A thiol-consuming anti-tumor nanomedicine

Abstract

The present invention discloses a thiol-consuming anti-tumor nanomedicine, which uses nanosheets Bi2Fe4O9 as a carrier and loads spherical Au nanoparticles to form a Bi2Fe4O9@Au nanomedicine. The Bi2Fe4O9@Au nanomedicine is not affected by the pH value of the tumor microenvironment, can target and reduce thiol groups under different pH environments, thereby inactivating them, and has a reaction time with reduced glutathione (GSH) of no more than 1 second. At the same time, when its active sites are completely consumed, the cytotoxicity of the Bi2Fe4O9@Au nanomedicine is significantly reduced. The nanomedicine is injected in situ into the tumor site, effectively reducing the exposure of the nanomedicine to normal tissues, avoiding the biotoxicity of the nanomedicine to normal cells, rapidly killing tumors and effectively stimulating anti-tumor immune responses.

Description

Technical Field

[0001] The present invention relates to the field of nano-biomedicine, and in particular to a thiol-consuming anti-tumor nano-medicine. Background Art

[0002] Tumor heterogeneity, drug resistance, and metastasis are largely influenced by tumor stem cells and their microenvironment. Tumor stem cells are usually located in the core area of ​​the tumor and have a strong ability to resist conventional treatment, which makes the tumor prone to recurrence after treatment. Therefore, deeply targeting the tumor core and effectively killing the deep-layer cells of the tumor has become an important strategy for completely eliminating the tumor. At present, the common solution to the challenge of penetrating the tumor core is usually to increase the treatment dose, such as increasing the radiation dose in radiotherapy or increasing the dosage of chemotherapy drugs. Although this method may have a certain inhibitory effect on the tumor in the short term, due to the lack of targeting, it often has a negative impact on the patient's overall health, especially causing significant damage to the immune system.

[0003] In recent years, nanomedicine-based therapies have gradually demonstrated their potential for deep-seated tumor treatment. These methods include surface modification, in situ injection, and physical stimulation. While in situ injection can deliver drugs directly into the tumor core, minimizing systemic effects and reducing side effects, it requires advanced technology and experience. Furthermore, the complex microenvironment (pH) within the tumor means that even if the drug can penetrate deeply into the tumor tissue, its distribution may vary across different regions, affecting its effectiveness. Summary of the Invention

[0004] The purpose of the present invention is to provide a thiol-consuming anti-tumor nanomedicine.

[0005] The purpose and innovation of the present invention lies in: using nanosheets Bi2Fe4O9 as a carrier, loading spherical Au nanoparticles to form Bi2Fe4O9@Au nanodrugs, which are not affected by the pH value of the internal microenvironment of the tumor, and can target and reduce thiol groups under different pH environments, thereby inactivating them; at the same time, when its active sites are completely consumed, the cytotoxicity of the Bi2Fe4O9@Au nanodrugs is significantly reduced; more importantly, the reaction efficiency of Bi2Fe4O9@Au nanodrugs and GSH is extremely rapid, and can be completed within 1 second; this application is injected in situ into the tumor site, effectively reducing the exposure of the application to normal tissues, avoiding biological toxicity to normal cells, quickly killing tumors and effectively stimulating anti-tumor immune responses.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is:

[0007] A thiol-consuming anti-tumor nanomedicine uses nanosheets Bi2Fe4O9 as a carrier and loads spherical Au nanoparticles.

[0008] Furthermore, the nanomedicine can target and reduce sulfhydryl groups under different pH environments in tumor cells, and the reaction time with reduced glutathione GSH does not exceed 1 second.

[0009] A method for preparing a thiol-consuming anti-tumor nanomedicine comprises the following steps:

[0010] Step S1, using deionized water as a solvent, adding HAuCl4 to the Bi2Fe4O9 nanosheet solution and mixing and stirring to obtain a mixed solution;

[0011] Step S2, adding NaBH4 as a reducing agent to the mixed solution obtained in step S1, and obtaining Bi2Fe4O9@Au nanosheets after stirring.

