A photosensitive SOD-like nanozyme Mn / CeO2@COF and its preparation method

Abstract

The application discloses a photosensitive SOD-like nanenzyme Mn / CeO2@COF and a preparation method thereof, and belongs to the technical field of nanomaterials. The technical problem to be solved is to provide a composite nanosystem which combines SOD-like enzyme activity and the light response characteristics of COF. The technical solution is as follows: a covalent bonding strategy is adopted, Mn / CeO2, DPP and TAPA are used as raw materials to form a synthesis formula, a Mn-doped CeO2 nanenzyme with high SOD-like enzyme activity is combined with a COF carrier with a highly ordered pore structure, a high specific surface area and good biocompatibility to obtain a Mn / CeO2@COF binary composite material, the Mn / CeO2@COF binary composite material has superior photothermal performance, photothermal stability and more significant SOD-like enzyme activity, and has great application potential in the biomedical field which needs anti-inflammatory, antibacterial and antioxidant synergistic treatment such as wound healing.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, specifically to a photosensitive SOD-like nanozyme Mn / CeO2@COF and its preparation method. Background Technology

[0002] For understanding the technical content of this invention: Reactive oxygen species (ROS) are inevitably produced during the metabolic processes of organisms. When ROS levels in the body are too high, it leads to oxidative stress, which in turn triggers various pathological processes such as inflammation, neurodegenerative diseases, and tumors. ROS mainly include the primary species superoxide anion (O2·4O3 ... - ) and its protonation products, hydroxyl radicals (·OH), hydrogen peroxide (H2O2), and singlet oxygen ( 1 O2) and peroxynitrite anion (ONOO) - They occur through metal-catalyzed Fenton reactions, NO / O2· - Rapid complexation and other pathways amplify the process, ultimately triggering oxidative damage to lipids, proteins, and nucleic acids. As the first line of defense against reactive oxygen species (ROS) damage, superoxide dismutase (SOD) effectively scavenges superoxide anions (O2·4O3) through its unique catalytic site formed by the coordination of metal ions and amino acid residues. - It can also reduce oxidative stress. However, natural SOD enzymes have inherent drawbacks such as easy inactivation, poor stability in physiological environments, high preparation costs, and difficulty in long-term preservation, which greatly limit their widespread application in the biomedical field. Therefore, the development of highly stable, low-cost artificial enzymes (nanozymes) with SOD-like activity has become a research hotspot in recent years.

[0003] Compared to the limitations of natural SOD enzymes, such as short half-life, poor membrane permeability, high production cost, and potential immunogenicity, artificially designed SOD-like nanozymes exhibit significant advantages, including high stability, scalable preparation, and ease of functionalization. Among these, cerium dioxide (CeO2) nanoparticles, due to their unique CeO2 content... 3+ / Ce 4+Redox cycling ability is widely considered a promising candidate material for SOD-like enzymes. However, its intrinsic catalytic activity and catalytic rate still need improvement, and its spatiotemporal controllability in complex biological environments is insufficient, limiting its therapeutic precision and application efficacy. To overcome these bottlenecks, research focus has shifted to optimizing electronic structure through elemental doping (such as Cu and Au) to enhance intrinsic activity. Although metal-doped CeO2 nanozymes have shown higher activity compared to pure CeO2, they still face significant challenges in practical applications. First, traditional inorganic nanozymes are usually in a "continuously activated" state, lacking spatiotemporal control over catalytic activity, making it difficult to achieve on-demand treatment in specific lesion areas. Second, inorganic nanoparticles are prone to aggregation or encapsulation by protein coronas in complex physiological environments, leading to shielding of active sites and poor long-term stability. Therefore, the current goal is to achieve efficient and on-demand regulation of nanozyme activity.

[0004] Introducing external stimuli (such as light, heat, and ultrasound) to modulate the activity of nanozymes has become a highly promising strategy. Among them, near-infrared light (NIR) is considered an ideal external excitation source due to its excellent tissue penetration and low phototoxicity. Covalent organic frameworks (COFs), as a class of porous materials with highly ordered pore structures, high specific surface areas, and good biocompatibility, can not only serve as excellent carriers for nanozymes to prevent their aggregation, but their rich large π-conjugated systems also endow them with potential photothermal conversion or photodynamic properties.

[0005] Currently, although there are studies on CeO2 and COF respectively, there are few reports on how to construct a composite nanosystem that integrates the high activity of Mn-doped CeO2 with the photoresponsive properties of COF. The existing technical challenge lies in the fact that simple physical bonding often increases the mass transfer resistance of the substrate, resulting in the composite material's basic activity being lower than that of bare nanoparticles in the absence of external stimulation. Therefore, there is an urgent need to develop a novel structural design that, while having limited activity under conventional conditions, can significantly enhance enzyme activity under near-infrared light excitation through photothermal or photoelectron transfer effects, thereby achieving highly efficient and controllable SOD-like catalytic performance that surpasses traditional single materials.

[0006] Relevant patent documents retrieved: This document, published in China (CN120040694A) on May 27, 2025, discloses a core-shell material CeO2@FePc / por-COF based on photoresponsive peroxidases. By integrating FePc into the COF structure, this material enhances its photoresponsive activity at 808 nm in the near-infrared region, exhibiting excellent ROS generation capacity and significant photoresponsive peroxidase activity. However, at least three critical interfaces exist within the material. Under thermal stress, ultrasonic treatment, or mechanical stress in practical applications, these interfaces are prone to peeling, cracking, or delamination, leading to the disintegration of the core-shell structure. FePc molecules may partially block the pore entrances of the COF or aggregate within the pores. This severely hinders the free diffusion of reactants and products within the COF pores, preventing the effective utilization of the internal CeO2 and FePc active sites and significantly reducing the apparent catalytic efficiency. Furthermore, this material does not possess SOD enzyme activity, but instead possesses peroxidase activity, primarily generating ROS, which exacerbates oxidative damage. In addition, this material loads photosensitizers via physical adsorption, exhibiting poor stability and agglomeration.

[0007] This document, published in China (CN119425670A) on February 14, 2025, discloses a highly active Mn / CeO2 nanozyme prepared via Ce-MOFs and its preparation method. Ce-MOFs are used as a precursor, utilizing the organic ligands in Ce-MOFs to react with Mn... 2+ Coordination interactions introduce Mn elements into Ce-MOFs, leading to the derivatization of Mn / CeO2 nanozymes after heat treatment. These nanozymes exhibit oxidase-like and excellent peroxidase-like activities, showing promising potential applications in numerous fields. However, the band structure of MOFs is primarily determined by metal nodes and ligands, resulting in less precision and flexibility in photothermal conversion control compared to fully organic COFs. Metal nodes may bind and perturb the functional groups of organic ligands through coordination interactions, and many MOFs contain potentially toxic metal ions. While some (such as Fe and Zn groups) are relatively safe, their long-term biocompatibility still requires rigorous evaluation. In contrast, COF materials exhibit greater stability and are suitable for harsh environments, such as the acidic environments of wounds or tumors. Furthermore, the band structure of COFs is entirely derived from organic building blocks, offering high predictability and designability.

[0008] Relevant non-patent literature retrieved: The journal or book title is *Nanoscale*, and the article title is "Modulation of the biocatalytic activity and selectivity of CeO2 nanoozymes via atomic doping engineering," published on January 23, 2023. This article discloses the preparation of manganese and cobalt-doped cerium dioxide nanozymes (denoted as M / CeO2, where M is manganese or cobalt) using atomic engineering technology, which significantly enhances their enzyme-mimicking activity. This M / CeO2 nanozyme exhibits excellent peroxidase-like activity, with a reaction rate approximately 8-10 times that of pure cerium dioxide nanozymes. Manganese-doped cerium dioxide nanozymes are more conducive to enhancing superoxide dismutase-like activity. However, single inorganic nanozymes are difficult to control efficiently and on demand.

