Application of manganese-doped porphyrin-based metal-organic framework material in preparation of near-infrared light-responsive photothermal conversion material

Abstract

The application discloses application of a manganese-doped porphyrin-based metal-organic framework material in preparation of a near-infrared light response photothermal conversion material. The manganese-doped porphyrin-based metal-organic framework material is Mn-doped zirconium-based PCN-224 nanoparticles, and a preparation method thereof is as follows: dissolving tetra(4-carboxyphenyl)porphyrin, zirconyl chloride octahydrate and benzoic acid into N,N-dimethylformamide (DMF), and preparing porphyrin-based metal-organic framework nanoparticles under heating. The nanoparticles are dispersed into a DMF solution containing anhydrous manganese chloride, and heated to obtain Mn-doped porphyrin-based metal-organic framework nanoparticles, which can be rapidly heated under irradiation of near-infrared light and have good photothermal antibacterial performance. The preparation method is simple, the material source is wide, the production efficiency is high, the obtained porphyrin-based metal-organic framework nanoparticles with near-infrared light response photothermal conversion capability have good stability and antibacterial capability, and have good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology and relates to a manganese-doped porphyrin-based metal-organic framework nanoparticle and its preparation method, especially its application in the preparation of near-infrared photoresponsive photothermal conversion materials. Background Technology

[0002] Bacterial infections are one of the major challenges facing global public health, triggering inflammatory responses and even leading to various diseases. Statistics show that bacterial infections and their related complications cause millions of deaths annually. Currently, antibiotic therapy remains the primary clinical treatment for bacterial infections. However, the increasingly serious problem of antibiotic resistance, coupled with the inherent physical barrier function of biofilms, presents significant difficulties and challenges to clinical infection management. Therefore, developing novel, highly effective, and less resistance-inducing antibacterial strategies has become an urgent need in the field of biomedical materials. Photothermal therapy, as an emerging antibacterial method, has attracted widespread attention due to its advantages such as non-invasiveness, high efficiency, controllability, and broad-spectrum antibacterial activity. Its core principle lies in utilizing photothermal agents to absorb light energy under irradiation and transferring energy to phonons through local surface plasmon resonance, non-radiative relaxation, or molecular thermal vibration. This process converts light energy into lattice thermal vibration, thereby generating heat. The localized high-temperature environment can inhibit bacterial growth, irreversibly destroy bacterial structure, impair protein activity, and induce DNA damage, thus effectively eliminating pathogens.

[0003] Porphyrins are common photothermal conversion agents. Metal-organic frameworks (MOFs) with porphyrin-containing organic compounds as ligands are increasingly considered ideal candidates for photothermal therapy due to their high porphyrin loading, excellent stability, and good biocompatibility. However, their common excitation wavelengths are in the red light range. Near-infrared light, on the other hand, is increasingly used as an excitation source for photothermal therapy due to its sufficient penetration depth, low biotoxicity, and precise controllability. Therefore, developing a porphyrin-based MOF with near-infrared light-responsive photothermal conversion capability is of great significance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides manganese-doped porphyrin-based metal-organic framework nanoparticles with near-infrared light-responsive photothermal conversion capabilities and their preparation method. The manganese-doped porphyrin-based metal-organic framework nanoparticles of this invention exhibit excellent photothermal effects under near-infrared light irradiation, enabling them to kill bacteria.

[0005] This invention is achieved using the following technical solution: Application of manganese-doped porphyrin-based metal-organic framework materials in the preparation of near-infrared photoresponsive photothermal conversion materials, wherein the manganese-doped porphyrin-based metal-organic framework material is Mn-doped zirconium-based PCN-224 nanoparticles.

[0006] The method for preparing the nanoparticles includes the following steps: 1) Tetra(4-carboxyphenyl)porphyrin, zirconium oxychloride octahydrate and benzoic acid were dissolved in N,N-dimethylformamide (DMF), heated for a period of time, and centrifuged to collect the precipitate. The precipitate was washed with DMF and deionized water in sequence and dried to obtain porphyrin-based metal-organic framework nanoparticles PCN-224. 2) Disperse the PCN-224 nanoparticles obtained in step 1) in a DMF solution containing anhydrous manganese chloride, heat for a period of time, centrifuge to collect the precipitate after the heating is completed, wash with DMF and deionized water in sequence, and dry to obtain manganese-doped porphyrin-based metal-organic framework (Mn@PCN-224) nanoparticles.

