ZIF-8 nano-composite, preparation method thereof and application of ZIF-8 nano-composite in sonodynamic inhibition of activity of drug-resistant bacteria
By preparing ZIF-8 nanocomposites and loading AgNPs on their surfaces, forming a Schottky junction structure, the problem of MRSA resistance to traditional antibiotics was solved, and the efficient acoustic dynamic antibacterial effect was achieved, with an antibacterial rate of 85.1%.
Patent Information
- Application Number
- CN202510090131.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2025-04-15
AI Technical Summary
Methicillin-resistant Staphylococcus aureus (MRSA) is highly resistant to traditional antibiotics, resulting in increased treatment difficulty. The existing acoustic dynamic antibacterial chemotherapy has the problems of low bioavailability of sound-sensitive agents and poor acoustic sensitivity.
ZIF-8@Ce6 (ZC) was prepared by the "one-pot method" and AgNPs were loaded on the surface of the complex by ion doping in situ reduction method to obtain Ag@ZIF-8@Ce6 (Ag@ZC). The complex structure can form a Schottky junction, which improves the acoustic sensitivity and thus enhances the acoustic dynamic antibacterial effect.
Through the combined effect of ZIF-8 complex and ultrasound, the antibacterial effect on MRSA is significantly improved, with the antibacterial rate reaching 85.1%, and the better antibacterial effect can be achieved using less drugs.
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Abstract
Description
Technical Field
[0001] The invention belongs to the field of medical technology, and specifically relates to a ZIF-8 nanocomposite and a preparation method thereof, and an application thereof in sonodynamic inhibition of drug-resistant bacteria activity. Background Art
[0002] Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most dangerous bacteria identified by the World Health Organization and has strong toxicity. The mechanism of MRSA resistance is the change in the properties of penicillin-binding proteins, which makes MRSA resistant to almost all β-lactam antibiotics. At present, the common clinical treatment methods are vancomycin, norvancomycin, etc. As the efficacy of these traditional drugs decreases and the development of new antibacterial drugs faces more challenges, adopting a new treatment mechanism, focusing on the development of non-antibiotic methods, and developing new antibacterial methods that can eradicate MRSA has become an important research direction.
[0003] Sonodynamic antibacterial chemotherapy (SACT) is an innovative treatment method that uses ultrasound to activate sonosensitizers enriched in inflammatory sites to produce reactive oxygen species, which then kills bacteria. It has attracted widespread attention due to its advantages such as strong tissue penetration, high target specificity, and the ability to overcome bacterial resistance. However, there are still problems such as low bioavailability of sonosensitizers and unsatisfactory sonosensitivity. The application of nanomedicine in the field of bacterial treatment is becoming more and more mature. Therefore, it is proposed to combine organic-inorganic hybrid sonosensitizers with ultrasound to act on MRSA in the hope of achieving better antibacterial effects. Summary of the invention
[0004] The purpose of the present invention is to provide an application of a ZIF-8 nanocomposite as a sonosensitizer in SACT. The present invention can effectively inhibit the growth of MRSA by using the ZIF-8 nanocomposite to cooperate with ultrasound to act on MRSA.
[0005] To achieve the above object, the technical solution adopted by the present invention is: a ZIF-8 nanocomposite, wherein the ZIF-8 composite is an organic framework of ZIF-8, and ZIF-8@Ce6 (ZC) is prepared by a "one-pot method", and then AgNPs are loaded on the surface of the composite by an ion doping in-situ reduction method to prepare Ag@ZIF-8@Ce6 (Ag@ZC). A Schottky junction can be formed between AgNPs and ZIF-8, and this structure can improve the acoustic sensitivity of the composite material by prolonging the separation of electron-hole pairs, thereby enhancing the effect of SACT. The specific steps are as follows:
[0006] Synthesis of ZC:
[0007] 1 mL Ce6 anhydrous methanol solution (1 mg / mL) was mixed with 7.15 mL anhydrous methanol solution containing 328.44 mg of 2-methylimidazole in the dark to obtain solution 1; 100 mg hexadecyltrimethylammonium bromide and 7.15 mL anhydrous methanol solution containing 148.75 mg Zn(NO3)2·6H2O were mixed to obtain solution 2. The above two solutions were mixed and stirred at 40°C for 24 hours. After the reaction, the mixed solution was washed three times with anhydrous methanol (10000 r / min, 10 min) and vacuum dried at 60°C for 12 hours to obtain ZC.
