A rare earth metal-based ternary composite antibacterial agent and its preparation method

Abstract

This invention provides a rare earth metal-based ternary composite antibacterial agent and its preparation method. The antibacterial agent is prepared from raw materials including GL-22, Eu-containing polyoxometalate clusters, and Spm. The rare earth metal-based ternary composite antibacterial agent of this invention, after fractional compounding of Eu-containing polyoxometalate clusters with peptides and biogenic amines, exhibits highly efficient antibacterial function against Escherichia coli and Staphylococcus aureus. The ternary assembly EuW... 10 The fluorescence emission of / GL-22 / Spm is enhanced by 30-40 times, and it is effective against Escherichia coli (E. coli). E. coli The antibacterial properties of the drug have been increased from 40%~30% to 90%~95%, and its efficacy against bacteria has been improved. E. coli The inhibition rate of biofilm (BME) formation was 21.8%.

Description

Technical Field

[0001] This invention belongs to the field of composite antibacterial agents, and in particular relates to a rare earth metal-based ternary composite antibacterial agent and its preparation method. Background Technology

[0002] Bacterial infections have always been a serious threat to the global economy, especially human health. In the global fight against the novel coronavirus, an even more significant challenge is the urgent response to the hazards encountered in combating viruses and bacteria. Although antibiotics have made significant contributions to effectively inhibiting or killing bacteria by suppressing protein synthesis or preventing DNA replication, the emergence of drug-resistant strains in patients has once again brought the fight against bacteria to a head. Developing a new class of antimicrobial materials as antibiotic alternatives, with highly effective and safe alternatives, has become a trend. In recent years, newly developed antimicrobial materials have been widely used in medical, food packaging, water treatment, and biopharmaceutical fields. With the development of nanotechnology, researchers are dedicated to discovering new antimicrobial nanocomposites, including antimicrobial nanocomposites constructed between polyoxometalate clusters (POMs) and cationic polymers, proteins, specific peptides, or other biomolecules.

[0003] Pomolecular oxygen (POMs) are negatively charged nanoclusters composed of transition metals, primarily europium (Eu), molybdenum (Mo), tungsten (W), vanadium (V), and oxygen (O). Their structural diversity and excellent physicochemical properties have led to their widespread application in materials science, photochemistry and electrochemistry, protein crystallography, catalysis, and especially medicine. The easily tunable binding modes between biotarget molecules and POMs are beneficial for enhancing their biological activity, attracting scientists to research them in antidiabetic, antitumor, and antiviral applications. The targeted electrostatic interactions between POMs and biomolecules have significant biological advantages, with the negatively charged metal clusters mostly located in or near the positively charged regions of proteins / peptides. Antibacterial research on POM-based nanocomposites has been a hot topic in recent years. Further improving the antibacterial properties of POMs is a key research focus in this field and is of great significance for expanding the application of POMs in antibacterial applications. Summary of the Invention

[0004] In view of this, the present invention aims to overcome the defects in the prior art and proposes a rare earth metal-based ternary composite antibacterial agent and its preparation method.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A rare earth metal-based ternary composite antibacterial agent, wherein the antibacterial agent is prepared from raw materials including GL-22, Eu-containing polymetallic oxy-oxide clusters, and Spm.

[0007] Preferably, the molar concentration ratio of GL-22, Eu-containing polymetallic oxy-oxide cluster, and Spm is 1:(1~2):(5~10).

[0008] Preferably, the molar ratio of the GL-22 peptide, the Eu-containing polymetallic oxo group, and Spm is 1:1:5.

[0009] Preferably, the Eu-containing polymetallic oxygen cluster is Na. x [EuW 10 O 36 •yH2O, where x is taken from 8, 9, 10, and y is taken from 30, 31, 32, 33, 34, 35.

[0010] Preferably, the Na x [EuW 10 O 36 In yH2O, x is 9 and y is 32.