[0007] In the above technical solution, further, the mass ratio of tetra(4-carboxyphenyl)porphyrin, zirconium oxychloride octahydrate and benzoic acid in step 1) is 1:3:28.

[0008] Furthermore, the heating temperature described in step 1) is 85~95 ℃, and the heating time is 5-7 h.

[0009] Furthermore, the mass ratio of PCN-224 nanoparticles to anhydrous manganese chloride in step 2) is 6:5~7.

[0010] Furthermore, the heating temperature described in step 2) is 115~125 ℃, and the heating time is 7-9 h.

[0011] Based on the above preparation method, this invention provides a manganese-doped porphyrin-based metal-organic framework nanoparticle with near-infrared light response and photothermal conversion capability.

[0012] The principle of this invention is: This invention utilizes the coordination of nitrogen atoms with manganese in tetra(4-carboxyphenyl)porphyrin to obtain manganese-doped porphyrin-based metal-organic framework (Mn@PCN-224) nanoparticles. Manganese doping increases near-infrared absorbance, reduces electron-hole recombination, and decreases the optical band gap, leading to increased near-infrared light absorption in Mn@PCN-224. Electron transitions become easier, and the absorbed energy is converted into heat through non-radiative relaxation, giving it near-infrared photothermal conversion capabilities that can effectively kill bacteria.

[0013] The beneficial effects of this invention are as follows: The raw materials are widely available, the preparation process is simple and controllable, and it can be scaled up; it has excellent photothermal conversion capabilities; it can achieve effective photothermal antibacterial effects through the control of near-infrared light; it has good stability under physiological conditions and good biocompatibility at the cellular level, and has practical application prospects. Attached Figure Description

[0014] Figure 1 This is a scanning electron microscope image of the Mn@PCN-224 nanoparticles in the embodiment.

[0015] Figure 2 These are high-angle annular dark-field scanning transmission electron microscope images of Mn@PCN-224 nanoparticles in the embodiments, and corresponding C, N, O, Zr, and Mn elemental distribution images.

[0016] Figure 3 This example shows the hydration particle size and dispersion index of Mn@PCN-224 nanoparticles treated in cell culture medium for two weeks.

[0017] Figure 4 In this embodiment, the Mn@PCN-224 nanoparticles are observed in near-infrared light (808 nm, 1 W / cm²). 2 The heating-cooling curves under irradiation, and the linear fitting graph of cooling time versus -lnθ.

[0018] Figure 5 In this embodiment, the Mn@PCN-224 nanoparticles are observed in near-infrared light (808 nm, 1 W / cm²). 2 A representative colony photograph after 10 minutes of irradiation.

[0019] Figure 6 The results show the cytotoxicity of Mn@PCN-224 nanoparticles after co-incubation with mouse fibroblasts for 24 h in the examples.

[0020] Figure 7 In the comparative example, PCN-224 nanoparticles and Mn@PCN-224 nanoparticles were compared under near-infrared light (808 nm, 1 W / cm²). 2 Temperature rise curve under irradiation.

[0021] Figure 8 The images show the absorption spectra of PCN-224 nanoparticles and Mn@PCN-224 nanoparticles in the near-infrared region in the comparative example.

[0022] Figure 9 The photoluminescence spectra of PCN-224 nanoparticles and Mn@PCN-224 nanoparticles in the comparative example are shown.

[0023] Figure 10The figures show the Tauc curves of PCN-224 nanoparticles and Mn@PCN-224 nanoparticles in the comparative example. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. Furthermore, it should be understood that after reading the content of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims and are all within the protection scope of the present invention.

[0025] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0026] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0027] Unless otherwise specified in this invention, the reagents, instruments, and equipment used in the following embodiments are all reagents, instruments, and equipment commonly used by those skilled in the art.

