Ag2o / ZIF-7 composite nanomaterial, preparation method thereof and application thereof in acoustic-dynamic antibacterial
Patent Information
- Application Number
- CN202610799675.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-04
- Publication Date
- 2026-08-18
AI Technical Summary
[0003]声动力抑菌是利用超声激活富集在炎症部位的声敏剂产生活性氧，继而杀死细菌的一种创新性手段，因其具有较强的组织穿透力、较高的靶点特异性以及可以克服细菌耐药性等优势引起了广泛的关注，但仍然存在声敏剂的生物利用度低、声敏性不理想等问题
[0016]本发明的有益效果为：首次成功合成了Ag2O/ZIF-7复合纳米材料，该材料在超声激发下能够高效产生活性氧物种，进而实现优异的抑菌效果。其独特的抑菌机制属于物理损伤途径，通过破坏细菌细胞结构直接杀灭病原菌，因而不易诱导细菌产生耐药性。特别值得注意的是，对于目前已广泛存在的耐药菌——耐甲氧西林金黄色葡萄球菌，该复合材料同样展现出显著的体外抑菌活性。这一发现为解决日益严峻的抗生素耐药性问题提供了新的策略和材料基础。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of pharmaceutical technology, specifically relating to an Ag2O / ZIF-7 composite nanomaterial, its preparation method, and its application in sonodynamic inhibition of drug-resistant bacterial activity. Background Technology
[0002] The spread of multidrug-resistant (MDR) pathogens (those resistant to almost any type of drug) is a major global public health problem. Microorganisms resistant to various antibiotics can lead to antibiotic suppression failure. This results in prolonged illness, more prescriptions for advanced antibiotics, and higher mortality rates. The World Health Organization has warned of the escalating global antibiotic resistance crisis. Given this dire situation, the development of non-antibiotic antibiotic suppression strategies is urgently needed.
[0003] Sonodynamic antibacterial therapy is an innovative approach that utilizes ultrasound to activate sonosensitive agents enriched at inflammatory sites, generating reactive oxygen species that kill bacteria. It has attracted widespread attention due to its advantages such as strong tissue penetration, high target specificity, and ability to overcome bacterial resistance. However, problems remain, including low bioavailability of sonosensitive agents and unsatisfactory sonosensitivity. Therefore, this paper proposes combining inorganic sonosensitive agents with ultrasound to target bacteria, hoping to achieve better antibacterial effects. Summary of the Invention
[0004] The purpose of this invention is to provide an application of Ag2O / ZIF-7 composite nanomaterials as a sonosensitive agent in sonodynamic antibacterial activity. This invention utilizes the synergistic effect of Ag2O / ZIF-7 composite nanomaterials with ultrasound to effectively inhibit bacterial growth. This invention provides the preparation of Ag2O / ZIF-7 composite nanomaterials and their application in conjunction with ultrasound in inhibiting the activity of *Escherichia coli*, *Staphylococcus aureus*, and methicillin-resistant *Staphylococcus aureus*. The sonodynamic antibacterial activity of the Ag2O / ZIF-7 composite nanomaterials was investigated using the inhibition rate of these three bacteria as an evaluation index.
[0005] The technical solution adopted in this invention is:
[0006] An Ag2O / ZIF-7 composite nanomaterial is produced by adding Ag2O nanoparticles during the synthesis of ZIF-7, thereby loading Ag2O into ZIF-7.
[0007] The preparation method of the Ag2O / ZIF-7 composite nanomaterial mentioned above includes the following steps: Ag2O and Zn(OAC)2·2H2O are dispersed in DMF and sonicated to form solution I; benzimidazole is dissolved in DMF and sonicated to form solution II; solution II is added dropwise to solution I; the resulting solution is stirred, centrifuged, washed with anhydrous methanol, and dried to obtain Ag2O / ZIF-7 composite nanomaterial.
[0008] Furthermore, in the above-mentioned method for preparing Ag2O / ZIF-7 composite nanomaterials, the preparation method of Ag2O includes the following steps: dissolving AgNO3 in deionized water, adjusting the pH to ≥14 with NaOH solution, filtering the resulting solution, washing, and drying.
[0009] Furthermore, in the above-mentioned method for preparing Ag2O / ZIF-7 composite nanomaterials, the molar ratio of Zn(OAC)2·2H2O to benzimidazole is 1:4.