[0009] The prior art represented by the aforementioned documents has at least the following unresolved technical problems or defects: (1) Unable to adjust as needed or poorly adjustable; (2) Lack of SOD-like enzyme activity; (3) Low stability; (4) Poor biocompatibility. Summary of the Invention

[0010] The purpose of this invention is to provide: A photosensitive SOD-like nanozyme (Mn / CeO2@COF), and related technologies, to solve technical problems such as efficiently regulating the activity of nanozymes and significantly enhancing SOD-like activity, or combinations thereof.

[0011] Terminology Explanation: Unless otherwise defined, all technical terms in this document have the same meanings as commonly understood by one of ordinary skill in the art to which the subject matter of the claims pertains. Unless otherwise stated, all patents, patent inventions, and publications cited in this document are incorporated herein by reference in their entirety. If multiple definitions exist for terms in this document, the definitions in this chapter shall prevail.

[0012] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0013] Definitions of standard chemical terms can be found in the references "Nanomaterials Science" and "Nano Science and Technology Series".

[0014] Unless otherwise stated, conventional methods within the scope of the art, such as hydrothermal reaction, centrifugation, aging, etc., shall be used.

[0015] Unless specifically defined herein, the use of all commercially available products herein employs standard techniques. For example, it may be carried out using the manufacturer's instructions for use with the kit, or in accordance with methods known in the art or the description of this invention. The techniques and methods described herein can generally be implemented according to conventional methods well known in the art, based on the descriptions in the various summary and more specific documents cited and discussed in this specification.

[0016] The term “reactive oxygen species (ROS)” as used in this article refers to the collective term for oxygen-containing free radicals and peroxides that are related to oxygen metabolism in living organisms and are prone to forming free radicals.

[0017] The term “superoxide dismutase (SOD)” used in this article refers to an antioxidant metalloenzyme present in living organisms that can catalyze the dismutation of superoxide anion free radicals into oxygen and hydrogen peroxide. It plays a crucial role in the balance between oxidation and antioxidation in the body and is closely related to the occurrence and development of many diseases.

[0018] The term "nanozyme" as used in this article refers to a class of nanomaterials with biocatalytic functions that can catalyze the substrates of natural enzymes based on specific nanostructures and serve as enzyme substitutes.

[0019] The term "covalent organic framework (COF)" as used in this article refers to a crystalline porous polymer material formed by organic monomers linked by covalent bonds. It is an emerging type of organic porous material with a high specific surface area and tunable pore size, and is widely used in fields such as gas storage, catalysis, and drug delivery.

[0020] The term “tris(4-aminophenyl)amine (TAPA)” as used in this article refers to a well-known electron-rich unit and hole transport material, which, as a trigonometric node monomer, has an intramolecular electron-rich triphenylamine structure that acts as a strong electron donor, while the three terminal amino groups provide chemically reactive sites.

[0021] The term “3,6-bis(5-aldehydethiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione (DPP)” used in this article refers to a typical derivative of the “diketonepyrrolopyrrole” core, which is currently the core building block of high-end organic semiconductors and photothermal materials. Its core skeleton, pyrrolo[3,4-c]pyrrolo-1,4-dione, has extremely strong electron-withdrawing ability and is an excellent acceptor unit for constructing narrow bandgap materials.

[0022] The term "cerium dioxide (CeO2)" as used in this article refers to a widely used functional catalytic material that exhibits excellent performance in various catalytic reactions due to its unique redox properties and abundant oxygen vacancies. It has a cubic fluorite crystal structure, with cerium atoms located at the center and vertices of the cube, and oxygen atoms forming the cubic framework.

[0023] The term "covalent bond" as used in this article refers to a chemical bond formed between atoms by sharing electrons. This type of bond typically occurs between atoms with similar electronegativity and achieves energy stability through the overlap of electron clouds.

[0024] The term "photothermal performance" as used in this article refers to the ability of a material to convert light energy into heat energy.

[0025] The term "XRD (X-ray diffraction)" used in this article refers to the technique of analyzing the structure of materials by utilizing the diffraction effect of X-rays on crystalline materials. Its principle follows the Bragg equation 2dsinθ=nλ, and by measuring the diffraction angle and intensity, it enables qualitative and quantitative analysis of compound composition, grain size, and morphology. It can be applied to the physical phase identification and structural characterization of materials such as metals, non-metals, and nanomaterials.

[0026] In a first aspect, the present invention provides: a method for preparing a photosensitive SOD-like nanozyme Mn / CeO2@COF, using cerium nitrate hexahydrate (Ce(NO3)3·6H2O), manganese nitrate hexahydrate (Mn(NO3)2·6H2O), 3,6-bis(5-aldehydethiophene-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) and tris(4-aminophenyl)amine (TAP). Using A) as raw material, under room temperature conditions, the terminal aldehyde group (-CHO) of the COF building unit DPP is used to generate a stable COC covalent bond through a condensation reaction with the abundant hydroxyl groups (-OH) retained in situ on the surface of the pre-synthesized Mn / CeO2 nanozyme, thus obtaining the prepolymer Mn / CeO2-DPP. Then, the aldehyde group on DPP that has not reacted with the hydroxyl group of Mn / CeO2 is used to carry out a Schiff base reaction with the amino group on TAPA to obtain the Mn / CeO2@COF binary composite material.

[0027] Preferably, the preparation method of the Mn / CeO2@COF composite nanozyme includes the following steps: (1) Dissolve DPP in dichloromethane until fully dissolved to obtain solution A; (2) Add Mn / CeO2 to solution A and add anhydrous acetic acid, mix well to obtain suspension B; (3) Dissolve TAPA in methanol until fully dissolved to obtain solution C; (4) Add solution C dropwise to suspension B, react, and obtain suspension D; (5) The suspension D was aged at room temperature to obtain suspension E; (6) Centrifuge the suspension E to collect the precipitate, wash with tetrahydrofuran, and dry to obtain the finished product.

[0028] The technical features include: the mass-to-volume ratio of DPP to dichloromethane, the mass-to-volume ratio of Mn / CeO2 to DPP, the mass-to-volume ratio of Mn / CeO2 to CH3COOH, the mass-to-volume ratio of TAPA to methanol, the mass-to-volume ratio of DPP to TAPA, ultrasonication, aging, and drying.

[0029] In step (1), the mass-to-volume ratio of DPP to dichloromethane is 2.5-20 g / L. Preferably, the mass-to-volume ratio of DPP to dichloromethane in step (1) is 5-20 g / L; More preferably, the mass-to-volume ratio of DPP to dichloromethane in step (1) is 10 g / L.

[0030] Preferably, the dissolution in step (1) is carried out under ultrasonic conditions for 5-30 min; preferably 10-20 min; and more preferably 10 min.

[0031] In step (2), the mass ratio of Mn / CeO2 to DPP is 1:0.5-4; preferably 1:1-3; and more preferably 1:2.

[0032] In step (2), the mass-to-volume ratio of Mn / CeO2 to CH3COOH is 50 mg: 0.05-0.4 mL. Preferably, the mass-to-volume ratio of Mn / CeO2 to CH3COOH in step (2) is 50 mg: 0.1-0.2 mL; More preferably, the mass-to-volume ratio of Mn / CeO2 to CH3COOH in step (2) is 50 mg: 0.1 mL.