[0012] Furthermore, in step S1, the mass ratio of Bi2Fe4O9 to HAuCl4 is 1:2.5 to 1:20, preferably 1:5; the stirring rate is 600 to 1000 rpm, preferably 800 rpm; and the stirring time is 0.5 to 2 h, preferably 1 h.

[0013] Furthermore, in step S2, the mass ratio of HAuCl4 to NaBH4 is 10:1 to 160:1; and the stirring time is 1-20 min, preferably 5 min.

[0014] The beneficial effects of the present invention are:

[0015] The nanomedicine of the present application uses Bi2Fe4O9 as a carrier and loads spherical Au nanoparticles to form Bi2Fe4O9@Au nanomedicine, which is not affected by the pH value of the microenvironment inside the tumor and can target and reduce sulfhydryl groups under different pH environments, thereby quickly inactivating them. At the same time, after its active sites are consumed, the cytotoxicity of Bi2Fe4O9@Au nanomedicine is significantly reduced. The present application is injected into the tumor site in situ, effectively reducing the exposure of the present application in normal tissues, avoiding biological toxicity to normal cells, quickly killing tumors and effectively stimulating anti-tumor immune responses. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a transmission electron microscope image of Bi2Fe4O9@Au nanosheets.

[0017] Figure 2 This is the XRD pattern of Bi2Fe4O9@Au nanosheets.

[0018] Figure 3This is a graph showing the changes in the GSH consumption effect detected by DTNB at different pH values ​​using Bi2Fe4O9@Au nanosheets with different concentrations (the contact time between Bi2Fe4O9@Au nanosheets and GSH is 1 min).

[0019] Figure 4 The effect of Bi2Fe4O9@Au nanosheets with the same concentration on consuming GSH was detected by DTNB under different contact times.

[0020] Figure 5 This is a diagram showing the killing effect of Bi2Fe4O9@Au nanosheets on L929 cells and 4T1 tumor cells at different concentrations.

[0021] Figure 6 Data from flow cytometry analysis showing that Bi2Fe4O9@Au nanosheets can effectively induce dendritic cell polarization and macrophage maturation.

[0022] Figure 7 The H&E-stained sections of tumor-bearing mice after in situ administration of Bi2Fe4O9@Au nanosheets at different concentrations were used to verify the in vivo biological toxicity effect.

[0023] Figure 8 This is a data chart showing that Bi2Fe4O9@Au nanosheets can effectively improve the immune ability of mice through flow cytometry analysis. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings.

[0025] Example 1:

[0026] In this example, deionized water was used as the solvent, HAuCl4 was added to the Bi2Fe4O9 nanosheet solution, and the mixture was stirred to obtain a mixed solution; and NaBH4 was added to the mixed solution as a reducing agent, and the mixture was stirred to obtain Bi2Fe4O9@Au nanosheets.

[0027] The mass ratio of Bi2Fe4O9 and HAuCl4 is 1:2.5~1:20, preferably 1:5; the stirring rate is 600~1000rpm, preferably 800rpm; the stirring time is 0.5-2h, preferably 1h; the mass ratio of HAuCl4 and NaBH4 is 10:1~160:1, preferably 20:1; the stirring time is 1-20min, preferably 5min.

[0028] Figure 1 and Figure 2The transmission electron microscopy (TEM) and XRD patterns of Bi2Fe4O9@Au nanosheets are shown in Figure 2. Through analysis, Bi2Fe4O9@Au nanosheets with an average size of about 117 nm were successfully prepared.

