Curcumin composite nanomaterial based on MOFs (Metal-Organic Frameworks) as well as preparation method and application thereof

Abstract

The invention relates to the technical field of biological medicines and nano materials, in particular to a curcumin composite nano material based on MOFs and a preparation method and application thereof. The curcumin composite nano material is prepared from an MOFs (Metal-Organic Frameworks) carrier and curcumin loaded on the MOFs carrier; wherein the MOFs carrier is Ag-MOF (silver-metal organic framework). The curcumin composite nanomaterial based on MOFs not only shows excellent antibacterial activity and biocompatibility, but also the curcumin loaded on the surface can effectively eliminate excessive free radicals, promote wound healing and reduce inflammatory response; meanwhile, the preparation method of the curcumin composite nanomaterial is simple in step, controllable in condition, low in production cost, green and environment-friendly, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedicine and nanomaterials, and in particular to a MOFs-based curcumin composite nanomaterial, a preparation method thereof, and applications thereof. Background Art

[0002] With the continuous development of humanity and the evolution of biological species, the world today faces serious public health challenges, particularly the prevalence of bacterial infections, which cannot be underestimated. Traditional antibiotic treatments have led to the development of drug resistance in bacteria, resulting in an increase in morbidity. It is estimated that approximately 700,000 people die annually from drug-resistant bacterial infections, and this number is projected to reach 10 million by 2050. Staphylococcus aureus and Escherichia coli, representative of Gram-positive and Gram-negative bacteria, are the most common pathogens, and the harm they cause significantly impacts human health. Escherichia coli, a Gram-negative bacterium, is an opportunistic pathogen that can cause gastrointestinal infections or localized infections of various tissues and organs. Staphylococcus aureus is a common foodborne pathogen that often inhabits the skin, nasal cavity, and throat of humans and animals. The increasing frequency of antimicrobial use, the expansion of clinical applications, and the proliferation of drug types have exacerbated the problem of bacterial resistance. Porous metal-organic frameworks (MOFs), due to their high porosity, good biocompatibility, and tunable surface functionality, have been widely used in cell imaging, antimicrobial therapy, and drug delivery.

[0003] Silver metal-organic frameworks (Ag-MOFs) are porous materials composed of silver ions and 2-methylimidazole. Ag-based MOFs can produce a sustained release of silver ions through MOF degradation, thereby prolonging their antibacterial effect. Curcumin, a natural hydrophobic polyphenol extracted from the ginger plant, is currently attracting considerable attention in the biomedical field. Due to its well-known anti-inflammatory and antioxidant properties, it is a promising wound healing agent. Curcumin exhibits significant bioactivity in inhibiting inflammation and combating oxidative stress. However, existing single antibacterial materials lack antioxidant properties, making it difficult to address the delayed healing caused by oxidative stress at the wound site. While curcumin possesses antioxidant properties, its hydrophobicity results in low bioavailability and a high minimum inhibitory concentration (MIC). Therefore, the development of new materials with synergistic antibacterial and antioxidant properties, as well as rapid repair of wounds infected with drug-resistant bacteria, is of particular importance. Summary of the Invention

[0004] The present invention aims to address the deficiencies in the prior art and provide a MOFs-based curcumin composite nanomaterial, a preparation method thereof, and applications thereof. The MOFs-based curcumin composite nanomaterial not only exhibits excellent antibacterial activity and biocompatibility, but also the curcumin loaded on the surface can effectively eliminate excess free radicals, promote wound healing, and reduce inflammatory responses. Furthermore, the preparation method of the curcumin composite nanomaterial has simple steps, controllable conditions, low production cost, is environmentally friendly, and has broad application prospects.

[0005] In order to achieve the above objectives, in a first aspect, the present invention provides a curcumin composite nanomaterial based on MOFs, wherein the curcumin composite nanomaterial is composed of a MOFs carrier and curcumin loaded on the MOFs carrier; wherein,

[0006] The MOFs carrier is Ag-MOF.

[0007] In a second aspect, the present invention provides a method for preparing a MOFs-based curcumin composite nanomaterial, the preparation method comprising: mixing a silver salt, an organic ligand and curcumin in the presence of a solvent, and allowing the mixture to react.

[0008] Preferably, the silver salt is selected from one or two or more of silver nitrate, silver chlorate and silver perchlorate.

[0009] Preferably, the organic ligand is selected from one or two or more of 2-methylimidazole, 4,4'-bipyridine and 1,4-phthalic acid.