[0033] Preferably, the mixing in step (2) is carried out under ultrasonic conditions for 5-30 min; more preferably 10-20 min; and even more preferably 10 min.

[0034] In step (3), the mass-to-volume ratio of TAPA to methanol is 0.5-8 g / L. Preferably, the mass-to-volume ratio of TAPA to methanol in step (3) is 1-5 g / L; More preferably, the mass-to-volume ratio of TAPA to methanol in step (3) is 3.33 g / L.

[0035] Preferably, the mass ratio of DPP to TAPA is 3:1.

[0036] Preferably, the dissolution in step (3) is carried out under ultrasonic conditions for 5-30 min; preferably 10-20 min; and more preferably 10 min.

[0037] The dripping rate described in step (4) is approximately 1 drop / second.

[0038] The reaction described in step (4) is carried out under ultrasound, and the ultrasound reaction time is 10-60 min; preferably 10-40 min, and more preferably 20-40 min. As a further preferred embodiment, the ultrasonic response time is any point or range value between 10 and 60 min, and can be selected from 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, and 60 min. As a further preferred embodiment, the ultrasonic response time is any value or range between 10 and 60 minutes, and can be selected from 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 55 minutes, and 60 minutes; As a further preferred embodiment, the ultrasonic response time is any point or range between 10 and 60 min, and can be selected from 10 min, 30 min, 50 min, and 60 min. As the most preferred embodiment, the ultrasonic response time is 30 min.

[0039] Preferably, the aging time in step (5) is selected from 24-48 h; more preferably 48 h.

[0040] Preferably, the drying conditions described in step (6) are selected from a drying temperature of 60-80℃ and a drying time of 8-16 h; More preferably, the drying conditions in step (6) are a drying temperature of 70°C and a drying time of 12 h.

[0041] Based on further solutions to the technical problems of the present invention, or simultaneous solutions to multiple technical problems, the preferred solution in the technical solution provided in the first aspect of the present invention includes: The first preferred option is as follows: the mass-to-volume ratio of DPP to dichloromethane in step (1) is 2.5-20 g / L, the mass ratio of Mn / CeO2 to DPP in step (2) is 1:0.5-4, the mass-to-volume ratio of Mn / CeO2 to CH3COOH is 50 mg:0.05-0.4 mL, the mass-to-volume ratio of TAPA to methanol in step (3) is 0.5-8 g / L, and the reaction in step (4) is carried out under ultrasound for 10-60 min. This technical solution solves the technical problem of "providing a Mn / CeO2@COF composite nanozyme" and further solves the technical problem of "regulating the activity of nanozymes".

[0042] The second preferred option is as follows: the mass-to-volume ratio of DPP to dichloromethane in step (1) is 5-20 g / L, the mass-to-volume ratio of Mn / CeO2 to CH3COOH in step (2) is 50 mg: 0.05-0.4 mL, the mass-to-volume ratio of TAPA to methanol in step (3) is 1-5 g / L, and the reaction in step (4) is carried out under ultrasound for 10-40 min. This technical solution solves the technical problem of "providing a Mn / CeO2@COF composite nanozyme" and further solves the technical problem of "efficiently regulating the activity of nanozymes".

[0043] The third preferred option is as follows: the mass-to-volume ratio of DPP to dichloromethane in step (1) is 10 g / L, the mass-to-volume ratio of Mn / CeO2 to CH3COOH in step (2) is 50 mg: 0.1 mL, the mass-to-volume ratio of TAPA to methanol in step (3) is 3.33 g / L, the mass ratio of DPP to TAPA is 3:1, and the reaction in step (4) is carried out under ultrasound for 20-40 min. This technical solution solves the technical problem of "providing a Mn / CeO2@COF composite nanozyme" and further solves the technical problem of "more efficiently regulating the activity of nanozymes".

[0044] Secondly, the present invention provides a method for preparing the above-mentioned Mn / CeO2 nanozyme, comprising the steps of: S1. Dissolve cerium nitrate hexahydrate in deionized water and stir until fully dissolved to obtain solution 1. S2. Slowly add ammonia water dropwise to solution 1, stir and mix evenly to obtain suspension 2; S3. Dissolve manganese nitrate hexahydrate in deionized water and stir until fully dissolved to obtain solution 3. S4. Slowly add ammonia water dropwise to solution 3, stir and mix evenly to obtain suspension 4; S5. Add suspension 4 dropwise to suspension 2 and stir to mix evenly to obtain suspension 5. S6. Transfer the suspension 5 to a high-pressure reactor for hydrothermal reaction to obtain suspension 6; S7. Centrifuge the suspension 6 to collect the precipitate, wash it 3 times with deionized water, and dry it overnight to obtain the finished product.

[0045] The technical features include: the mass-to-volume ratio of cerium nitrate hexahydrate to deionized water, the mass-to-volume ratio of manganese nitrate hexahydrate to deionized water, the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate, ammonia water, hydrothermal reaction, and drying.

[0046] In step S1, the mass-to-volume ratio of cerium nitrate hexahydrate to deionized water is 6-10 g / L. Preferably, the mass-to-volume ratio of cerium nitrate hexahydrate to deionized water in step S1 is 7-9 g / L; More preferably, the mass-to-volume ratio of cerium nitrate hexahydrate to deionized water in step S1 is 8.125 g / L.

[0047] Preferably, the ammonia solution used in step S2 adjusts the pH of suspension 2 to 8-9; In step S3, the mass-to-volume ratio of manganese nitrate hexahydrate to deionized water is 2-6 g / L. Preferably, the mass-to-volume ratio of manganese nitrate hexahydrate to deionized water in step S3 is 2-4 g / L; More preferably, the mass-to-volume ratio of manganese nitrate hexahydrate to deionized water in step S3 is 3 g / L.

[0048] Preferably, the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is 2-4:1; More preferably, the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is 2:1.

[0049] Preferably, the ammonia solution used in step S4 adjusts the pH of suspension 4 to 8-9; Preferably, the hydrothermal reaction conditions in step S6 are selected from a reaction temperature of 180-200℃ and a reaction time of 5-8 h; More preferably, the hydrothermal reaction conditions in step S6 are a reaction temperature of 180°C and a reaction time of 6 h. Preferably, the drying temperature in step S7 is 50-70°C, and more preferably 60°C.

[0050] Based on further solutions to the technical problems of the present invention, or simultaneous solutions to multiple technical problems, the preferred solution in the technical solution provided in the second aspect of the present invention includes: The first preferred option is as follows: the mass-to-volume ratio of cerium nitrate hexahydrate to deionized water in step S1 is 6-10 g / L, the mass-to-volume ratio of manganese nitrate hexahydrate to deionized water in step S3 is 2-6 g / L, the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is 2-4:1, and the hydrothermal reaction conditions in step S6 are selected from a reaction temperature of 180-200℃ and a reaction time of 5-8 h. This technical solution, based on solving the technical problem of "providing a Mn / CeO2 nanozyme", further solves the technical problem of "SOD-like activity".

[0051] The second preferred option is as follows: the mass-to-volume ratio of cerium nitrate hexahydrate to deionized water in step S1 is 7-9 g / L, the mass-to-volume ratio of manganese nitrate hexahydrate to deionized water in step S3 is 2-4 g / L, the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is 2-4:1, and the hydrothermal reaction conditions in step S6 are selected from a reaction temperature of 180-200℃ and a reaction time of 5-8 h. This technical solution, based on solving the technical problem of "providing a Mn / CeO2 nanozyme", further solves the technical problem of "enhancing SOD-like activity".

