Preparation Method and Application of an Antibacterial Activity MnS Material

Abstract

The present invention discloses a preparation method and application of an antibacterial active MnS material. The preparation includes: (1) Mixing manganese chloride, sodium hydroxide, sodium polysulfide, polyvinylpyrrolidone and ultrapure water, stirring until completely dissolved, heating for reaction and then cooling. After centrifuging the reaction solution, washing the solid, and vacuum drying, α-MnS is obtained; Mixing manganese carbonate, sodium sulfide nonahydrate and ultrapure water, stirring until completely dissolved, heating for reaction and then cooling. After centrifuging the reaction solution, washing the solid, and vacuum drying, γ-MnS is obtained. The present invention synthesizes two different crystal forms of manganese sulfide, α-MnS and γ-MnS, by regulating the reaction raw materials. Both of them have the ability to release hydrogen sulfide and have certain antibacterial effects. Compared with α-MnS, γ-MnS has a stronger hydrogen sulfide release ability and better antibacterial effect. The present invention realizes the improvement of its antibacterial activity by regulating the crystal form of MnS.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomaterials, and relates to a preparation method and application of an antibacterial active MnS material. Background Art

[0002] Different crystal forms of the same drug often have different physical and chemical properties, and may also have different solubility, dissolution rate, bioavailability, drug activity, etc. For example, aspirin has crystal form I and crystal form II, and the blood drug concentration of form II aspirin exceeds that of form I aspirin by 70%. Therefore, it is of great significance to develop new drugs based on crystal form regulation.

[0003] In recent years, the number of deaths caused by bacterial infections has been increasing. At present, antibiotic drugs are mostly used for the treatment of bacterial infections. However, in the past few decades, the abuse of antibiotic drugs has led to the multiple drug resistance of bacteria to these drugs, resulting in serious global public health risks. Some inorganic nanomaterials have good antibacterial effects and are potential alternative drugs to traditional antibiotics. At present, there are many studies on the antibacterial activities of different metal nanomaterials, but there are no reports on the differences in antibacterial activities of different crystal forms of the same nanomaterial. Summary of the Invention

[0004] Object of the Invention: Aiming at the problems existing in the prior art, the present invention provides a preparation method of an antibacterial active MnS material. By regulating the reaction raw materials, the present invention synthesizes two different crystal forms of manganese sulfide, α-MnS and γ-MnS, which have good antibacterial activity and hydrogen sulfide release ability. The present invention discovers for the first time that different crystal forms of manganese sulfide have a significant impact on antibacterial ability. Compared with α-MnS, γ-MnS has a more significant hydrogen sulfide release ability and stronger activity against killing Escherichia coli. The present invention realizes for the first time the improvement of its own antibacterial activity by regulating the crystal form of MnS; the use of the specific crystal form of γ-MnS can achieve efficient antibacterial, and is used for preparing an efficient antibacterial reagent or material.

[0005] The present invention also provides the antibacterial active MnS material and its application.

[0006] Technical Solution: In order to achieve the above object, a preparation method of an antibacterial active MnS material according to the present invention is characterized by including the following steps:

[0007] (1) Mix manganese chloride, sodium hydroxide, sodium polysulfide, polyvinylpyrrolidone and ultrapure water, stir until completely dissolved, heat and react, then cool. After centrifuging the reaction solution, wash the solid, and vacuum dry to obtain α-MnS;

[0008] (2) Mix manganese carbonate, sodium sulfide nonahydrate with ultrapure water, stir until completely dissolved, heat for reaction and then cool. After centrifuging the reaction solution, wash the solid, and vacuum dry to obtain γ-MnS.

[0009] Among them, for the preparation of α-MnS in step (1): the dosage of manganese chloride is 2 - 8 mmol, the dosage of sodium polysulfide is 5 - 20 mmol, the dosage of polyvinylpyrrolidone is 200 - 800 mg, the dosage of sodium hydroxide is 150 - 600 mg, and the total volume of ultrapure water is 10 - 40 mL.

[0010] Preferably, the dosage of manganese chloride is 4 mmol, the dosage of sodium polysulfide is 10 mmol, the dosage of PVP is 400 mg, the dosage of sodium hydroxide is 300 mg, and the total volume of ultrapure water is 20 mL.

[0011] Among them, the heating reaction in step (1) is carried out in a tetrafluoroethylene high-pressure reactor, the heating temperature is 70 - 120 °C, and after continuous reaction for 12 - 48 h, it is naturally cooled to room temperature.

[0012] Among them, for the preparation of γ-MnS in step (2): the dosage of manganese carbonate is 2 - 8 mmol, the dosage of sodium sulfide nonahydrate is 4 - 16 mmol, and the total volume of ultrapure water is 10 - 40 mL.

