanoplatform provided by this invention utilizes the doxorubicin hydrophilic sugar ring on the surface of the nanocarrier to recognize glucose transporter 1 (GLUT1) on the surface of brain microvascular endothelial cells and glioma cells, mediating the entry of nanoparticles into cells, exhibiting good ability to cross the blood-brain barrier and anti-tumor effects. Experiments have confirmed that the above-mentioned carrier can target the blood-brain barrier and glioma cell surface receptors, effectively improving the brain accumulation capacity of drugs.

[0025] (3) The “target-drug” adaptive cross-linking self-assembly nanoplatform provided by this invention has nanoparticles with positive charges on their surface after self-assembly, which can increase the intestinal retention time and enhance the interaction with intestinal epithelial cells. Furthermore, due to the hydrophilicity of the hydrophilic sugar ring of doxorubicin, the interaction between the nanoparticles and mucus layer proteins can be reduced, thereby efficiently penetrating the mucus to reach the surface of the intestinal epithelial cell layer and exerting a dual-targeting effect. Attached Figure Description

[0026] Figure 1 This is a particle size potential analysis diagram of the "target-drug" adaptive transformation crosslinking self-assembly nanoplatform (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs) in Example 1 of the present invention.

[0027] Figure 2 This is a mapping elemental analysis diagram of the "target-drug" adaptive transformation cross-linking self-assembly nanoplatform (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs) in Example 1 of the present invention.

[0028] Figure 3This is a transmission electron microscope image of the "target-drug" adaptive transformation cross-linking self-assembly nanoplatform (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs) in Example 1 of the present invention.

[0029] Figure 4 This is a cellular uptake diagram of the "target-drug" adaptive transformation cross-linking self-assembly nanoplatform (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs) in Experimental Example 1 of this invention.

[0030] Figure 5 Immunofluorescence colocalization analysis of DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs (SGLT1, OCTN2) for the adaptive conversion cross-linking self-assembly nanoplatforms for "target-drug" (DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs).

[0031] Figure 6 Immunofluorescence colocalization analysis (GLUT2) of the "target-drug" adaptive transformation cross-linked self-assembly nanoplatform (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs).

[0032] Figure 7 Immunofluorescence colocalization analysis of DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs (with GLUT1 on the surface of bEnd.3 cells) for the adaptive conversion cross-linking self-assembly nanoplatform of "target-drug".

[0033] Figure 8 Immunofluorescence colocalization analysis of DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs (with GLUT1 on the surface of C6 cells) for the "target-drug" adaptive cross-linking self-assembly nanoplatform (DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs).

[0034] Figure 9 Mucus-penetrating fluorescence images of the self-adaptive cross-linking self-assembly nanoplatforms for "target-drug" (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs).

[0035] Figure 10 The anti-tumor effect of the "target-drug" adaptive transformation cross-linking self-assembly nanoplatform (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs).

[0036] Figure 11 Comparison of tumor fluorescence signal intensity in the last week for each group of "target-drug" adaptive cross-linking self-assembly nanoplatforms (DOX-NPs, DOX-CBP-NPs, DOX-IRT-NPs). Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0039] The following specific embodiments illustrate the solution proposed in this invention: Example 1 Preparation of a target-drug adaptive cross-linking self-assembly nanoplatform Doxorubicin hydrochloride, doxorubicin hydrochloride and carboplatin, and doxorubicin hydrochloride and irinotecan hydrochloride were weighed and dissolved in 100 µL of dimethyl sulfoxide (DMSO), wherein the mass of doxorubicin hydrochloride was 8 mg. Carboplatin and irinotecan hydrochloride were weighed according to a molar ratio of doxorubicin hydrochloride to carboplatin of 1:0.6 and a molar ratio of doxorubicin hydrochloride to irinotecan hydrochloride of 1:0.3. The cross-linking agent (2,2'-(1,2-ethylenedioxy)diethylthiol) was dissolved in 100 µL of methanol, and the molar ratio of cross-linking agent to doxorubicin hydrochloride was 1.5:1. After mixing the cross-linking agent and the drugs, the mixture was added dropwise to 5 ml of pure water with an open syringe and stirred at room temperature for 24 h. DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs were obtained respectively.