[0052] The third preferred option is as follows: the mass-to-volume ratio of cerium nitrate hexahydrate to deionized water in step S1 is 8.125 g / L, the mass-to-volume ratio of manganese nitrate hexahydrate to deionized water in step S3 is 3 g / L, the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is 2:1, and the hydrothermal reaction conditions in step S6 are a reaction temperature of 180℃ and a reaction time of 6 h. This technical solution, based on solving the technical problem of "providing a Mn / CeO2 nanozyme", further solves the technical problem of "significantly enhancing SOD-like activity".

[0053] Thirdly, the present invention provides the application of the above-mentioned photosensitive SOD nanozyme Mn / CeO2@COF in the preparation of products with anti-inflammatory, antibacterial and antioxidant effects.

[0054] Fourthly, the present invention provides the application of the above-mentioned photosensitive SOD-like nanozyme Mn / CeO2@COF in the preparation of products that promote wound healing.

[0055] Fifthly, the present invention provides a product with anti-inflammatory, antibacterial and antioxidant effects, comprising the above-mentioned photosensitive SOD nanozyme Mn / CeO2@COF and its excipients.

[0056] In a sixth aspect, the present invention provides: a product for promoting wound healing, comprising the above-mentioned photosensitive SOD-like nanozyme Mn / CeO2@COF and its excipients.

[0057] Examples 9-12 of this invention at least support the protection scope of the ratio of reaction raw materials and the specific preparation method.

[0058] The mass ratio of Mn / CeO2 to 3,6-bis(5-aldehydethiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione is summarized from the foregoing explanation and / or the corresponding technical features "1:0.5, 1:1, 1:2, 1:4" in Examples 9-12. Therefore, based on reasonable presumption, those skilled in the art can determine that the technical feature “the mass ratio of Mn / CeO2 to 3,6-bis(5-aldehydethiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione is 1:0.5-4”, its subordinate concept, its essentially equivalent technical means, and technical means that can replace it based on the existing level of technology and within the scope of conventional technical means and common knowledge, should all fall within the protection scope of the mass ratio of Mn / CeO2 to 3,6-bis(5-aldehydethiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione.

[0059] The mass-to-volume ratio of Mn / CeO2 to anhydrous acetic acid is summarized from the foregoing explanation and / or the corresponding technical features "50 mg: 0.05 mL, 50 mg: 0.1 mL, 50 mg: 0.2 mL, 50 mg: 0.4 mL" in Examples 9-12. Therefore, those skilled in the art can reasonably infer that the technical feature "the mass-to-volume ratio of Mn / CeO2 to anhydrous acetic acid is 50 mg: 0.05-0.4 mL", its subordinate concepts, its substantially equivalent technical means, and technical means that can replace it within the scope of conventional technical means and common knowledge based on the existing level of technology should all fall within the protection scope of the mass-to-volume ratio of Mn / CeO2 to anhydrous acetic acid.

[0060] As the ultrasound time is summarized by the foregoing explanation and / or the corresponding technical features "10 min, 30 min, 60 min" in Examples 9-12, those skilled in the art can reasonably infer that the technical feature "ultrasound time is 10-60 min", its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "ultrasound time" based on existing technology and conventional technical means and common knowledge should all fall within the scope of protection of ultrasound time.

[0061] The aging time is summarized by the foregoing explanation and / or the corresponding technical features "24 h, 48 h" in Examples 9-12. Therefore, those skilled in the art can reasonably presume that the technical feature "aging time is 24-48 h", its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "aging" based on existing technology and conventional technical means and common knowledge should all fall within the scope of protection for aging time.

[0062] Examples 1-8 of this invention at least support the protection scope of the ratio of reaction raw materials and the specific preparation method.

[0063] The molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is summarized by the foregoing explanation and / or the corresponding technical features "2:1, 3:1, 4:1" in Examples 1-8. Therefore, those skilled in the art can reasonably infer that the technical feature "the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is 2-4:1", its subordinate concepts, its substantially equivalent technical means, and technical means that can replace it within the scope of conventional technical means and common knowledge based on the existing technical level should all fall within the protection scope of the molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate.

[0064] For example, the hydrothermal reaction conditions are summarized from the foregoing explanation and / or the corresponding technical features in Examples 1-8: "the hydrothermal reaction conditions are reaction temperatures of 180°C, 190°C, and 200°C, and reaction times of 5 h, 6 h, 7 h, and 8 h." Therefore, those skilled in the art can reasonably infer that the technical feature "hydrothermal reaction temperature of 180-200°C and time of 5-8 h," its subordinate concepts, its essentially equivalent technical means, and technical means that can replace "hydrothermal reaction conditions" based on existing technology and conventional technical means and common knowledge should all fall within the scope of protection of hydrothermal reaction conditions.

[0065] The beneficial effects of this invention are as follows: The present invention has at least the following beneficial effects: 1. Compared with the prior art, the Mn / CeO2@COF interfacial composite material prepared by the technical solution of the present invention breaks through the traditional physical mixing or adsorption loading method. Through the covalent condensation reaction between the aldehyde group of DPP monomer and the hydroxyl group on the surface of Mn / CeO2, the inorganic nanozyme is chemically anchored on the surface of the organic framework, forming a Mn / CeO2@COF binary composite material with a firm interface and stable structure, thus solving the key technical problems of easy agglomeration and easy detachment of nanozymes.

[0066] 2. The Mn / CeO2@COF binary composite material was prepared at room temperature by controlling the covalent condensation reaction of the DPP monomer aldehyde group and the Mn / CeO2 surface hydroxyl group with a certain concentration of anhydrous acetic acid. The synthesis scheme is not only mild, controllable and simple, but also has good biocompatibility.

[0067] 3. Compared with existing technologies, this invention precisely integrates a COF carrier with near-infrared photothermal response capability and a Mn / CeO2 nanozyme with SOD-like enzyme activity through a covalent bonding strategy, achieving deep integration and dynamic synergy of functional modules. When irradiated with NIR, the COF, as a highly efficient energy conversion unit, converts light energy into localized heat energy, generating a direct bactericidal effect and promoting local microcirculation. Simultaneously, this heat energy can be directly conducted to the tightly bound Mn / CeO2 catalytic center, significantly enhancing its enzyme-like catalytic activity according to Arrhenius kinetics, thereby achieving efficient removal of excess reactive oxygen species from the wound microenvironment.

[0068] 4. Compared with the prior art, the present invention has better technical effects in terms of photothermal performance, photothermal stability, SOD-like enzyme activity, and biocompatibility.

[0069] According to experimental tests, the present invention increases the temperature rise after near-infrared irradiation from 3°C in the prior art (Comparative Example 1) to 20.8°C.

[0070] According to experimental tests, the present invention increases the percentage of superoxide anion free radical inhibition by SOD from 60% in the prior art (Comparative Example 1) to more than 80%.

[0071] Furthermore, based on the present invention: Based on the comparison between Examples 11-1 and Comparative Example 1, this invention employs a covalent bonding strategy to combine manganese-doped CeO2 nanozymes with excellent SOD-like enzyme activity with a COF carrier possessing a highly ordered porous structure, high specific surface area, and good biocompatibility to prepare a Mn / CeO2@COF binary composite material. This results in superior photothermal performance, photothermal stability, and more significant SOD-like enzyme activity. The combined technical effect is superior to the sum of the effects of each individual technique. Attached Figure Description

[0072] Figure 1 XRD patterns of CeO2, Mn / CeO2, COF, and MCC-3.1.

[0073] Figure 2 The graph shows the relationship between different mass ratios of Mn / CeO2 and DPP and photothermal performance.

[0074] Figure 3The graph shows the relationship between different catalyst dosages and photothermal performance when the mass ratio of Mn / CeO2 and DPP is 1:1.

