A material for improving tumor microenvironment and preparation method and application thereof

Abstract

The application discloses a material for improving tumor microenvironment and a preparation method and application thereof, and relates to a material comprising: a magnesium-containing metal, and nano calcium carbonate particles for modifying the surface of the magnesium-containing metal; wherein the mass ratio of the magnesium-containing metal and the nano calcium carbonate particles is 10:1-4:1. + The application finds that the magnesium metal can inhibit CAFs from releasing cancer-promoting factors and weaken the inhibition of immune cells by CAFs by releasing hydrogen, thereby enhancing the expression of activation genes in CD4 T cells, and achieving the effect of improving the tumor microenvironment. Based on this, the application develops a material for improving the tumor microenvironment. The degradation rate of the magnesium metal material is moderate, and the material can weaken the inhibition of immune cells by CAFs, achieve the effect of improving the tumor microenvironment, and improve the tumor treatment effect of immunotherapy.

Description

Technical Field

[0001] This invention relates to the field of biotechnology, specifically to a material for improving the tumor microenvironment, its preparation method, and its application. Background Technology

[0002] Cancer is a serious disease that threatens life and health, and is considered a major obstacle to the continuous development of human society. Compared with traditional treatments such as surgery, drugs, and radiotherapy, emerging cancer treatments show great potential.

[0003] Immunotherapy is one of the emerging treatment methods for cancer. This method mainly works by adjusting or stimulating the body's own immune system, relying on its own immune function to kill tumor cells, thus showing great promise for application. However, since immunotherapy uses the body's own immune cells to kill tumors, its efficacy is highly dependent on the environment surrounding the tumor—the tumor microenvironment. If the tumor microenvironment is unfavorable for the recruitment and infiltration of immune cells, the effect of immunotherapy will be very limited.

[0004] Cancer-associated fibroblasts (CAFs) are a major component of the tumor microenvironment. They are activated from normal fibroblasts and are a type of cell that promotes tumor growth. Simultaneously, in immunotherapy, CAFs inhibit the recruitment and intratumoral invasion of immune cells, affecting the efficacy of immunotherapy. Currently, research on CAFs is relatively limited, mainly focusing on which factors CAFs secrete and how they affect immunotherapy. However, there are no reports on how to regulate CAFs and how they influence the tumor microenvironment to improve the efficacy of immunotherapy.

[0005] Therefore, there is an urgent need to provide a method for regulating CAFs and modulating the tumor microenvironment in order to improve the efficacy of immunotherapy. Summary of the Invention

[0006] The purpose of this invention is to improve the tumor microenvironment, and to provide a material for improving the tumor microenvironment, its preparation method and application. This material can inhibit the expression of oncogenes by CAFs, weaken the inhibition of immune cells by CAFs, and improve the tumor microenvironment.

[0007] To achieve the above objectives, the present invention provides a material for improving the tumor microenvironment, the material comprising: a magnesium-containing metal, and nano-calcium carbonate particles modified on the surface of the magnesium-containing metal; wherein the mass ratio of the magnesium-containing metal to the nano-calcium carbonate particles is 10:1-4:1.

[0008] Optionally, the magnesium-containing metal mentioned above is metallic magnesium and / or medical magnesium alloy.

[0009] Optionally, the aforementioned nano-calcium carbonate particles are modified onto the magnesium-containing metal by an organic coating, wherein the organic coating is an organopolysilazane (OPSZ) coating.

[0010] Optionally, the magnesium-containing metal may be in any one of the following forms: granules, filaments, strips, or flakes.

[0011] The present invention also provides a method for preparing the above-mentioned material for improving the tumor microenvironment, comprising the following steps:

[0012] Step S1: Add nano-calcium carbonate powder to an organic solution and mix to obtain a nano-calcium carbonate dispersion;

[0013] Step S2: Take a magnesium-containing metal, coat the surface of the nano-calcium carbonate dispersion onto the magnesium-containing metal, and heat to cure. The nano-calcium carbonate dispersion forms a nano-calcium carbonate coating that covers the magnesium-containing metal.

[0014] Step S3: Remove part of the nano-calcium carbonate coating from the magnesium-containing metal surface to expose part of the magnesium-containing metal surface, thereby obtaining the material that improves the tumor microenvironment.

