A two-dimensional iodine nanomaterial and its preparation method and application

Abstract

The present invention relates to a two-dimensional iodine olefin nanomaterial and its preparation method and application. The preparation method of the two-dimensional iodine olefin nanomaterial comprises: grinding iodine single substance crystal into powder in a mortar and preparing it into a water dispersion; then, ultrasonically crushing the water dispersion of the iodine single substance, and obtaining the two-dimensional iodine olefin nanomaterial by mechanical exfoliation.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic nanomaterials, and specifically relates to a two-dimensional iodine olefin nanomaterial and a preparation method and application thereof. Background Art

[0002] Iodine (I) is a kind of halogen element. In 1830, iodine tincture (ethanol solution of iodine) was included in the United States Pharmacopoeia. Iodine is widely used in clinical practice due to its bactericidal properties such as high efficiency, broad spectrum, and low resistance to drug resistance. Iodine-containing disinfectants have always been called the most effective and ideal disinfectants by researchers. However, the high reactivity, extremely poor water solubility and strong skin irritation of elemental iodine limit its application expansion in the biomedical field.

[0003] Based on the special property that molecular iodine can combine with polymer materials through complexation reactions, different polymers are used to combine with molecular iodine to make various antibacterial preparations such as iodine tincture and polyiodinated resins. However, these iodine-based bactericidal agents that are widely used in clinical practice still have the limitations of instability and excessive irritation. In order to further improve the bactericidal efficiency and stability of iodine-containing antibacterial agents, more and more new iodine-containing antibacterial materials are being studied and developed. He et al. combined cationic acrylic polyvidone copolymer with iodine molecules. This new iodine-based bactericide has dual antibacterial active centers of iodine and cations, and has more efficient and lasting antibacterial activity (Nanoscale, 2020, 12, 21940-21950).

[0004] Although this polymer complexation method increases the stability of iodine-based antibacterial preparations, due to the high chemical activity of iodine, how to controllably release iodine molecules in the body and use them to effectively treat infectious lesions in the body while ensuring biosafety remains a key scientific problem. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a novel nano-iodine-based antibacterial agent that is responsive to the disease microenvironment in vivo and has high biosafety, as well as a preparation method and application in biomedicine.

[0006] In a first aspect, the present invention provides a method for preparing a two-dimensional iodine olefin nanomaterial, comprising: grinding iodine olefin crystals into powder in a mortar and preparing an aqueous dispersion; then, ultrasonically crushing the aqueous dispersion of iodine olefin, and obtaining the two-dimensional iodine olefin nanomaterial by mechanical exfoliation.

[0007] Preferably, the grinding of the iodine crystals is carried out in a closed inert gas atmosphere, and the inert gas is preferably nitrogen; the grinding method is manual grinding with an agate mortar, and the grinding time is 1-3 minutes.

[0008] Preferably, the particle size of the powdered iodine crystals after grinding is controlled to be 20-100 meshes.

[0009] Preferably, the concentration of the aqueous dispersion of the iodine elemental crystals is 4 to 8 mg / mL, preferably 5 mg / mL.

[0010] Preferably, the ultrasonic method is water bath ultrasound or probe ultrasound, preferably water bath ultrasound; the power of the ultrasonic crushing is 250-400W, preferably 300W; the ultrasonic time is 4-6h, preferably 5h; the ultrasonic temperature is 4-10°C, preferably 4°C.

[0011] In a second aspect, the present invention provides a two-dimensional iodine olefin nanomaterial obtained by the above-mentioned preparation method.

[0012] Preferably, the lateral size of the two-dimensional iodine olefin nanomaterial is 100-300 nm, and the thickness is 0.5-1.5 nm.

[0013] Preferably, the two-dimensional iodine olefin nanomaterial has the performance of catalyzing the decomposition of hydrogen peroxide.

[0014] In a third aspect, the present invention provides an application of the above-mentioned two-dimensional iodine olefin nanomaterial as a biomedical nano broad-spectrum bactericidal material and in anti-infection preparations.

[0015] Beneficial Effects

[0016] The method for preparing the two-dimensional iodine olefin nanomaterial provided by the present invention has mild conditions, simple operation, low cost, high efficiency and environmental friendliness; the two-dimensional iodine olefin nanomaterial has controllable size and uniform morphology, and its dispersibility and stability in water are superior to other iodine-based two-dimensional nanomaterial systems and has excellent cell safety; the two-dimensional iodine olefin material has good bactericidal efficiency and hydrogen peroxide response performance, and can exhibit excellent bactericidal performance higher than clinical povidone iodine in the presence of hydrogen peroxide;