[0075] Figure 4 The graph shows the relationship between different catalyst dosages and photothermal performance when the mass ratio of Mn / CeO2 and DPP is 1:2.

[0076] Figure 5 The graph shows a comparison of the photothermal properties of MCC-3.1 with those of H2O, CeO2, Mn / CeO2, and COF.

[0077] Figure 6 Comparison of photothermal properties of Mn / CeO2, COF, physically mixed Mn / CeO2+COF, and MCC-3.1.

[0078] Figure 7 The photothermal stability is MCC-3.1.

[0079] Figure 8 The graph shows the relationship between the photothermal conversion efficiency of COF and MCC-3.1 and the time-dependent curves of the cooling stage, and -ln(θ).

[0080] Figure 9 The graph shows the SOD enzyme activities of MCC-3.1 and the control group (CeO2, Mn / CeO2, CC), and compares the SOD-like enzyme activity of MCC-3.1 under 808 nm near-infrared lamp irradiation.

[0081] Figure 10 Electrochemical impedance spectroscopy and transient photocurrent response diagrams of MCC-3.1 and the control group CeO2, Mn / CeO2, and COF are presented. Detailed Implementation

[0082] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0083] The present invention will be further described below by way of specific embodiments. All instruments, devices, equipment, reagents, products, etc., used in the embodiments of the present invention, unless otherwise specified, are obtained through conventional commercial channels, and all reagents and raw materials are used directly without further processing unless otherwise specified.

[0084] The specific implementation of this invention mainly consists of two steps: The first step is the preparation of Mn / CeO2. Mn / CeO2 is synthesized using Ce(NO3)3·6H2O and Mn(NO3)2·6H2O as raw materials; the second step is the preparation of Mn / CeO2@COF. Mn / CeO2@COF is synthesized using Mn / CeO2, DPP, and TAPA as raw materials.

[0085] The first step, the preparation of Mn / CeO2, follows this route: A synthetic formula is constructed using Ce(NO3)3·6H2O and Mn(NO3)2·6H2O as raw materials. The pH is adjusted to 8.0-9.0 using ammonia water. A hydrothermal reaction is then performed. The resulting precipitate is washed three times with deionized water, dried overnight at 60°C, and the final product is obtained and stored in a sealed container at room temperature. The specific implementation is as follows: Example 1: Preparation of Mn / CeO2: (1) Dissolve 0.065 g Ce(NO3)3·6H2O in 8 mL of deionized water and stir until fully dissolved to obtain solution A; (2) Slowly add 100 μL of NH3·H2O to solution A, stir and mix evenly to obtain suspension B; (3) Dissolve 0.021 g Mn(NO3)2·6H2O in 7 mL of deionized water and stir until fully dissolved to obtain solution C; (4) Slowly add 100 μL of NH3·H2O to solution C, stir and mix well to obtain suspension D; (5) Add suspension D dropwise to suspension B and stir to mix evenly to obtain suspension E; (6) The suspension E was transferred to a high-pressure reactor for hydrothermal reaction at 180°C for 6 h to obtain suspension F; (7) Centrifuge the suspension F to collect the precipitate, wash it three times with deionized water, and dry it overnight at 60°C to obtain brown powder G (Mn / CeO2), which is labeled as Mn / CeO2.

[0086] Example 2: Preparation of Mn / CeO2 1.1: The difference from Example 1 is that the molar ratio of Ce(NO3)3·6H2O and Mn(NO3)2·6H2O is 3:1 (mmol:mmol), and all other aspects are the same as in Example 1, which is numbered Mn / CeO21.1.

[0087] Example 3: Preparation of Mn / CeO2 1.2: The difference from Example 1 is that the molar ratio of Ce(NO3)3·6H2O and Mn(NO3)2·6H2O is 4:1 (mmol:mmol), and all other aspects are the same as in Example 1. It is numbered Mn / CeO21.2.

[0088] Example 4: Preparation of Mn / CeO2 1.3: The difference from Example 1 is that the hydrothermal reaction conditions are 180°C for 5 hours, while the rest are the same as Example 1, and it is numbered Mn / CeO21.3.

[0089] Example 5: Preparation of Mn / CeO2 1.4: The difference from Example 1 is that the hydrothermal reaction conditions are 180°C for 7 hours, while the rest are the same as Example 1, and it is numbered Mn / CeO21.4.

[0090] Example 6: Preparation of Mn / CeO21.5: The difference from Example 1 is that the hydrothermal reaction conditions are 180°C for 8 hours, while the rest are the same as Example 1, and it is numbered Mn / CeO21.5.

[0091] Example 7: Preparation of Mn / CeO2 1.6: The difference from Example 1 is that the hydrothermal reaction conditions are 190°C for 6 hours, while the rest are the same as Example 1, and it is numbered Mn / CeO21.6.

[0092] Example 8: Preparation of Mn / CeO2 1.7: The difference from Example 1 is that the hydrothermal reaction conditions are 200℃ for 6 hours, while the rest are the same as Example 1, and it is numbered Mn / CeO21.7.

[0093] The photothermal performance test data of Examples 1-8 are shown in Table 1 below.

[0094] Table 1. Photothermal performance test data of Examples 1-8

[0095] According to the test results in Table 1 above, Example 1 (Mn / CeO2) exhibited the best photothermal performance under hydrothermal conditions of Ce / Mn molar ratio 2:1 and reaction at 180℃ for 6 h, with a temperature increase of 2.8°C within 20 min. Changing these conditions, such as reducing the Mn doping amount (Ce / Mn=3:1, 4:1, etc.), insufficient or excessive reaction time (5 h, 8 h, etc.), and increasing the reaction temperature (190, 200℃, etc.), all led to a certain degree of reduction in photothermal performance, but it still met the requirements.

[0096] The Mn / CeO2 described in Example 1 was selected for the preparation of Mn / CeO2@COF as described below.

[0097] The second step is the preparation of Mn / CeO2@COF. The preparation route is as follows: A synthetic formula is constructed using Mn / CeO2, DPP, and TAPA as raw materials. After ultrasonication, the mixture is aged at room temperature for a certain time. The resulting precipitate is washed with THF, dried at 70℃ for 12 h, and the final product is obtained and stored in a sealed container at room temperature. The specific implementation is as follows: Example 9 (1) Dissolve 25 mg DPP in 10 mL CH2Cl and sonicate until fully dissolved to obtain solution A; (2) Add 50 mg Mn / CeO2 to solution A and add 100 μL CH3COOH. Sonicate for 10 min to mix evenly to obtain suspension B; (3) Dissolve 8.33 mg TAPA in 10 mL CH3OH and sonicate until fully dissolved to obtain solution C; (4) Slowly add solution C to suspension B, and sonicate for 30 min to obtain suspension D; (5) The suspension D was aged at room temperature for 48 h to obtain suspension E; (6) Centrifuge the suspension E to collect the precipitate, wash with tetrahydrofuran (THF), and dry at 70 °C for 12 h to obtain a blackish-blue powder (Mn / CeO2@COF), which is numbered MCC1.

[0098] Example 10: Preparation of Mn / CeO2@COF (MCC2): Example 10-1 The difference from Example 9 is that the mass ratio of Mn / CeO2 to DPP is changed to 50:50 (mg:mg). The specific steps are as follows: (1) Dissolve 50 mg DPP in 10 mL CH2Cl and sonicate until fully dissolved to obtain solution A; (2) Add 50 mg Mn / CeO2 to solution A and add 100 μL CH3COOH. Sonicate for 10 min to mix evenly to obtain suspension B; (3) Dissolve 16.67 mg TAPA in 10 mL CH3OH and sonicate until fully dissolved to obtain solution C; (4) Slowly add solution C to suspension B, and sonicate for 30 min to obtain suspension D; (5) The suspension D was aged at room temperature for 48 h to obtain suspension E; (6) Centrifuge the suspension E to collect the precipitate, wash it with tetrahydrofuran (THF), and dry it at 70 °C for 12 h to obtain a blackish-blue powder (Mn / CeO2@COF), which is numbered MCC2.1.