[0015] Optionally, in step S1, the organic solution is a butyl acetate solution containing 15-30% organopolysilazane.

[0016] Optionally, in step S3, the method for removing part of the nano-calcium carbonate coating includes: cutting and / or grinding away part of the nano-calcium carbonate coating.

[0017] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0018] (1) This invention is the first to discover that metallic magnesium can inhibit the release of cancer-promoting factors by CAFs through the release of hydrogen gas, thereby weakening the inhibitory effect of CAFs on immune cells and enhancing CD4. + Activating gene expression in T cells can improve the tumor microenvironment.

[0019] Magnesium, as an implantable alkaline metal for medical use, possesses excellent biocompatibility and biodegradability, making it a promising new type of medical functional material for clinical applications. However, magnesium metal degrades upon in-situ implantation into tumor tissue, producing Mg... 2+ And H2. During the experimental process, the inventors of this application discovered for the first time that H2 produced after the degradation of magnesium metal can inhibit the release of pro-cancer factors by CAFs, weaken the inhibitory effect of CAFs on immune cells, and thus enhance CD4. + Activating gene expression in T cells improves the tumor microenvironment.

[0020] (2) Although this application has discovered that metallic magnesium can improve the tumor microenvironment, in practical applications it has been found that magnesium degrades rapidly, and therefore, implanting magnesium metal alone into the human body can easily cause damage. Based on this, the present invention synthesizes a magnesium-containing metal material modified with calcium carbonate. The material includes: magnesium-containing metal and nano-calcium carbonate particles that modify the surface of the magnesium-containing metal portion. By modifying the magnesium-containing metal with nano-calcium carbonate particles, the internal magnesium metal is protected by the nano-calcium carbonate particles, thereby achieving the effect of slowing down the degradation rate of magnesium metal.

[0021] (3) In the calcium carbonate-modified magnesium-containing metal material synthesized in this invention, the magnesium-containing metal and the nano-calcium carbonate particles can jointly improve the tumor microenvironment:

[0022] ① Magnesium-containing metals degrade to produce H2 after being implanted in situ into tumor tissue, inhibiting the release of cancer-promoting factors by cancer cells (CAFs) and enhancing CD4. + Activating gene expression in T cells improves the tumor microenvironment.

[0023] ② Calcium carbonate will degrade and produce OH after being implanted in situ into tumor tissue. - It increases the pH of the tumor microenvironment, reduces the acidity of the tumor microenvironment, and improves the tumor microenvironment.

[0024] Therefore, in terms of improving the tumor microenvironment, the magnesium-containing metal and the nano-calcium carbonate particles in the calcium carbonate-modified magnesium-containing metal material synthesized in this invention can work together to improve the tumor microenvironment. Attached Figure Description

[0025] Figure 1 A comparison chart showing the amount of hydrogen produced by the in vitro degradation of magnesium wire (Mg), magnesium wire modified with organopolysilazane (OPSZ) (Mg-OPSZ), and magnesium wire modified with calcium carbonate (Mg-CaCO3).

[0026] Figure 2 This image shows a comparison of intratumoral hydrogen volume during the degradation of OPSZ-modified magnesium wire (Mg-OPSZ) and calcium carbonate-modified magnesium wire (Mg-CaCO3) in mice; where:

[0027] A shows the results of ultrasound imaging detection of intratumoral hydrogen volume in mice in the Mg-CaCO3 group.

[0028] B is a line graph comparing the intratumoral hydrogen volume in the Mg-OPSZ group and the Mg-CaCO3 group of mice.

[0029] Figure 3 The figure shows the results of qPCR detection of the expression of oncogenes in CTL control group (CTL) and magnesium wire group (Mg) CAFs.

[0030] Figure 4The figures show the results of detecting the expression levels of CAF cell markers after treatment (I), magnesium ion treatment (II), nano-calcium carbonate treatment (III), OPSZ-modified magnesium wire treatment (IV), and calcium carbonate-modified magnesium wire treatment (V); where:

[0031] A shows the results of qPCR detection of CAF cell marker expression levels after different material treatments;

[0032] Figure B shows the results of Western blot analysis of the expression levels of CAF cell markers after different material treatments.