[0029] Example 2:

[0030] The consumption of reduced glutathione GSH by Bi2Fe4O9@Au nanosheets was detected by DTNB. Figure 3 As shown in Figure 2, pH value has no significant effect on the ability of Bi2Fe4O9@Au nanosheets to consume GSH. Under different pH conditions, Bi2Fe4O9@Au nanosheets can effectively consume GSH. Figure 4 As shown, when the contact time between Bi2Fe4O9@Au nanosheets and GHS varies from 1 second, 5 seconds, 10 seconds, 20 seconds, 40 seconds, 60 seconds, and 120 seconds, the residual GSH content is almost the same. Because the experimental time cannot be reduced any further, the minimum time is selected as 1 second. In fact, the reaction time between Bi2Fe4O9@Au nanosheets and GHS does not exceed 1 second. This shows that in the tumor microenvironment, the anti-tumor therapeutic effect of Bi2Fe4O9@Au nanosheets is not reduced by different pH values ​​and can quickly kill tumor cells.

[0031] Example 3:

[0032] L929 and 4T1 tumor cells were cultured in RMPI 1640 medium supplemented with 1% (v / v) penicillin / streptomycin and 10% (v / v) fetal bovine serum (FBS) at 37°C in a 5% CO2 incubator. 8,000 4T1 cells were seeded per well of a 96-well plate and incubated with Bi2Fe4O9@Au nanosheets at varying concentrations (0, 5, 10, 15, 20, and 25 μg mL⁻¹) for 5 minutes. Relative cell viability was measured using a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

[0033] like Figure 5 As shown, Bi2Fe4O9@Au nanosheets can not only effectively kill 4T1 tumor cells at trace concentrations to achieve anti-tumor therapeutic effects, but also have low toxicity to normal L929 cells, which is beneficial to reducing biological toxicity.

[0034] Example 4:

[0035] The ability of Bi2Fe4O9@Au nanosheets to induce dendritic cell polarization and macrophage maturation in vitro was characterized by Transwell assay. Figure 6As shown, compared with the control group, Bi2O3@Au group and Bi2Fe4O9@Pt group, Bi2Fe4O9@Au nanosheets can effectively induce dendritic cell polarization and promote macrophage maturation.

[0036] Example 5:

[0037] The biotoxicity of Bi2Fe4O9@Au nanosheets was verified in vivo by 4T1 tumor-bearing mice. Figure 7 As shown, different concentrations of Bi2Fe4O9@Au nanosheets were administered in situ, and H&E staining of the five internal organs of mice showed that Bi2Fe4O9@Au nanosheets did not produce obvious toxic side effects on mice, indicating that they have good biocompatibility.

[0038] Example 6:

[0039] Fifteen days after administration, the 4T1 tumor-bearing mice were dissected and their immune capacity was further verified. Figure 8 As shown, compared with the control group, Bi2O3@Au group and Bi2Fe4O9@Pt group, the CD4 and CD8+ positive cells of mice treated with Bi2Fe4O9@Au nanosheets increased significantly, proving that it improved the immune capacity of mice.

[0040] The embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A thiol-consuming anti-tumor nanomedicine, characterized by: The nanomedicine uses nanosheet Bi2Fe4O9 as a carrier and loads spherical Au nanoparticles.

2. The thiol-consuming anti-tumor nanomedicine according to claim 1, characterized in that: The nano drug can target and reduce sulfhydryl groups under different pH environments in tumor cells, and the reaction time with reduced glutathione GSH does not exceed 1 second.

3. The method for preparing the nano drug according to claim 1, wherein: The following steps are included: Step S1, using deionized water as a solvent, adding HAuCl4 to the Bi2Fe4O9 nanosheet solution and mixing and stirring to obtain a mixed solution; Step S2, adding NaBH4 as a reducing agent to the mixed solution obtained in step S1, and obtaining Bi2Fe4O9@Au nanosheets after stirring.

4. The method for preparing the nanomedicine according to claim 3, wherein: In step S1, the mass ratio of Bi2Fe4O9 to HAuCl4 is 1:2.5 to 1:20; the stirring rate is 600 to 1000 rpm; and the stirring time is 0.5 to 2 h.

5. The method for preparing the nano drug according to claim 3, wherein: In step S2, the mass ratio of HAuCl4 to NaBH4 is 10:1 to 160:1; and the stirring time is 1 to 20 minutes.

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