[0099] Example 10-2 The difference from Example 10-1 is that the amount of CH3COOH used is changed to 50 μL, while the rest is the same as Example 10-1, which is numbered MCC2.2.

[0100] Example 10-3 The difference from Example 10-1 is that the amount of CH3COOH is changed to 200 μL, while the rest is the same as Example 10-1, which is numbered MCC2.3.

[0101] Example 10-4 The difference from Example 10-1 is that the amount of CH3COOH is changed to 400 μL, while the rest is the same as Example 10-1, which is numbered MCC2.4.

[0102] Example 11 Preparation of Mn / CeO2@COF (MCC3): Example 11-1 The difference from Example 9 is that the mass ratio of Mn / CeO2 to DPP is changed to 50:100 (mg:mg). The specific steps are as follows: (1) Dissolve 100 mg DPP in 10 mL CH2Cl and sonicate until fully dissolved to obtain solution A; (2) Add 50 mg Mn / CeO2 to solution A and add 100 μL CH3COOH. Sonicate for 10 min to mix evenly to obtain suspension B; (3) Dissolve 33.33 mg TAPA in 10 mL CH3OH and sonicate until fully dissolved to obtain solution C; (4) Slowly add solution C to suspension B, and sonicate for 30 min to obtain suspension D; (5) The suspension D was aged at room temperature for 48 h to obtain suspension E; (6) Centrifuge the suspension E to collect the precipitate, wash it with tetrahydrofuran (THF), and dry it at 70°C for 12 h to obtain a blackish-blue powder (Mn / CeO2@COF), which is numbered MCC3.1.

[0103] Example 11-2 The difference from Example 11-1 is that the amount of CH3COOH is changed to 50 μL, while the rest is the same as Example 11-1, and it is numbered MCC3.2.

[0104] Examples 11-3 The difference from Example 11-1 is that the amount of CH3COOH is changed to 200 μL, while the rest is the same as Example 11-1, which is numbered MCC3.3.

[0105] Examples 11-4 The difference from Example 11-1 is that the amount of CH3COOH is changed to 400 μL, while the rest is the same as Example 11-1, which is numbered MCC3.4.

[0106] Examples 11-5 The difference from Example 11-1 is that the ultrasonic reaction time is 10 min, and the rest is the same as Example 11-1, which is numbered MCC3.5.

[0107] Examples 11-6 The difference from Example 11-1 is that the ultrasonic reaction time is 60 min, while the rest is the same as Example 11-1, which is numbered MCC3.6.

[0108] Examples 11-7 The difference from Example 11-1 is that the aging time is 24 hours, while the rest is the same as Example 11-1, which is numbered MCC3.7.

[0109] Example 12 The difference from Example 9 is that the mass ratio of Mn / CeO2 to DPP is changed to 50:200 (mg:mg). The specific steps are as follows: (1) Dissolve 200 mg DPP in 10 mL CH2Cl and sonicate until fully dissolved to obtain solution A; (2) Add 50 mg Mn / CeO2 to solution A and add 100 μL CH3COOH. Sonicate for 10 min to mix evenly to obtain suspension B; (3) Dissolve 66.67 mg TAPA in 10 mL CH3OH and sonicate until fully dissolved to obtain solution C; (4) Slowly add solution C to suspension B, and sonicate for 30 min to obtain suspension D; (5) The suspension D was aged at room temperature for 48 h to obtain suspension E; (6) Centrifuge the suspension E to collect the precipitate, wash with tetrahydrofuran (THF), and dry at 70 °C for 12 h to obtain a blackish-blue powder (Mn / CeO2@COF), which is designated as MCC4.

[0110] Table 2 below shows the photothermal performance test results of Examples 9-12. Table 2. Photothermal performance test data of Examples 9-12

[0111] According to the test results in Table 2 above, Examples 9-12 systematically investigated the effects of the mass ratio of Mn / CeO2 to DPP, the amount of CH3COOH, and the ultrasonic reaction time on the photothermal properties of the Mn / CeO2@COF composite material. The results showed that MCC3.1 (Mn / CeO2:DPP = 50 mg:100 mg, CH3COOH 100 μL, ultrasonication for 30 min) had the best photothermal properties, with a temperature rise of 20.8℃ within 20 min, which was significantly better than the other groups.

[0112] Preparation of CeO2 in Comparative Example 1: (1) Dissolve 0.065 g Ce(NO3)3·6H2O in 8 mL of deionized water and stir until fully dissolved to obtain solution A; (2) Slowly add 200 μL of NH3·H2O to solution A, stir and mix well to obtain suspension B; (3) The suspension B was transferred to a high-pressure reactor for hydrothermal reaction at 180°C for 6 h to obtain suspension C; (4) Centrifuge the suspension C to collect the precipitate, wash it three times with deionized water, dry it overnight at 60°C to obtain a light yellow powder D (CeO2), and store it at room temperature.

[0113] Preparation of COF in Comparative Example 2: (1) Dissolve 100 mg DPP in 10 mL CH2Cl and sonicate until fully dissolved to obtain solution A; (2) Dissolve 33.3 mg TAPA in 10 mL CH3OH and sonicate until fully dissolved to obtain solution B; (3) Slowly add solution B to solution A and sonicate for 30 min to obtain suspension C; (4) The suspension C was aged at room temperature for 48 h to obtain suspension D; (5) Centrifuge the suspension D to collect the precipitate, wash with tetrahydrofuran (THF), and dry at 70°C for 12 h to obtain a black powder (COF).

[0114] Preparation of comparative example 3CeO2@COF(CC): (1) Dissolve 100 mg DPP in 10 mL CH2Cl and sonicate until fully dissolved to obtain solution A; (2) Add 50 mg CeO2 to solution A and add 100 μL CH3COOH, sonicate for 10 min to mix evenly, and obtain suspension B; (3) Dissolve 33.3 mg TAPA in 10 mL CH3OH and sonicate until fully dissolved to obtain solution C; (4) Slowly add solution C to suspension B, and sonicate for 30 min to obtain suspension D; (5) The suspension D was aged at room temperature for 48 h to obtain suspension E; (6) Centrifuge the suspension E to collect the precipitate, wash it with tetrahydrofuran (THF), and dry it at 70 °C for 12 h to obtain a blue powder (CeO2@COF), which is labeled CC.

[0115] Comparative Example 4: Preparation of a physical mixture of Mn / CeO2+COF (1) Weigh out Mn / CeO2 powder and COF powder respectively at a mass ratio of 1:9; (2) Grind the two powders in an agate mortar to ensure that the two materials are in full contact and evenly dispersed; (3) The mixture was placed in a vacuum drying oven and dried at 70 °C for 12 h. The physical mixture of Mn / CeO2+COF was collected.