[0011] Preferably, the Na x [EuW 10 O 36 The preparation method of yH2O includes the following steps:

[0012] Dissolve Na₂WO₄•₂H₂O in distilled water and adjust the pH to 7.0–7.5. Add an aqueous solution containing Eu(NO₃)₃•₆H₂O dropwise to the above solution, stir at 80–90°C, and cool to room temperature to obtain crystallized Na. x [EuW 10 O 36 •yH2O.

[0013] Preferably, the mass ratio of Na2WO4•2H2O to Eu(NO3)3•6H2O is (8.0 ~ 9.0):(1.0 ~ 1.3).

[0014] This invention also provides a method for preparing the above-mentioned rare earth metal-based ternary composite antibacterial agent, specifically including the following steps:

[0015] S1: Construct a binary assembly;

[0016] Eu-containing polymetallic oxy-oxide clusters were mixed with Spm and GL-22 respectively in MES-NaOH buffer at pH 6-7, and incubated at room temperature for 5-15 min to obtain EuW. 10 / GL-22 binary assembly and EuW 10 / Spm binary assembly;

[0017] S2: Constructing a ternary assembly;

[0018] In a MES-NaOH buffer solution with a pH of 6-7, add EuW 10 Adding Spm to / GL-22 and to EuW 10 After adding GL-22 to / Spm and incubating at room temperature for 5-15 minutes, structures with EuW were obtained. 10 / Spm / GL-22 and EuW 10 The ternary assembly of / GL-22 / Spm yields a rare earth metal-based ternary composite antibacterial agent.

[0019] Preferably, the molar concentration ratio of GL-22, Eu-containing polymetallic oxy-oxide cluster, and Spm is 1:(1~2):(5~10).

[0020] Preferably, the Eu-containing polymetallic oxygen cluster is Na. x [EuW 10 O 36 • yH2O, where x is taken from 8, 9, 10, and y is taken from 30, 31, 32, 33, 34, 35.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The rare earth metal-based ternary composite antibacterial agent of the present invention uses Na x [EuW 10 O 36 • After being fractionally compounded with peptides and biogenic amines, yH2O exhibits highly effective antibacterial activity against Escherichia coli and Staphylococcus aureus. The ternary assembly EuW 10 The fluorescence emission of / GL-22 / Spm is enhanced by 30 to 40 times, and it is effective against Escherichia coli (E. coli). E. coli The antibacterial properties of the drug were improved from 30% to 40% to 90% to 95%, and the inhibition rate of biofilm (BME) formation of E. coli was 21.8%.

[0023] (2) In this invention, Weakley type POM: Na x [EuW 10 O 36 •yH2O (EuW 10 A ternary assembly was constructed from spermine (Spm) and arginine-rich peptide (GL-22) from the high-risk subtype of HPV E6 early oncoprotein. With both surfaces carrying a positive charge, Spm and GL-22, along with EuW... 10Instead of competitive binding, a synergistic effect occurred, leading to a gradual increase in fluorescence emission and significantly enhancing its antibacterial activity. Furthermore, fluorescence spectroscopy, DLS, zeta-potential analysis, and transmission electron microscopy (TEM) results indicate that the formed nanosphere-shaped ternary assembly is dominated by electrostatic synergistic interactions between its components. EuW 10 The enhanced luminescence is primarily attributed to: the shielding of water molecules in the environment after assembly with Spm and GL-22; and the large amount of ROS generated when the assembly is incubated with E. coli, which kills the bacteria. Therefore, EuW... 10 The / Spm / GL-22 assembly is considered a novel rare earth material with broad antibacterial activity. (Based on EuW...) 10 Using nanoparticles composed of GL-22 as a model, this paves the way for the preparation of rare earth inorganic materials with solid fluorescence and extends the antibacterial mechanism of POMs through the generation of ROS.

