Preparation and application of novel ultrasonic-driven nano-enzyme MOF (Hf)-Pt

Abstract

The invention discloses preparation and application of a novel ultrasonic-driven nano-enzyme MOF (Hf)-Pt, the novel piezoelectric nano-enzyme MOF (Hf)-Pt is composed of UIO-66-NH2 (Hf) and an ultra-small Pt nano-enzyme and presents a regular octahedron shape, and the diameter of the novel piezoelectric nano-enzyme MOF (Hf)-Pt is 180-200 nm; the piezoelectric effect is achieved, external ultrasonic stimulation is utilized, and variable electrical stimulation is provided through piezoelectric catalysis; in addition, the composite material has the advantages of being small in size and easy to prepare, has catalase-like activity and superoxide dismutase activity at the same time, and has good biocompatibility. The MOF (Hf)-Pt is used as a novel piezoelectric catalyst, and the technical effect of treating OA is achieved by improving the enzyme catalytic activity of the nano-enzyme, relieving oxygen deficit of an inflammation part, recovering the mitochondrial function, removing excessive ROS in an inflammation tissue and promoting cartilage regeneration through the piezoelectric effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomedicine, and specifically relates to the preparation and application of a novel ultrasound-driven nanozyme MOF (Hf)-Pt. Background Art

[0002] Osteoarthritis (OA), as the most common chronic degenerative bone and joint disease, has become one of the most important factors causing human limb pain and dysfunction.

[0003] The current clinically developed therapies are aimed at relieving pain and have not yet been able to effectively inhibit the progression of OA. In OA joints, ROS-induced oxidative stress is a key part of promoting chondrocyte apoptosis and extracellular matrix enzyme degradation, ultimately destroying joint homeostasis. Therefore, removing ROS and alleviating oxidative stress is an effective measure to inhibit OA. However, during the pathological development of OA, due to impaired mitochondrial function, the activity of antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) is significantly reduced, and the excessive ROS produced in the body cannot be removed.

[0004] Chinese patent CN118697871A (publication date: September 27, 2024) discloses a supramolecular hybrid nanozyme cascade delivery system and its preparation method and application. The preparation method includes the following steps: constructing a plasmon material library and a multivalent transition metal oxide and sulfide database; using plasmon materials and multivalent transition metal oxides and sulfides to construct a plasmon nanozyme substrate; using water-soluble macrocyclic aromatic hydrocarbons to construct a supramolecular hybrid nanozyme cascade delivery system. The present invention is based on the treatment status and needs of deep infected wounds, and uses the plasmon effect to accurately control the wavelength of the localized surface plasmon resonance absorption peak, significantly improving the catalytic activity of hybrid nanozymes, and constructing a supramolecular hybrid nanozyme cascade delivery system with stimulus response based on the modification and complexation of macrocyclic aromatic hydrocarbons, providing guidance for the development of a multifunctional antibacterial platform, realizing the visualization of deep infected wounds and promoting their healing.

[0005] Chinese patent CN118634864A (publication date: September 13, 2024) discloses a heteroatom ligand MOF nanozyme and its preparation method and application. The heteroatom ligand MOF nanozyme is prepared according to the following steps: N, N-dimethylformamide is added to a pressure-resistant bottle, and after blowing nitrogen, ferrous chloride tetrahydrate and 1H1,2,3 triazole ligand salt and sulfur atom ligand salt are added. Two mixed ligands are synthesized by solvothermal method to synthesize sulfur-doped SMET (Fe) nanozyme. The present invention can simply and efficiently prepare sulfur-doped SMET (Fe) nanozyme by solvothermal method within 130 ° C, and the synthesis step is simple and easy to control, the reaction process is stable and controllable, and it can be mass-produced, which solves the problems of complex preparation process, high energy consumption and high cost of existing heteroatom-doped nanozymes. The nanozyme of the present invention has a high affinity with the substrate, greatly improves the catalytic activity, has good antibacterial activity, and has a very broad application prospect in the fields of catalysis and biomedicine.

[0006] Chinese patent CN118491556A (publication date: August 16, 2024) discloses a carbon nitride nanozyme and its preparation method and application, wherein the carbon nitride nanozyme contains a copper-iron alloy, wherein the molar ratio of copper to iron in the copper-iron alloy is 1:(0.33), and in the carbon nitride nanozyme, the molar ratio of carbon nitride to the copper-iron alloy is 3:(35). The present invention adopts a green and simple method to prepare a copper-iron alloy-doped carbon nitride nanozyme, which efficiently catalyzes the TMB color development reaction, has economical raw materials, and the final product has significantly higher peroxidase-like activity than ordinary nanozymes, and is even better than the natural horseradish peroxidase on sale, and has broad application prospects.