[0116] Example 1: Characterization of the structures of MCC3.1, CeO2, Mn / CeO2, and COF Appendix Figure 1The XRD patterns of Example 11-1 (MCC-3.1), Comparative Example 1 (CeO2), Example 1 (Mn / CeO2), and Comparative Example 2 (COF) are shown in the figure. As can be seen from the figure, the characteristic peaks of CeO2 are located at 28.53°, 33.08°, 47.49°, 56.31°, 59.05°, 69.51°, 76.72°, 79.02°, and 88.52°. These peaks are related to the (111), (200), (220), (311), (222), (400), (331), (420), and (422) diffraction planes of CeO2, indicating that CeO2 has a single cubic fluorite phase (PDF#34-0394). Similarly, three distinct diffraction peaks are clearly visible in Mn / CeO2 around 36.08°, 44.46°, and 64.68°, which are attributed to the standard Mn spectrum (PDF#21-0547). Furthermore, the XRD pattern of the COF sample shows its main diffraction peaks at 5.75° and 17.9°, indicating moderate crystallinity of COF. Characteristic peaks of both Mn / CeO2 and COF can be found in the composite MCC-3.1 sample, and the XRD peak positions of Mn / CeO2 do not show significant changes, while the 5.75° peak of COF disappears and the 17.9° peak weakens.

[0117] Example 2: Relationship between different mass ratios of Mn / CeO2 and DPP and photothermal properties Examples 1, 9, 10-1, 11-1, 12, Comparative Example 1, and Comparative Example 2 were dispersed in deionized water to obtain stable aqueous dispersions with a concentration of 1.0 mg / mL. These dispersions were irradiated with a near-infrared laser (808 nm), and temperature changes were monitored and recorded using an infrared thermal imager. The differences in photothermal performance at different mass ratios were ultimately evaluated. The experimental results are shown in the appendix. Figure 2 .

[0118] From the appendix Figure 2 It can be seen that the photothermal performance of Examples 9, 10-1, 11-1, and 12 (MCC1, MCC2.1, MCC3.1, and MCC4) is superior to that of the control groups CeO2, Mn / CeO2, and COF. As the mass ratio of Mn / CeO2 to DPP decreases, the photothermal performance improves significantly, but when the mass ratio of Mn / CeO2 to DPP is 1:4, the photothermal performance decreases significantly. When the mass ratio of Mn / CeO2 to DPP is 1:1 and 1:2, both exhibit good photothermal performance, with temperature increases of 19.1℃ and 20.8℃ respectively, showing relatively small differences. Therefore, subsequent experiments will further refine the selection by adjusting other experimental parameters for these two materials.

[0119] Example 3: Relationship between different catalyst dosages and photothermal performance Examples 1, 10, 11, Comparative Example 1, and Comparative Example 2 were prepared to the same concentration (1.0 mg). mL -1 An aqueous dispersion of [agent name] was irradiated with a near-infrared laser (808 nm), and the temperature change curve was monitored and recorded using an infrared thermal imager. The final result was used to evaluate the differences in photothermal performance of different catalyst dosages at Mn / CeO2 and DPP mass ratios of 1:1 and 1:2. The experimental results are shown in the appendix. Figure 3 , 4 .

[0120] From the appendix Figure 3 It can be seen that the photothermal performance of Examples 10 (MCC-2.1, MCC-2.2, MCC-2.3, and MCC-2.4) is superior to that of the control groups CeO2, Mn / CeO2, and COF. When the mass ratio of Mn / CeO2 to DPP is 1:1, the photothermal performance weakens with increasing catalyst dosage. When the catalyst dosage is 50 μL and 100 μL, the temperature rise is similar, with increases of 13.2℃ and 12.9℃, respectively.

[0121] From the appendix Figure 4 It can be seen that the photothermal performance of Examples 11 (MCC-3.1, MCC-3.2, MCC-3.3, MCC-3.4) is superior to that of the control groups CeO2, Mn / CeO2, and COF. Figure 3 Similarly, when the mass ratio of Mn / CeO2 to DPP is 1:2, the photothermal performance weakens with increasing catalyst dosage. The best photothermal performance is achieved when the catalyst dosage is 100 μL, with a temperature increase of 17.3℃. Therefore, in this experiment, a mass ratio of Mn / CeO2 to DPP of 1:2 and a catalyst dosage of 100 μL were selected.

[0122] Test Example 4: Comparison of photothermal properties of Example 11-1 (MCC-3.1) with H2O, CeO2, Mn / CeO2 and COF Examples 1, 11-1, Comparative Example 1, and Comparative Example 2 were prepared to the same concentration (1.0 mg). mL -1 The aqueous dispersion of [product name] was irradiated with a near-infrared laser (808 nm), and the temperature change curve was monitored and recorded using an infrared thermal imager. The differences in photothermal properties between Example 11-1 (MCC-3.1) and H2O, CeO2, Mn / CeO2, and COF were ultimately evaluated. Experimental results are shown in the appendix. Figure 5 .

[0123] From the appendix Figure 5It can be seen that after irradiation with an 808 nm near-infrared lamp and monitoring with an infrared thermal imager for 20 min, MCC-3.1 exhibited the best photothermal performance, with a temperature increase of 20.8℃. The photothermal performance of COF was significantly weaker than that of MCC-3.1, the photothermal performance of Mn / CeO2 was significantly weaker than that of both MCC-3.1 and COF, and the photothermal performance of CeO2 was weaker than that of Mn / CeO2. This indicates that Mn doping optimizes the light absorption and carrier behavior of CeO2, while COF, as an organic porous material, inherently possesses a certain near-infrared light absorption capacity, contributing to its basic photothermal performance. The combination of both further enhances the near-infrared light capture and thermal conversion efficiency.

[0124] Comparison of photothermal properties of Example 5 (Mn / CeO2, COF, physically mixed Mn / CeO2+COF) and Example 11-1 (MCC-3.1) Examples 1, 11-1, Comparative Example 1, Comparative Example 2, and Comparative Example 4 were prepared to the same concentration (1.0 mg). mL -1 An aqueous dispersion of [a substance] was irradiated with a near-infrared laser (808 nm), and the temperature change curve was monitored and recorded using an infrared thermal imager. The differences in photothermal performance at different mass ratios were ultimately evaluated. The experimental results are shown in the appendix. Figure 6 .

[0125] From the appendix Figure 6 It can be seen that the photothermal performance of Example 11-1 (MCC-3.1) is significantly better than that of the physically mixed Mn / CeO2+COF. This indicates that the Mn / CeO2 and COF in the composite material are not simply physically mixed, but rather there is a synergistic effect.

[0126] Photothermal stability of Example 6, Example 11-1 (MCC-3.1) The aqueous dispersion (1.0 mg / mL) of Example 11-1 (MCC-3.1) was subjected to five consecutive on / off cycles of irradiation under a near-infrared laser (808 nm) (on for 10 min / off for 20 min), and the temperature changes were monitored and recorded using an infrared thermal imager.

[0127] From the appendix Figure 7 It can be seen that MCC-3.1 maintains its good photothermal performance during five consecutive on / off laser cycles (808 nm), indicating that the material has excellent photothermal stability and reliable reusability.

[0128] Photothermal conversion efficiency of Example 7, Example 11-1 (MCC-3.1) was tested. The aqueous dispersion (1.0 mg / mL) of Example 11-1 (MCC-3.1) was irradiated under a near-infrared laser (808 nm) until the temperature stabilized, and the temperature rise curve was recorded. Then the laser was turned off, and the temperature was monitored to decrease naturally over time. The time constant τ was obtained based on the linear relationship between the cooling stage -ln(θ) and time. s Substituting into the formula η = [hS(T max - T sur ) - Q dis ] / [I(1-10 -A808 )] × 100% to calculate the photothermal conversion efficiency, where h is the heat transfer coefficient, S is the heat dissipation area, and T max T represents the highest temperature at which light reaches equilibrium. sur Q represents the ambient temperature. dis I is the heat generated by water absorbing light (i.e., the highest temperature water can reach under the same conditions), I is the laser power, and A is the laser heat generated by water absorbing light. 808 The absorbance of the sample at 808 nm is given.