[0010] Preferably, the mass ratio of the silver salt, the organic ligand and curcumin is 1:1.5-2.0:0.03-0.10.

[0011] Preferably, the solvent is selected from one or two or more of ethanol aqueous solution, PBS buffer solution and deionized water.

[0012] Preferably, the mixing conditions include: a stirring rate of 6000-8000 rpm and a time of 30-60 min.

[0013] Preferably, the conditions for the static reaction include: a time of 30-90 minutes and a temperature of 15-30°C.

[0014] In a third aspect, the present invention provides a curcumin composite nanomaterial prepared by the preparation method described in the second aspect.

[0015] In a fourth aspect, the present invention provides a use of the curcumin composite nanomaterial as described in the first aspect or the third aspect in the preparation of an antibacterial product.

[0016] In a fifth aspect, the present invention provides a use of the curcumin composite nanomaterial as described in the first aspect or the third aspect in the preparation of an antioxidant product.

[0017] In a sixth aspect, the present invention provides a use of the curcumin composite nanomaterial as described in the first aspect or the third aspect in the preparation of a medicament for promoting wound healing.

[0018] In the above technical solution, the curcumin composite nanomaterial based on MOFs of the present invention is synthesized by loading curcumin (Curcumin) into a silver-based metal-organic framework (Ag-MOF) to synthesize curcumin composite nanomaterial (Cur / Ag-MOF). The curcumin composite nanomaterial adheres to the bacterial surface and interacts with the sulfur-containing protein in the bacterial cell wall, causing cell membrane damage and cytoplasm leakage, thereby leading to bacterial death, achieving a bactericidal and antibacterial effect. At the same time, due to the loading of curcumin, it has good antioxidant capacity and can effectively capture and remove reactive oxygen.

[0019] At the same time, the preparation method of the MOFs-based curcumin composite nanomaterial of the present invention has a simple process, low cost, environmental friendliness, and is convenient for industrial production and commercial utilization.

[0020] Not only that, this curcumin composite nanomaterial has multiple functions of efficiently scavenging reactive oxygen species (ROS), broad-spectrum antibacterial and promoting wound healing. It is suitable for the treatment of skin wounds infected by drug-resistant bacteria and has high economic value and broad application prospects.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 Transmission electron microscopy (TEM) images of the Ag-MOF prepared in Comparative Example 1 of the present invention (left) and the Cur / Ag-MOF prepared in Example 1 (right);

[0024] Figure 2 X-ray diffraction patterns (XRD) of the Ag-MOF prepared in Comparative Example 1 of the present invention and the Cur / Ag-MOF prepared in Example 1;

[0025] Figure 3 The infrared spectra of the Ag-MOF prepared in Comparative Example 1 of the present invention, the Cur / Ag-MOF prepared in Example 1, and curcumin;

[0026] Figure 4 UV-visible spectra of the Ag-MOF prepared in Comparative Example 1 of the present invention, the Cur / Ag-MOF prepared in Example 1, and curcumin;

[0027] Figure 5 This is the X-ray photoelectron spectroscopy (XPS) of the Cur / Ag-MOF prepared in Example 1 of the present invention;

[0028] Figure 6 This is a growth curve of Staphylococcus aureus treated with the Cur / Ag-MOF prepared in Example 1 of the present invention according to the method of Test Example 1;

[0029] Figure 7 This is a growth curve of Escherichia coli treated with the Cur / Ag-MOF prepared in Example 1 according to the method of Test Example 1;

[0030] Figure 8 This is a bacterial colony image of the Ag-MOF prepared in Comparative Example 1 of the present invention, the Cur / Ag-MOF prepared in Example 1, and curcumin after being treated according to the method of Test Example 2;

[0031] Figure 9 The inhibition zone diagram of the Ag-MOF prepared in Comparative Example 1 of the present invention, the Cur / Ag-MOF prepared in Example 1, and curcumin treated according to the method of Test Example 3;

[0032] Figure 10 The UV-visible spectra of the DPPH absorbance changes of the Cur / Ag-MOF prepared in Example 1 at different concentrations after being treated according to Test Example 4;

[0033] Figure 11 The UV-visible spectra of the DPPH absorbance changes of the Ag-MOF prepared in Comparative Example 1 of the present invention, the Cur / Ag-MOF prepared in Example 1, and curcumin at the same concentrations after being treated according to the method of Detection Example 4;

