Two-dimensional nano heterojunction with space-time antibacterial and anti-inflammatory functions as well as preparation method and application of two-dimensional nano heterojunction

Abstract

The invention relates to a two-dimensional nano heterojunction with space-time antibacterial and anti-inflammatory functions and a preparation method and application thereof, and belongs to the field of biomedical materials. The preparation method comprises the following steps: firstly, generating a BiCuSeO nanosheet, and resuspending the BiCuSeO nanosheet by using deionized water; the preparation method comprises the following steps: adding cerium nitrate hexahydrate into ethylene glycol, mixing with a BiCuSeO nanosheet resuspended by deionized water, and preparing the two-dimensional nano heterojunction with space-time antibacterial and anti-inflammatory functions by taking the BiCuSeO nanosheet as a seed and the cerium nitrate hexahydrate as a raw material through a hydrothermal synthesis method. Compared with the prior art, good photo-thermal performance of the heterojunction can be utilized, near infrared is used as an external field excitation source to regulate and control the temperature difference and excite the thermoelectric performance of the heterojunction, collaborative treatment of the photo-thermal performance and the thermoelectric performance is achieved, the enhanced anti-inflammatory function of the heterojunction is combined, and the heterojunction becomes a potential application material for infectious bone defects. The preparation method is simple, stable in condition and high in repeatability.

Description

Technical Field

[0001] The present invention relates to the field of biomedical materials, and particularly to a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions, a preparation method thereof, and an application thereof. Background Art

[0002] Infectious bone defect is a large-area defect of bone tissue caused by severe trauma, bone tumor resection, osteomyelitis, etc., often accompanied by uncontrollable infection. Although traditional treatment methods such as surgical debridement, bone grafting, and antibiotic treatment can improve symptoms to a certain extent, they often have problems such as long treatment cycles, limited effects, and antibiotic resistance. For example, surgical debridement can effectively remove the infection source and necrotic tissue, but it may cause further tissue damage; bone grafting is considered the gold standard for treating bone defects, but its application is limited by donor sources, immune rejection, and postoperative complications such as infection, donor site pain, and bone graft absorption. Antibiotic treatment plays an important role in anti-infection, but with the emergence of drug-resistant strains, its efficacy gradually decreases. In addition, the bacterial biofilm and antibiotic barrier in the infected microenvironment make the treatment more difficult. The biofilm not only protects bacteria from the attack of the host immune system but also significantly reduces the effective concentration of antibiotics, further increasing the treatment complexity.

[0003] A key challenge in infectious bone defect is how to optimize the bone repair environment while anti-infecting. For example, sonosensitization therapy can kill bacteria by inducing ROS generation with ultrasound, but at the same time, it is necessary to inhibit the inflammation and bone destruction caused by ROS to avoid secondary damage to host tissues. Similarly, electroactive scaffolds induce oxidative stress through the release of silver ions and electrochemical reactions to achieve the dual effects of antibacterial and bone regeneration. The core of these technologies lies in balancing antibacterial activity and tissue friendliness, while ensuring the biocompatibility and degradability of the material to reduce the potential risks to the long-term health of patients.

[0004] However, currently, the implanted biomaterials for bone injury are prone to bacterial infection, which reduces the bone repair effect. Summary of the Invention

[0005] Based on the current situation that the implanted biomaterials for bone injury are prone to bacterial infection and reduce the bone repair effect, the present invention provides a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions, a preparation method thereof, and an application thereof.

[0006] The present invention provides a two-dimensional nanoheterojunction with thermoelectric effect and spatiotemporal antibacterial and anti-inflammatory functions. Through the stimulation of light conditions, the photothermal effect of the material itself in the obtained two-dimensional nanoheterojunction converts light energy into heat energy, stimulates the generation of ROS, and kills and removes bacteria at the infection site by destroying the bacterial membrane of bacteria, etc., and can repair the physiological environment of the bone defect site. At the same time, when the light stimulation condition disappears, anti-inflammatory functions such as the generation of highly active SOD enzyme activity are produced through the formation of the heterojunction, and excess ROS at the lesion site are removed. At the same time, the presence of Cu 2+ plays a positive role in promoting the repair of bone tissue and the regeneration of blood vessels.