[0129] From the appendix Figure 8 It can be seen that the photothermal conversion efficiency of COF is 8.00%, while that of the composite material MCC-3.1 is 10.91%, indicating that the composite material has a better ability to convert light energy into heat energy than the COF material.

[0130] The SOD enzyme activities of Example 8 (Example 11) (MCC-3.1) and the control group were detected, and the relationship between the SOD-like enzyme activities of MCC-3.1 under 808 nm near-infrared lamp irradiation and the control group was compared. The total SOD activity assay kit (WST-8 method) was used for detection. The SOD sample to be tested was mixed with WST-8 working solution and xanthine oxidase, incubated at 37°C for 20 minutes, and the absorbance was measured at 450 nm. The inhibition rate of SOD against superoxide anion free radicals was calculated by comparing with a control group without SOD. The experimental results are shown in the appendix. Figure 9 .

[0131] From the appendix Figure 9It can be seen that, without 808 nm near-infrared lamp irradiation, the SOD-like enzyme activity of Mn / CeO2 is stronger than that of CeO2, the SOD-like enzyme activity of CeO2 is stronger than that of Example 11 (MCC-3.1), and the SOD-like enzyme activity of MCC-3.1 is stronger than that of CC. Under 808 nm near-infrared lamp irradiation, the SOD-like enzyme activity of MCC-3.1 is significantly enhanced, and its inhibition percentage is higher than that of Mn / CeO2, CeO2, and CC. This phenomenon indicates that MCC-3.1 of the present invention possesses unique photoresponsive SOD-like enzyme activity. Under light-free conditions, its activity mainly comes from the intrinsic catalytic properties of Mn / CeO2; while under 808 nm near-infrared light irradiation, the photothermal conversion and photogenerated charge effect of MCC-3.1 are efficiently activated, synergistically with chemical catalysis, thereby achieving a significant enhancement of enzyme activity.

[0132] Electrochemical impedance spectroscopy and transient photocurrent response of CeO2, Mn / CeO2, and COF in Example 9, Example 11-1 (MCC-3.1) and the control group. Electrochemical impedance spectroscopy (EIS) was performed using a three-electrode system: a conductive substrate coated with the sample as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. The EIS was measured in a selected electrolyte at room temperature in the dark. 5 -10 - 2 Impedance data were collected within the Hz frequency range, and parameters such as charge transfer resistance were obtained through equivalent circuit model fitting. Transient photocurrent response tests were conducted under the same three-electrode system and electrolyte. Before testing, high-purity nitrogen was purged for 15 min to remove oxygen. An 808 nm near-infrared lamp was used as the light source. Under a constant applied bias voltage, the current-time curve was recorded through periodic alternation of illumination and shading (20 s illumination, 200 s shading, repeated 5 times) to evaluate the separation and migration performance of photogenerated carriers in the material. Experimental results are attached. Figure 10 .

[0133] From the appendix Figure 10It is known that the electrical impedance of Mn / CeO2 is lower than that of CeO2, while its photocurrent is higher. This is mainly because Mn doping introduces defects such as oxygen vacancies into the CeO2 lattice. These defects can act as electron trapping centers, effectively suppressing the recombination of photogenerated electron-hole pairs, while simultaneously increasing the intrinsic conductivity of the material, thereby reducing charge transfer resistance and enhancing photoresponse. The electrical impedance of COF is lower than that of Mn / CeO2, while its photocurrent is higher. This is mainly due to the highly ordered π-conjugated structure of COF itself, which provides an efficient channel for charge transport, giving it excellent carrier migration capabilities. The electrical impedance of MCC-3.1 is lower than that of COF, while its photocurrent is higher. This is mainly attributed to the high-speed electron channel constructed by the composite material and the expanded light absorption. Specifically, the conjugated framework of COF is in close contact with Mn / CeO2, providing a fast exit channel for the electrons separated by the latter, significantly reducing interfacial transport resistance, thus leading to a decrease in electrical impedance. Meanwhile, COF broadens the light absorption range of the composite material, generating more photogenerated charge carriers and increasing the photocurrent. This highly efficient photogenerated charge generation and transport capability is the electronic basis for MCC-3.1 to achieve excellent photothermal conversion efficiency and near-infrared light-enhanced SOD-like enzyme activity.

[0134] Verification of technical effectiveness and / or analysis of solutions to technical problems: The Mn / CeO2@COF binary composite material of this invention utilizes the chemical reaction of active genes, specifically the condensation reaction between the aldehyde groups at the ends of DPP and the hydroxyl groups (-OH) on the surface of pre-synthesized Mn / CeO2 nanoparticles, to form strong covalent bonds. This strategy successfully anchors Mn / CeO2 nanozymes to the surface of COF via chemical bonding, constructing a structurally stable composite material that combines the NIR-responsive photothermal properties of COF with the enzyme-like activity of Mn / CeO2. Therefore, this material exhibits excellent near-infrared light responsiveness, tunable catalytic activity, and structural stability, demonstrating great application potential in biomedical fields such as wound healing where synergistic anti-inflammatory, antibacterial, and antioxidant therapies are required.

[0135] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a photosensitive SOD-like nanozyme Mn / CeO2@COF, characterized in that, Including the following steps: (1) Dissolve 3,6-bis(5-aldehydethiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione in dichloromethane to obtain solution A; (2) Add Mn / CeO2 to solution A to obtain suspension B; (3) Dissolve tris(4-aminophenyl)amine in methanol to obtain solution C; (4) Add solution C dropwise to suspension B to carry out the synthesis reaction of covalent organic framework. Wash the precipitate with tetrahydrofuran and dry it to obtain the finished product.

2. The preparation method according to claim 1, characterized in that, The mass ratio of Mn / CeO2 to 3,6-bis(5-aldehydethiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione is 1:0.5-4.

3. The preparation method according to claim 1, characterized in that, The mass ratio of 3,6-bis(5-aldehydethiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione to tris(4-aminophenyl)amine is 3:

1.

4. The preparation method according to claim 1, characterized in that, In step (2), anhydrous acetic acid needs to be added to the suspension B. The mass-volume ratio of Mn / CeO2 to anhydrous acetic acid is 50 mg: 0.05-0.4 mL.

5. The preparation method according to claim 1, characterized in that, The synthesis reaction of the covalent organic framework is carried out under ultrasonic conditions for 10-60 min. After ultrasonication, aging is required for 24-48 h.

6. The preparation method according to claim 1, characterized in that, The Mn / CeO2 mentioned in step (2) is prepared by the following method: S1. Dissolve cerium nitrate hexahydrate in deionized water to obtain solution 1; S2. Dissolve manganese nitrate hexahydrate in deionized water to obtain solution 2; S3. Add solution 2 dropwise to solution 1, mix well, carry out hydrothermal reaction, collect the precipitate by centrifugation, wash with deionized water, and dry overnight to obtain the finished product.

7. The preparation method according to claim 6, characterized in that, The molar ratio of cerium nitrate hexahydrate to manganese nitrate hexahydrate is 2-4:

1.

8. The preparation method according to claim 6, characterized in that, The pH values ​​of solution 1 in step S1 and solution 2 in step S2 are both 8-9.

9. The preparation method according to claim 6, characterized in that, The hydrothermal reaction is carried out at a temperature of 180-200℃ for 5-8 hours.

10. The photosensitive SOD-like nanozyme Mn / CeO2@COF prepared by the preparation method according to any one of claims 1-9.

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