[0017] The two-dimensional iodine olefin nanomaterial provided by the present invention can accurately and efficiently kill bacteria in the body through hydrogen peroxide response and release of active iodine molecules, while effectively avoiding the toxic side effects and drug resistance caused by antibiotics, greatly improving the therapeutic effect of bacterial infection in the body. This iodine-based nanomaterial effectively solves the drawbacks of iodine-based antibacterial agents, effectively expands the application scope of iodine in antibacterial, and is expected to solve the current major scientific problem of antibiotic resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart for preparing the two-dimensional iodine olefin nanomaterial of Example 1;

[0019] Figure 2 TEM image of the two-dimensional iodine olefin nanomaterial prepared in Example 1;

[0020] Figure 3 This is the ultraviolet absorption spectrum of the aqueous dispersion of two-dimensional iodine nanomaterials in the stability evaluation test of two-dimensional iodine nanomaterials;

[0021] Figure 4 This is a diagram showing the changes in dissolved oxygen in the solution system during the evaluation of the hydrogen peroxide response effect of two-dimensional iodine olefin nanomaterials;

[0022] Figure 5 This is the bactericidal efficiency diagram of Staphylococcus aureus of two-dimensional iodine nanomaterials;

[0023] Figure 6 This is a diagram showing the cytotoxicity test of two-dimensional iodine nanosheets on L929 cells. DETAILED DESCRIPTION

[0024] The present invention is further described by way of embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, rather than to limit the present invention.

[0025] The present invention discloses a functionalized two-dimensional iodine olefin nanomaterial, which has an ultra-thin two-dimensional layered structure, is different from traditional iodine molecules (I2), and has good water dispersibility and aqueous solution stability. In addition, iodine olefin, as a two-dimensional existence form of iodine molecules, has special properties and also has the same chemical properties as iodine, such as the ability to catalyze hydrogen peroxide reactions.

[0026] The following is an exemplary description of a method for preparing a two-dimensional iodine olefin nanomaterial with high dispersibility and uniform size provided by the present invention. The method may include the following steps: grinding iodine crystals into powder in a mortar and preparing an aqueous dispersion; then, ultrasonically crushing the aqueous dispersion of iodine to obtain the two-dimensional iodine olefin nanomaterial by mechanical stripping; and removing the precipitated iodine crystals by centrifugation to further obtain a stably dispersed two-dimensional iodine olefin nanomaterial solution.

[0027] The aqueous dispersion of the two-dimensional iodine olefin nanomaterial can be stored for a long time under light-proof conditions, and its concentration can be obtained by inductively coupled plasma mass spectrometry (ICP-MS).

[0028] Since iodine is easily sublimated into toxic iodine vapor, the grinding of iodine crystals is carried out in a closed inert gas atmosphere, and the inert gas is preferably nitrogen; the grinding method can be manual grinding in an agate mortar, and the grinding time can be 1-3 minutes; the particle size of the powdered iodine crystals after grinding can be controlled to be 20-100 mesh.

[0029] In some embodiments, the concentration of the aqueous dispersion of the iodine elemental crystals may be 4 to 8 mg / mL, preferably 5 mg / mL.

[0030] The ultrasonic method can be water bath ultrasonic or probe ultrasonic, preferably water bath ultrasonic. The ultrasonic power can be 250-400W, preferably 300W; the ultrasonic time can be 4-6h, preferably 5h; the ultrasonic temperature can be 4-10°C, preferably 4°C.

[0031] Since the van der Waals force between iodine molecular layers is decomposed by liquid phase exfoliation, the concentration of iodine dispersion should be controlled within a reasonable range. Too high or too low concentration will affect the uniformity of the obtained nanosheets.

[0032] The centrifugal speed may be 2500-3500 rpm, preferably 3000 rpm; the centrifugal time may be 10 minutes.

[0033] The two-dimensional iodine olefin nanomaterial (Iodinene) obtained by the preparation method provided by the present invention has an ultra-thin layered structure, uniform and adjustable size, and a two-dimensional layered topological structure different from traditional iodine molecules, and is stable in aqueous solution and has good dispersibility.

[0034] In some embodiments, the lateral size of the two-dimensional iodine olefin nanomaterial can be controlled to be 100-300 nm, and the thickness can be 0.5-1.5 nm. The two-dimensional iodine olefin nanomaterial with such size and morphology has excellent specific surface area, and the size meets the requirements of biomedical applications.

[0035] The two-dimensional iodine olefin nanomaterial provided by the present invention has the performance of catalytic decomposition of hydrogen peroxide. The two-dimensional iodine olefin nanomaterial can undergo allotropic transformation after being treated with hydrogen peroxide (such as H2O2 aqueous solution system) and be transformed into free iodine molecules. The two-dimensional iodine olefin nanomaterial can be used as a high-efficiency, low-toxic biomedical nano-broad-spectrum bactericidal material or anti-infection preparation.