[0008] Synthesis of Ag@ZC:
[0009] Take 200 mL of ZC anhydrous methanol solution (2 mg / mL) and 10 mL of silver nitrate anhydrous methanol solution (7 mg / mL), ultrasonically treat them for 5 min respectively, then mix them, stir and react at 25 °C for 3 h, collect the product by centrifugation, wash it three times with anhydrous methanol (10000 r / min, 10 min), resuspend it in 200 mL of anhydrous methanol, add 80 mg of sodium borohydride, continue to stir and react at 25 °C for 30 min, wash the mixed solution three times with anhydrous methanol (10000 r / min, 10 min) and vacuum dry it at 60 °C for 12 h to obtain Ag@ZC.
[0010] The application of the above-mentioned ZIF-8 complex combined with ultrasound in inhibiting MRSA activity.
[0011] The above application method is as follows: the above ZIF-8 complex phosphate buffer solution (PBS, pH=7.4) and MRSA bacterial suspension are added to centrifuge tubes filled with sterile saline, mixed, and transferred into a 35 mm single-cup culture dish for ultrasonic treatment.
[0012] In the above application, the concentration of MRSA in the suspension was 1×10 5 CFU / mL.
[0013] In the above application, the concentration of ZIF-8 complex in the suspension was 50 μg / mL.
[0014] In the above application, the ultrasonic frequency is 1.0 MHz.
[0015] In the above application, the ultrasonic power is 1.0W / cm 2 .
[0016] In the above application, the ultrasonic time is 3.0 min.
[0017] The invention provides the preparation of ZIF-8 complex and its application in inhibiting MRSA activity in combination with ultrasound. The sonodynamic antibacterial activity of ZIF-8 complex is investigated with MRSA antibacterial rate as evaluation index. ZIF-8 is advantageous in exerting sonodynamic antibacterial effect and can load nano drugs, so that better antibacterial effect can be achieved with less drugs. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 A is the particle size diagram of ZIF-8.
[0019] Figure 1 B is the particle size diagram of the ZC composite.
[0020] Figure 1 C is the particle size diagram of Ag@ZC composite.
[0021] Figure 2 UV-visible spectrum of ZIF-8 complex.
[0022] Figure 3 Fourier transform infrared spectrum of ZIF-8 complex.
[0023] Figure 4 The effect of ZIF-8 complex on MRSA antibacterial effect before and after ultrasound. DETAILED DESCRIPTION
[0024] The technical solution of the present invention is described in detail below through specific examples.
[0025] Example 1 Preparation and Characterization of ZIF-8 Composites (I) Synthesis of ZIF-8@Ce6(ZC)
[0026] ZC was prepared using a one-pot method as follows:
[0027] 1 mL Ce6 anhydrous methanol solution (1 mg / mL) was mixed with 7.15 mL anhydrous methanol solution containing 328.44 mg of 2-methylimidazole in the dark to obtain solution 1; 100 mg hexadecyltrimethylammonium bromide and 7.15 mL anhydrous methanol solution containing 148.75 mg Zn(NO3)2·6H2O were mixed to obtain solution 2. The above two solutions were mixed and stirred at 40°C for 24 hours. After the reaction, the mixed solution was washed three times with anhydrous methanol (10000 r / min, 10 min) and vacuum dried at 60°C for 12 hours to obtain ZC.