[0034] Figure 12 This is a DPPH radical scavenging rate spectrum of the Cur / Ag-MOF prepared in Example 1 of the present invention after being treated according to the method of Test Example 4;

[0035] Figure 13 The fluorescence spectra of the changes in ROS in bacteria after the Ag-MOF prepared in Comparative Example 1 of the present invention, the Cur / Ag-MOF prepared in Example 1, and curcumin were treated according to the method of Detection Example 5;

[0036] Figure 14 Schematic diagram of the morphology of normal Staphylococcus aureus and Escherichia coli before treatment with Cur / Ag-MOF prepared in Example 1 of the present invention;

[0037] Figure 15 Schematic diagram of the morphology of Staphylococcus aureus and Escherichia coli after being treated with the Cur / Ag-MOF prepared in Example 1 of the present invention according to the method of Detection Example 6;

[0038] Figure 16 Schematic diagram of confocal laser scanning microscopy (CLSM) of Staphylococcus aureus treated with the Cur / Ag-MOF prepared in Example 1 of the present invention according to the method of Detection Example 7;

[0039] Figure 17 Schematic diagram of confocal laser scanning microscopy (CLSM) of Escherichia coli treated with the Cur / Ag-MOF prepared in Example 1 of the present invention according to the method of Detection Example 7;

[0040] Figure 18 Schematic diagram of the construction and treatment of a mouse wound infection model using the Cur / Ag-MOF prepared in Example 1 of the present invention and treated according to the method of Application Example 1;

[0041] Figure 19 Schematic diagram of wound healing area and mouse weight of wounds treated with Cur / Ag-MOF prepared in Example 1 of the present invention according to the method of Application Example 1;

[0042] Figure 20 Schematic diagram of a study on drug resistance of Staphylococcus aureus and Escherichia coli using the Cur / Ag-MOF prepared in Example 1 of the present invention and treated according to the method of Test Example 8;

[0043] Figure 21 This is a schematic diagram of the cytotoxicity of the Cur / Ag-MOF prepared in Example 1 of the present invention treated according to the method of Test Example 9;

[0044] Figure 22 Schematic diagram of hemolysis rate using the Cur / Ag-MOF prepared in Example 1 of the present invention treated according to the method of Test Example 10;

[0045] Figure 23 This is a schematic diagram of the curcumin composite nanomaterial of the present invention acting on a wound to promote wound healing. DETAILED DESCRIPTION

[0046] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0047] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0048] In a first aspect, the present invention provides a curcumin composite nanomaterial based on MOFs, wherein the curcumin composite nanomaterial is composed of a MOFs carrier and curcumin loaded on the MOFs carrier; wherein,

[0049] The MOFs carrier is Ag-MOF.

[0050] The MOFs-based curcumin composite nanomaterial of the present invention is synthesized by loading curcumin (Curcumin) into a silver-based metal-organic framework (Ag-MOF) to synthesize a curcumin composite nanomaterial (Cur / Ag-MOF). The curcumin composite nanomaterial adheres to the bacterial surface and interacts with the sulfur-containing protein in the bacterial cell wall, causing cell membrane damage and cytoplasm leakage, thereby leading to bacterial death, achieving a bactericidal and antibacterial effect. At the same time, due to the loading of curcumin, it has good antioxidant capacity and can effectively capture and remove reactive oxygen.

[0051] In a second aspect, the present invention provides a method for preparing a MOFs-based curcumin composite nanomaterial, the preparation method comprising: mixing a silver salt, an organic ligand and curcumin in the presence of a solvent, and allowing the mixture to react.

[0052] The preparation method of the MOFs-based curcumin composite nanomaterial of the present invention has a simple process, low cost, is environmentally friendly, and is convenient for industrial production and commercial utilization.

[0053] In a preferred embodiment of the present invention, the silver salt is selected from one or two or more of silver nitrate, silver chlorate and silver perchlorate.

[0054] In a preferred embodiment of the present invention, the organic ligand is selected from one or two or more of 2-methylimidazole, 4,4'-bipyridine and 1,4-phthalic acid.

[0055] In a preferred embodiment of the present invention, the mass ratio of the silver salt, the organic ligand and curcumin is 1:1.5-2.0:0.03-0.10, for example, it can be 1:1.5:0.03, 1:1.5:0.04, 1:1.5:0.06, 1:1.5:0.08, 1:1.5:0.10, 1:2:0.03 or 1:2:0.05, etc.

[0056] In a preferred embodiment of the present invention, the solvent is selected from one or two or more of ethanol aqueous solution, PBS buffer solution and deionized water.

