Nano-composite system for synergistic treatment of cancers and preparation method and application of nano-composite system

Abstract

The invention provides a nano-composite system for synergistic treatment of cancers and a preparation method and application thereof, and relates to the technical field of nano-medicines.The nano-composite system is characterized in that a zeolite imidazate framework material is used as a carrier, and a Cu-MOF carrier is constructed through copper doping; meanwhile, silver sulfide nanoparticles modified by bovine serum albumin are loaded as an efficient near-infrared photothermal conversion agent, and an anti-cancer drug adriamycin is further entrapped, so that a triple synergistic treatment system integrating photothermal treatment, chemical kinetics treatment and chemical treatment is formed. According to the nano-composite system, through the synergistic effect of three treatment modes, the tumor treatment effect is remarkably improved, meanwhile, the toxic and side effects of a traditional single therapy method are reduced, and the nano-composite system shows a good application prospect in treatment of various cancers.

Description

Technical Field

[0001] This invention relates to the field of nanomedicine technology, and more specifically, to a nanocomposite system for synergistic cancer treatment, its preparation method, and its application. Background Technology

[0002] While the field of cancer treatment continues to develop, traditional therapies still face serious challenges. Photothermal therapy (PTT) uses near-infrared photothermal conversion materials (such as silver sulfide) to generate localized high heat to kill cancer cells, offering advantages in terms of minimal invasiveness and precision. However, its efficacy is limited by insufficient tissue penetration depth and the heat resistance of tumor cells, making it difficult to achieve a complete cure.

[0003] Chemokinetic therapy (CDT) generates reactive oxygen species (such as hydroxyl radicals ·OH) in the tumor microenvironment through Fenton or Fenton-like reactions, which specifically kill cancer cells. However, the traditional Fenton reaction mainly relies on iron ions, and its catalytic efficiency under physiological conditions is limited, and it is prone to causing systemic oxidative damage.

[0004] To improve therapeutic efficacy, researchers are attempting to combine multiple treatment modalities. Metal-organic frameworks (MOFs) have become ideal drug carriers due to their high porosity and tunability. Among them, ZIF-8, with its good biocompatibility and pH responsiveness, is particularly suitable as a nanocarrier for tumor therapy. Bovine serum albumin (BSA), due to its excellent biocompatibility, ease of modification, and low cost, is often used for surface modification of nanomaterials.

[0005] However, existing composite systems have significant drawbacks: for example, iron-doped MOF supports (such as MIL-101) have limited catalytic activity; ZIF-8-loaded photothermal agents can only achieve a simple superposition of PTT and chemotherapy, failing to integrate efficient CDT function; while bovine serum albumin (BSA)-modified silver sulfide nanoparticles improve biocompatibility, they lack controlled release and reactive oxygen species generation capabilities. The core bottlenecks of these technologies are: firstly, existing methods struggle to couple the triple synergistic mechanism of photothermal effect, chemokinetic reaction, and chemotherapy; secondly, the efficiency of traditional Fenton reactions is insufficient, especially in the tumor microenvironment, where copper ions exhibit significantly better Fenton-like reaction kinetics than iron ions, but a stable support is required to prevent ion leakage; and thirdly, there is a lack of multi-response drug release capabilities in response to the tumor microenvironment (acidic pH / high glutathione) and exogenous stimuli (near-infrared light). Therefore, developing a multifunctional nanoplatform that integrates PTT, CDT, and CT is of great significance. Summary of the Invention

[0006] In view of this, the present invention proposes a nanocomposite system for synergistic cancer therapy, its preparation method and application, in order to solve the problems existing in the prior art.

[0007] This invention achieves triple synergistic therapy by constructing a copper-doped MOF support, combining the photothermal properties of BSA-Ag2S NPs and the CDT effect of copper ions, and integrating chemotherapeutic drugs, providing a new solution for cancer treatment.

[0008] To achieve the above objectives, this invention proposes a nanocomposite system for synergistic cancer therapy, comprising: The carrier is a copper-doped metal-organic framework material; Bovine serum albumin-modified silver sulfide nanoparticles loaded onto the surface of the copper-doped metal-organic framework material.

[0009] Furthermore, it also includes chemotherapeutic drugs loaded onto the copper-doped metal-organic framework material.

[0010] Furthermore, the chemotherapy drug includes doxorubicin, and the loading of the chemotherapy drug is 5-30% of the mass of the carrier.

[0011] Furthermore, the substrate material of the copper-doped metal-organic framework material is zeolite imidazole ester framework material ZIF-8, and the copper source in the copper-doped metal-organic framework material is copper acetate, with a molar ratio of zinc to copper of 1-3:1.

[0012] Furthermore, the bovine serum albumin-modified silver sulfide nanoparticles have a particle size of 5-20 nm and a near-infrared absorption wavelength of 700-900 nm.