[0024] (3) The arginine-rich peptide (GL-22) based on HPV E6 and inorganic rare earth metal-containing POM (EuW) prepared in this invention 10 The ternary assembly constructed from EuW and biogenic amines (Spm) exhibits significant luminescence and antibacterial enhancement effects. This assembly demonstrates strong biofilm disruption, membrane penetration, and BME-adaptive ROS generation, leading to rapid biofilm elimination and significantly improved antibacterial activity. 10 The intrinsic mechanism by which the assembly enhances antibacterial properties is mainly: EuW 10 The peroxidase-like activity of bacteria and the endogenous hydrogen peroxide (H2O2) in BME promote the generation of ROS during the antibacterial process. Therefore, H2O2 involved in bacteria and BME plays a crucial role in enhancing ROS production.

[0025] (4) The novel rare-earth-containing polyoxometalate cluster composite material of this invention solves the problem of biofilm infection and achieves excellent antibacterial effect. This invention constructs a concept of a novel bio-inorganic composite antibacterial material and will help promote the assembly structure of rare earth metals and biogenic amines / peptides to develop novel antiviral drugs. Attached Figure Description

[0026] Figure 1 The fluorescence spectrum of the binary assembly prepared in Example 2;

[0027] Figure 2 The fluorescence spectrum of the ternary assembly prepared in Example 3;

[0028] Figure 3 This is a graph showing the change in particle size during the preparation of binary assemblies.

[0029] Figure 4 A graph showing the particle size variation trend during the preparation of binary assemblies;

[0030] Figure 5 This is a transmission electron microscope (TEM) image of the ternary assembly.

[0031] Figure 6 This diagram illustrates the surface potential changes during the fabrication of the binary assembly.

[0032] Figure 7 This diagram shows the surface potential changes during the fabrication of the ternary assembly.

[0033] Figure 8 These are photographs of the antibacterial test process against Escherichia coli for different assemblies in Example 6;

[0034] Figure 9 This is a statistical chart showing the survival rate of E. coli in different assemblies in Example 6;

[0035] Figure 10 Photographs of the antibacterial test process of different assemblies against Staphylococcus aureus in Example 6;

[0036] Figure 11 This is a statistical chart showing the survival rate of Staphylococcus aureus in different assemblies in Example 6;

[0037] Figure 12 ROS generation for different assemblies;

[0038] Figure 13 For different assemblies E. coli The formation of biofilms;

[0039] Figure 14 For different assemblies and E. coli The absorption of the bacterial biofilm at 595 nm after incubation. Detailed Implementation

[0040] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The experimental reagents used in the following embodiments are as follows:

[0041] Spermine (Spm), 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) and crystal violet were purchased from Aladdin Chemical Co., Ltd.

[0042] The GL-22 peptide of the HPV E6 protein GRWTGRCMSCCRSSRTRRETQL sequence was ordered from Apeptide Co., Ltd. (Shanghai, China). According to the company's HPLC analysis, the purity is higher than 99%.

[0043] Na9[EuW 10 O36 ·32H2O, hereinafter referred to as EuW 10 .

[0044] 2-(N-Morpholino)ethanesulfonic acid (MES) and sodium hydroxide (NaOH) were purchased from Beijing Chemical Plant (Beijing, China). All chemicals were used without further treatment. Distilled water (ρ = 18.2 MΩ·cm, 25℃) was obtained from the Millipore Milli-Q water purification system. Furthermore, a 10.0 mM MES-NaOH buffer solution with pH = 6.0 was prepared using 10.0 mM MES and NaOH as raw materials and distilled water. EuW was prepared separately in a 2.0 mM aqueous solution. 10 The stock solution of SpM was prepared and stored in the dark (4°C), then diluted to the required concentration according to different experimental requirements. (Luria Broth (LB) was purchased from Sigma-Aldrich, Wicklow, Ireland). Gram-negative bacteria. E. coli and Staphylococcus aureus S.aureus All reagents are from Beijing Sihuan Biopharmaceutical Co., Ltd. Unless otherwise specified, all reagents are standard biochemical reagents; all experimental methods, unless otherwise specified, are standard methods.

[0045] The invention will be described in detail below with reference to specific embodiments.