[0040] Comparative Example 1 Sodium thioctic acid was used as a crosslinking agent to prepare a target-drug adaptive transformation crosslinking self-assembly nanoplatform. Doxorubicin hydrochloride, doxorubicin hydrochloride and carboplatin, and doxorubicin hydrochloride and irinotecan hydrochloride were dissolved in 100 µL of dimethyl sulfoxide (DMSO), with the mass of doxorubicin hydrochloride being 8 mg. Carboplatin and irinotecan hydrochloride were weighed according to a molar ratio of doxorubicin hydrochloride to carboplatin of 1:0.6 and a molar ratio of doxorubicin hydrochloride to irinotecan hydrochloride of 1:0.3. The cross-linking agent, sodium thiocate, was dissolved in 100 µL of methanol at a molar ratio of 1.5:1 to doxorubicin hydrochloride. After mixing the cross-linking agent and the drugs, the mixture was added dropwise to 5 ml of pure water using a syringe and stirred at room temperature for 24 h with the mixture exposed to the open air. DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs were obtained respectively using sodium thiocate as the cross-linking agent.

[0041] Comparative Example 2 A target-drug adaptive transformation crosslinking self-assembly nanoplatform was prepared using dimercaptopropanol as a crosslinking agent. Doxorubicin hydrochloride, doxorubicin hydrochloride and carboplatin, and doxorubicin hydrochloride and irinotecan hydrochloride were weighed and dissolved in 100 µL of dimethyl sulfoxide (DMSO), with the mass of doxorubicin hydrochloride being 8 mg. Carboplatin and irinotecan hydrochloride were weighed according to a molar ratio of doxorubicin hydrochloride to carboplatin of 1:0.6 and a molar ratio of doxorubicin hydrochloride to irinotecan hydrochloride of 1:0.3. The cross-linking agent, which was dimercaprol, was dissolved in 100 µL of methanol at a molar ratio of 1.5:1 to doxorubicin hydrochloride. After mixing the cross-linking agent and the drugs, the mixture was added dropwise to 5 ml of pure water using a syringe and stirred at room temperature for 24 h with the mixture exposed to the open air. DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs were obtained respectively using dimercaprol as the cross-linking agent.

[0042] The nanoparticles prepared using the crosslinking agents of Comparative Examples 1 and 2 had an average particle size of approximately 400 nm and a wide particle size distribution range, with Zeta potentials ranging from -25 to 35 mV. This suggests that the hydrophilic end of doxorubicin may be masked by the carboxyl group of sodium thiocate or the hydroxyl group of dimercaprol, thus preventing it from achieving targeted delivery.

[0043] In Examples 1, 1, and 2 of this invention, different crosslinking agents were selected, and DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs were prepared by nanoprecipitation crosslinking method. Finally, it was found that the nanoparticles prepared by using 2,2'-(1,2-ethylenedioxy)diethylthiol as crosslinking agent had the best physicochemical properties, and it had the function of binding the water end of doxorubicin and effectively exposing its hydrophilic end.

[0044] Example 2 Characterization of the "target-drug" adaptive transformation cross-linking self-assembly nanoplatform Particle size and potential were analyzed for the DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs prepared in Example 1. The results are as follows: Figure 1 As shown, the three types of nanoparticles have an average particle size of 180 nm and a uniform particle size distribution, with zeta potentials of +38.33 ± 1.24 mV, +32.01 ± 1.63 mV, and +22.67 ± 2.05 mV, respectively. This indicates that the hydrophilic end of doxorubicin is exposed on the nanoparticle surface. Further mapping elemental analysis and morphological observation will be conducted. Figures 2-3 It can be seen that the nanoparticles of the present invention are nearly spherical and have the characteristic N element distributed on the surface of the hydrophilic end of doxorubicin.

[0045] Example 3 Cellular uptake experiments of a target-drug adaptive conversion cross-linked self-assembly nanoplatform. Caco-2 cells / bEnd.3 cells / C6 cells were fed at a rate of 2 × 10⁻⁶. 5 Cells were seeded per well in 12-well plates with climbing surfaces. When the cell density reached approximately 80%, drug treatment was initiated. Before drug treatment, the cells were washed three times with PBS solution, and then the nanoparticles diluted in culture medium were added and incubated with the cells for 4 hours. After incubation, the cells were fixed with 4% paraformaldehyde solution for 15 minutes, washed three times with PBS, and the nuclei were stained with DAPI solution for 10 minutes, followed by three more washes with PBS solution. The climbing surfaces were placed on a glass slide, and the uptake behavior of the three cell types on the nanoparticles was observed under a laser confocal microscope. The results of the cell uptake experiment are shown below. Figure 4 As shown. By Figure 4 It can be seen that, compared with doxorubicin solution, nanoparticles can significantly improve the uptake capacity of the three cell types.