[0013] Furthermore, the copper-doped metal-organic framework material is modified with β-cyclodextrin, and the bovine serum albumin-modified silver sulfide nanoparticles are surface-coordinated and anchored to the surface of the copper-doped metal-organic framework material.

[0014] The nanocomposite system of this invention has the following functional characteristics: Multiple response release: Under the stimulation of tumor micro-acidic environment (pH=5.5), glutathione (GSH) and near-infrared light (808 nm), the drug release rate is significantly improved (e.g., the release rate exceeds 10% within 5 hours at pH=5.5, the release rate reaches 47.86% in the presence of GSH, and the release rate increases to 68.46% under NIR irradiation).

[0015] Targeted delivery and fluorescence tracing: BSA modification endows nanoparticles with folic acid receptor targeting, and combined with the fluorescence emission peak of Ag2S at 830 nm, tumor-specific enrichment and real-time monitoring are achieved.

[0016] Synergistic effect of photothermal-chemical kinetics: At 808 nm laser (2.0 W / cm²), 2 Under irradiation, the system's photothermal conversion efficiency reached 20.9%, and localized heating accelerated the decomposition of H2O2 and Cu.2+ / Cu + The cycle promotes the formation of ·OH.

[0017] The present invention also provides the application of the nanocomposite system described above in the preparation of antitumor drugs, wherein the tumors include breast cancer, lung cancer and / or liver cancer.

[0018] Furthermore, the anti-tumor drug achieves synergistic therapy through the following mechanism: Under near-infrared light irradiation, bovine serum albumin-modified silver sulfide nanoparticles achieve photothermal conversion, and local heating promotes the generation of ·OH and the release of chemotherapy drugs; The tumor's slightly acidic environment and high GSH concentration activate Cu 2+ A Fenton-like reaction, continuously producing ·OH; Chemotherapy drugs are precisely released under various stimuli, forming a triple synergistic effect with photothermal therapy and chemokinetic therapy.

[0019] Specifically, the synergistic treatment of the antitumor drugs of the present invention is as follows: Photothermal therapy (PTT): Ag2S nanoparticles directly kill tumor cells and enhance oxidative stress through photothermal effects.

[0020] Chemokinetic Therapy (CDT): Cu 2+ The reaction catalyzes the formation of ·OH from H₂O₂ via a Fenton-like reaction, while GSH reduction maintains Cu. 2+ / Cu + Circulation increases the production of reactive oxygen species.

[0021] Chemotherapy (CT): DOX is precisely released under multiple responses and synergistically inhibits tumor cell proliferation with PTT / CDT (e.g., cell survival rate in the combination therapy group decreased to 39.8%).

[0022] The present invention also provides a method for preparing the above-mentioned nanocomposite system, comprising the following steps: a) Dissolve Zn(CH3COO)2·2H2O and Cu(CH3COO)2·H2O at a Zn:Cu molar ratio of 3:1, add to an aqueous solution containing 2-methylimidazole, CTAB and β-cyclodextrin, let stand for 2 hours, centrifuge and wash to obtain β-CD / Cu-ZIF support; b) Mix the AgNO3 aqueous solution with the BSA aqueous solution and stir in the dark for 24 hours to form BSA-Ag. + The complex was reacted with Na2S solution at 80℃ for 2 hours, and then purified by dialysis to obtain BSA-Ag2S NPs; c) Using the BSA-Ag2S solution obtained in step b) as a solvent, add Zn(CH3COO)2·2H2O, Cu(CH3COO)2·H2O, 2-methylimidazole, CTAB and β-cyclodextrin according to the formula and proportion in step a) to synthesize β-CD / Cu-ZIF@BSA-Ag2S. d) Mix β-CD / Cu-ZIF@BSA-Ag2S with DOX at a mass ratio of 1:1, stir in the dark for 24 hours, and centrifuge and dry to obtain β-CD / Cu-ZIF@BSA-Ag2S / DOX.

[0023] Further, in step b), the mass ratio of AgNO3 to BSA is 1:8, and the amount of Na2S added is Ag... + 1.2 times the molar amount.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) Triple synergistic therapy breaks through the limitations of single therapy: By combining photothermal effect, chemokinetic reaction and chemotherapy drugs, the efficiency of tumor cell killing is significantly improved (e.g., the efficacy of the combined therapy group is more than 1.5 times higher than that of single therapy).

[0025] 2) High-efficiency copper-based Fenton-like system: Cu 2+ The catalytic reaction kinetics are faster than those of traditional iron-based systems, the utilization rate of H2O2 is improved, and the cycle stability is better.

[0026] 3) Intelligent targeting and low toxicity: BSA modification enhances tumor targeting, and Cu-MOF carrier reduces systemic toxicity through pH-responsive release.

[0027] 4) Integrated diagnosis and treatment design: Integrates fluorescence tracing, targeted delivery and synergistic treatment functions to simplify the treatment process and improve controllability.