[0007] Nanomaterials based on enzyme catalytic properties have attracted great attention. Unlike natural enzymes that can only function in mild environments, nanozymes are able to maintain catalytic activity in complex microenvironments and control redox balance by simulating the catalytic cascade system of endogenous antioxidants. Platinum (Pt) nanozymes have excellent multi-enzyme mimetic activity and can catalyze the dismutation of superoxide anion radicals (O2-) into H2O2 and O2, and further convert H2O2 into O2 and H2O through cascade reactions. They can relieve hypoxia at the site of inflammation and remove excess ROS in inflammatory tissues, making them ideal antioxidants for the treatment of OA. However, as a substitute for natural enzymes, nanozymes still have inherent defects in the treatment of diseases, such as the lack of high active centers and low activity density on their surfaces, resulting in low catalytic activity and poor therapeutic effects.

[0008] In summary, the present invention provides a preparation and application of a novel ultrasound-driven nanozyme MOF (Hf) -Pt, aiming to form a novel ultrasound-driven nanozyme with piezoelectric catalysis, thereby expanding the new field of nanozymes in the treatment of OA. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a new type of piezoelectric nanozyme with enhanced enzyme-like catalytic activity and good in vivo biocompatibility. Under the action of ultrasound, it synergizes the piezoelectric catalytic effect to clear excess ROS in inflammatory tissues and restore mitochondrial function. At the same time, it provides a safe and effective bionic electrophysiological microenvironment for cartilage regeneration, promotes cartilage regeneration, and achieves the effect of treating OA.

[0010] To this end, this application provides the following technical solutions:

[0011] A method for preparing a novel ultrasonically driven piezoelectric nanozyme MOF (Hf)-Pt comprises the following steps:

[0012] Step S1, mixing HfCl4 solid and BDC-NH2 solid with DMF solution;

[0013] Step S2, adding glacial acetic acid to the mixture obtained in step S1, and subjecting the mixture to water bath ultrasonic treatment;

[0014] Step S3, placing the product of S2 into a reactor and subjecting it to high temperature treatment;

[0015] Step S4, cooling the product of S3, centrifuging and washing the precipitate and then vacuum drying;

[0016] Step S5, adding H2PtCl6·6H2O to the product of S4, stirring to react;

[0017] Step S6, adding NaBH4 and continuing to stir the reaction;

[0018] Step S7, centrifuging the product of S6 and washing the precipitate;

[0019] Step S8, vacuum drying the product of S7 to obtain the MOF (Hf) -Pt finished product.

[0020] Preferably, in step S1, the material ratio of HfCl4 solid, BDC-NH2 solid and DMF solution is 200-220 mg HfCl4 solid: 100-125 mg BDC-NH2 solid: 45-50 ml DMF solution.

[0021] Preferably, in step S2, the water bath ultrasonic treatment time is 5-10 min.

[0022] Preferably, in step S3, the temperature of the high temperature treatment is 110-120° C.; and the time of the high temperature treatment is 12-24 hours.

[0023] Preferably, in step S4, the washing material is anhydrous ethanol, and the washing times are 2-3 times.

[0024] Preferably, in step S5, the concentration of H2PtCl6·6H2O is 10-20 mM, and the stirring reaction time is 1-2 h.

[0025] Preferably, in step S6, the concentration of NaBH4 is 50 mM and the stirring reaction time is 12 h.

[0026] Preferably, in step S7, the washing material is anhydrous ethanol, and the washing times are 2-3 times.

[0027] Preferably, in step S8, the drying time is 12 to 24 hours.

[0028] Preferably, the novel piezoelectric nanozyme catalyst is composed of UIO-66-NH2(Hf) and ultrasmall Pt nanozyme, and the Pt content is 6-8%.

[0029] Preferably, the piezoelectric performance of MOF (Hf) is improved after loading PtNPs, and variable electrical stimulation is provided through piezoelectric catalysis using external ultrasonic stimulation.