[0046] Example 4 Immunofluorescence colocalization assay of a target-drug adaptive cross-linking self-assembly nanoplatform To further investigate the roles of SGLT1, OCTN2, GLUT2, and GLUT1 in the transmembrane transport of nanoparticles, this example uses an immunofluorescence colocalization assay of the nanoparticles from Example 1. The experimental principle is as follows: Caco-2 cells / bEnd.3 cells / C6 cells are incubated with nanoparticles, followed by immunofluorescence staining of the SGLT1, OCTN2, GLUT2, and GLUT1 transporters to examine the colocalization of the nanoparticles and transporters. The specific procedure is as follows: cells are incubated at a concentration of 2 × 10⁶ cells / cells. 5 Cells were seeded per well in 12-well plates with a climbing plate. When the cell density reached approximately 80%, the cells were treated with PBS. The cells were washed twice with PBS, and then incubated with nanoparticles for 4 hours. The cells were then gently washed three times with PBS. Cells were fixed with 4% paraformaldehyde solution, then washed with PBS to remove excess solution. Blocking solution was added to cover the cells, and the cells were blocked at room temperature for 15 minutes. The blocking solution was discarded, and diluted primary antibody was added directly. The cells were incubated overnight at 4°C. The cells were rinsed with PBS for 3 minutes, then incubated with DyLight 488-labeled secondary antibody for 2 hours. Excess staining solution was washed with PBS, and the nuclei were stained with DAPI for 10 minutes. The cells were then gently washed three times with PBS. The climbing plate was placed on a slide with an anti-fluorescence quencher, and the co-localization of the nanoparticles and transporters was observed using a confocal microscope. Results are as follows: Figures 5-8 As shown.

[0047] Depend on Figures 5-8 It can be seen that the nanoparticles have obvious co-localization with SGLT1, OCTN2, GLUT1, and GLUT2, which confirms that the nanoparticles can achieve efficient cellular uptake through the above transporters.

[0048] Example 5 Mucus Penetration Experiment of a Target-Drug Adaptive Transformation Crosslinked Self-Assembly Nanoplatform SD rats were randomly divided into groups of three. They were fasted for 12 hours prior to the experiment, but allowed water. Anesthetized rats were administered an intraperitoneal injection of 7% chloral hydrate (0.5 mL / 100 g). The jejunum was surgically exposed and ligated into 2-3 cm segments. Each segment was injected with 200 μL of DOX solution and three nanoparticle solutions (DOX concentration 20 μg / mL). Two hours later, the rats were euthanized. 100 μL of Alexa Fluor 488-labeled wheat germ lectin solution was injected into the ligated intestinal segments for mucus staining. The ligated intestinal segments were then dissected along the longitudinal axis, fixed lumen-side down on a confocal dish, and 3D layer scanning was performed using CLSM. The experimental results are as follows: Figure 9 As shown, the DOX group exhibited strong red fluorescence only on the surface of the mucus layer, while the nanoparticles showed strong red fluorescence throughout the entire mucus layer, and also exhibited significant fluorescence on the cell surface. With increasing mucus layer depth, the red fluorescence of the DOX group disappeared faster than that of the nanoparticles.

[0049] Example 6 Antitumor effects of the "target-drug" adaptive cross-linking self-assembly nanoplatform Male Balb / C mice (20 ± 5 g) were anesthetized with isoflurane gas and fixed using a stereotaxic apparatus. After exposing the skull, a hole was drilled 1.8 mm to the right and 0.2 mm posterior to the anterior fontanelle. The needle was inserted vertically 3 mm along the drilled hole, and 5 µL of Luciferase-labeled C6 cell suspension (8 × 10⁸ g) was slowly injected using a microsyringe. 4 (cells / µL), the needle was slowly withdrawn and the incision sutured. Mice inoculated with tumor cells were fed normally for 7 days, then intraperitoneally injected with potassium fluorescein and images were acquired on an IVIS in vivo imaging system to confirm the successful establishment of the orthotopic glioma model. Mice were randomly divided into 8 groups (n=3 per group): saline group, intravenous DOX group, oral DOX group, oral DOX+CBP physical mixture group, oral DOX+IRT physical mixture group, oral DOX-NPs group, oral DOX-CBP-NPs group, and oral DOX-IRT-NPs group. The oral DOX dose was 15 mg / kg, and the intravenous DOX dose was 10 mg / kg. Administration was every other day for 21 days. Fluorescent images of mouse brain tumors were acquired using a small animal in vivo imaging system on days 7, 14, and 21 after administration.