[0028] In summary, this nanocomposite system can be applied to the synergistic treatment of solid tumors such as breast cancer (e.g., MCF-7 cells) and liver cancer, and provides a new strategy for developing multifunctional anti-tumor platforms. Attached Figure Description

[0029] Figure 1 The images show the morphological characterization results of the samples; where a is a scanning electron microscope (SEM) image of β-CD / ZIF-8; b is a SEM image of β-CD / Cu-ZIF; c is a SEM image of β-CD / Cu-ZIF@BSA-Ag2S; d is a transmission electron microscope (TEM) image of BSA-Ag2S; e is a TEM image of β-CD / ZIF-8; f is a TEM image of β-CD / Cu-ZIF; and g is a TEM image of β-CD / Cu-ZIF@BSA-Ag2S. Figure 2TEM elemental distribution map of the β-CD / Cu-ZIF@BSA-Ag2S sample (scale bar is 200 nm); Figure 3 XRD images of BSA-Ag2S, β-CD / ZIF-8, β-CD / Cu-ZIF, and β-CD / Cu-ZIF@BSA-Ag2S; Figure 4 Nitrogen adsorption-desorption analysis curves for β-CD / ZIF-8, β-CD / Cu-ZIF, and β-CD / Cu-ZIF@BSA-Ag2S are shown; where a is the BET isotherm and b is the NLDFT pore size distribution curve of the corresponding sample. Figure 5 The graphs show the dynamic light scattering (DLS) and zeta potential measurements of BSA-Ag2S, β-CD / ZIF-8, β-CD / Cu-ZIF, β-CD / Cu-ZIF@BSA-Ag2S, and β-CD / Cu-ZIF@BSA-Ag2S / DOX. In the graphs, a represents the dynamic light scattering (DLS) particle size distribution of BSA-Ag2S; b represents the DLS particle size comparison; and c represents the zeta potential values ​​for each material. Figure 6 The images show the UV-Vis absorption and fluorescence spectra of the samples; where a is the UV-Vis absorption spectrum and b is the fluorescence emission spectrum of the corresponding material. Figure 7 The graphs show the photothermal properties of β-CD / Cu-ZIF@BSA-Ag2S after laser irradiation; where a is the UV spectrum of β-CD / Cu-ZIF@BSA-Ag2S; and b is the UV spectrum of samples with different concentrations under 808 nm laser (1.5 W / cm²) irradiation. 2 The heating curves under irradiation are shown in Figure 1; c represents the heating curves under different laser powers (0.5-2.0 W / cm²). 2 ) is the temperature change curve of a 200 μg / mL solution; d is the temperature change curve of BSA-Ag2S in four laser-switched cycles; Figure 8 For photothermal conversion efficiency calculation and thermal imaging; where a is BSA-Ag2S in 808 nm laser (1.5 W / cm²). 2 a) Heating-cooling curves under irradiation; b) Fitting curve of cooling time t against -ln(θ); c) Infrared thermal images of solutions of different concentrations after 5 and 10 minutes of laser irradiation; d) Comparison of thermal images of the same solution (200 μg / mL) under different laser powers. Figure 9For the verification of chemical kinetic performance (methylene blue degradation experiment); where a is the degradation graph of different supports; b is the degradation efficiency curve of different H2O2 concentrations; c is the degradation rate change under different GSH concentrations; d is the bar chart of quantitative analysis of degradation efficiency; Figure 10 The effect of pH and concentration on degradation efficiency is shown; where a is the UV absorption spectrum of methylene blue degradation under different pH conditions; b is the UV spectrum of methylene blue degradation under the same pH conditions with different carrier concentrations. Figure 11 The DOX release behavior and kinetics are shown in Figure 1; where a represents the cumulative release rate of DOX under different pH conditions; b represents the effect of GSH concentration on the release rate at pH 5.5; c represents the release curve under near-infrared (NIR) irradiation; and d represents the fitting results of the release kinetic model. Figure 12 The cell survival rate after 24 hours of culture with different carriers and cells; where a is the biocompatibility test; b is the comparison of cell survival rates of the four treatment regimens; Figure 13 This is a schematic diagram illustrating the preparation of the nanocomposite system of the present invention. Detailed Implementation

[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0031] All raw materials used in this invention are not particularly restricted in their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0032] There are no particular restrictions on the purity of any of the raw materials used in this invention. However, this invention preferably uses raw materials of analytical grade or purity commonly used in the field of chemical synthesis.

[0033] A schematic diagram of the preparation of β-CD / Cu-ZIF@BSA-Ag2S / DOX in this invention is shown below. Figure 13 As shown.

[0034] Example 1: Preparation of BSA-Ag2S nanoparticles Under light-protected conditions, 2.0 mL of 0.05 mol / L silver nitrate (AgNO3) aqueous solution and 48 mL of 3.33 mg / mL bovine serum albumin (BSA) aqueous solution were mixed and magnetically stirred at room temperature for 24 hours to form BSA-Ag. +The complex was then formed. 0.1 mL of a 320 mg / mL sodium sulfide (Na₂S) aqueous solution was added, and the mixture was slowly heated to 80 °C and reacted for 2 hours. After cooling to room temperature, a transparent brown reaction solution was obtained. This solution was transferred to a dialysis bag with a molecular cutoff of 10 kDa and purified by dialyzing in deionized water for 48 hours to obtain dark brown BSA-Ag₂S nanoparticles (BSA-Ag₂S NPs).