[0030] Compared with the prior art, the advantages and effects of the present invention are as follows:

[0031] 1. The present invention loads ultrasmall Pt nanozymes onto hafnium-based metal organic framework materials (UIO-66-NH2(Hf)) to synthesize novel nanozymes with piezoelectric catalysis. This novel nanozyme MOF(Hf)-Pt has excellent piezoelectric effect and provides variable electrical stimulation through piezoelectric catalysis using external ultrasonic stimulation.

[0032] 2. The novel piezoelectric catalytic nanozyme MOF (Hf) -Pt provided by the present invention has the advantages of small size and easy preparation, and simultaneously possesses catalase-like activity and superoxide dismutase activity, and has good biocompatibility.

[0033] 3. The ultrasound-driven nanozyme MOF (Hf) -Pt provided by the present invention is a new type of piezoelectric catalyst. It improves the enzymatic catalytic activity of the nanozyme through the piezoelectric effect, relieves hypoxia in the inflammatory site, restores mitochondrial function, removes excess ROS in the inflammatory tissue, promotes cartilage regeneration, and achieves the technical effect of treating OA.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application so that it can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following is a detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings as follows.

[0035] Based on the detailed description of the specific embodiments of the present application in combination with the accompanying drawings below, those skilled in the art will become more aware of the above and other objects, advantages and features of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0037] in:

[0038] Figure 1 A flow chart of the preparation method of the novel piezoelectric nanozyme MOF (Hf) -Pt provided by the present invention;

[0039] Figure 2 This is a transmission electron microscope image of the novel piezoelectric nanozyme MOF (Hf)-Pt provided by the present invention.

[0040] in Figure 2 (A) is the transmission electron microscopy image of the piezoelectric nanozyme MOF (Hf)-Pt before loading PtNPs.

[0041] Figure 2 (B) is the transmission electron microscopy image of the piezoelectric nanozyme MOF (Hf)-Pt after loading PtNPs;

[0042] Figure 3 This is a graph showing the catalase-like activity detection of the novel piezoelectric nanozyme MOF (Hf)-Pt provided by the present invention;

[0043] Figure 4 This is the ESR detection diagram of the novel piezoelectric nanozyme MOF (Hf) -Pt provided by the present invention.

[0044] in Figure 4 (A) is the ESR spectrum of MOF(Hf)-Pt and MOF(Hf)-Pt+US materials removing superoxide anions (O2-) before and after adding ultrasound at the same concentration.

[0045] Figure 4 (B) ESR spectra of MOF(Hf)-Pt and MOF(Hf)-Pt+US materials removing hydroxyl radicals (OH) before and after ultrasound at the same concentration.

[0046] Figure 5This is a piezoelectric performance test diagram of the new piezoelectric nanozyme MOF (Hf) -Pt provided by the present invention.

[0047] in Figure 5 (A) is the surface potential image of MOF (Hf),

[0048] Figure 5 (B) is the amplitude loop diagram of MOF (Hf),

[0049] Figure 5 (C) is the surface potential image of MOF(Hf)-Pt.

[0050] Figure 5 (D) is the amplitude loop diagram of MOF(Hf)-Pt;

[0051] Figure 6 The biocompatibility diagram of the novel piezoelectric nanozyme MOF (Hf) -Pt provided by the present invention is shown in FIG.

[0052] Figure 7 This is a diagram showing the ability of the novel piezoelectric nanozyme MOF (Hf) -Pt provided by the present invention to remove intracellular ROS.

[0053] in Figure 7 (A) is the fluorescence image of DCFH-DA fluorescence probe experiment.

[0054] Figure 7 (B) is the fluorescence quantitative results of the DCFH-DA fluorescent probe experiment. DETAILED DESCRIPTION

[0055] To make the purpose, technical scheme and advantages of the embodiment of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, rather than all of the embodiments. In the following description, specific details such as specific configuration and components are provided only to help fully understand the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, for clarity and brevity, the description of known functions and structures is omitted in the embodiment.

[0056] It should be understood that the references to "one embodiment" or "this embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present application. Therefore, the references to "one embodiment" or "this embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0057] In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0058] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" in this article describes another type of association object relationship, indicating that there can be two relationships. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0059] The term "at least one" in this article is merely a description of the association relationship of associated objects, indicating that there may be three relationships. For example, at least one of A and B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0060] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusions.

[0061] Example 1

[0062] This embodiment is a novel piezoelectric nanozyme MOF (Hf) -Pt and its preparation method.