[0033] Figure 5 The figure shows the results of qPCR detection of the expression of oncogenes in CAFs after untreated (I), magnesium ion treated (II), nano-calcium carbonate treated (III), OPSZ-modified magnesium wire treated (IV), and calcium carbonate-modified magnesium wire treated (V).

[0034] Figure 6 To detect the correlation between CAFs and CD4 after qPCR treatment (I), magnesium ion treatment (II), nano-calcium carbonate treatment (III), OPSZ-modified magnesium wire treatment (IV), and calcium carbonate-modified magnesium wire treatment (V), the following treatments were used. + T cell co-culture, CD4 + The results of T cell immune-related gene expression levels are shown in the figure.

[0035] Figure 7 To detect the correlation between CAFs and CD4 in flow cytometry after treatment (I), magnesium ion treatment (II), nano-calcium carbonate treatment (III), OPSZ-modified magnesium wire treatment (IV), and calcium carbonate-modified magnesium wire treatment (V), the following assays were performed. + T cell co-culture, CD4 + The result of T cell activation gene expression level.

[0036] Figure 8 The image shows the results of an in vivo tumor experiment in mice; where:

[0037] A is a schematic diagram of the in vivo tumor experiment in mice;

[0038] B is a comparison of tumor quality in mice in the CTL control group, Mg-OPSZ group and Mg-CaCO3 group 14 days after Mg-OPSZ and Mg-CaCO3 were implanted into the tumor.

[0039] C is a comparison of tumor growth inhibition rates in CTL control group, Mg-OPSZ group and Mg-CaCO3 group mice;

[0040] D is a comparison of tumor volume in mice from the CTL control group, Mg-OPSZ group, and Mg-CaCO3 group;

[0041] E represents CD4 counts in mice from the CTL control group, Mg-OPSZ group, and Mg-CaCO3 group. + Comparison of the proportion of T-cell tumor infiltration;

[0042] F represents the CD8+ nucleotide sequence of mice in the CTL control group, Mg-OPSZ group, and Mg-CaCO3 group. + Comparison of the proportion of T-cell tumor infiltration. Detailed Implementation

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the materials and reagents used are all commercially available.

[0044] Terminology Explanation

[0045] "Tumor-associated fibroblast markers" refer to substances specifically expressed by tumor-associated fibroblasts.

[0046] "Cancer-promoting factors" refer to factors that promote the development of cancer.

[0047] "Immunosuppressive genes" refer to genes that suppress cellular immunity.

[0048] CD4 + "T cell activation gene" refers to the gene that promotes CD4 activation. + Genes that activate T cells and enhance tumor-killing effects.

[0049] The tumor microenvironment refers to the microenvironment surrounding tumor cells, including blood vessels, tumor-associated fibroblasts, and various signaling molecules. It is characterized by a low pH and immunosuppression, thus inhibiting the killing of tumor cells by immune cells and affecting immunotherapy. Currently, improving the tumor microenvironment has become a key means to enhance the efficacy of immunotherapy.

[0050] To improve the tumor microenvironment, the inventors of this application discovered through in vivo and in vitro cell experiments in mice that after magnesium is implanted in vivo, its degradation product H2 can inhibit the release of tumor-promoting factors by cancer cells (CAFs), weaken the inhibitory effect of CAFs on immune cells, and thereby enhance CD4+. + Activating gene expression in T cells improves the tumor microenvironment and enhances the efficacy of immunotherapy for tumors. Based on these findings, this invention synthesizes a material that improves the tumor microenvironment. This material comprises a magnesium-containing metal material modified with calcium carbonate. This magnesium-containing metal material exhibits a moderate degradation rate and can weaken the inhibitory effect of calcium carbonate ions (CAFs) on immune cells, thereby improving the tumor microenvironment and enhancing the efficacy of immunotherapy for tumors.

[0051] The following description is based on specific embodiments.