[0007] In addition, the two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions of the present invention can be combined with 3D printing technology for customized printing to prepare a biomedical filling material, which is also an effective therapy for treating bone defects. The customized printing of 3D printing technology can not only better fit the shape of the wound, but also maximize the stability and functionality of the implant by optimizing the geometric structure and biomechanical properties of the implant material. Combining the nanoheterojunction with the printed scaffold is expected to promote the repair of infectious bone defects faster and better.

[0008] The object of the present invention can be achieved by the following technical solutions:

[0009] In the first aspect, the present invention provides a preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions, including the following steps:

[0010] Mix absolute ethanol, deionized water, bismuth nitrate pentahydrate, selenourea, polyvinylpyrrolidone, copper nitrate trihydrate, potassium hydroxide, and sodium hydroxide to obtain a solution, carry out a high-temperature reaction to generate BiCuSeO nanosheets, and resuspend the BiCuSeO nanosheets with deionized water;

[0011] Add cerium nitrate hexahydrate to ethylene glycol and mix it with the BiCuSeO nanosheets resuspended with deionized water. Using the BiCuSeO nanosheets as seeds and cerium nitrate hexahydrate as raw materials, a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions is prepared by a hydrothermal synthesis method.

[0012] In an embodiment of the present invention, the preparation method of the two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions specifically includes the following steps:

[0013] Step 1: Mix equal volumes of absolute ethanol and deionized water to prepare solution A;

[0014] Step 2: Add bismuth nitrate pentahydrate to solution A and stir magnetically for 10 min to obtain solution B;

[0015] Step 3: Add selenourea into solution B and stir magnetically for 1 min to obtain solution C;

[0016] Step 4: Add polyvinylpyrrolidone (PVP) into solution C and stir magnetically for 1 min to obtain solution D;

[0017] Step 5: Add copper nitrate trihydrate into solution D and stir magnetically for 1 min to obtain solution E;

[0018] Step 6: Add potassium hydroxide into solution E and stir magnetically for 1 min to obtain solution F;

[0019] Step 7: Add sodium hydroxide into solution F and stir magnetically for 1 min to obtain solution G;

[0020] Step 8: Transfer solution G into a reaction kettle, heat it at a high temperature, and cool it to room temperature to obtain solution H;

[0021] Step 9: Centrifuge solution H to collect the precipitate, wash the precipitate several times, and resuspend it with deionized water to obtain solution I;

[0022] Step 10: Add cerium nitrate hexahydrate into ethylene glycol and mix it evenly by ultrasonic to obtain solution J;

[0023] Step 11: Mix equal volumes of solution I and J evenly and stir vigorously at room temperature to obtain solution K;

[0024] Step 12: Transfer solution K into an oil bath, continue stirring for 10 min, add ammonia water dropwise, and continue stirring to obtain solution L;

[0025] Step 13: Centrifuge the above solution L to collect the precipitate, wash the precipitate several times, and obtain a heterojunction with antibacterial and anti-inflammatory effects controlled by temperature difference.

[0026] In an embodiment of the present invention, in step 2, the concentration of bismuth nitrate pentahydrate in solution B is 9 - 10 mg / mL;

[0027] In an embodiment of the present invention, in step 3, the concentration of selenourea is 2.5 - 3.0 mg / mL;

[0028] In an embodiment of the present invention, in step 4, the molecular weight of polyvinylpyrrolidone is 40000, and the concentration of polyvinylpyrrolidone is 10 mg / mL;

[0029] In an embodiment of the present invention, in step 5, the concentration of copper nitrate trihydrate is 5 mg / mL;

[0030] In an embodiment of the present invention, in step 6, the concentration of potassium hydroxide is 12 mg / mL;

[0031] In one embodiment of the present invention, in step 7, the concentration of sodium hydroxide is 32 mg / mL;

[0032] In one embodiment of the present invention, in step 9, in solution I, the precipitate is BiCuSeO nanosheets (BiCuSeONs), and the concentration of BiCuSeO Ns is 2 mg / mL;

[0033] In one embodiment of the present invention, in step 10, the concentration of cerium nitrate hexahydrate is 1.2 - 1.5 mg / mL;

[0034] In one embodiment of the present invention, in step 8, the heating temperature of solution G is 180 °C, and the heating time is 24 hours.