[0013] Preferably, the dosage of manganese carbonate is 4 mmol, the dosage of sodium sulfide nonahydrate is 8 mmol, and the total volume of ultrapure water is 20 mL.

[0014] Among them, the heating reaction in step (2) is carried out in a tetrafluoroethylene high-pressure reactor, the heating temperature is 70 - 120 °C, and after continuous reaction for 12 - 48 h, it is naturally cooled to room temperature.

[0015] Among them, the solution cooled to room temperature in steps (1) and (2) is transferred to a centrifuge tube, centrifuged to remove the supernatant, then ultrasonicated with ultrapure water and centrifuged again. Repeat the washing operation three times; then add anhydrous ethanol for ultrasonic dispersion and centrifugation, and repeat the washing operation three times. Finally, put the material after alcohol washing into a vacuum drying oven to dry completely.

[0016] Preferably, the heating reaction is to transfer the reaction solution to a tetrafluoroethylene high-pressure reactor, seal it, heat to 100 °C, continuously react for 24 h, and then naturally cool to room temperature. Then transfer the solution cooled to room temperature to a centrifuge tube, centrifuge to remove the supernatant, then ultrasonicate with ultrapure water and centrifuged again. Repeat the washing operation three times. Then add anhydrous ethanol for ultrasonic dispersion and centrifugation, and repeat the washing operation three times. Finally, put the material after alcohol washing into a vacuum drying oven to dry completely to obtain manganese sulfide nanomaterials with two different crystal forms of α and γ.

[0017] The two different crystal forms of MnS prepared by the preparation method of the present invention are α-MnS and γ-MnS respectively. The present invention prepares nano-materials of two different crystal forms, α and γ, of manganese sulfide.

[0018] Application of the MnS described in the present invention in the preparation of antibacterial reagents or materials.

[0019] Application of the nano-materials of two different crystal forms, α and γ, of manganese sulfide prepared by the present invention in antibacterial.

[0020] Application of the nano-materials of two different crystal forms, α and γ, of manganese sulfide prepared by the present invention in the preparation of antibacterial reagents or materials.

[0021] Furthermore, application of the γ-MnS in high-efficiency antibacterial; application of the γ-MnS in the high-efficiency preparation of antibacterial reagents or materials.

[0022] Among them, the antibacterial is Escherichia coli.

[0023] The present invention synthesizes two different crystal forms of manganese sulfide - α-MnS and γ-MnS, and for the first time discovers that the antibacterial activity of this kind of material is closely related to the crystal form of the material, and the activity is regulated by the crystal form. The present invention can achieve high-efficiency antibacterial by using γ-MnS with a specific crystal form, and is used to prepare high-efficiency antibacterial reagents or materials.

[0024] The present invention mixes manganese chloride, sodium hydroxide, sodium polysulfide, PVP and ultrapure water, and stirs until completely dissolved. Mix manganese carbonate, sodium sulfide nonahydrate and ultrapure water, and stir until completely dissolved. After the two are heated and reacted and then cooled, green and gray-pink solutions are obtained respectively. After centrifugal separation, they are washed with water and alcohol, and after vacuum drying, nano-materials of two different crystal forms, α and γ, of manganese sulfide are obtained. The present invention realizes for the first time the improvement of its antibacterial activity by regulating the crystal form of MnS, and for the first time discovers that compared with α-MnS, γ-MnS has stronger activity against killing Escherichia coli. The present invention realizes the purpose of improving its antibacterial activity by regulating the crystal form of MnS for the first time.

[0025] The present invention discovers for the first time that the antibacterial effects of different crystal forms of manganese sulfide are different and the difference is obvious. The α type is green crystals, rock salt type, and cubic close-packed; the γ type is light red powder, wurtzite type, and hexagonal close-packed.

[0026] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0027] 1. The MnS of different crystal forms prepared by the present invention all have the ability to trigger the release of hydrogen sulfide under acidic conditions, but compared with α-MnS, γ-MnS has a better effect of generating hydrogen sulfide.

[0028] 2. The MnS with different crystal forms prepared by the present invention all have good antibacterial effects. However, compared with α-MnS, γ-MnS has a better antibacterial effect, and high-efficiency antibacterial materials can be prepared by using γ-MnS.