[0057] In a preferred embodiment of the present invention, the mixing conditions include: a stirring rate of 6000-8000 rpm and a time of 30-60 min;

[0058] In a preferred embodiment of the present invention, the conditions for the static reaction include: a time of 30-90 minutes and a temperature of 15-30°C.

[0059] In a third aspect, the present invention provides a curcumin composite nanomaterial prepared by the preparation method described in the second aspect.

[0060] In a fourth aspect, the present invention provides a use of the curcumin composite nanomaterial as described in the first aspect or the third aspect in the preparation of an antibacterial product.

[0061] In a fifth aspect, the present invention provides a use of the curcumin composite nanomaterial as described in the first aspect or the third aspect in the preparation of an antioxidant product.

[0062] In a sixth aspect, the present invention provides a use of the curcumin composite nanomaterial as described in the first aspect or the third aspect in the preparation of a medicament for promoting wound healing.

[0063] The curcumin composite nanomaterial of the present invention has multiple functions of efficiently scavenging reactive oxygen species (ROS), broad-spectrum antibacterial properties, and promoting wound healing. It is suitable for treating skin wounds infected by drug-resistant bacteria and has high economic value and broad application prospects.

[0064] In the present invention, the room temperature is 15-35°C.

[0065] The present invention will be described in detail below by way of examples. In the following examples, the drugs and pharmaceuticals are all conventional commercial products.

[0066] Preparation Example 1

[0067] (1) Culture medium configuration:

[0068] Liquid culture medium: 2 g tryptone, 2 g sodium chloride, 1 g yeast extract powder, 200 mL deionized water;

[0069] Solid culture medium: 2 g tryptone, 2 g sodium chloride, 1 g yeast extract powder, 1.8 g agar, and 200 mL deionized water.

[0070] (2) Bacterial culture:

[0071] 20 μL of Staphylococcus aureus and 20 μL of Escherichia coli were transferred from a −80° C. freezer to 20 mL of liquid culture medium, and then cultured in a 37° C. incubator at a shaking speed of 180 rpm until the optical density absorption value at 600 nm reached 0.5 (OD600=0.5).

[0072] Example 1

[0073] Preparation of Cur / Ag-MOF:

[0074] 0.6 g of AgNO3 was dissolved in 30 mL of deionized water to obtain an AgNO3 solution, and then 1 g of 2-methylimidazole and 0.06 g of curcumin were dissolved in 30 mL of ethanol to obtain a mixed solution of ligand and curcumin;

[0075] The AgNO3 solution was mixed with the ligand and curcumin mixed solution and stirred at 6000 rpm for 30 min. The mixture was allowed to react at 25°C for 1 h, centrifuged at 8000 rpm for 10 min, the supernatant was discarded, and the suspension was washed three times by centrifugation. Finally, it was dried in a vacuum oven at 60°C for 24 h to obtain curcumin composite nanomaterial (Cur / Ag-MOF), which was recorded as B1.

[0076] Example 2

[0077] The method described in Example 1 was followed, except that “0.06 g of curcumin” in Example 1 was replaced with “0.02 g of curcumin” to obtain Cur / Ag-MOF, which was designated as B2.

[0078] Example 3

[0079] The method described in Example 1 was followed, except that “0.06 g of curcumin” in Example 1 was replaced with “0.04 g of curcumin” to obtain Cur / Ag-MOF, which was designated as B3.

[0080] Comparative Example 1

[0081] The method described in Example 1 was followed, except that curcumin was not added, to obtain Ag-MOF, which was designated as D1.

[0082] Test Example 1

[0083] The minimum inhibitory concentration (MIC) was determined by monitoring the bacterial growth curve. The specific method is as follows:

[0084] The bacterial suspension (concentration of about 10 8CFU / mL), and then washed with PBS buffer (pH 7.4) to remove impurities; the washed bacteria were mixed with 0, 8, 10, 20, and 30 ppm of the Cur / Ag-MOF deionized water solution prepared in Example 1, and co-cultured on a 37°C constant temperature shaker for 0, 2, 4, 6, 8, 10, 12, and 24 h; samples were taken at each specified time, and the growth of bacteria was monitored by measuring the absorbance at 600 nm to evaluate the inhibitory effect of the Cur / Ag-MOF prepared in Example 1 on bacterial growth. All experiments were repeated three times, and the results are shown in Figure 2. Figure 6-Figure 7 shown.