[0028] (II) Synthesis of Ag@ZIF-8@Ce6 (Ag@ZC)
[0029] Ag@ZC was prepared by ion doping in-situ reduction method as follows:
[0030] Take 200 mL of ZC anhydrous methanol solution (2 mg / mL) and 10 mL of silver nitrate anhydrous methanol solution (7 mg / mL), ultrasonically treat them for 5 minutes respectively, then mix them, stir and react at 25°C for 3 hours, collect the product by centrifugation, wash it three times with anhydrous methanol (10000 r / min, 10 min), resuspend it in 200 mL of anhydrous methanol, add 80 mg of sodium borohydride, continue to stir and react at 25°C for 30 minutes, wash the mixed solution three times with anhydrous methanol (10000 r / min, 10 min) and vacuum dry it at 60°C for 12 hours to obtain Ag@ZC, i.e., ZIF-8 complex.
[0031] (III) Complex structure characterization
[0032] Figure 1 Figure 2 is the particle size diagram of ZIF-8 complex. Figure 1 As shown, the hydrodynamic diameters of ZIF-8, ZC and Ag@ZC nanoparticles are 100.2 nm, 107.4 nm and 148.0 nm, respectively, and the polydispersity indices are 0.009, 0.072 and 0.012, respectively, indicating that the particles are formed uniformly and the particle size is reasonable, which can be used for subsequent research.
[0033] Figure 2 is the UV-visible spectrum of ZIF-8 complex. Figure 2 As shown in the figure, ZIF-8 has no obvious absorption peak in the range of 300-600nm; free Ce6 has a characteristic absorption peak at 402nm; the absorption peaks of ZC and Ag@ZC appear at 407nm and 414nm, respectively; compared with Ce6, the Soret bands of ZC and Ag@ZC at 402nm are red-shifted, which can be attributed to the Zn 2+ The insertion into the dihydrochlorin ring of Ce6 also proves the successful loading of Ce6. In addition, due to the local surface plasmon resonance effect of AgNPs, the absorption peak of ZC at 407nm is red-shifted and the absorption range is broadened.
[0034] Figure 3 The Fourier transform infrared spectrum of ZIF-8 complex. Figure 3 As shown, 420.5cm -1 、760.0cm -1 、993.3cm -1 、1147.6cm -1 、1583.4cm -1 、2929.9cm -1 and 3136.3cm -1The stretching vibration absorption peaks are respectively attributed to Zn-N bond, Zn-O bond, CN bond, CN bond, C=N bond, aliphatic CH bond and aromatic CH bond. These results prove the successful preparation of ZIF-8. In the infrared spectra of ZC and Ag@ZC, 3423.6cm -1 and 1670.4cm -1 The broad peaks attributed to the stretching vibration of OH and C=O respectively proved the successful loading of Ce6. In addition, the loading of AgNPs did not change the structure of ZC.
[0035] Example 2 Application of ZIF-8 complex as sonosensitizer in SACT in combination with ultrasound
[0036] This example verifies the effect of the sonodynamic antibacterial activity of the ZIF-8 complex provided in Example 1. The specific experimental steps and results are as follows:
[0037] Under sterile conditions, when the temperature of TSA medium drops to 45°C, pour it into a glass culture dish, wait for it to completely cool and solidify at room temperature, and then store it upside down at 4°C. Under sterile conditions, use LB broth to make a bacterial suspension, and dilute it with physiological saline to make the final MRSA concentration of 1×10 5 CFU / mL.
[0038] Under sterile conditions, after marking the centrifuge tubes, add samples to the centrifuge tubes according to Table 1, and place the sample-added centrifuge tubes No. 1-4 in a 25°C constant temperature water bath incubated for 10 minutes in a dark place. Place the suspension samples in the sample-added centrifuge tubes No. 5-8 in a 35mm single-cup culture dish in a dark place, and place it on the ultrasonic probe, turn on the power, set the ultrasonic frequency to 1.0MHz, and the power to 1W / cm 2 , the ultrasonic time was 3.0min. After irradiation, it was poured back into the No. 5-8 centrifuge tube and placed in a 25℃ constant temperature water bath to incubate for 10min away from light. After incubation, samples were taken and graded diluted, evenly spread on TSA medium, and then cultured in a 37℃ constant temperature incubator for 24h. Each group of experiments was performed 3 times, and the antibacterial rate was calculated by colony counting method.