[0029] 3. The preparation method of the present invention is simple, the raw materials are widely available, and the raw material prices are low, so it can be produced and utilized on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the transmission electron microscope of α-MnS nanomaterial (scale bar of the figure = 0.2 μm);

[0031] Figure 2 is the transmission electron microscope of γ-MnS nanomaterial (scale bar of the figure = 50 nm);

[0032] Figure 3 is the XRD pattern of α-MnS and γ-MnS nanomaterials;

[0033] Figure 4 is the antibacterial effect diagram of α-MnS and γ-MnS nanomaterials;

[0034] Figure 5 is the hydrogen sulfide release rate of α-MnS and γ-MnS nanomaterials at pH = 4;

[0035] Figure 6 is the hydrogen sulfide release rate of α-MnS and γ-MnS nanomaterials at pH = 5;

[0036] Figure 7 is the hydrogen sulfide release rate of α-MnS and γ-MnS nanomaterials at pH = 6. DETAILED DESCRIPTION OF THE INVENTION

[0037] According to the following examples, the present invention can be better understood. Those skilled in the art can easily understand that the content described in the examples is only used to illustrate the present invention and should not and will not limit the present invention described in detail in the claims. The materials, reagents, etc. used in the following examples can be obtained from commercial channels without special instructions. The experimental methods without specific conditions noted in the examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0038] In the present invention, Escherichia coli standard strain ATCC 25922 is used, and various other types of Escherichia coli can also be used.

[0039] Example 1

[0040] Synthesis and Structure Verification of α-MnS and γ-MnS

[0041] Mix manganese chloride (4 mmol), sodium hydroxide (300 mg), sodium polysulfide (Na2S4) (10 mmol), PVP (molecular weight 30000, 400 mg) with ultrapure water (20 mL), stir until completely dissolved, transfer the reaction solution to a Teflon high-pressure reactor, seal it, heat it to 100 °C, continue to react for 24 h, and then cool it to room temperature naturally. Then transfer the solution cooled to room temperature to a centrifuge tube, centrifuge to remove the supernatant, add ultrapure water and ultrasonically disperse it, then centrifuge again, and repeat the washing operation three times. Remove the supernatant, add absolute ethanol and ultrasonically disperse it, then centrifuge again, and repeat the washing operation three times. Finally, put the material after alcohol washing into a vacuum drying oven to dry completely to obtain α-MnS nanomaterials.

[0042] Mix manganese carbonate (4 mmol), sodium sulfide nonahydrate (8 mmol) with ultrapure water (20 mL), stir until completely dissolved, transfer the reaction solution to a Teflon high-pressure reactor, seal it, heat it to 100 °C, continue to react for 24 h, and then cool it to room temperature naturally. Then transfer the solution cooled to room temperature to a centrifuge tube, centrifuge to remove the supernatant, add ultrapure water and ultrasonically disperse it, then centrifuge again, and repeat the washing operation three times. Remove the supernatant, add absolute ethanol and ultrasonically disperse it, then centrifuge again, and repeat the washing operation three times. Finally, put the material after alcohol washing into a vacuum drying oven to dry completely to obtain γ-MnS nanomaterials.

[0043] Figure 1 and Figure 2 are the transmission electron microscopy images of α-MnS and γ-MnS nanomaterials. Figure 3 are the X-ray crystal diffraction patterns of α-MnS and γ-MnS. By comparing with the standard cards, it can be verified that the obtained materials are α-MnS and γ-MnS respectively.

[0044] Example 2

[0045] Comparison of antibacterial activities of α-MnS and γ-MnS

[0046] Inoculate Escherichia coli in broth liquid medium, and then culture it at 180 rpm and 37 °C for 24 h. When the absorbance at 600 nm is 1.0, dilute the bacterial solution to 10 6 CFU / mL with 0.9% sodium chloride solution (pH = 6). Then mix the different concentrations of α-MnS and γ-MnS nanomaterials prepared in Example (1) (at final concentrations of 5 μg / mL and 10 μg / mL) with the bacteria respectively, and co-incubate them in a bacterial incubator at 37 °C for 20 h. Then take 60 μL and evenly coat it on an LB solid agar medium, and observe the colony growth status and count after culturing for 24 h, with no addition of nanomaterials as the control. Figure 4 is the comparison chart of the antibacterial effects of α-MnS and γ-MnS. As Figure 4As shown in the figure, at a concentration of 5 μg / mL, the antibacterial rates of α-MnS and γ-MnS (inhibition rate (%) = (number of colonies in the control group - number of colonies in the treatment group) / number of colonies in the control group) x 100) were 25.6% and 80.5%, respectively; at a concentration of 10 μg / mL, the antibacterial rates of α-MnS and γ-MnS were 63.3% and 97.5%, respectively. The experimental results show that both α-MnS and γ-MnS have a certain antibacterial effect, but compared with α-MnS, γ-MnS has a better antibacterial effect, and has a significant effect at a low concentration of 5 μg / mL.