[0010] Furthermore, in the above-mentioned method for preparing Ag2O / ZIF-7 composite nanomaterials, the ultrasonic time is 5 min.
[0011] The above-mentioned Ag2O / ZIF-7 composite nanomaterial is used in combined ultrasonic antibacterial treatment.
[0012] Further, the above application is carried out as follows: A physiological saline suspension and a bacterial suspension of the Ag2O / ZIF-7 composite nanomaterials are added to a centrifuge tube containing sterile physiological saline and mixed thoroughly. The mixture is then transferred to a 35 mm single-cup culture dish for ultrasonic treatment at a frequency of 1.0 MHz and a power of 1.5 W / cm². 2 The ultrasound time was 10 minutes.
[0013] Furthermore, in the above applications, the bacteria include Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus.
[0014] Furthermore, in the above application, the bacterial concentration in the bacterial suspension is 1×10⁻⁶. 6 The concentration of the physiological saline suspension of Ag2O / ZIF-7 composite nanomaterials was 4.5-8 μg / mL.
[0015] Preferably, the bacterial concentration in the Escherichia coli suspension is 1×10⁻⁶. 6 The concentration of the Ag2O / ZIF-7 composite nanomaterial in physiological saline suspension was 4.5 μg / mL; the bacterial concentration in the Staphylococcus aureus suspension was 1×10⁻⁶ CFU / mL. 6 The concentration of the Ag2O / ZIF-7 composite nanomaterial in physiological saline suspension was 8 μg / mL; the bacterial concentration in the methicillin-resistant Staphylococcus aureus suspension was 1×10⁻⁶ CFU / mL. 6 The concentration of the physiological saline suspension of Ag2O / ZIF-7 composite nanomaterials was 6 μg / mL.
[0016] The beneficial effects of this invention are as follows: For the first time, Ag2O / ZIF-7 composite nanomaterials were successfully synthesized. This material can efficiently generate reactive oxygen species under ultrasonic excitation, thereby achieving excellent antibacterial effects. Its unique antibacterial mechanism belongs to the physical damage pathway, directly killing pathogens by disrupting bacterial cell structure, thus making it less likely to induce drug resistance in bacteria. Particularly noteworthy is that this composite material also exhibits significant in vitro antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), a currently widespread drug-resistant bacterium. This discovery provides a new strategy and material basis for solving the increasingly serious problem of antibiotic resistance. Attached Figure Description
[0017] Figure 1 Scanning electron microscopy (SEM) spectra of Ag2O (A), ZIF-7 (B), and Ag2O / ZIF-7 (C).
[0018] Figure 2 This is an elemental mapping diagram of Ag2O / ZIF-7.
[0019] Figure 3 XPS spectra of ZIF-7, pure phase Ag2O, and Ag2O / ZIF-7 are shown, where (A) is the full scan spectrum, and (B)-(E) are the elemental spectra of N, Zn, Ag, and O, respectively.
[0020] Figure 4 The in vitro antibacterial effects of ZIF-7, Ag2O, and Ag2O / ZIF-7 on Escherichia coli with and without ultrasound are shown.
[0021] Figure 5 The in vitro antibacterial effects of ZIF-7, Ag2O, and Ag2O / ZIF-7 on Staphylococcus aureus with and without ultrasound are shown.
[0022] Figure 6 The in vitro antibacterial effects of ZIF-7, Ag2O, and Ag2O / ZIF-7 with and without ultrasound on methicillin-resistant Staphylococcus aureus are shown in the graph. Detailed Implementation
[0023] Example 1: Preparation of Ag2O / ZIF-7 composite nanomaterials
[0024] (I) The preparation method of ZIF-7 includes the following steps: 219.51 mg Zn(OAC)2·2H2O is dissolved in 30 mL DMF and sonicated for 5 min to form Zn(OAC)2·2H2O solution; 472.56 mg benzimidazole is dissolved in 30 mL DMF and sonicated for 5 min to form DMF solution containing benzimidazole; then the DMF solution containing benzimidazole is slowly added dropwise to the Zn(OAC)2·2H2O solution, and the mixture is stirred continuously at room temperature for 24 h. The resulting mixture is then centrifuged, washed and dried to obtain ZIF-7.