[0036] The decomposition of H2O2 catalyzed by iodine is mainly divided into two steps: the first step is that iodine molecules are oxidized by H2O2 to form strongly oxidizing hypoiodous acid and generate water, and the chemical reaction that occurs is 2H2O2+I2=2HIO+H2O; the second step is that hypoiodous acid is reduced by H2O2 to form iodine and generate water and oxygen, and the chemical reaction that occurs is H2O2+2HIO=I2+O2↑+2H2O. The two-dimensional iodine alkene nanomaterial provided by the present invention is a two-dimensional topological configuration of elemental iodine and also has the ability to react with H2O2. However, due to its unique two-dimensional topological structure, the two-dimensional structure cannot be reconstructed after the generation of hypoiodous acid, so an allotropic transformation from iodine alkene to free iodine molecules (I2) occurs.

[0037] The response effect of hydrogen peroxide is based on the reaction between two-dimensional iodine alkene nanomaterials (i.e., two-dimensional iodine alkene simple substance) and hydrogen peroxide. This reaction is not only the reason for the transformation of the two-dimensional layered structure of iodine alkene into a three-dimensional bulk structure, but also the generation of highly oxidizing hypoiodous acid (HCIO) during the response process, which causes oxidative stress to bacteria. Combined with the sterilization of generated free iodine molecules, a double sterilization effect gain is achieved.

[0038] In a preferred embodiment, the two-dimensional iodine ene nanosheet can react with hydrogen peroxide in a solution environment containing hydrogen peroxide, generating hypoiodous acid and then releasing the allotropic transformation of bulk iodine molecules, and producing oxygen, achieving the dual effect of generating strong oxidizing hypoiodous acid and releasing highly reactive iodine molecules. This is consistent with the disease microenvironment characteristic of high expression of hydrogen peroxide at the infection site. The two-dimensional iodine ene nanomaterial can respond to H2O2 in the infection microenvironment at the infection site in the organism, showing an efficient dual antibacterial effect, which can avoid the drug resistance caused by excessive use of antibiotics. At the same time, the specific infection microenvironment responsiveness can also avoid the potential toxic and side effects of iodine ene in vivo.

[0039] The preparation process disclosed in the present invention has simple raw materials, simple operation, and is environmentally friendly. The synthesized ultra-thin two-dimensional iodine olefin nanomaterial has uniform size, good dispersibility, easy storage, safety, low toxicity, and a broad-spectrum antibacterial effect. The two-dimensional iodine olefin nanomaterial has excellent cell safety and good bactericidal effect. The two-dimensional iodine olefin nanomaterial provided by the present invention has an allotropic transformation property of specific hydrogen peroxide response, which makes it responsive to the endogenous physiological microenvironment and can achieve the controlled release of elemental iodine, effectively solving the problems of instability of iodine-based bactericides under physiological conditions, poor biocompatibility, and inability to be used in vivo. This efficient and safe two-dimensional iodine-based nanomaterial has good application prospects in the treatment of bacterial-related infectious diseases in vivo.

[0040] The following examples are further listed to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples in a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values ​​​​exemplified below.

[0041] Example 1

[0042] Take 250 mg of iodine crystals and grind them into powder with an agate mortar in a nitrogen atmosphere, then place them in 50 mL of deionized water to prepare an aqueous dispersion; then place them in a 300W ultrasonic cleaner in an ice-water mixed bath for 5 hours, during which the temperature is maintained at 4-10°C; then, keep the resulting solution system away from light for 12 hours, centrifuge at 3000 rpm for 10 minutes, discard the precipitate after two centrifugations, and store the supernatant away from light.

[0043] Figure 1 This is a flow chart for preparing the two-dimensional iodine olefin nanomaterial of Example 1.

[0044] Figure 2 This is a TEM image of the two-dimensional iodine nanomaterial prepared in Example 1. As can be seen from the figure, the two-dimensional iodine nanomaterial prepared in Example 1 has an ultra-thin and regular sheet-like morphology and a uniform size structure.

[0045] Stability evaluation of two-dimensional iodoene nanomaterials

[0046] The two-dimensional iodine olefin nanomaterial aqueous dispersion prepared in Example 1 with a concentration of 30 μg / mL was taken, and its absorption spectrum was tested by UV-visible spectrophotometer; then, the two-dimensional iodine olefin nanomaterial aqueous dispersion was placed in a dark place for 45 days, and its absorption spectrum was tested again.

[0047] Figure 3 This is the ultraviolet absorption spectrum of the aqueous dispersion of the two-dimensional iodine nanomaterial in the stability evaluation test of the two-dimensional iodine nanomaterial. It can be seen from the figure that the absorbance of the aqueous dispersion of the two-dimensional iodine nanomaterial has no obvious change before and after 45 days, indicating that the two-dimensional iodine nanomaterial has good stability.