[0028] Example This embodiment provides a manganese-doped porphyrin-based metal-organic framework nanoparticle with near-infrared photothermal conversion capability, comprising the following steps: 1) Dissolve 100 mg tetrakis(4-carboxyphenyl)porphyrin, 300 mg zirconium chloride octahydrate and 2.8 g benzoic acid in 100 mL N,N-dimethylformamide, heat to 90 °C and react for 5 h. After the reaction, centrifuge at 15000 rpm for 30 min to collect the precipitate, wash three times with N,N-dimethylformamide and deionized water respectively, and dry to obtain PCN-224 nanoparticles.

[0029] 2) Disperse 30 mg of PCN-224 nanoparticles obtained in step 1) in 10 mL of N,N-dimethylformamide containing 31 mg of anhydrous manganese chloride, heat to 120 °C and react for 7 h. After the reaction is completed, collect the precipitate at 15000 rpm, wash three times with N,N-dimethylformamide and deionized water respectively, and dry to obtain Mn@PCN-224 nanoparticles.

[0030] Figure 1 The images show scanning electron microscope (SEM) images of Mn@PCN-224 nanoparticles prepared according to this method. The images reveal that the Mn@PCN-224 nanoparticles are spherical with a particle size of approximately 120 nm. High-angle circular dark-field scanning transmission electron microscope (SEM) images of the Mn@PCN-224 nanoparticles and their corresponding elemental distribution are shown below. Figure 2 As shown, the elements are uniformly dispersed in the nanoparticles, and the presence of the Mn element signal indicates successful Mn doping. Figure 3 As shown, the hydrated particle size and dispersion index of Mn@PCN-224 nanoparticles did not show significant differences in cell culture medium within two weeks, indicating that Mn@PCN-224 nanoparticles have extremely high stability in physiological environment, while the increase in particle size may be due to the protein crown formed by protein adsorption in the culture medium.

[0031] Figure 4 This indicates the photothermal conversion capability of Mn@PCN-224 nanoparticles in the near-infrared light response. With a particle concentration of 300 μg / mL, it can be seen that Mn@PCN-224 nanoparticles exhibit photothermal conversion capability in the near-infrared light response (808 nm, 1 W / cm²). 2 The temperature rapidly increased under irradiation, reaching 61.7 °C in 10 min, an increase of 37.8 °C. Through a heating-cooling cycle, the photothermal conversion efficiency of the Mn@PCN-224 nanoparticles was calculated to be 34.1%, indicating that the Mn@PCN-224 nanoparticles prepared by this method possess excellent near-infrared light-responsive photothermal conversion capabilities.

[0032] The photothermal antibacterial function of Mn@PCN-224 nanoparticles, such as... Figure 5 As shown, Staphylococcus aureus and Escherichia coli were selected as representative Gram-positive and Gram-negative strains, respectively. Bacteria cultured to the plateau phase were diluted to 10⁻⁶. 6 CFU / mL, add Mn@PCN-224 to make a final concentration of 300 μg / mL. Under near-infrared light (808 nm, 1 W / cm²), 2After irradiation for 10 min, the sample was diluted to a suitable concentration with physiological saline, spread on agar plates, and incubated at 37 ℃ for 16 h before counting. The images show that the combination of Mn@PCN-224 and near-infrared light exhibited significant killing ability against both bacteria, demonstrating the excellent photothermal antibacterial ability of Mn@PCN-224 nanoparticles.

[0033] Figure 6 The cytotoxicity of Mn@PCN-224 nanoparticles was demonstrated. Mouse fibroblasts were co-incubated with different concentrations of Mn@PCN-224 nanoparticles for 24 h, and cytotoxicity was detected using a cell counting kit (CCK-8). The results showed that within the experimental concentration gradient range, cell viability was above 85% in all groups, indicating that Mn@PCN-224 nanoparticles possess low cytotoxicity.

[0034] Comparative Example This comparative example provides a porphyrin-based metal-organic framework nanoparticle without manganese doping, comprising the following steps: 100 mg of tetrakis(4-carboxyphenyl)porphyrin, 300 mg of zirconium chloride octahydrate and 2.8 g of benzoic acid were dissolved in 100 mL of N,N-dimethylformamide and heated to 90 °C for 5 h. After the reaction was completed, the precipitate was collected by centrifugation at 15000 rpm for 30 min. The precipitate was washed three times with N,N-dimethylformamide and deionized water, respectively, and dried to obtain PCN-224 nanoparticles.