[0052] Example 1: Preparation of calcium carbonate-modified magnesium-containing metallic materials

[0053] This embodiment provides a method for preparing a calcium carbonate-modified magnesium-containing metallic material, comprising the following steps:

[0054] Step S1: Add nano-calcium carbonate powder to an organic solution and mix to obtain a nano-calcium carbonate dispersion;

[0055] Step S2: Take a magnesium-containing metal, coat the surface of the nano-calcium carbonate dispersion onto the magnesium-containing metal, and heat to cure. The nano-calcium carbonate dispersion forms a nano-calcium carbonate coating that covers the magnesium-containing metal.

[0056] Step S3: Remove part of the nano-calcium carbonate coating from the magnesium-containing metal surface, exposing part of the magnesium-containing metal surface, to obtain a magnesium-containing metal material modified with calcium carbonate.

[0057] In this embodiment, the organic solution in step S1 is a butyl acetate solution containing 15-30% organopolysilazane (OPSZ). The OPSZ used in this embodiment is Durazane 1500SC. OPSZ is a biocompatible organic material that dissolves in organic solvents (such as butyl acetate) in a liquid state. After solidification, it can form a film to adhere nano-calcium carbonate powder to a magnesium-containing metal surface.

[0058] In this embodiment, the magnesium-containing metal can be metallic magnesium and / or medical-grade magnesium alloys. Metallic magnesium, as a medically implantable alkaline metal, possesses good biocompatibility and biodegradability, making it a promising new type of medical functional material for clinical applications. After in-situ implantation into tumor tissue, magnesium metal degrades, producing Mg. 2+ While magnesium can produce H2, its degradation rate is relatively fast when implanted alone, potentially causing damage to the human body. This embodiment addresses this by modifying the surface of a magnesium-containing metal with a nano-calcium carbonate coating. This nano-calcium carbonate coating protects the internal magnesium metal, thereby slowing down magnesium degradation and reducing H2 production.

[0059] Since magnesium metal requires external contact to degrade, this embodiment pre-treats the magnesium-containing metal before step S2 to remove oxides from its surface: the surface is sanded with sandpaper, and then ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and deionized water, before being dried with a lint-free cloth. Simultaneously, after the nano-calcium carbonate coating completely encapsulates the magnesium-containing metal in step S2, a portion of the nano-calcium carbonate coating must be removed to expose some of the magnesium metal, allowing it to contact the external environment and degrade. The nano-calcium carbonate coating can be removed by cutting and / or grinding off a portion of the coating.

[0060] In the calcium carbonate-modified magnesium-containing metal material prepared in this embodiment, the nano-calcium carbonate coating can cover more than 90% of the surface of the magnesium-containing metal. After implantation, both the outer nano-calcium carbonate coating and the exposed magnesium-containing metal degrade, and both work together to improve the tumor microenvironment. Specifically, the magnesium-containing metal inhibits the release of tumor-promoting factors from cancer cells (CAFs) by generating H2 through degradation, thereby improving the tumor microenvironment; calcium carbonate degrades to generate OH... - Reduce the acidity of the tumor microenvironment and improve the tumor microenvironment.

[0061] Furthermore, as the nano-calcium carbonate coating gradually degrades, the magnesium-containing metal encapsulated within the nano-calcium carbonate coating is also gradually exposed and degraded. Therefore, the material can continuously and slowly release H2, thereby achieving the effect of continuously inhibiting the release of cancer-promoting factors by CAFs and improving the tumor microenvironment.

[0062] Example 2: Hydrogen Production Experiment with Magnesium Materials

[0063] I. In vitro hydrogen production experiment

[0064] (1) Material preparation:

[0065] ① Magnesium wire (Mg): Magnesium ingots were purchased from Suzhou Xinghai High-Tech Materials Co., Ltd., and were drawn into magnesium wires with diameters of 1.0 mm and 0.5 mm. They were polished with 2000-grit sandpaper, and then ultrasonically cleaned with acetone, anhydrous ethanol, and deionized water for 5 minutes in sequence, and then dried for use.

[0066] ② OPSZ-modified magnesium wire (Mg-OPSZ): 6.0g of butyl acetate and 2.0g of OPSZ were added to a glass bottle and magnetically stirred for 1 hour to obtain an organopolysilazane coating material with a solid content of 25%. The coating material was applied to magnesium wire using a dip-coating method, heated and cured at 150℃ for 4 hours, and then cut into segments. At this time, magnesium was exposed at the cross-section produced by the cutting, thus obtaining OPSZ-modified magnesium wire.