[0048] Hydrogen peroxide response of two-dimensional iodoene nanomaterials

[0049] 1 mL of the 100 μg / mL aqueous solution of the two-dimensional iodine nanomaterial prepared in Example 1 was added to 30 mL of 1 mM H2O2 aqueous solution, and the oxygen content in the solution was detected using a dissolved oxygen meter.

[0050] Figure 4 This is a diagram showing the change of dissolved oxygen in the solution system during the evaluation of the hydrogen peroxide response effect of two-dimensional iodine olefin nanomaterials. As can be seen from the figure, the dissolved oxygen content in the solution system continues to increase, indicating that the two-dimensional iodine olefin nanomaterial can react with H2O2, and one of the products is O2.

[0051] Bactericidal effect of two-dimensional iodine nanomaterials on Staphylococcus aureus

[0052] 100 μL of Staphylococcus aureus in the logarithmic growth phase was centrifuged and resuspended in 100 μL of saline, and 900 μL of 10 ug / mL of the saline dispersion of the two-dimensional iodine nanomaterial prepared in Example 1 was added, and a H2O2 aqueous solution (100 μM) was set as a control group. The system was placed in a 37°C shaker for incubation for 1 hour and then diluted 2000 times, and its survival rate was counted by the plate coating method.

[0053] Figure 5 The figure shows the bactericidal efficiency of two-dimensional iodine nanomaterials against Staphylococcus aureus. The blank group represents the group containing only physiological saline, the H2O2 group represents the group dispersed in 100μMH2O2 aqueous solution, the povidone iodine group represents the povidone iodine group with the same effective iodine concentration (10μg / mL), and the Iodinene+H2O2 group represents the group treated with iodine plus hydrogen peroxide. As can be seen from the figure, the bactericidal effect of the two-dimensional iodine nanomaterial is significant, and the bactericidal rate reaches nearly 100% under the condition of containing hydrogen peroxide.

[0054] Evaluation of the CCK-8 test kit for cytotoxicity of two-dimensional iodine nanomaterials

[0055] First, L929 cells were cultured at 1×10 4 / well are inoculated into a 96-well plate, and then cultured in a CO2 incubator at 37°C and 5% CO2 humidified air for 24 hours to allow the cells to adhere to the wall; then, the original culture medium of the cells is discarded and replaced with a culture medium containing different concentrations (5, 10, 20, 40, 80 μg / mL) of the two-dimensional iodine olefin nanomaterial prepared in Example 1, and culture is continued for 24 hours; then, the cell culture medium is discarded and replaced with a fresh cell culture medium, and 10 μL of CCK-8 solution is added to each well; incubation is continued at 37°C for 2 hours, and then the absorbance value of the solution in each well of the 96-well plate at 450 nm is measured with an enzyme marker to calculate the relative survival rate of the cells.

[0056] Figure 6 The cytotoxicity test of two-dimensional iodine nanosheets on L929 cells shows that iodine nanosheets do not produce obvious toxicity to cells and have good cell safety.

[0057] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. Application of a two-dimensional iodine nanomaterial in biomedical nano broad-spectrum bactericidal materials and anti-infective preparations, characterized in that: The lateral size of the two-dimensional iodine olefin nanomaterial is 100-300 nm, and the thickness is 0.5-1.5 nm; The preparation method of the two-dimensional iodine olefin nanomaterial comprises: grinding iodine single crystal into powder in a mortar and preparing the powder into a water dispersion; then, ultrasonically crushing the water dispersion of iodine single crystal, and obtaining the two-dimensional iodine olefin nanomaterial by mechanical exfoliation; The particle size of the powdered iodine crystals after grinding is 20 to 100 meshes; The concentration of the aqueous dispersion of the iodine elemental crystals is 4-8 mg / mL.

2. The use according to claim 1, characterized in that: In the preparation method of the two-dimensional iodine olefin nanomaterial, the grinding of the iodine single substance crystal is carried out in a closed inert gas atmosphere; the grinding method is manual grinding in an agate mortar, and the grinding time is 1-3 minutes.

3. The use according to claim 2, characterized in that: The inert gas is nitrogen.

4. The use according to claim 1, characterized in that: The concentration of the aqueous dispersion of the iodine elemental crystals is 5 mg / mL.

5. The use according to claim 1, characterized in that: The ultrasonic crushing method is water bath ultrasonic or probe ultrasonic; the power of the ultrasonic crushing is 250-400 W; the ultrasonic crushing time is 4-6 h; the ultrasonic crushing temperature is 4-10°C.

6. The use according to claim 5, characterized in that: The power of the ultrasonic crushing is 300W; the time of the ultrasonic crushing is 5h; and the temperature of the ultrasonic crushing is 4°C.

7. The use according to claim 1, characterized in that: The two-dimensional iodine ene nanomaterial has the performance of catalyzing the decomposition of hydrogen peroxide.

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