[0039] The experimental results are as follows Figure 4 As shown in the figure, ultrasound irradiation alone has a slight inhibitory effect on MRSA, and ultrasound combined with ZIF-8 or ZC has a certain promoting effect on the antibacterial effect of the initial compound. However, after ultrasound combined with ZIF-8 composite Ag@ZC, its sonodynamic antibacterial effect can reach 85.1%.
[0040] Table 1 Sample packing table of ZIF-8 complex sonodynamic inhibition MRSA experiment
[0041]
Claims
1. A ZIF-8 nanocomposite, characterized in that: The preparation method is as follows: encapsulating dihydrochlorin e6 in the ZIF-8 framework to obtain ZIF-8@Ce6, and loading silver nanoparticles AgNPs on the surface to obtain ZIF-8 nanocomposite Ag@ZIF-8@Ce6.
2. A ZIF-8 nanocomposite according to claim 1, characterized in that: The preparation method of Ag@ZIF-8@Ce6 includes the following steps: ultrasonically treating ZIF-8@Ce6 in anhydrous methanol, adding an anhydrous methanol solution of silver nitrate thereto, stirring and reacting at 25°C for 3 hours, collecting the product by centrifugation, washing it with anhydrous methanol, resuspending it in anhydrous methanol, adding sodium borohydride thereto, continuing to stir and react at 25°C for 30 minutes, washing the mixed solution with anhydrous methanol and vacuum drying it to obtain Ag@ZIF-8@Ce6.
3. A ZIF-8 nanocomposite according to claim 2, characterized in that: In terms of mass ratio, ZIF-8@Ce6:silver nitrate=40:
7.
4. A ZIF-8 nanocomposite according to claim 1, characterized in that: The preparation method of ZIF-8@Ce6 includes the following steps: mixing an anhydrous methanol solution of Ce6 and an anhydrous methanol solution of 2-methylimidazole in the dark to obtain solution 1; mixing an anhydrous methanol solution of hexadecyltrimethylammonium bromide and Zn(NO3)2·6H2O to obtain solution 2, mixing the above two solutions, stirring and reacting, and after the reaction is completed, washing the mixed solution with anhydrous methanol and vacuum drying to obtain ZIF-8@Ce6.
5. A ZIF-8 nanocomposite according to claim 4, characterized in that: The stirring reaction is carried out at 40° C. for 24 hours.
6. A ZIF-8 nanocomposite according to claim 4, characterized in that: In terms of mass ratio, Ce6:2-methylimidazole:hexadecyltrimethylammonium bromide:Zn(NO3)2·6H2O=1:328:100:
149.
7. Use of the ZIF-8 complex according to claim 1 in combination with ultrasound in inhibiting the activity of methicillin-resistant Staphylococcus aureus (MRSA).
8. The use according to claim 4, characterized in that: The method is as follows: the phosphate buffer solution of the ZIF-8 complex according to claim 1 and the MRSA bacterial suspension are respectively added into a centrifuge tube filled with sterile saline, mixed, and the suspension is poured into a culture dish and placed on an ultrasonic device for ultrasonic treatment.
9. The use according to claim 5, characterized in that: The concentration of MRSA in the suspension was 1×10 5 CFU / mL; The concentration of ZIF-8 complex was 50 μg / mL.
10. The use according to claim 5, characterized in that: The ultrasonic frequency is 1.0 MHz; the ultrasonic power is 1.0 W / cm 2 ; Ultrasonic time is 3.0min.