[0035] Figure 7 This indicates that in near-infrared light (808 nm, 1 W / cm²) 2 The difference in photothermal properties between PCN-224 nanoparticles and Mn@PCN-224 nanoparticles under irradiation shows that Mn@PCN-224 nanoparticles rapidly heat up within 10 min, with a temperature increase of 37.8 ℃. In contrast, the temperature increase of PCN-224 nanoparticles is only 4.3 ℃, which is not significantly different from the temperature increase of deionized water (4 ℃). This result indicates that Mn doping is the main reason for the photothermal effect that endows this porphyrin-based metal-organic framework with near-infrared light response.

[0036] Figure 8 The figures show the absorption spectra of PCN-224 nanoparticles and Mn@PCN-224 nanoparticles in the near-infrared region. It can be seen that the absorbance of the nanoparticles in the near-infrared region increases significantly after Mn doping, indicating that the Mn@PCN-224 nanoparticles absorb more near-infrared light, which is the basis for the photothermal effect.

[0037] The photoluminescence spectra of PCN-224 nanoparticles and Mn@PCN-224 nanoparticles are as follows: Figure 9As shown, compared to PCN-224 nanoparticles, Mn@PCN-224 exhibits significant fluorescence quenching. This indicates that electron-hole recombination is reduced after excitation, and the energy of the excited state is dissipated in a non-relaxed form, transferred to phonons, causing lattice thermal vibrations, thereby generating heat.

[0038] Figure 10 The image shows the Tauc plots of PCN-224 nanoparticles and Mn@PCN-224 nanoparticles. Tauc plots are commonly used to calculate the optical band gap of materials. It can be seen that the optical band gap of PCN-224 is 2.51 eV, while the optical band gap decreases to 2.36 eV after Mn doping, a reduction of 0.15 eV. A smaller band gap facilitates electron transitions, meaning that electrons in Mn@PCN-224 are more easily excited into the conduction band, resulting in better photoresponsivity.

Claims

1. Application of manganese-doped porphyrin-based metal-organic framework materials in the preparation of near-infrared photoresponsive photothermal conversion materials, wherein the manganese-doped porphyrin-based metal-organic framework material is Mn-doped zirconium-based PCN-224 nanoparticles.

2. The application according to claim 1, characterized in that, The method for preparing the manganese-doped porphyrin-based metal-organic framework nanoparticles includes the following steps: 1) Tetra(4-carboxyphenyl)porphyrin, zirconium oxychloride octahydrate and benzoic acid were dissolved in N,N-dimethylformamide (DMF), heated, and centrifuged to collect the precipitate. The precipitate was washed with DMF and deionized water in sequence and dried to obtain porphyrin-based metal-organic framework nanoparticles PCN-224. 2) The PCN-224 nanoparticles obtained in step 1) were dispersed in an N,N-dimethylformamide solution containing anhydrous manganese chloride, heated, and centrifuged to collect the precipitate after heating. The precipitate was washed with DMF and deionized water in sequence and dried to obtain manganese-doped porphyrin-based metal-organic framework (Mn@PCN-224) nanoparticles.

3. The application according to claim 2, characterized in that, The mass ratio of tetra(4-carboxyphenyl)porphyrin, zirconium oxychloride octahydrate, and benzoic acid in step 1) is 1:3:

28.

4. The application according to claim 2, characterized in that, The heating temperature mentioned in step 1) is 85~95 ℃, and the heating time is 5-7 h.

5. The application according to claim 2, characterized in that, The mass ratio of PCN-224 nanoparticles to anhydrous manganese chloride in step 2) is 6:5~7.

6. The application according to claim 2, characterized in that, The heating temperature mentioned in step 2) is 115~125 ℃, and the heating time is 7-9 h.

7. The application according to claim 1, characterized in that, The manganese-doped porphyrin-based metal-organic framework nanoparticles are used to prepare photothermal antibacterial materials based on near-infrared photothermal conversion.

Images