[0035] Example 2 Preparation of β-CD / Cu-ZIF support 1.50 g of zinc acetate dihydrate (Zn(CH3COO)2·2H2O) and 0.46 g of copper acetate monohydrate (Cu(CH3COO)2·H2O) (molar ratio Zn:Cu = 3:1) were dispersed and dissolved in 25 mL of deionized water to form a homogeneous solution. This solution was added to a 25 mL aqueous solution containing 5.60 g of 2-methylimidazole (2-MI), 9 mg of hexadecyltrimethylammonium bromide (CTAB), and 0.75 g of β-cyclodextrin (β-CD). The mixture was magnetically stirred for 2 minutes and then allowed to stand at room temperature for 2 hours. The precipitate was collected by centrifugation (9000 r / min, 5 min), washed three times with deionized water, and dried under vacuum at 40 °C overnight to obtain the β-CD / Cu-ZIF support.

[0036] Example 3: Preparation of β-CD / Cu-ZIF@BSA-Ag2S / DOX Carrier composite: The BSA-Ag2S prepared in Example 1 was used as a solvent to dissolve Zn(CH3COO)2·2H2O (1.50 g) and Cu(CH3COO)2·H2O (0.46 g) to form a homogeneous solution. Then, it was added dropwise to an aqueous solution containing β-CD (0.75 g), CTAB (9 mg), and 2-MI (5.60 g). After stirring for 2 minutes and standing for 2 hours, the mixture was centrifuged to obtain β-CD / Cu-ZIF@BSA-Ag2S.

[0037] Drug loading: 30 mg β-CD / Cu-ZIF@BSA-Ag2S and 30 mg doxorubicin (DOX) were dissolved in 10 mL of water and stirred at room temperature in the dark for 24 hours. The precipitate was collected by centrifugation, washed until the supernatant was colorless, and freeze-dried to obtain the final product β-CD / Cu-ZIF@BSA-Ag2S / DOX. The absorbance of the supernatant at 480 nm was measured by UV-Vis, and the DOX drug loading rate was calculated according to the DOX standard curve.

[0038] Test Example 1: Morphology and XRD Test The samples β-CD / Cu-ZIF, BSA-Ag2S, and β-CD / Cu-ZIF@BSA-Ag2S were tested by scanning electron microscopy and transmission electron microscopy.

[0039] Figure 1 These are scanning electron microscope (SEM) images and transmission electron microscope (TEM) images of β-CD / Cu-ZIF, BSA-Ag2S, and β-CD / Cu-ZIF@BSA-Ag2S.

[0040] from Figure 1 As can be seen from the scanning and transmission images (a, e), the synthesized β-CD / ZIF-8 exhibits a polyhedral shape with regular edges and facets, and a size of approximately 100-200 nm. Furthermore, when copper ions are introduced, the shape of β-CD / Cu-ZIF becomes smoother, the edges and facets are less pronounced than in β-CD / ZIF-8, and the size is relatively larger. This characteristic can be observed in… Figure 1 See (b,f).

[0041] Transmission electron microscopy (TEM) analysis Figure 1 (d) shows that the prepared BSA-Ag2S nanoparticles have a uniform morphology and narrow size distribution.

[0042] Characterization from scanning electron microscopy (SEM) Figure 1 (c) It can be seen that the morphology of the composite material β-CD / Cu-ZIF@BSA-Ag2S has changed significantly compared with the original β-CD / Cu-ZIF, exhibiting obvious surface coating structure characteristics, and its average particle size has increased from 220±15 nm of the basic framework to 345±18 nm.

[0043] Transmission electron microscopy-elemental surface mapping (TEM-mapping) Figure 2 This further confirms that the Ag and S element signals exhibit high-intensity enrichment on the surface of the composite material, forming spatial complementarity with the uniform distribution of Zn and Cu elements, thus confirming the composite mechanism of BSA-Ag2S anchored on the surface of the metal-organic framework through surface coordination.

[0044] XRD analysis was performed on the crystal structures of the BSA-Ag2S, β-CD / ZIF-8, β-CD / Cu-ZIF, and β-CD / Cu-ZIF@BSA-Ag2S nanocomposites. Figure 3As shown, the diffraction peaks of the Ag₂S sample are distributed in the 20°-40° region, the same as the diffraction peak distribution range of Ag₂S. For the β-CD / ZIF-8 sample, it exhibits distinct diffraction peaks, consistent with the calculated ZIF-8 standard card, indicating that the β-CD modification did not disrupt the ZIF-8 structure. The peak positions of the subsequently tested β-CD / Cu-ZIF and β-CD / Cu-ZIF@BSA-Ag₂S samples showed no significant difference from those of β-CD / ZIF-8, indicating that Cu… 2 + The doping and further coating with BSA-Ag2S did not change the crystal structure.