[0085] Depend on Figure 6 and Figure 7 It can be seen that when the concentration of Cur / Ag-MOF is 10 ppm, the growth of Staphylococcus aureus and Escherichia coli are significantly inhibited, and as the concentration increases, the inhibitory effect on bacterial growth activity becomes more obvious.

[0086] Test Example 2

[0087] The bactericidal activity of the Cur / Ag-MOF prepared in Example 1 was evaluated by the plate count method.

[0088] First, Staphylococcus aureus and Escherichia coli in Preparation Example 1 were cultured to the exponential growth phase, and then low-speed centrifugation was performed to obtain bacterial colonies; after dilution with phosphate buffer solution (PBS), curcumin, Ag-MOF prepared in Comparative Example 1, and Cur / Ag-MOF prepared in Example 1 were mixed with the diluted bacterial solution; 100 μL of the diluted solution was evenly coated on a nutrient agar plate, and finally incubated in a 37°C incubator for 24 hours, and the number of surviving colonies on the plate was estimated. Under the same concentration of 10 ppm, the antibacterial properties of Curcumin, Ag-MOF, and Cur / Ag-MOF were further tested and compared. The results are as follows: Figure 8 shown.

[0089] from Figure 8 It can be seen that the number of bacterial colonies co-cultured with curcumin did not decrease significantly, indicating that curcumin had almost no bactericidal effect, and the number of bacterial colonies co-cultured with the Ag-MOF prepared in Comparative Example 1 decreased significantly, indicating that Ag-MOF had a strong bactericidal effect. Only a few bacterial colonies were left after co-cultured with the Cur / Ag-MOF of Example 1 of the present invention, indicating that the Cur / Ag-MOF of Example 1 of the present invention had the strongest bactericidal effect, which is consistent with the results of the growth curve in Detection Example 1.

[0090] Test Example 3

[0091] The antibacterial test was carried out using the disk diffusion method.

[0092] The bacterial suspension of Staphylococcus aureus and Escherichia coli was appropriately diluted and coated on agar plates, and incubated at 37°C for 12 h; the bacterial suspension (concentration of about 10 8 CFU / mL) was evenly spread on the agar culture medium, and then the paper discs containing curcumin, Ag-MOF prepared in Comparative Example 1 and Cur / Ag-MOF prepared in Example 1 were evenly placed on the agar culture plate. After incubation at 37°C for 12h, the inhibition zone diameter around each disc was measured. The results are shown in FIG. Figure 9 shown.

[0093] Figure 9 Typical photos clearly show the inhibition zones formed around the samples. Staphylococcus aureus and Escherichia coli have no obvious inhibition zones near curcumin, indicating that curcumin has low antibacterial activity at this dose. However, Staphylococcus aureus and Escherichia coli both have obvious inhibition zones formed near the Cur / Ag-MOF of Example 1 of the present invention and the Ag-MOF of Comparative Example 1. However, the two exhibit significant differences in the diameter of the bacterial inhibition zones. A larger inhibition zone is observed around the Cur / Ag-MOF of Example 1 of the present invention, further confirming that the Cur / Ag-MOF of Example 1 of the present invention has superior antibacterial properties.

[0094] Test Example 4

[0095] The DPPH method was used to evaluate the antioxidant capacity of the Cur / Ag-MOF prepared in Example 1.

[0096] (1) 500 μL of 100 μM DPPH ethanol solution was added to 500 μL of 0, 10, 25, 50, and 100 ppm Cur / Ag-MOF solutions prepared in Example 1, and the mixture was incubated in a dark room at 25°C for 1 h. The absorbance was measured in the range of 450-750 nm using a UV-visible spectrophotometer.

[0097] (2) 500 μL of 100 μM DPPH ethanol solution was added to 500 μL of the same concentration (50 ppm) of curcumin, the Ag-MOF prepared in Preparation Example 1, and the Cur / Ag-MOF solution prepared in Example 1, and incubated in a dark room at 25°C for 1 h. The absorbance was measured in the range of 450-750 nm using a UV-visible spectrophotometer;

[0098] The scavenging ability of Cur / Ag-MOF for DPPH was calculated by the following formula:

[0099] DPPH scavenging ability = (Aa-As) / Aa×100%

[0100] Where Aa and As represent the absorbance values ​​(λ = 517 nm) in the absence and presence of the sample, respectively;

[0101] The experimental results are shown in Figure 10-12 .

