Sulfydryl-consuming anti-tumor nano-drug

Abstract

A nanosheet Bi2Fe4O9 is used as a carrier, spherical Au nanoparticles are loaded, the Bi2Fe4O9-coated Au nano-drug is formed, the Bi2Fe4O9-coated Au nano-drug is not affected by the pH value of a tumor microenvironment, sulfydryl can be targeted and reduced in different pH environments, then the sulfydryl is inactivated, and the reaction time of the sulfydryl-consuming anti-tumor nano-drug and reduced glutathione (GSH) does not exceed 1 second; meanwhile, after the active sites are consumed completely, the cytotoxicity of the Bi2Fe4O9 (at) Au nano-drug is remarkably reduced; through in-situ injection to a tumor site, the application effectively reduces the exposure of the application in normal tissues, avoids the biotoxicity of the application to normal cells, rapidly kills tumors and effectively excites anti-tumor immune response.

Description

Technical Field

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

[0002] The heterogeneity, drug resistance, and metastasis of tumors are largely affected 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 core of the tumor and effectively killing the deep 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 core of the tumor 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 overall health of the patient, especially causing significant damage to the immune system.

[0003] In recent years, nanomedicine-based treatment methods have gradually shown their potential in deep tumor treatment, including surface modification, in situ injection, and physical stimulation. Among them, in situ injection can directly deliver drugs into the tumor core, reduce the impact of drugs on the whole body, and reduce side effects, but in addition to requiring a high level of technology and experience, the microenvironment (pH value) inside the tumor is complex. Even if it can penetrate deeply into the tumor tissue, the distribution of drugs in different areas may be different, affecting the effect. Summary of the invention

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

[0005] The purpose and innovation of the present invention are: using nanosheet Bi2Fe4O9 as a carrier, loading spherical Au nanoparticles to form Bi2Fe4O9@Au nanodrugs, which are not affected by the pH value of the microenvironment inside 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 consumed, the cytotoxicity of Bi2Fe4O9@Au nanodrugs is significantly reduced; it is particularly important that the reaction efficiency of Bi2Fe4O9@Au nanodrugs and GSH is extremely rapid and can be completed within 1 second; the present application is injected in situ into the tumor site, 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.

[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, wherein the nanomedicine uses nanosheet 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, 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 0.5-2 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, when 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, which effectively reduces the exposure of the present application in normal tissues, avoids biological toxicity to normal cells, quickly kills tumors and effectively stimulates 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 consumption of GSH by DTNB detection 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 graph 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 H&E stained sections of tumor-bearing mice after in situ administration of different concentrations of Bi2Fe4O9@Au nanosheets to verify the in vivo biological toxicity effect.

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

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

[0025] Embodiment 1:

[0026] In this example, deionized water is used as a solvent, HAuCl4 is added to the Bi2Fe4O9 nanosheet solution, and a mixed solution is obtained by stirring; and NaBH4 is added to the mixed solution as a reducing agent, and Bi2Fe4O9@Au nanosheets are obtained after stirring.

[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 microscope and XRD patterns of Bi2Fe4O9@Au nanosheets are shown in Figure 1. Through analysis, Bi2Fe4O9@Au nanosheets with an average size of about 117nm were successfully prepared.

[0029] Embodiment 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 in the figure, when the contact time between Bi2Fe4O9@Au nanosheets and GHS is 1 second, 5 seconds, 10 seconds, 20 seconds, 40 seconds, 60 seconds and 120 seconds, the residual content of GSH is almost the same. Since the artificial experimental time cannot be lower, the minimum time is 1 second. The actual reaction time between Bi2Fe4O9@Au nanosheets and GHS does not exceed 1 second. This shows that if in the tumor microenvironment, Bi2Fe4O9@Au nanosheets will not reduce the anti-tumor therapeutic effect due to different pH values, and can quickly kill tumor cells.

[0031] Embodiment 3:

[0032] L929 and 4T1 tumor cells were placed in RMPI 1640 medium containing 1% (v / v) penicillin / streptomycin and 10% (v / v) fetal bovine serum (FBS) and cultured in a 37°C, 5% CO2 incubator. 8000 4T1 cells were seeded into 96-well plates per well and incubated with Bi2Fe4O9@Au nanosheets containing different concentrations (0, 5, 10, 15, 20, 25 μg mL-1) for 5 minutes. Relative cell viability was detected by 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] Embodiment 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] Embodiment 5:

[0037] The biotoxicity of Bi2Fe4O9@Au nanosheets in vivo was verified by 4T1 tumor-bearing mice. Figure 7 As shown, different concentrations of Bi2Fe4O9@Au nanosheets were administered in situ, and H&E staining sections 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] Embodiment 6:

[0039] Fifteen days after administration, the 4T1 tumor-bearing mice were dissected and the immune capacity of the mice 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 described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A thiol-consuming anti-tumor nanomedicine, characterized in that: The nano drug 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, characterized in that: The following steps are included: Step S1, using deionized water as a solvent, adding HAuCl4 to the Bi2Fe4O9 nanosheet solution, 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 nano drug according to claim 3, characterized in that: In the step S1, the mass ratio of Bi2Fe4O9 to HAuCl4 is 1:2.5-1:20; the stirring rate is 600-1000 rpm; and the stirring time is 0.5-2 h.

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

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