[0050] The results are as follows Figure 10In the Saline group, the tumor fluorescence signal intensity gradually increased, indicating that the tumor gradually grew and spread. Compared with the Saline group, the tumor growth rate slowed down with the extension of drug administration time in the other experimental groups. Especially on day 21, compared with DOX (po), DOX+CBP (po), and DOX+IRT (po), the DOX-NPs, DOX-CBP NPs, and DOX-IRT-NPs groups showed stronger tumor growth inhibition ability. This is presumably due to the poor targeting and slow gastrointestinal absorption of DOX solution, DOX and CBP mixture, and DOX and IRT mixture after oral administration. It is worth noting that a comparative analysis of the tumor fluorescence signal intensity in each group was performed in the last week, and the results are as follows: Figure 11 As shown, the DOX-NPs, DOX-CBP-NPs, and DOX-IRT-NPs groups were similar to DOX (iv), indicating that their tumor growth inhibition ability was similar to that of DOX (iv), demonstrating good oral therapeutic effects for gliomas. Compared with the DOX+CBP mixture and DOX+IRT mixture groups, the DOX-CBP-NPs and DOX-IRT-NPs groups showed slower tumor fluorescence signal growth, suggesting that CBP and IRT, as model drugs, loaded onto the nanoplatform and synergistically inhibited tumor proliferation after self-assembling with DOX to form nanoparticles.

[0051] In summary, this invention, based on the similarity between the hydrophilic terminal sugar ring in the structure of doxorubicin hydrochloride and the substrates bound by glucose transporters and organic cation transporters, creatively utilizes doxorubicin as a carrier and targeting ligand for its own oral delivery, achieving specific targeting and therapeutic effects at tumor sites. Doxorubicin hydrochloride is stably self-assembled via disulfide bond cross-linking using specific cross-linking materials, anchoring its hydrophilic terminal sugar ring to the surface of nanoparticles. By recognizing SGLT1 and OCTN2 highly expressed on the apical membrane of intestinal epithelial cells and GLUT2 on the basal side, as well as GLUT1 on the surface of brain microvascular endothelial cells and glioma cells, it crosses the intestinal epithelial cell barrier and the blood-brain barrier. These nanoparticles not only significantly improve the oral bioavailability of doxorubicin but also exhibit efficient accumulation in the brain. Furthermore, under a high GSH environment, the disulfide bonds are broken, releasing doxorubicin and achieving a safe and efficient anti-tumor effect. This invention has broad application prospects in the field of targeted oral drug delivery system construction.

[0052] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0053] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a "target-drug" adaptive transformation cross-linking self-assembly nanoplatform, characterized in that, Includes the following steps: (1) Weigh the drug and dissolve it in an organic solvent to obtain a drug solution; the drug contains at least doxorubicin; (2) Weigh the crosslinking agent and dissolve it in an organic solvent to obtain a crosslinking agent solution. The crosslinking agent has a six-carbon chain with a thiol group at each end in its molecular structure, and also contains an ether bond in its structure. (3) Mix the drug solution with the cross-linking agent solution, add the mixed liquid dropwise to ultrapure water and stir in an open container to obtain the final product.

2. The preparation method according to claim 1, characterized in that, In step (1), the drug also includes an anti-tumor drug.

3. The preparation method according to claim 1, characterized in that, The antitumor drug is one or more of carboplatin and irinotecan hydrochloride.

4. The preparation method according to claim 3, characterized in that, The molar ratio of doxorubicin to carboplatin is 1:0.1~2; the molar ratio of doxorubicin to irinotecan hydrochloride is 1:0.1~2.

5. The preparation method according to claim 1, characterized in that, In step (1), the organic solvent is one or more of acetonitrile, methanol, ethanol, and dimethyl sulfoxide.

6. The preparation method according to claim 1, characterized in that, In step (2), the crosslinking agent is 2,2'-(1,2-ethylenedioxy)diethylthiol; the organic solvent is methanol.

7. The preparation method according to claim 6, characterized in that, The molar ratio of doxorubicin to cross-linking agent is 1:0.5~3.

8. The preparation method according to claim 6, characterized in that, In step (3), the temperature during stirring and mixing is room temperature to 45°C, and the time is 20 to 30 hours.

9. A "target-drug" adaptive transformation crosslinking self-assembly nanoplatform prepared by any of the preparation methods described in claims 1-8.

10. The application of the "target-drug" adaptive transformation crosslinking self-assembly nanomedicine according to claim 9 in the preparation of oral antitumor drugs.

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