[0102] like Figure 10 As shown, as the concentration of Cur / Ag-MOF of Example 1 of the present invention increases, the absorbance of DPPH at 517 nm gradually decreases, indicating that the inhibitory activity of Cur / Ag-MOF of Example 1 of the present invention on DPPH free radicals is steadily improved;

[0103] Depend on Figure 12 It can be seen that the inhibitory activity of Cur / Ag-MOF of Example 1 of the present invention on DPPH free radicals increased from 11% to 51%, which is comparable to Figure 10 The results are consistent with;

[0104] like Figure 11 As shown, at a concentration of 50 ppm, the Cur / Ag-MOF of Example 1 of the present invention exhibited excellent antioxidant effect, with a DPPH scavenging rate of up to 38%, which was more than three times that of Ag-MOF.

[0105] Test Example 5

[0106] ROS levels were detected using a commercial ROS assay kit based on DCFH-DA.

[0107] When DCFH-DA is oxidized by ROS, a strong fluorescence signal is observed. Generally, the level of intracellular ROS is proportional to the fluorescence intensity. Specifically, Staphylococcus aureus and Escherichia coli were co-cultured with the same concentration (50 ppm) of curcumin, the Ag-MOF prepared in Comparative Example 1, and the Cur / Ag-MOF prepared in Example 1 at 37°C for 6 hours; then, the cellular components of the bacterial suspension were separated from the supernatant by centrifugation at 8000 rpm for 5 minutes; the supernatant was incubated with DCFH-DA (100 mM) for 30 minutes, and finally, the fluorescence was measured using a fluorescence spectrometer at λ ex = Fluorescence spectrum was measured at 488 nm. Figure 13 .

[0108] Depend on Figure 13 It can be seen that the intracellular ROS levels of Staphylococcus aureus and Escherichia coli strains exposed to Cur / Ag-MOF and curcumin in Example 1 of the present invention decreased most significantly, while the Ag-MOF in Comparative Example 1 had the opposite effect; the research results show that the Cur / Ag-MOF produced by the combination of Ag-MOF and curcumin has the same excellent ROS scavenging ability as curcumin, because the presence of curcumin enhances its antioxidant capacity and subsequently significantly reduces intracellular ROS.

[0109] Test Example 6

[0110] The morphologies of Staphylococcus aureus and Escherichia coli before and after treatment with the Cur / Ag-MOF of Example 1 of the present invention were characterized using a scanning electron microscope (SEM).

[0111] 100 μL of bacterial suspension was incubated with 50 ppm of Cur / Ag-MOF of Example 1 of the present invention at 37°C for 3 h, centrifuged at 8000 rpm for 5 min, and washed with PBS at pH 7.4; then fixed with 2.5% glutaraldehyde at 4°C for 2 h, the fixed bacterial suspension was centrifuged, and the precipitate was washed with PBS at pH 7.4 to remove excess reagents and cell debris; then, the sample was dehydrated with 30%, 50%, 70%, 80%, 90% and 100% ethanol solutions in sequence; then, 10 μL of the suspension was dropped onto a clean silicon wafer and naturally dried at room temperature; finally, the morphology of Staphylococcus aureus and Escherichia coli was observed by scanning electron microscopy, as shown in FIG. Figure 14-15 shown.

[0112] Depend on Figure 14 It can be seen that normal Staphylococcus aureus is spherical with a smooth and complete surface, and normal Escherichia coli has a typical rod-shaped structure; Figure 15 After being treated with the Cur / Ag-MOF of Example 1 of the present invention, the shapes of Staphylococcus aureus and Escherichia coli became irregular, the cell membranes were broken, and the cell fluid flowed out, indicating that the Cur / Ag-MOF of Example 1 of the present invention has an excellent bactericidal effect.

[0113] Test Example 7

[0114] The live and dead bacteria staining test was used to evaluate the antibacterial ability of the Cur / Ag-MOF prepared in Example 1 of the present invention.

[0115] The green fluorescent dye FITC was used to stain both live and dead bacteria, and the red fluorescent dye PI was used to mark dead bacteria. Typically, 2 mL of bacterial suspension was mixed with 50 ppm of Cur / Ag-MOF prepared in Example 1 and incubated at 37°C for 3 h. After centrifugation at 6000 rpm for 5 minutes, the mixture was fluorescently stained with FITC (PI) for 15 minutes at room temperature. After centrifugation and three washes with PBS (pH 7.4) to remove excess dye, 10 μL of bacterial suspension was aspirated and gently placed on a microscope slide. High-precision imaging was then performed using a confocal laser scanning microscope (CLSM), as shown in Figure 2. Figure 16-17 .