[0045] Test Example 2: Nitrogen Adsorption-Desorption Isotherm Test N2 adsorption / desorption experiments were conducted on samples β-CD / ZIF-8, β-CD / Cu-ZIF, and β-CD / Cu-ZIF@BSA-Ag2S, and the pore size distribution of the samples was analyzed based on the NLDFT model. Figure 4 As shown in (a), three material curves can be obtained, among which β-CD / ZIF-8 exhibits a type IV isotherm curve, while Cu-doped... 2+ Afterwards, the hysteresis loop relatively decreases, which may be due to Cu 2+ The specific surface area is the smallest among the three materials after further coating with BSA-Ag2S, possibly because Ag2S nanoparticles (average size 9.2 nm) form a dense coating layer on the framework surface, which partially blocks the mesoporous channels, resulting in a decrease in specific surface area.

[0046] Figure 4 (b) is the NLDFT pore size analysis diagram. It can be seen from the figure that there is a porous structure inside the three samples, which can be used as drug carriers for loading drugs. The experimental results are consistent with the BET results, and the β-CD / ZIF-8 sample has the highest relative value.

[0047] Test Example 3: Particle Size and Zeta Potential Test DLS and zeta potentials were measured on samples BSA-Ag2S, β-CD / ZIF-8, β-CD / Cu-ZIF, β-CD / Cu-ZIF@BSA-Ag2S, and β-CD / Cu-ZIF@BSA-Ag2S / DOX. Figure 5 As shown in (a), the average particle size of BSA-Ag2S is between 3.5 and 7 nm, which is similar to the size of quantum dots, proving the synthesis of small-sized Ag2S nanomaterials. Figure 5(b) The average particle sizes of β-CD / ZIF-8, β-CD / Cu-ZIF, β-CD / Cu-ZIF@BSA-Ag2S and β-CD / Cu-ZIF@BSA-Ag2S / DOX are 131.68 nm, 179.16 nm, 238.73 nm and 353.59 nm, respectively. The particle size gradually increases with each step, which also confirms the successful synthesis of each sample.

[0048] The Zeta values ​​of each sample were tested, such as Figure 5 As shown in (c), the Zeta potential of BSA-Ag2S is -11.79 mV, while the potential of β-CD / ZIF-8 is positive at +5.95 mV. When Cu is doped... 2+ Subsequently, the potential rose slightly to +7.21 mV. However, when BSA-Ag2S and β-CD / Cu-ZIF were combined, the Zeta value became negative, -27.64 mV, possibly because BSA-Ag2S was distributed on the surface. When DOX was loaded onto the support, since the Zeta potential of DOX is positively charged, the potential value of β-CD / Cu-ZIF@BSA-Ag2S / DOX rose to -15.24 mV, indicating that DOX was successfully loaded into the β-CD / Cu-ZIF@BSA-Ag2S support.

[0049] Test Example 4: Spectral Testing BSA, BSA-Ag2S, β-CD / ZIF-8, β-CD / Cu-ZIF and β-CD / Cu-ZIF@BSA-Ag2S solutions (concentration 500 μg / mL) were respectively placed in cuvettes, and the UV-Vis absorption spectrum and fluorescence spectrum of the materials were measured.

[0050] Figure 6 These are the UV-Vis absorption and fluorescence spectra of each sample. Figure 6 (a, b) are the UV-Vis absorption and fluorescence spectra of the sample. From the fluorescence spectrum... Figure 6 As can be seen from b, both BSA-Ag2S and β-CD / Cu-ZIF@BSA-Ag2S exhibit fluorescence emission peaks at approximately 830 nm, and the fluorescence intensity of the two materials remains almost unchanged, indicating that the nanocomposite system has the function of fluorescence tracer.

[0051] Test Example 5: Photothermal Performance Test An infrared laser was used as the heat source, with a wavelength set to 808 nm. Samples with different concentration gradients (0, 100, 200, 500, 1000 μg / mL) were heated using a laser with a wavelength of 1.5 W / cm². 2Irradiate with high power for 10 min and record the temperature change of the solution (at 30 s intervals). The solution is 1.0 mL of β-CD / Cu-ZIF@BSA-Ag2S, placed in a cuvette.

[0052] An 808 nm infrared laser was used as a heat source to irradiate the solution with different laser powers for 10 minutes, and the temperature change of the solution was recorded every 30 seconds. The power and frequency were set to 0.5, 1.0, 1.5, and 2.0 W / cm². 2 The solution volume is 1.0 mL, the solution concentration is 200 μg / mL, and the solution is placed in a cuvette.