[0046] Example 1 Na9[EuW 10 O 36 Preparation and purification of ·32H2O (EuW10)

[0047] Dissolve 8.3 g of Na₂WO₄·2H₂O in 20 mL of distilled water, and adjust the pH to 7.0–7.5 with acetic acid (CH₃COOH). Add 2 mL of an aqueous solution containing 1.1 g of Eu(NO₃)₃·6H₂O dropwise to the above solution, stir at 80–90 °C, and cool to room temperature to obtain crystalline Na₂[EuW₄]₂. 10 O 36 ]·32H2O, filtered, and dried in air to obtain Na9[EuW 10 O 36 ]·32H2O.

[0048] Example 2: Constructing EuW 10 / GL-22 and EuW 10 / Spm binary assembly

[0049] 12.5 μL GL-22 (2.0 mM) was mixed with EuW 10(50 μM) was mixed thoroughly in MES-NaOH (10.0 mM, pH=6.5) buffer to a final volume of 1.0 mL. After incubation at room temperature for 10 min, EuW was constructed. 10 / GL-22 binary assembly.

[0050] Different volumes of 0–125 μL Spm (2.0 mM) were added to a solution containing 25 μL 2.0 mM EuW. 10 The mixture was added to a MES-NaOH (10.0 mM, pH=6.5) buffer solution and stirred vigorously. The final volume of each mixture was fixed at 1.0 mL. After incubation at room temperature for 10 min, EuW was constructed. 10 / Spm binary assemblies were used to record the fluorescence spectra of each mixed solution at an excitation wavelength of 500 nm.

[0051] The results are as follows Figure 1 As shown, EuW prepared in Example 2 10 Fluorescence spectra of (50 μM) and Spm (0.25–50 μM, from bottom to top: 0, 0.25, 0.50, 1.00, 1.50, 2.00, 3.00, 5.00, 10.0, 15.0, 25.0, 35.0, 50.0 μM) in the 580–635 nm wavelength range were obtained. The results showed that... 10 Titration of Spm in a solution resulted in a gradual increase in fluorescence emission, reaching a maximum at a Spm concentration of 50 μM, with a 21.92-fold increase in fluorescence emission at 591 nm. This confirms the EuW... 10 It exhibits a strong affinity with Spm. Through ratio optimization, EuW was ultimately determined. 10 The concentrations of Spm were 50 μM and 50 μM, respectively.

[0052] Example 3: Constructing EuW 10 / Spm / GL-22 and EuW 10 / GL-22 / Spm ternary assembly

[0053] The binary assembly EuW prepared in Example 2 10 Add 2.0 mM GL-22 in a 0.5–30 μL volume to a 50 μM / 50 μM MES-NaOH (10.0 mM, pH=6.5) buffer solution to a final volume of 1.0 mL. After incubation at room temperature for 10 min, record the fluorescence spectrum changes at an excitation wavelength of 500 nm. EuW 10 The construction of / GL-22 / Spm is the same as described above, but the order of component addition is different.

[0054] The results are as follows Figure 2 As shown, to contain EuW 10 / Spm (50 μM / 50 μM) assembly solution ( Figure 1 Based on this, GL-22 was further titrated (0-35 μM, from bottom to top: 0, 0.50, 1.00, 1.50, 2.00, 3.00, 5.00, 10.0, 15.0, 25.0, 35.0), and its fluorescence spectrum in the 580-635 nm band was tested. The results showed that its fluorescence emission continued to increase, and the fluorescence reached its maximum value when the concentration of GL-22 was 35.0 μM.

[0055] Example 4: Particle size and potential variation trends of binary and ternary assemblies

[0056] During the preparation of the binary assembly in Example 2, EuW 10 The particle size variation of assemblies formed by / Spm (50 μM / 50 μM) and GL-22 (0–70 μM, from left to right: 0, 0.5, 1.0, 2.5, 5.0, 10, 15, 25, 35, 50, 70 μM). DLS results are shown below. Figure 3 As shown, it can be seen that: EuW 10 The average particle size of the / Spm assembly in buffer was 37.8 nm. Upon introduction of 5 μM GL-22, the assembly size increased to 50.7 nm; when the GL-22 concentration increased to 35.0 μM, the particle size increased to 165 nm. Finally, upon introduction of 70 μM GL-22, the particle size increased to approximately 295 nm. Figure 4 for Figure 3 The particle size variation trend graph shows that the particle size of the assembly increases sequentially with the titration of GL-22, which confirms the EuW... 10 / Spm / GL-22 forms a large assembly structure.