[0063] Research reports that nanozymes can further enhance their nanozyme activity through external stimulation, such as photothermal catalysis and piezoelectric catalysis. Piezoelectric catalysis technology shows great development potential in the medical field. The piezoelectric polarization field generated by the mechanical deformation of piezoelectric materials promotes the separation of electron-hole pairs and triggers cascade redox reactions with surrounding molecules, thereby enhancing the catalytic activity of nanozymes.

[0064] The novel piezoelectric nanozyme is composed of UIO-66-NH2(Hf) and ultra-small Pt nanozyme. Figure 1 , is a method for preparing a novel piezoelectric nanozyme MOF (Hf) -Pt provided by the present invention, comprising:

[0065] Step S1, mixing HfCl4 solid and BDC-NH2 solid with DMF solution;

[0066] Step S2, adding glacial acetic acid to the mixture obtained in step S1, and subjecting the mixture to water bath ultrasonic treatment;

[0067] Step S3, placing the product of S2 into a reactor and subjecting it to high temperature treatment;

[0068] Step S4, cooling the product of S3, centrifuging and washing the precipitate and then vacuum drying;

[0069] Step S5, adding H2PtCl6·6H2O to the product of S4, stirring to react;

[0070] Step S6, adding NaBH4 and continuing to stir the reaction;

[0071] Step S7, centrifuging the product of S6 and washing the precipitate;

[0072] Step S8, vacuum drying the product of S7 to obtain the MOF (Hf) -Pt finished product.

[0073] Furthermore, the material ratio of HfCl4 solid, BDC-NH2 solid and DMF solution is 200-220 mg HfCl4 solid: 100-125 mg BDC-NH2 solid: 45-50 ml DMF solution.

[0074] Furthermore, in step S2, the water bath ultrasonic treatment time is 5-10 min.

[0075] Furthermore, in step S3, the temperature of the high temperature treatment is 110° C.-120° C.; and the time of the high temperature treatment is 12-24 hours.

[0076] Furthermore, in step S4, the washing material is anhydrous ethanol, and the washing times are 2-3 times.

[0077] Furthermore, in step S5, the concentration of H2PtCl6·6H2O is 10-20 mM, and the stirring reaction time is 1-2 h.

[0078] Furthermore, in step S6, the concentration of NaBH4 is 50 mM and the stirring reaction time is 12 h.

[0079] Furthermore, in step S7, the washing material is anhydrous ethanol, and the washing times are 2-3 times.

[0080] Furthermore, in step S8, the drying time is 1224 hours.

[0081] Example 2

[0082] Based on the above Example 1, this example introduces the morphology, size and distribution of the new piezoelectric nanozyme MOF (Hf) -Pt.

[0083] Please refer to Figure 2, is the transmission electron microscopy (TEM) image of the piezoelectric nanozyme MOF (Hf)-Pt, where Figure 2 (A) is a transmission electron microscopy image of the piezoelectric nanozyme MOF (Hf) -Pt before loading PtNPs. The morphology, size and distribution of the nanomaterials were observed by TEM. The results showed that the MOF (Hf) nanomaterial was in the shape of a regular octahedron with a diameter of about 100-150nm. Figure 2 (B) is a transmission electron microscopy image of the piezoelectric nanozyme MOF (Hf) -Pt after loading with PtNPs. The morphology, size and distribution of the nanomaterials were observed by TEM. The results showed that after loading with PtNPs, black PtNPs particles with a diameter of about 180-200nm were evenly distributed on the surface of MOF (Hf) -Pt.

[0084] Example 3

[0085] Based on the above Example 1, this example verifies the effect of the CAT-like catalytic activity of the new piezoelectric nanozyme MOF (Hf)-Pt.

[0086] Please refer to Figure 3 , is a catalase (CAT) activity detection diagram of the piezoelectric nanozyme MOF (Hf) -Pt. The CAT activity of the nanozyme MOF (Hf) -Pt was detected by a dissolved oxygen meter. The results showed that at the same concentration (100 μg / mL), the concentration of oxygen produced by the decomposition of hydrogen peroxide in the MOF (Hf) -Pt group was higher, indicating that it has good CAT-like activity. Compared with the MOF (Hf) -Pt group, the MOF (Hf) -Pt + US group produced more oxygen, indicating that under ultrasound, the MOF (Hf) -Pt nanozyme has enhanced CAT-like catalytic activity.

[0087] Example 4

[0088] Based on the above Example 1, this example verifies the effect of piezoelectrically enhanced SOD-like catalytic activity of the new piezoelectric nanozyme MOF (Hf)-Pt.