[0053] The results show that... Figure 7 As shown in (a), the absorbance gradually increases with increasing concentration, indicating that the concentration of the carrier is concentration-dependent on ultraviolet absorption. Figure 7 (b) shows the temperature change curve of the solution after laser irradiation based on the increase of concentration. The results show that the temperature of the sample in the 1000 μg / mL solution increased by 25 °C compared with the aqueous solution which increased by 5 °C, indicating that the carrier has good concentration gradient correlation. Figure 7 (c) shows the temperature change of the sample under different laser frequencies. The results are shown in the figure. As the laser frequency increases, the temperature rise rate of the sample also increases. When the concentration is 1 mg / mL, the solution rises by 35 °C after 10 minutes, and the sample shows good photothermal results.

[0054] The photothermal stability of the BSA-Ag2S sample was also tested. The specific test procedure was as follows: a 1 mg / mL solution was repeatedly irradiated with an 808 nm laser. The solution was circulated through multiple switching cycles, and the temperature change was recorded every 30 seconds. The test results are as follows: Figure 7 As shown in (d), after the laser was switched on and off three times in succession, the temperature rise of the sample did not decrease significantly, but instead showed a slight upward trend, which indicates that the sample has good photothermal stability.

[0055] Test Example 6: Photothermal Conversion Efficiency (PCE) Test Through 808 nm, 1.5 W / cm 2 The solution (2 mg / mL) was irradiated with a laser. Once the temperature reached its maximum, the light source was turned off, and the solution was allowed to cool naturally to room temperature. Temperature data was recorded every 30 seconds.

[0056] Then, the PCE is calculated according to the method of Roper and Hu, as follows: Equation (1) The parameter hS required in equation (1) can be obtained by creating a custom function.

[0057] Equation (2) Equation (3) Equation (4) Combining equations (2), (3), and (4), based on the slope τ s Calculate hS to obtain η.

[0058] The heating and cooling curves of BSA-Ag2S nanomaterials were obtained by irradiating the solution with a laser. Figure 8 (a) and illustrations). Figure 8 (b) is obtained by fitting the cooling curve. According to the formula, the PCE of BSA-Ag2S is 20.9%, and the BSA-Ag2S carrier has a good photothermal conversion effect.

[0059] The last Figure 8 (c, d) are thermal infrared imagers of the solutions. Image c shows thermal images of solutions with different concentrations and the same laser frequency after irradiation for 5 min and 10 min. Image d shows thermal images of photothermal heating curves of the same solution concentration with different laser frequencies taken under the same time change. As can be seen from the images, with the increase of concentration and laser frequency, the temperature change and thermal image gradually become larger or brighter, showing a dependence of the heating curve on the brightness of the thermal image.

[0060] Test Example 7: Chemical Kinetic Performance Test The chemical kinetics of β-CD / Cu-ZIF@BSA-Ag2S were evaluated by assessing its effectiveness in oxidative degradation of methylene blue (MB) by ·OH. The specific test steps are as follows: Take β-CD / Cu-ZIF@BSA-Ag2S solution (200 μL, 1 mmol / L) and reduce glutathione (GSH, 400 μL, 1 mmol / L) and mix them. Incubate in a 37°C constant temperature oven for 15 minutes (min) in the dark to activate the catalytic activity of material A. Add methylene blue (MB, 800 μL, 25 μg / mL) and hydrogen peroxide (H2O2, 800 μL, 100 mmol / L) to the above mixture in sequence. After thorough mixing, continue the reaction at a constant temperature of 37°C before the reaction (t=0) and after the reaction (t=3 h). Centrifuge the reaction solution (12000 rpm, 10 min) to remove catalyst particles. Use a UV-Vis spectrometer to measure the absorbance of the supernatant at the characteristic absorption wavelength of MB (664 nm).

[0061] Six parallel sets of experiments were designed and prepared for investigation, and the results are as follows: Figure 9 As shown in (a), compared with other experimental groups, only the β-CD / Cu-ZIF@BSA-Ag2S+GSH+H2O2 experimental group showed a significant decrease in the MB UV absorption peak, indicating that Cu in the β-CD / Cu-ZIF@BSA-Ag2S nanomaterials... 2+ Reduced to Cu by GSH + A Fenton or Fenton-like reaction occurred, producing ·OH, which caused MB to fade and subsequently reduced the UV absorption peak. This indicates that β-CD / Cu-ZIF@BSA-Ag2S has good degradation efficiency and can generate ·OH, thereby inducing apoptosis in cancer cells.

[0062] Figure 10 (a) shows the intensity of the ultraviolet absorption peak under different pH values ​​(5.5, 6.5, 7.4). The results show that as the pH gradually decreases, the intensity of the ultraviolet absorption peak also gradually decreases. The weakly acidic pH=5.5 can show better degradation efficiency, which coincides with the weakly acidic environment of tumor cells and is more conducive to the implementation of chemokinetics. Figure 10 (b) shows the changes in UV absorption peak intensity of carrier solutions with different concentrations (0, 0.5, 1.0, 2.0 mg / mL) at pH=5.5. As the concentration of the carrier solution increases, the UV absorption peak intensity decreases continuously, confirming the effect of concentration on the chemical kinetics experiment.