[0067] ③ Calcium carbonate-modified magnesium-containing metal material (Mg-CaCO3): 6.0 g of butyl acetate and 0.6 g of OPSZ were added to a glass bottle and magnetically stirred for 1 hour. Then, 1.4 g of nano-CaCO3 powder was added, and stirring was continued for 30 minutes to obtain a nano-calcium carbonate dispersion. The nano-calcium carbonate dispersion was coated onto magnesium wire using a dip-coating method, and then cured at 150°C for 4 hours. The wire was then cut into segments, at which point the magnesium was exposed at the cross-section created by the cutting, thus obtaining the calcium carbonate-modified magnesium-containing metal material.

[0068] (2) Experimental results:

[0069] The hydrogen release curves of the above three materials in PBS aqueous solution (pH 7.4) were determined using a UNISENSE electrode, and the results are as follows: Figure 1As shown, Mg-CaCO3 can stably and continuously release H2 in a deionized water environment, and the release rate is moderate.

[0070] II. In vivo hydrogen production experiment in mice

[0071] According to 1×10 6 Cells / Mouse injected the 4T1 breast cancer cell line subcutaneously into the right back of 6-week-old Balb / c female mice. Seven days later, the mice were randomly divided into two groups: the Mg-OPSZ group and the Mg-CaCO3 group. One Mg-OPSZ tube was implanted into the tumor of the Mg-OPSZ group mice, and one Mg-CaCO3 tube of the same size was implanted into the tumor of the Mg-CaCO3 group mice. The hydrogen volume in the tumors of both groups of mice was measured using ultrasound imaging at 10 min, 30 min, 2 h, 6 h, 12 h, 24 h, and 36 h after material implantation.

[0072] The results are as follows Figure 2 As shown, both materials produced H2 after being implanted into mice. After 6 hours, the volume of hydrogen in the tumor of the Mg-CaCO3 group was higher than that of the Mg-OPSZ group, and reached its peak after 24 hours, indicating that the hydrogen production capacity of Mg-CaCO3 is better than that of Mg-OPSZ.

[0073] Example 3: Investigating the effects of H2 on the tumor microenvironment

[0074] I. The effect of metallic magnesium on CAFs

[0075] 1 mL of DMEM medium containing 10% fetal bovine serum was added to each well of a 12-well plate, and the plates were randomly divided into two groups: a CTL control group and a magnesium metal group (Mg). The CTL control group received no treatment, while the magnesium metal (Mg) medium contained 0.2 g of magnesium wire. The magnesium metal was degraded in the DMEM medium and produced hydrogen gas.

[0076] Furthermore, Transwell chamber experiments were conducted in the CTL control group and the magnesium metal group (Mg) to investigate the effect of metallic magnesium on CAFs. The specific procedures are as follows:

[0077] Transwell chambers were placed in each well of a 12-well plate, and mouse CAFs were seeded in the upper chamber. After incubating the cells at 37°C for 24 hours, qPCR was used to detect the expression of oncogenes in the two groups of CAFs.

[0078] The results are as follows Figure 3 As shown, compared with the CTL control group, the amount of cancer-promoting factors il-6, cxcl1, cxcl5 and mmp11 expressed by CAFs was significantly reduced after treatment with magnesium metal (Mg), indicating that magnesium metal has an inhibitory effect on the expression of cancer-promoting factors in CAFs.

[0079] Among them, the oncogenes IL-6 and CXCL1 are associated with the growth of breast cancer and have the ability to induce breast cancer cell proliferation, angiogenesis, and the development of treatment resistance in breast cancer cells.

[0080] The cancer-promoting factor CXCL5 is associated with gastric cancer and endometrial cancer, and can promote the occurrence, development and metastasis of gastric cancer and endometrial cancer.

[0081] The tumor-promoting factor MMP11 is associated with the growth of lung adenocarcinoma and can promote its occurrence, development and metastasis.

[0082] To investigate the degradation products of magnesium metal, Mg 2+ To determine which substance, H2 or H2, plays a major role, the present invention continues to conduct the following exploratory experiments.