[0116] Depend on Figure 16-17It can be seen from the content that the FITC of Staphylococcus aureus and Escherichia coli not treated with Cur / Ag-MOF prepared in Example 1 are green and the PI is not red, indicating that the bacteria are alive; the FITC of Staphylococcus aureus and Escherichia coli treated with Cur / Ag-MOF prepared in Example 1 are green and the PI is red, indicating that a large number of bacteria are dead, indicating that the Cur / Ag-MOF of the present invention has good antibacterial and bactericidal ability.

[0117] Application Example 1

[0118] In vivo antibacterial performance evaluation

[0119] Animal experiments were approved by the Animal Care Committee of Anhui Normal University (AHNUET2022028) and conducted in accordance with the Guide for the Care and Use of Laboratory Animals. Female mice aged 6 to 8 weeks and weighing 19 to 22 g were anesthetized and their dorsal hair was shaved to establish a skin wound model. 100 μL of Staphylococcus aureus suspension (10 8 After the wound was infected with 100 CFU / mL, the wound was covered with sterile cotton moistened with PBS for 24 hours. Then, the wound of the experimental group was treated with 50 ppm of the Cur / Ag-MOF solution prepared in Example 1, and the wound of the control group was treated with PBS at pH 7.4. Wound photos were taken at different time intervals (0, 2, 4, 6, 8, 10 and 12 days). The wound contraction rate was quantified using ImageJ software, and the weight changes of the mice were recorded to detect the health status of the mice during the wound healing process. The results are shown in Figure 2. Figure 18-19 .

[0120] Depend on Figure 18 (b) It can be seen that after 12 days, the wounds of the mice in the experimental group treated with the Cur / Ag-MOF solution prepared in Example 1 were basically healed, while the wounds of the mice in the control group treated with PBS were still very obvious; Figure 19 (a) It can be seen that after 12 days, the wound healing rate of the experimental group of mice treated with the Cur / Ag-MOF solution prepared in Example 1 reached 99.6%, while the wound healing rate of the control group of mice treated with PBS was only 87%, indicating that the Cur / Ag-MOF of the present invention can promote wound healing.

[0121] Test Example 8

[0122] Study on the drug resistance of Cur / Ag-MOF.

[0123] First, the initial MIC of the Cur / Ag-MOF prepared in Example 1 against Staphylococcus aureus and Escherichia coli was used to evaluate bacterial resistance. Then, bacterial dilutions were prepared at half the MIC concentration for subsequent MIC testing, and new MICs were obtained after incubation at 37°C for 16 hours. The same experimental process was repeated for 8 generations, and the MIC values ​​of each generation were recorded and compared with those of generation 1 to evaluate drug resistance. As a control, the bacterial resistance to tetracycline was determined, and the results are shown in Figure 2. Figure 20 shown.

[0124] Depend on Figure 20 It can be seen that during the 8 generations of co-culture with bacteria, the MIC of bacteria co-incubated with the Cur / Ag-MOF prepared in Example 1 did not increase significantly; in contrast, the MIC of the 5th generation Staphylococcus aureus and the 6th generation Escherichia coli co-incubated with tetracycline increased sharply. These results clearly show that compared with traditional antibiotics, the Cur / Ag-MOF of the present invention will not induce bacterial resistance during long-term use and can be used continuously.

[0125] Test Case 9

[0126] Cytotoxicity assay

[0127] In order to study the cytotoxicity of the Cur / Ag-MOF of the present invention, the cell viability was detected using a cell counting kit-8 (CCK-8). AML12 cells and HepG2 cells were cultured in RPMI 1640 medium with 5% CO2 gas at 37°C. Different concentrations of the Cur / Ag-MOF samples prepared in Example 1 (final concentrations of 0, 5, 10, 20, 40, and 80 ppm) were incubated with the cultured cells for 12 h. The treated cells were seeded on a 96-well plate and incubated with 10 μL of CCK-8 solution (2 mg / mL) for 4 h. Finally, the absorbance at 450 nm was measured using an enzyme meter and the cell viability was calculated. Each experiment was repeated 3 times. The results are shown in Table 1. Figure 21 shown.