[0063] Test Example 8: Preparation of the DOX standard curve and experiment on optimal drug loading rate Preparation of the DOX standard curve: Weigh 1.0 mg of the drug and prepare a 200 μg / mL stock solution. Dilute the stock solution to a concentration gradient (10-50 μg / mL). Then, measure the absorbance at 480 nm using UV light. Finally, plot the DOX standard curve.

[0064] The obtained standard curve is y = 0.01536x + 0.00854206, R0 2 =0.999. The residual amount of DOX in the supernatant was calculated based on the standard curve, and the drug loading rate was calculated using the following formula.

[0065]

[0066] In the formula, m dox（0） For dosage, m dox（1） m represents the mass of residual DOX in the supernatant. carrier For carrier quality.

[0067] After drug loading of the carrier β-CD / Cu-ZIF@BSA-Ag2S, the drug loading of DOX was calculated to be 24.6% according to the formula.

[0068] Test Example 9: In vitro drug release experiment Multifactorial design: (1) pH gradient group: Prepare phosphate buffer (PBS, 0.01 M) and adjust to the target pH values ​​(5.5, 6.5, 7.4) to simulate the physiological and pathological microenvironment. (2) Near-infrared response group: Under the above pH conditions, apply 808nm near-infrared laser (NIR, power density: 0.5 W / cm²). 2 (Spot diameter: 2 cm) Vertical irradiation for 5 minutes to evaluate the photothermal synergistic release effect.

[0069] The specific testing procedure is as follows: β-CD / Cu-ZIF@BSA-Ag2S / DOX (1 mg / mL) sample solution was added to a dialysis bag (Mw = 8000~14000 Da) and placed in a beaker, ensuring the liquid just submerged the sample solution. The solution volume was 45 mL. All experimental groups were set up uniformly according to this method. The beaker was then placed in a shaker at 37 °C and shaken to maintain the solution as dispersed as possible. Time intervals were 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 24, 36, and 48 h. Each time a sample was taken, the volume of released solution was the same (e.g., 1.0 mL), and an equal amount of fresh medium solution was added to maintain a constant volume of released solution. After collecting all the extracted liquid, the absorbance was measured to calculate the release rate of the controlled release.

[0070] In the experiment investigating the release behavior of DOX under near-infrared light irradiation, before conducting the release experiment, a laser at 808nm and 0.5W / cm² was used. 2 The thermal infrared emitter was used to irradiate the release liquid for 5 minutes, then the laser was turned off, with all other conditions remaining unchanged. All of the above experiments were repeated three times in parallel.

[0071] The results are as follows Figure 11 As shown in Figure a, under different pH conditions, only pH 5.5 showed a controlled release rate exceeding 10% within 5 hours, indicating that acidic environments are more conducive to DOX release. Figure 11 b indicates that the cumulative release rate gradually increases with increasing GSH concentration, suggesting that the carrier possesses a certain GSH-responsive release function. At pH 5.5 and a GSH solution (5 mg / mL), the release rate reached 47.86%. Figure 11 b also shows that the carrier has NIR responsiveness, and with increased NIR irradiation, the release rate reached a maximum of 68.46%.

[0072] Test Example 10: Cytotoxicity Assay Biocompatibility of the samples was assessed using the MTT assay. MCF-7 cells were cultured to their optimal state before being used in the experiments. The original culture medium was replaced with fresh medium containing β-CD / Cu-ZIF@BSA-Ag2S / DOX. The culture medium was then removed, and the cells were exposed to different concentrations of β-CD / Cu-ZIF@BSA-Ag2S / DOX (12.5, 25, 50, 100, and 200 μg / mL). β-CD / Cu-ZIF@BSA-Ag2S served as a control group, and the tests were conducted under the same conditions.

[0073] Experimental results show that, Figure 12 As shown in (a), the drug-free β-CD / Cu-ZIF@BSA-Ag2S nanocarriers still maintained a high survival rate of over 90.3% after 24 h of culture. This indicates that the synthesized β-CD / Cu-ZIF@BSA-Ag2S nanocarriers have good biocompatibility.

[0074] Cell viability was determined using the MTT assay. A nanocomposite system (divided into four groups: (1) β-CD / Cu-ZIF@BSA-Ag2S; (2) β-CD / Cu-ZIF@BSA-Ag2S / DOX (CT group); (3) β-CD / Cu-ZIF@BSA-Ag2S + light (PTT+CDT group); (4) β-CD / Cu-ZIF@BSA-Ag2S / DOX + light (PTT+CDT+CT group)) was added to human breast cells MCF-7 and cultured together. A control group (equal volume of culture medium) and a blank group (equal volume of PBS solution) were also set up. After 24 h, 10 μL of 5 mg / mL MTT was added to each well in the dark, and the cells were cultured for another 4 h. The supernatant was then discarded, and 100 μL of LDMSO solution was added to each well. The crystals were dissolved by shaking for 8 min. Finally, the OD (optical density) value was quantitatively recorded at 490 nm using a microplate reader, and cell viability was calculated. All of the above experiments were conducted in parallel three times.