[0057] Example 3: During the preparation of the ternary assembly, (A) EuW 10 / Spm / GL-22 (50 μM / 50 μM / 5 μM) and (B) EuW 10 Transmission electron microscopy (TEM) images of / Spm / GL-22 (50 μM / 50 μM / 50 μM) are shown below. Figure 5 As shown, it can be seen that when 5 μM GL-22 is added to a solution containing EuW... 10 When the / Spm assemblies are in solution, the particles are monodisperse with an average diameter of 51.0 nm. As GL-22 is increased to 50 μM, the cross-linked network structure becomes more compact, and some aggregates begin to expand into spherical particles of approximately 250 nm.

[0058] EuW during the preparation of the binary assembly in Example 2 10 The surface potential variations of (50 μM) and Spm (0.25–50 μM, from left to right: 0, 0.50, 1.00, 2.00, 3.00, 5.00, 10.0, 15.0, 25.0, 35.0, 50.0 μM) are shown below. Figure 6 As shown, when the Spm concentration is 40 μM, the surface potential approaches 0 mV, and then increases with increasing Spm concentration. When the Spm concentration increases to 80 μM, the assembly surface saturates, and the surface potential approaches 60 mV, nearing equilibrium. This further confirms the EuW... 10 And the electrostatic driving effect between the two components.

[0059] EuW during the preparation of the binary assembly in Example 3 10 The surface potential variations of / Spm (50 μM / 50 μM) and GL-22 (0.25~50 μM, from bottom to top: 0, 3.00, 5.00, 10.0, 15.0, 20.0, 25.0, 30.0 μM) are as follows: Figure 7 As shown, it can be seen that when 3.00 μM Spm is introduced, the surface potential is close to 0 mV. As the Spm concentration increases, the surface potential of the assembly gradually increases.

[0060] Example 5 Gram-negative bacteria E. coli and Staphylococcus aureus S.aureus cultivation

[0061] Single colonies of MRSA were inoculated into Luria-Bertani (LB) agar medium and cultured at 37°C and 180 rpm for 14–16 h to obtain suspensions of different bacterial types. The optical density at 600 nm (OD) was [not specified in the original text]. 600 The ultraviolet absorbance value is used to evaluate E. coli and S.aureus The growth status of OD in this invention is controlled. 600 =0.4 ~ 0.6.

[0062] Example 6 Antibacterial test on agar plates

[0063] raw material EuW 10 (12.5 μM), Spm (12.5 μM), and GL-22 (6.25 μM) were assembled into a binary (EuW) compound in phosphate-buffered saline (PBS, negative control). 10 / Spm、EuW 10 / GL-22, GL-22 / Spm) and triad (EuW 10 / Spm / GL-22、EuW 10 Different assemblies of / GL-22 / Spm, respectively with E. coli suspension (OD) 600 = 0.2) and S.aureus suspension (OD) 600 = 0.2) Mix. After incubating at 37℃ for 3 h, spread 0.2 mL of the diluted bacterial suspension on LB agar and incubate at 37℃ for 18 h. Determine the bacterial survival rate using the standard plate count method and take a photograph.

[0064] Results of the effect on Escherichia coli: Figure 8 and Figure 9 As shown, a significant reduction in *E. coli* colonies was observed after incubation with binary and ternary assemblies. Based on counts, individual Spm and GL-22 cells in the plates showed almost no inhibitory effect on *E. coli* growth compared to the control, indicating that they had no antibacterial effect against *E. coli*. In contrast, EuW... 10 It showed a significant inhibitory effect on Escherichia coli, with a bacterial survival rate of 65.22%. When combined with Spm and GL-22, respectively, the activity of E. coli decreased to 31.44% and 23.08%, respectively. Furthermore, EuW... 10 The ternary assembly of / Spm / GL-22 resulted in a 0% survival rate for E. coli.