[0083] II. The Influence of Various Materials on CAFs

[0084] According to 5×10 5 Cells / well: 3T3 mouse fibroblasts were seeded into 12-well plates. After reaching 50% confluence, the cells were induced with 100 ng / ml TGF-β for 48 h to transform them into tumor-associated fibroblasts (CAFs). The cells were then randomly divided into 5 groups: blank control group (I), Mg... 2+ Group (II), CaCO3 group (III), Mg-OPSZ group (IV), and Mg-CaCO3 group (V), with three replicates per group. The following substances were added to each cell culture plate:

[0085] ① Blank control group (I): No additional substances were added.

[0086] ②Mg 2+ Group (II): Add MgCl2 to make Mg 2+ The concentration is 6.5 μg / mL.

[0087] ③ CaCO3 group (III): 100 μg / mL of nano calcium carbonate was added.

[0088] ④ Mg-OPSZ group (IV): 0.0272 g of Mg-OPSZ was added, and the magnesium ion concentration was approximately 3.6 μg / mL after 24 h.

[0089] ⑤ Mg-CaCO3 group (V): 0.0328 g of Mg-CaCO3 was added, and after 24 h, the magnesium ion concentration was approximately 5.8 μg / mL and the calcium ion concentration was approximately 2.4 μg / mL.

[0090] After incubating the cells at 37°C for 24 hours, the expression of tumor-associated fibroblast markers and oncogenes was detected by qPCR and Western blot.

[0091] like Figure 4 As shown, from Figure 4 It can be seen that after treatment with each material, the Mg-CaCO3 group (V) has the best effect in inhibiting the expression of CAF cell markers (fap, tgf-β1, COL1A1, FN1).

[0092] Comparing the CaCO3 group (III), the Mg-OPSZ group (IV), and the Mg-CaCO3 group (V), it can be found that CaCO3 has a very limited effect in inhibiting CAF expression. This indicates that in Mg-CaCO3, CaCO3 is not the main substance that inhibits CAF expression; the main inhibitory substance is metallic magnesium.

[0093] Furthermore, from Figure 5 It can be seen from this that: in the degradation products of metallic magnesium (Mg 2+ In H2, the inhibitory effect of H2 on CAF expression is stronger than that of Mg. 2+ Details are as follows:

[0094] like Figure 5 As shown, Mg 2+ A comparison of group (II), Mg-OPSZ group (IV), and Mg-CaCO3 group (V) showed that the Mg-OPSZ group (IV) and Mg-CaCO3 group (V) had significantly stronger inhibitory effects on the expression of oncogenes in CAFs than the Mg group. 2+ Group (II). This indicates that in the degradation products of Mg (Mg 2+ In H2), Mg 2+ The inhibitory effect on CAF expression is very limited; H2 is the substance that plays the main inhibitory role.

[0095] III. CAFs and CD4 + T cell co-culture experiment

[0096] The CAF induction, culture, and grouping procedures in this experiment were the same as those in the aforementioned CAF expression experiment. MgCl2, nano-calcium carbonate, Mg-OPSZ, and Mg-CaCO3 were added to the five cell groups respectively. After incubation at 37℃ for 24 h, the effects of different materials on CAFs-CD4 were detected using a Transwell assay. + The effects of T cell co-culture. Specifically, in the Transwell chamber experiment, mouse CD4... + T cells were placed in the upper chamber at a seeding density of 2 × 10⁶ cells / cells. 5 cells / chamber, 37℃, CAFs and CD4+ After T cells were co-cultured for 24 hours, CD4+ was detected by qPCR and flow cytometry. + Expression of T cell immune-related genes.

[0097] like Figure 6 As shown, compared with the blank control group (I), after treatment in the Mg-CaCO3 group (V), CD4+ levels were significantly lower. + The expression of the T cell activation gene nkg7 was significantly increased, while the expression of the immunosuppressive genes lag3 and foxp3 was significantly decreased.

[0098] like Figure 7 As shown, compared with the blank control group (I), after treatment in the Mg-CaCO3 group (V), CD4+ levels were significantly lower. + The positive rates of CD69 and ICOS on T cells were significantly increased.