[0075] The results are as follows Figure 12 As shown in (a), for the carrier β-CD / Cu-ZIF@BSA-Ag2S / DOX, the cell viability gradually decreased with increasing carrier concentration. At a concentration of 400 μg / mL, the cell viability was less than 60%, indicating that β-CD / Cu-ZIF@BSA-Ag2S / DOX has good chemotherapeutic efficacy. Cells containing β-CD / Cu-ZIF@BSA-Ag2S were irradiated with a near-infrared laser and then cultured for another 24 h. The results are as follows. Figure 12As shown in (b), at a concentration of 400 μg / mL, the cell viability was 60.7%, achieving a dual effect of photothermal and chemokinetic action. For the final triple-combination synergistic therapy group, when the experimental group's concentration reached 400 μg / mL, the cell viability was only 39.8%, exhibiting the most significant cell-killing effect. The results indicate that β-CD / Cu-ZIF@BSA-Ag2S / DOX has a good combined photothermal / chemo / chemokinetic synergistic therapeutic effect.

[0076] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A nanocomposite system for synergistic cancer therapy, characterized in that, include: The carrier is a copper-doped metal-organic framework material; Bovine serum albumin-modified silver sulfide nanoparticles loaded onto the surface of the copper-doped metal-organic framework material.

2. The nanocomposite system according to claim 1, characterized in that, It also includes chemotherapeutic drugs loaded onto the copper-doped metal-organic framework material.

3. The nanocomposite system according to claim 2, characterized in that, The chemotherapy drug includes doxorubicin, and the loading of the chemotherapy drug is 5-30% of the mass of the carrier.

4. The nanocomposite system according to claim 1, characterized in that, The substrate material of the copper-doped metal-organic framework is zeolite imidazole ester framework material ZIF-8, and the copper source in the copper-doped metal-organic framework is copper acetate, with a zinc to copper molar ratio of 1-3:

1.

5. The nanocomposite system according to claim 1, characterized in that, The bovine serum albumin-modified silver sulfide nanoparticles have a particle size of 5-20 nm and a near-infrared absorption wavelength of 700-900 nm.

6. The nanocomposite system according to claim 1, characterized in that, The copper-doped metal-organic framework material is modified with β-cyclodextrin, and the bovine serum albumin-modified silver sulfide nanoparticles are surface-coordinated and anchored to the surface of the copper-doped metal-organic framework material.

7. The application of the nanocomposite system according to any one of claims 1-6 in the preparation of antitumor drugs, characterized in that, The tumors include breast cancer, lung cancer, and / or liver cancer.

8. The application according to claim 7, characterized in that, The anti-tumor drugs achieve synergistic therapy through the following mechanisms: Under near-infrared light irradiation, bovine serum albumin-modified silver sulfide nanoparticles achieve photothermal conversion, and local heating promotes the generation of ·OH and the release of chemotherapy drugs; The tumor's slightly acidic environment and high GSH concentration activate Cu 2+ A Fenton-like reaction, continuously producing ·OH; Chemotherapy drugs are precisely released under various stimuli, forming a triple synergistic effect with photothermal therapy and chemokinetic therapy.

9. A method for preparing the nanocomposite system according to any one of claims 1-6, characterized in that, Includes the following steps: a) Dissolve Zn(CH3COO)2·2H2O and Cu(CH3COO)2·H2O at a Zn:Cu molar ratio of 3:1, add to an aqueous solution containing 2-methylimidazole, CTAB and β-cyclodextrin, let stand for 2 hours, centrifuge and wash to obtain β-CD / Cu-ZIF support; b) Mix the AgNO3 aqueous solution with the BSA aqueous solution and stir in the dark for 24 hours to form BSA-Ag. + The complex was reacted with Na2S solution at 80℃ for 2 hours, and then purified by dialysis to obtain BSA-Ag2S NPs; c) Using the BSA-Ag2S solution obtained in step b) as a solvent, add Zn(CH3COO)2·2H2O, Cu(CH3COO)2·H2O, 2-methylimidazole, CTAB and β-cyclodextrin according to the formula and proportion in step a) to synthesize β-CD / Cu-ZIF@BSA-Ag2S. d) Mix β-CD / Cu-ZIF@BSA-Ag2S with DOX at a mass ratio of 1:1, stir in the dark for 24 hours, and centrifuge and dry to obtain β-CD / Cu-ZIF@BSA-Ag2S / DOX.

10. The preparation method according to claim 9, characterized in that, In step b), the mass ratio of AgNO3 to BSA is 1:8, and the amount of Na2S added is Ag. + 1.2 times the molar amount.

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