[0128] Depend on Figure 21 It can be seen that when the Cur / Ag-MOF concentration increases from 5 ppm to 80 ppm, the cell survival rate remains above 90%, indicating that the cytotoxicity is negligible. The Cur / Ag-MOF concentration used in the experiment is less than 80 ppm, and the cytotoxicity of the Cur / Ag-MOF of the present invention is stable.

[0129] Test Example 10

[0130] In order to evaluate the blood compatibility of the Cur / Ag-MOF of the present invention, the following tests were performed:

[0131] First, 1 mL of mouse blood was mixed with 1 mL of PBS and centrifuged multiple times to collect red blood cells. Then, 100 μL of red blood cell suspension was added to 900 μL of Cur / Ag-MOF solution of Example 1 at concentrations of 5, 10, 20, 40, 80, and 100 ppm, respectively, and the mixture was incubated at 37°C for 3 h. The red blood cells were treated with PBS buffer and deionized water as negative and positive controls, respectively. Finally, the mixture of red blood cells and Cur / Ag-MOF sample was centrifuged, the supernatant was collected, and the hemolysis rate was calculated by measuring its absorbance at 540 nm. The results are shown in Figure 2. Figure 22 shown.

[0132] Depend on Figure 22 It can be seen from the content that when the concentration of Cur / Ag-MOF in Example 1 of the present invention reaches 100 ppm, the hemolysis rate is less than 3%. According to the relevant regulations of the International Organization for Standardization (ISO), a hemolysis rate greater than 5% is defined as hemolysis, indicating that a large number of red blood cells have ruptured. The results show that under physiological conditions, the Cur / Ag-MOF of the present invention does not cause red blood cell rupture and hemolysis, and has good biocompatibility.

[0133] In summary, the present invention provides a simple and effective method for synthesizing multifunctional Cur / Ag-MOF composite nanomaterials, which can be used to prepare in vitro antibacterial products and drugs for promoting wound healing. The Cur / Ag-MOF of the present invention effectively adheres to the bacterial surface and interacts with sulfur-containing proteins in the cell wall, causing bacterial membrane damage and cytoplasm leakage, ultimately leading to bacterial death, and has good antibacterial activity. In addition, due to the antioxidant ability of curcumin, the Cur / Ag-MOF of the present invention can also effectively capture and remove ROS, thereby protecting wounds from oxidative stress and promoting wound healing. At the same time, the Cur / Ag-MOF of the present invention has good in vitro and in vivo biocompatibility and does not cause obvious drug resistance in bacteria. According to the Staphylococcus aureus infection mouse back wound model, it can be clearly seen that the application of Cur / Ag-MOF to traumatic wounds can effectively promote wound healing without any side effects.

[0134] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0135] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0136] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A curcumin composite nanomaterial based on MOFs, characterized in that: The curcumin composite nanomaterial consists of a MOFs carrier and curcumin loaded on the MOFs carrier; wherein, The MOFs carrier is Ag-MOF.

2. A method for preparing a curcumin composite nanomaterial based on MOFs, characterized in that: The preparation method comprises: mixing silver salt, organic ligand and curcumin in the presence of a solvent, and allowing the mixture to stand for reaction.

3. The preparation method according to claim 2, characterized in that The silver salt is selected from one or two or more of silver nitrate, silver chlorate and silver perchlorate; Preferably, the organic ligand is selected from one or two or more of 2-methylimidazole, 4,4'-bipyridine and 1,4-phthalic acid.

4. The preparation method according to claim 2 or 3, characterized in that The mass ratio of the silver salt, the organic ligand and curcumin is 1:1.5-2.0:0.03-0.

10.

5. The preparation method according to any one of claims 2 to 4, characterized in that The solvent is selected from one or two or more of ethanol aqueous solution, PBS buffer solution and deionized water.

6. The preparation method according to any one of claims 2 to 5, characterized in that The mixing conditions include: a stirring rate of 6000-8000 rpm and a time of 30-60 min; Preferably, the conditions for the static reaction include: a time of 30-90 minutes and a temperature of 15-30°C.

7. A curcumin composite nanomaterial prepared by the preparation method according to any one of claims 2 to 6.

8. Use of the curcumin composite nanomaterial according to claim 1 or the curcumin composite nanomaterial according to claim 7 in the preparation of an antibacterial product.

9. Use of the curcumin composite nanomaterial according to claim 1 or the curcumin composite nanomaterial according to claim 7 in the preparation of an antioxidant product.

10. Use of the curcumin composite nanomaterial according to claim 1 or the curcumin composite nanomaterial according to claim 7 in preparing a medicament for promoting wound healing.

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