[0025] (II) The preparation method of Ag2O includes the following steps: 231.4 mg AgNO3 is dissolved in 100 mL of deionized water, the pH is adjusted to ≥14 with 2 M NaOH solution, the resulting solution is filtered, washed and dried to obtain Ag2O nanoparticles.
[0026] (III) The preparation method of Ag2O / ZIF-7 composite nanomaterials includes the following steps: 92.7 mg Ag2O and 219.51 mg Zn(OAC)2·2H2O are dispersed in 30 mL DMF and sonicated for 5 min to form solution I; 472.56 mg benzimidazole is dissolved in 30 mL DMF and sonicated for 5 min to form solution II; solution II is added dropwise to solution I, the resulting solution is stirred, centrifuged, washed with anhydrous methanol, and dried to obtain Ag2O / ZIF-7 composite nanomaterials.
[0027] Example 2 Characterization and analysis of pure-phase ZIF-7, pure-phase Ag2O, and Ag2O / ZIF-7 composite materials
[0028] (a) such as Figure 1 Scanning electron micrographs of pure-phase Ag₂O, ZIF-7, and Ag₂O / ZIF-7 are shown. The morphology of the prepared Ag₂O, ZIF-7, and Ag₂O / ZIF-7 complexes was characterized using scanning electron microscopy (SEM), as shown below. Figure 1 (A) is a morphological structure diagram of Ag2O, showing an irregular blocky structure; Figure 1 (B) ZIF-7 consists of nanospheres with smooth surfaces and clear outlines; Figure 1 (C) shows that the spherical particles in the Ag2O / ZIF-7 composite are attached to the surface of the blocky matrix, and the boundaries between the particles tend to be blurred, which proves that Ag2O and ZIF-7 were successfully composited.
[0029] (ii) such as Figure 2The image shows an elemental mapping of the Ag2O / ZIF-7 complex. The image shows that the five elements Ag (purple), O (green), C (red), Zn (blue), and N (yellow) are evenly distributed, further confirming the successful preparation of the complex.
[0030] (iii) If Figure 3 XPS spectra of ZIF-7, pure-phase Ag₂O, and Ag₂O / ZIF-7 are shown. XPS was used to analyze the chemical state and molecular structure of the compounds in the samples. Full-scan spectra are shown below. Figure 3 (A) indicates that the Ag2O / ZIF-7 composite (AZ) clearly contains elements such as Zn, O, Ag, C, and N, further proving the successful preparation of this composite material. Figure 3 As shown in (B), the peaks at 405.91 eV, 399.24 eV and 398.99 eV are attributed to the N1s of ZIF-7. Figure 3 (C) shows the peaks of Zn at 1021.95 eV and 1044.95 eV, which are attributed to Zn2p, respectively. 3 / 2 and Zn2p 1 / 2 . Figure 3 (D) shows the high-resolution spectrum of Ag, where the peaks at 368.29 eV and 347.30 eV are attributed to Ag3d. 5 / 2 and Ag3d 3 / 2 .exist Figure 3 In (E), the O1s peaks at 531.23 eV and 531.79 eV are attributed to Ag₂O and ZIF-7, respectively. After the combination of Ag₂O and ZIF-7, the peaks of N, Zn, and Ag in AZ shift to lower binding energies, while the peak of O shifts to the left, biased towards higher binding energies. This indicates that the combination alters the electron cloud density and also demonstrates the successful construction of the heterojunction.
[0031] Example 3: Application of Ag2O / ZIF-7 composite nanomaterials as a sonic sensitizer in synergistic ultrasound inhibition of Escherichia coli, Staphylococcus aureus, and methoxystaphylococcus aureus.
[0032] This embodiment verifies the sonodynamic antibacterial activity of the Ag2O / ZIF-7 complex prepared in Example 1. The specific experimental steps and results are as follows:
[0033] Under aseptic conditions, the nutrient agar medium was sterilized. After sterilization, it was cooled to 45-50°C in a laminar flow hood and poured into petri dishes to solidify at room temperature. A bacterial suspension was prepared using LB broth and diluted with physiological saline to a final bacterial concentration of 1×10⁻⁶. 6 CFU / mL.