[0089] Please refer to Figure 4 , is the ESR detection diagram of piezoelectric nanozyme MOF (Hf)-Pt, where Figure 4 (A) is the ESR spectrum of MOF(Hf)-Pt and MOF(Hf)-Pt+US materials removing superoxide anions (O2-) before and after adding ultrasound at the same concentration. Figure 4(B) is the ESR spectrum of MOF(Hf)-Pt and MOF(Hf)-Pt+US materials at the same concentration before and after adding ultrasound to scavenge hydroxyl radicals (OH); the results show that when MOF(Hf)-Pt is not added, the ESR signal of O2·- is the strongest, indicating the presence of excess O2·-, and after adding MOF(Hf)-Pt, the ESR signal decreases, indicating that MOF(Hf)-Pt has excellent scavenging effect on O2·-free radicals. The scavenging effect of MOF(Hf)-Pt on ·OH was also investigated, and the trend was consistent with that of O2·-, further proving the superior SOD-like activity of MOF(Hf)-Pt nanozyme. Moreover, under external ultrasound, the signal intensities of O2·- and ·OH were significantly weaker than before ultrasound treatment, and the signal intensities were the lowest among the five groups, indicating that the MOF(Hf)-Pt+US group can scavenge more O2·- and ·OH. This indicates that MOF(Hf) has limited piezoelectrically enhanced SOD-like catalytic activity.

[0090] Example 5

[0091] Based on the above Example 1, this example verifies the effect of the piezoelectric performance of the new piezoelectric nanozyme MOF (Hf)-Pt.

[0092] Studies have shown that MOF(Hf) has piezoelectric properties, and experiments have shown that the overall piezoelectric properties of MOF(Hf)-Pt materials are improved after loading PtNPs. Figure 5 , is the piezoelectric performance test diagram of the piezoelectric nanozyme MOF (Hf) -Pt. Figure 5 (A) is the surface potential diagram of MOF (Hf), Figure 5 (C) is the surface potential diagram of MOF(Hf)-Pt. The results show that under the scanning bias from -10V to 10V, the phase change in the piezoelectric response phase hysteresis loop of MOF(Hf) and MOF(Hf)-Pt is about 180°, indicating that both nanoparticles have good piezoelectric responsiveness. Figure 5 (B) is the amplitude loop diagram of MOF (Hf), Figure 5 (D) is the amplitude loop diagram of MOF(Hf)-Pt. The results show that a typical butterfly shape can be observed in the "butterfly" amplitude loop results. The maximum amplitude changes of both are quite large. From the recorded amplitude butterfly loop, it is found that the d of MOF(Hf) 33 The value is 45.20 pmV-1, and the d 33 The value is 54.37 pmV-1, indicating that the piezoelectric performance of MOF(Hf)-Pt nanozyme is higher.

[0093] Example 6

[0094] Based on the above Example 1, this example verifies the biocompatibility of the new piezoelectric nanozyme MOF (Hf) -Pt.

[0095] After co-culturing the nanomaterials and chondrocytes, the CCK8 experiment was used to detect the toxicity of the nanozymes on chondrocytes. The results showed that when the concentration was 0-200 μg / mL, MOF(Hf) had no obvious toxicity to chondrocytes, and when the concentration was 0-50 μg / mL, MOF(Hf)-Pt also had no obvious cytotoxic effect. Only when the concentration was greater than 100 μg / mL did MOF(Hf)-Pt show certain cytotoxicity.

[0096] Example 7

[0097] Based on the above Example 1, this example verifies the ability of the new piezoelectric nanozyme MOF (Hf) -Pt to remove intracellular ROS.

[0098] Please refer to Figure 7 , which is a graph showing the ability of piezoelectric nanozyme MOF (Hf) -Pt to remove intracellular ROS. Chondrocytes pretreated with H2O2 were used as an in vitro oxidative stress and inflammation model, and the ability of nanozyme MOF (Hf) -Pt to remove intracellular ROS was determined by DCFH-DA fluorescent probe experiment. Figure 6 (A) is the fluorescence image of the DCFH-DA fluorescence probe experiment. The results show that the green fluorescence intensity of the H2O2 group is significantly enhanced, indicating that the H2O2-induced chondrocyte oxidative stress model was successfully established. Compared with the MOF(Hf)-Pt group, the fluorescence intensity of the MOF(Hf)-Pt+US group decreased more significantly, and the fluorescence intensity was close to that of the Normal group. This shows that the MOF(Hf)-Pt nanozyme with excellent CAT and SOD-like activity can significantly reduce the excessive ROS level in chondrocytes under the action of US. Figure 6 (B) is the fluorescence quantitative result of the DCFH-DA fluorescent probe experiment, where “#” indicates the statistical difference between each experimental group and the Normal group, #P<0.05, ##P<0.01, ###P<0.001; “*” indicates the statistical difference between any two experimental groups, *P<0.05, **P<0.01, ***P<0.001.