[0047] Example 3

[0048] Comparison of H2S generation capacity between α-MnS and γ-MnS

[0049] Under acidic conditions, NN-dimethyl-p-phenylenediamine hydrochloride and ferric chloride were used as probes to detect H2S released from MnS. MnS (18μg / mL), ferric chloride (0.5mM, 3μL) and NN-dimethyl-p-phenylenediamine hydrochloride (0.5mM, 3μL) were added to 3mL of acidic aqueous solution with different pH values (pH=4, pH=5 and pH=6), and the product methylene blue was immediately monitored for absorption peak at 665nm after mixing evenly. The absorption value was measured every two seconds for ten minutes. The greater the amount of H2S generated, the greater the absorption value at 665nm. Therefore, tracking the rate and degree of increase in the absorption peak intensity at 665nm of the mixed solution can judge the material's ability to produce H2S. Figure 5 , Figure 6 and Figure 7 As shown in the figure, both α-MnS and γ-MnS nanomaterials can produce H2S under the conditions of pH 4, 5 and 6. However, no matter under what degree of acidic pH conditions, the rate and yield of H2S produced by γ-MnS are significantly higher than that of α-MnS. Therefore, compared with α-MnS, γ-MnS has a better antibacterial effect.

[0050] Example 4

[0051] The preparation method of Example 4 is the same as that of Example 1, except that:

[0052] Preparation of α-MnS: the amount of manganese chloride is 2 mmol, the amount of sodium polysulfide is 5 mmol, the amount of polyvinyl pyrrolidone is 200 mg, the amount of sodium hydroxide is 150 mg, and the total volume of ultrapure water is 10 mL; the heating reaction is carried out in a tetrafluoroethylene high-pressure reactor at a heating temperature of 70°C. The reaction is continued for 48 hours and then naturally cooled to room temperature.

[0053] Preparation of γ-MnS: The dosage of manganese carbonate is 2 mmol, the dosage of sodium sulfide nonahydrate is 4 mmol, and the total volume of ultrapure water is 10 mL; The heating reaction is carried out in a tetrafluoroethylene high-pressure reactor at a heating temperature of 70 °C. After continuous reaction for 48 h, it is naturally cooled to room temperature.

[0054] Example 5

[0055] The preparation method of Example 5 is the same as that of Example 1, except that:

[0056] Preparation of α-MnS: The dosage of manganese chloride is 8 mmol, the dosage of sodium polysulfide is 20 mmol, the dosage of polyvinylpyrrolidone is 800 mg, the dosage of sodium hydroxide is 600 mg, and the total volume of ultrapure water is 40 mL; The heating reaction is carried out in a tetrafluoroethylene high-pressure reactor at a heating temperature of 120 °C. After continuous reaction for 12 h, it is naturally cooled to room temperature.

[0057] Preparation of γ-MnS: The dosage of manganese carbonate is 8 mmol, the dosage of sodium sulfide nonahydrate is 16 mmol, and the total volume of ultrapure water is 40 mL; The heating reaction is carried out in a tetrafluoroethylene high-pressure reactor at a heating temperature of 120 °C. After continuous reaction for 12 h, it is naturally cooled to room temperature.

Claims

1. A preparation method of an antibacterial active MnS material, characterized in that, It includes the following steps: (1) Mix manganese chloride, sodium hydroxide, sodium polysulfide, polyvinylpyrrolidone and ultrapure water, stir to completely dissolve it, heat for reaction and then cool. After centrifuging the reaction solution, wash the solid, and obtain α-MnS after vacuum drying; (2) Mix manganese carbonate, sodium sulfide nonahydrate and ultrapure water, stir until completely dissolved, heat for reaction and then cool. After centrifuging the reaction solution, wash the solid, and obtain γ-MnS after vacuum drying; Among them, in steps (1) and (2), cooling after heating for reaction is carried out in a tetrafluoroethylene autoclave. The heating temperature is 70-120 °C, and after continuous reaction for 12-48 h, it is naturally cooled to room temperature.

2. The preparation method of the antibacterial active MnS material according to claim 1, characterized in that, Preparation of α-MnS in step (1): The dosage of manganese chloride is 2-8 mmol, the dosage of sodium polysulfide is 5-20 mmol, the dosage of polyvinylpyrrolidone is 200-800 mg, the dosage of sodium hydroxide is 150-600 mg, and the total volume of ultrapure water is 10-40 mL.

3. The preparation method of the antibacterial active MnS material according to claim 1, characterized in that, Preparation of γ-MnS in step (2): The dosage of manganese carbonate is 2-8 mmol, the dosage of sodium sulfide nonahydrate is 4-16 mmol, and the total volume of ultrapure water is 10-40 mL.

4. Two different crystal forms of MnS, namely α-MnS and γ-MnS, prepared by the preparation method described in claim 1.

5. Application of the MnS described in claim 4 in the preparation of antibacterial reagents or materials.

6. The application according to claim 5, wherein Application of the γ-MnS in the preparation of antibacterial reagents or materials.

7. The application according to claim 6, characterized in that, The antibacterial action is to inhibit Escherichia coli.

8. Application of the MnS described in claim 4 in hydrogen sulfide release.

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