[0034] Under aseptic conditions, centrifuge tubes containing the added materials and bacterial solution were incubated at 37 ℃ for 10 min without sonication. The resulting tubes were then transferred to 35 mm single culture dishes and placed on an ultrasonic probe for sonication. The ultrasonic frequency was set to 1.0 MHz and the power to 1.5 W / cm². 2 The sonication time was 10 min. After sonication, the sample was poured back into a centrifuge tube, serially diluted, and spread evenly on nutrient agar medium. The sample was then incubated in a constant temperature incubator at 37 ℃ for 12 h. Each group was repeated in triplicate. The inhibition rate was calculated using the colony plate counting method.
[0035] (a) Experimental results are as follows Figure 4 The Control group showed a slight inhibitory effect on Escherichia coli after ultrasound, while the Ag2O and ZIF-7 groups showed a certain degree of inhibition. The inhibition rate of Escherichia coli after ultrasound combined with AZ (4.5 μg / mL) reached over 99.8%.
[0036] (II) Experimental results are as follows Figure 5 The Control group showed a slight inhibitory effect on Staphylococcus aureus after ultrasound, while the Ag2O and ZIF-7 groups showed a certain degree of inhibition. The combined ultrasound treatment with AZ (8 μg / mL) achieved an inhibition rate of over 98.9% against Staphylococcus aureus.
[0037] (III) Experimental results are as follows Figure 6 The Control group showed a slight inhibitory effect on methicillin-resistant Staphylococcus aureus after ultrasound, while the Ag2O and ZIF-7 groups showed a certain degree of inhibition. The combined ultrasound treatment with AZ (6 μg / mL) achieved an inhibition rate of over 96.0% against methicillin-resistant Staphylococcus aureus.
Claims
1. An Ag₂O / ZIF-7 composite nanomaterial, characterized in that, The Ag2O / ZIF-7 composite nanomaterial is prepared by adding Ag2O nanoparticles during the synthesis of ZIF-7, thereby loading Ag2O into ZIF-7.
2. The preparation method of the Ag2O / ZIF-7 composite nanomaterial according to claim 1, characterized in that, The preparation method includes the following steps: dispersing Ag2O and Zn(OAC)2·2H2O in DMF and sonicating to form solution I; dissolving benzimidazole in DMF and sonicating to form solution II; Solution II was added dropwise to solution I, the resulting solution was stirred, centrifuged, washed with anhydrous methanol, and dried to obtain Ag2O / ZIF-7 composite nanomaterials.
3. The preparation method according to claim 2, characterized in that, The preparation method of Ag2O includes the following steps: dissolving AgNO3 in deionized water, adjusting the pH to ≥14 with NaOH solution, filtering the resulting solution, washing, and drying.
4. The preparation method according to claim 2, characterized in that, The molar ratio of Zn(OAC)2·2H2O to benzimidazole is 1:
4.
5. The preparation method according to claim 2, characterized in that, The ultrasound time was 5 minutes.
6. The application of the Ag2O / ZIF-7 composite nanomaterial as described in claim 1 in combined ultrasonic antibacterial treatment.
7. The application according to claim 6, characterized in that, The application method is as follows: Add the physiological saline suspension and bacterial suspension of the Ag2O / ZIF-7 composite nanomaterials to a centrifuge tube containing sterile physiological saline and mix well. Transfer the mixture to a 35 mm single-cup culture dish for ultrasonic treatment. The ultrasonic frequency is 1.0 MHz and the ultrasonic power is 1.5 W / cm². 2 The ultrasound time was 10 minutes.
8. The application according to claim 7, characterized in that, The bacteria include Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus.
9. The application according to claim 8, characterized in that, The bacterial concentration in the bacterial suspension was 1×10⁻⁶. 6 The concentration of the physiological saline suspension of Ag2O / ZIF-7 composite nanomaterials was 4.5-8 μg / mL.
10. The application according to claim 9, characterized in that, The bacterial concentration in the E. coli suspension was 1×10⁻⁶. 6 The concentration of the Ag2O / ZIF-7 composite nanomaterial in physiological saline suspension was 4.5 μg / mL; the bacterial concentration in the Staphylococcus aureus suspension was 1×10⁻⁶ CFU / mL. 6 The concentration of the Ag2O / ZIF-7 composite nanomaterial in physiological saline suspension was 8 μg / mL; the bacterial concentration in the methicillin-resistant Staphylococcus aureus suspension was 1×10⁻⁶ CFU / mL. 6 The concentration of the physiological saline suspension of Ag2O / ZIF-7 composite nanomaterials was 6 μg / mL.