[0099] The above experiments demonstrate that Mg-CaCO3 can weaken the inhibitory effect of CAFs on immune cells and enhance CD4. + The expression of activated genes in T cells can enhance the effectiveness of immunotherapy by improving the tumor microenvironment.

[0100] IV. In vivo tumor experiment in mice

[0101] like Figure 8 As shown in A, according to 1×10 6 Cells / mouse injected the 4T1 breast cancer cell line subcutaneously into the right back of 6-week-old Balb / c female mice. Seven days later, the mice were randomly divided into three groups: a CTL control group, a Mg-OPSZ group, and a Mg-CaCO3 group. The CTL control group received no treatment. Mice in the Mg-OPSZ group had two OPSZ-modified magnesium wires implanted into their tumors, while mice in the Mg-CaCO3 group had two identical calcium carbonate-modified magnesium-containing metal wires implanted into their tumors. Tumor volume was observed and measured every two days, and samples were harvested after two weeks. Mouse tumor samples were paraffin-fixed, embedded, sectioned, and multicolor immunofluorescence was used to detect CD4+ within the tumor. + T cell infiltration rate.

[0102] The experimental results are as follows:

[0103] like Figure 8 As shown in B, the tumor mass of the Mg-CaCO3 group of mice was the smallest among the three groups of mice.

[0104] like Figure 8 As shown in C, Mg-CaCO3 has the strongest effect in inhibiting tumor growth;

[0105] like Figure 8 As shown in D, the tumor volume of the Mg-CaCO3 group mice was the smallest among the three groups of mouse tumors;

[0106] like Figure 8 As shown in E and F, CD4 in tumors of mice in the Mg-CaCO3 group + T, CD8 + The highest T cell infiltration rate indicates that the Mg-CaCO3 group of mice exhibited the strongest anti-tumor response.

[0107] The above results indicate that Mg-CaCO3 has an excellent ability to improve the tumor microenvironment and can achieve highly effective treatment of tumors.

[0108] In summary, this invention is the first to discover that metallic magnesium can inhibit the release of oncogenes by cancer cells (CAFs), weaken the inhibitory effect of CAFs on immune cells, and thereby enhance CD4. + This invention activates gene expression in T cells, thereby improving the tumor microenvironment. Furthermore, based on these findings, the present invention synthesizes a calcium carbonate-modified magnesium-containing metal material. This material exhibits a moderate magnesium degradation rate, making it suitable for use as a material to improve the tumor microenvironment, reduce the inhibitory effect of CAFs on immune cells, improve the tumor microenvironment, and enhance the efficacy of immunotherapy.

[0109] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A material for improving the tumor microenvironment, characterized in that, include: The method for preparing the material for improving the tumor microenvironment includes the following steps: a magnesium-containing metal and nano-calcium carbonate particles modified on the surface of the magnesium-containing metal; wherein the mass ratio of the magnesium-containing metal to the nano-calcium carbonate particles is 10:1-4:1; the magnesium-containing metal is metallic magnesium and / or a magnesium alloy; the nano-calcium carbonate particles are modified onto the magnesium-containing metal by an organic coating; the organic coating is an organopolysilazane coating; Step S1: Add nano-calcium carbonate powder to an organic solution and mix to obtain a nano-calcium carbonate dispersion; the organic solution is a butyl acetate solution containing 15-30 wt% organopolysilazane. Step S2: Take a magnesium-containing metal, coat the surface of the nano-calcium carbonate dispersion onto the magnesium-containing metal, and heat to cure. The nano-calcium carbonate dispersion forms a nano-calcium carbonate coating that covers the magnesium-containing metal. Step S3: Remove part of the nano-calcium carbonate coating from the magnesium-containing metal surface to expose part of the magnesium-containing metal surface, thereby obtaining the material that improves the tumor microenvironment.

2. The material for improving the tumor microenvironment as described in claim 1, characterized in that, The magnesium-containing metal is in any one of the following forms: granular, filamentous, strip-shaped, or flake-shaped.

3. The material for improving the tumor microenvironment as described in claim 1, characterized in that, In step S3, the method for removing part of the nano-calcium carbonate coating includes: cutting off and / or grinding off part of the nano-calcium carbonate coating.

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