[0099] In summary, the present invention applies a hafnium-based metal organic framework material (UIO-66-NH2(Hf)), namely MOF(Hf), to the preparation of ultra-small Pt nanozymes, and demonstrates that piezoelectric catalysis technology enables it to generate a built-in electric field under conditions of mechanical stress such as ultrasound, providing variable electrical stimulation in the absence of an external power supply, effectively enhancing the activity of the nanozymes, and stimulating increased subchondral bone formation, driving the healing of OA-damaged cartilage. The invention is original and innovative.

[0100] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method 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 in the scope of protection of the present invention.

Claims

1. A method for preparing a novel ultrasound-driven nanozyme MOF (Hf)-Pt, characterized in that: The following steps are involved: Step S1, mixing HfCl4 solid and BDC-NH2 solid with DMF solution; Step S2, adding glacial acetic acid to the mixture obtained in step S1, and subjecting the mixture to water bath ultrasonic treatment; Step S3, placing the product of S2 into a reactor and subjecting it to high temperature treatment; Step S4, cooling the product of S3, centrifuging and washing the precipitate and then vacuum drying; Step S5, adding H2PtCl6·6H2O to the product of S4, stirring to react; Step S6, adding NaBH4 and continuing to stir the reaction; Step S7, centrifuging the product of S6 and washing the precipitate; Step S8, vacuum drying the product of S7 to obtain the MOF (Hf) -Pt finished product.

2. The method for preparing a novel ultrasound-driven nanozyme MOF (Hf)-Pt according to claim 1, characterized in that: In the step S1, the material ratio of HfCl4 solid, BDC-NH2 solid and DMF solution is 200-220 mg HfCl4 solid: 100-125 mg BDC-NH2 solid: 45-50 ml DMF solution.

3. The method for preparing a novel ultrasound-driven nanozyme MOF (Hf)-Pt according to claim 1 or 2, characterized in that: In the step S2, the water bath ultrasonic treatment time is 5-10 minutes; in the step S3, the temperature of the high temperature treatment is 110° C.-120° C.; and the time of the high temperature treatment is 12-24 hours.

4. The method for preparing a novel ultrasound-driven nanozyme MOF (Hf)-Pt according to claim 3, characterized in that: In step S4, the washing material is anhydrous ethanol, and the washing times are 2-3 times.

5. The method for preparing a novel ultrasound-driven nanozyme MOF (Hf)-Pt according to claim 4, characterized in that: In the step S5, the concentration of H2PtCl6·6H2O is 10-20 mM, and the stirring reaction time is 1-2 h; in the step S6, the concentration of NaBH4 is 50 mM, and the stirring reaction time is 12 h.

6. The method for preparing a novel ultrasound-driven nanozyme MOF (Hf)-Pt according to claim 5, characterized in that: In step S7, the washing material is anhydrous ethanol, and the washing times are 2-3 times.

7. The method for preparing a novel ultrasound-driven nanozyme MOF (Hf)-Pt according to claim 6, characterized in that: In step S8, the drying time is 12-24 hours.

8. An ultrasound-driven novel nanozyme MOF (Hf)-Pt prepared according to the preparation method according to any one of claims 1 to 7, characterized in that: The novel nanozyme MOF (Hf) -Pt is composed of UIO-66-NH2 (Hf) and ultra-small Pt nanozyme, and the Pt content is 6-8%; the novel nanozyme MOF (Hf) -Pt presents a regular octahedral morphology and a diameter of 180-200nm.

9. An ultrasound-driven novel nanozyme MOF (Hf)-Pt according to claim 8, characterized in that: After MOF(Hf) was loaded with PtNPs, external ultrasonic stimulation was used to provide variable electrical stimulation through piezoelectric catalysis.

10. Use of the ultrasound-driven novel nanozyme MOF (Hf) -Pt according to claim 8 or 9 in the preparation of a product for treating osteoarthritis (OA).

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