[0065] Results of the effect on Staphylococcus aureus are as follows Figure 10 and Figure 11 As shown, EuW is introduced respectively. 10 / Spm / GL-22 and EuW 10 / GL-22 / Spm S.aureus The survival rates were 6.29% and 11.10%, respectively. Compared with the control, 6.25 μM GL-22 significantly improved the survival rate of the control group. S.aureus It had a slight inhibitory effect on the growth of [the organism], with an activity of 84.71%; 12.5 μM Spm [drug name missing] had a slight inhibitory effect on [the organism's] growth. S.aureus Growth was significantly inhibited, with activity reduced to only 2.34%. Multiple studies have shown that exogenous Spm has a cumulative toxicity to bacteria and exhibits strong inhibitory effects. Furthermore, the addition of GL-22 to EuW... 10 The antimicrobial capacity was further enhanced in the / Spm assembly, with a bacterial survival rate of only 0.25%. Similarly, EuW... 10 / GL-22 / Spm caused S.aureus The survival rate dropped to 0.12%.

[0066] Example 7: Determination of ROS

[0067] Using EuW respectively 10 Treatment of three components, Spm and GL-22, and their binary or ternary assemblies E. coli Collect after 9 hours of incubation E. coli Intracellular ROS levels were determined using a standard method. Bacterial samples were treated with 30 μL × 1.0 mM 2',7'-dichlorofluorescein diacetate (DCFH-DA). DCFH-DA is a specific indicator of ROS generation. Non-fluorescent DCFH-DA was oxidized to fluorescent DFC using a Shimadzu RF-5301PC fluorescence spectrophotometer (λex = 488 nm; λem = 525 nm). Results are shown below. Figure 12 As shown, under the same in vitro conditions, the ROS generation of binary and ternary assemblies gradually increases. Therefore, we speculate that positively charged Spm and GL-22 in EuW... 10 Surface bonding may expose more catalytic active sites and promote ROS generation to some extent.

[0068] Example 8 BME Elimination Test

[0069] The ability of bacteria to form BME was evaluated using the crystal violet method in a 96-well microtiter plate. OD 600 = 0.3 ~ 0.5 dilution E. coli The suspension (100 μL) was co-cultured with 800–900 μL of LB medium at pH = 6.0. E. coli The cells were cultured continuously at 37°C for 8 hours. PBS (control) and EuW were used. 10 , Spm, GL-22, Spm / GL-22, EuW 10 / GL-22、EuW 10 / Spm、EuW 10 / Spm / GL-22、EuW 10 / GL-22、Spm / GL-22 / EuW 10 Treatment of mixed solutions E. coli Then, the bacterial BME was incubated at 37°C for 8 hours. After the BME was formed, the supernatant was removed, and each biofilm pore was rinsed with sterile water to remove the sample and dead bacteria.

[0070] Add 200 μL of 0.1% crystal violet staining solution to each well and stain BME for 30 min. Then, wash each well with PBS buffer and allow the biofilm to dry at room temperature. Finally, rinse each well with anhydrous ethanol / acetic acid (v / v = 1:1) to remove bacterial BME from the well walls. The OD595 absorbance of each group of BME was monitored using a multi-functional microplate reader (Thermo Scientific, Varioskan LUK), and the color was recorded using a digital camera. Results are as follows: Figure 13 and Figure 14 As shown, bacterial biofilms adhere to the surface of substances or tissues, encapsulating extracellular polymeric substances and preventing antibiotics from penetrating the bacterial cells. This leads to antibiotic resistance and treatment failure. Therefore, biofilm removal is crucial in antibacterial detection. This invention uses crystal violet staining to study individual EuW... 10 Biofilm formation and elimination of Spm and GL-22 or their assemblies. Using PBS (blank control), EuW... 10 Spm, GL-22, EuW 10 / GL-22、EuW 10 / Spm、EuW 10 / Spm / GL-22、EuW 10 / GL-22 / Spm (from top to bottom) and E. coli Analysis of the elimination effect of bacterial biofilm after incubation and crystal violet staining. Figure 13 The control group without any drug treatment is shown in dark blue, indicating that under current conditions... E. coli The formation of biofilms. Figure 13 Different assemblies and E. coli After incubation, the absorbance of the bacterial biofilm stained with crystal violet at 595 nm was analyzed. Figure 14 It can be seen that EuW alone 10 After treatment with Spm, the blue color significantly decreased. UV-Vis spectrophotometry analysis showed that the biofilm retention rates were 30–40% and 20–25%, respectively, while the effect of GL-22 was relatively low (60–65%). EuW was introduced... 10 / GL-22 and EuW 10 Following the assembly of the / Spm assembly, the fluctuations in biofilm formation were relatively small, at 38.8% and 31.0%, respectively. Meanwhile, EuW... 10 / Spm / GL-22 and EuW 10 The / GL-22 / Spm ternary assembly significantly inhibited biofilm formation, with biofilm formation rates of 26.8% and 21.8%, respectively.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Use of a rare earth metal-based ternary composite antibacterial agent in the preparation of an antibacterial medicament, characterized in that: The antibacterial agent is a ternary assembly formed by assembling GL-22, a Eu-containing polyoxometalate and spermine (Spm) through electrostatic interaction; wherein the molar concentration ratio of GL-22, the Eu-containing polyoxometalate and Spm is 1: (1-2): (5-10), the amino acid sequence of GL-22 is GRWTGRCMSCCRSSRTRRETQL, and the Eu-containing polyoxometalate is Na x [EuW 10 O 36 ]•yH2O, wherein x is 9, y is 32, and the Eu-containing polyoxometalate is abbreviated as EuW 10 .

2. Use of the rare earth metal-based ternary composite antibacterial agent according to claim 1 in the preparation of an antibacterial medicament, characterized in that: GL-22, a polyoxometalate containing Eu, the molar concentration ratio of Spm is 1:1:

5.

3. Use of the rare earth metal-based ternary composite antibacterial agent according to claim 1 in the preparation of an antibacterial medicament, characterized in that: The Na x [EuW 10 O 36 The method for producing Na2[EuW4O16]•yH2O comprises the following steps: After dissolving Na2WO4-2H2O in distilled water, the pH value is adjusted to 7.0-7.5, an aqueous solution containing Eu(NO3)3-6H2O is added dropwise into the above solution, stirred uniformly at 80-90°C, and cooled to room temperature to obtain crystallized Na x [EuW 10 O 36 ]•yH2O.

4. Use of the rare earth metal-based ternary composite antibacterial agent according to claim 3 for the preparation of an antibacterial medicament, characterized in that: The mass ratio of the Na2WO4*2H2O to the Eu(NO3)3*6H2O is (8.0~9.0):(1.0~1.3).

5. Use of the ternary composite antibacterial agent of rare earth metal base according to any one of claims 1 to 4 for the preparation of an antibacterial medicament, characterized in that: The preparation method of the rare earth metal-based ternary composite antibacterial agent comprises the following steps: S1: constructing a binary assembly; In MES-NaOH buffer with pH value of 6 ~ 7, the Eu-containing polyoxometalate was mixed with Spm and GL-22 respectively, and after incubation at room temperature for 5 ~ 15 min, EuW 10 / Spm binary assembly and EuW 10 / GL-22 binary assembly were obtained respectively. S2: constructing a ternary assembly; In MES-NaOH buffer solution with pH value of 6-7, Spm was added to EuW 10 / GL-22, and EuW 10 / Spm was obtained after incubation at room temperature for 5-15 min, and EuW 10 / GL-22 / Spm and EuW 10 / Spm / GL-22, namely, the rare earth metal-based ternary composite antibacterial agent was obtained.

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