[0035] In one embodiment of the present invention, in step 11, the rotation speed is 1000 - 1200 rpm, and the stirring time is 4 hours;

[0036] In one embodiment of the present invention, in step 12, the temperature of the oil bath is 60 °C, and the stirring time is 3 hours.

[0037] In a second aspect, the present invention provides a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions obtained by any of the above preparation methods.

[0038] In a third aspect, the present invention provides the application of the obtained two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions in the preparation of antibacterial and anti-inflammatory materials.

[0039] Furthermore, the application of the two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions in the preparation of infectious bone defect materials is provided.

[0040] The present invention uses BiCuSeO nanosheets as seeds and cerium nitrate hexahydrate as raw materials to prepare a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions by a hydrothermal synthesis method. The preparation method of the present invention is simple, has stable conditions, and high reproducibility.

[0041] This heterojunction has relatively significant antibacterial and anti-inflammatory effects, and has advantages such as good stability and remarkable effects. At the same time, the photothermal effect of this heterojunction can be utilized to link the thermoelectric performance to achieve the synergistic treatment of photo-thermal-electric performance. Specifically, by providing a temperature difference condition through external field excitation, the material itself can exert a thermoelectric effect, generate a large amount of reactive oxygen species, play an antibacterial role, and at the same time promote the valence state transformation of cerium elements in the material, enhance its anti-inflammatory effect, and promote postoperative bone repair. Therefore, this two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions has good application prospects in antibacterial and anti-inflammatory aspects.

[0042] Compared with the prior art, the advantages and beneficial effects of the present invention are mainly reflected in the following aspects:

[0043] The heterojunction of the present invention can be prepared by a hydrothermal synthesis method using BiCuSeO Ns and cerium nitrate hexahydrate as raw materials. The synthesis method is simple, the conditions are stable, and the repeatability is high.

[0044] Meanwhile, by utilizing the good photothermal performance of the heterojunction, the temperature difference can be regulated by using near-infrared as an external field excitation source to excite the thermoelectric performance of the heterojunction, realizing the synergistic treatment of photothermal performance and thermoelectric performance. Combining its enhanced anti-inflammatory function, it becomes a potential application material for infectious bone defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 , TEM image of BiCuSeO-CeO2 HJ;

[0046] Figure 2 , EDS of BiCuSeO-CeO2 HJ;

[0047] Figure 3 , Comparison of photothermal performance between BiCuSeO-CeO2 HJ and BiCuSeO Ns;

[0048] Figure 4 , POD enzyme activity of BiCuSeO-CeO2 HJ;

[0049] Figure 5 , Comparison of SOD enzyme activity between BiCuSeO-CeO2 HJ and CeO2 Np;

[0050] Figure 6 , Photothermal curve of BiCuSeO-CeO2 HJ;

[0051] Figure 7 , Photothermal stability of BiCuSeO-CeO2 HJ. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] Example 1

[0054] This example provides a preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory effects, and the steps are as follows:

[0055] Step 1: Mix 5 mL of absolute ethanol and 5 mL of deionized water to prepare solution A;

[0056] Step 2: Dissolve 95 mg of bismuth nitrate pentahydrate in solution A and stir magnetically for 10 min to obtain solution B;

[0057] Step 3, dissolve 26 mg of selenourea in solution B and stir magnetically for 1 min to obtain solution C;

[0058] Step 4, dissolving 100 mg of polyvinyl pyrrolidone in solution C, and stirring magnetically for 1 min to obtain solution D;

[0059] Step 5, dissolve 50 mg of copper nitrate trihydrate in solution D, and stir magnetically for 1 min to obtain solution E;

[0060] Step 6, dissolve 120 mg of potassium hydroxide in solution E, and stir magnetically for 1 min to obtain solution F;

[0061] Step 7, dissolve 320 mg of sodium hydroxide in solution F, and stir magnetically for 1 min to obtain solution G;

[0062] Step 8, transfer the above solution G into a reactor and heat at 180°C for 24 hours, then cool to room temperature to obtain solution H;

[0063] Step 9, centrifuging the solution H to collect the precipitate, washing the precipitate with ethanol and water alternately for several times, and then resuspending it with deionized water to obtain a solution I;

[0064] Step 10, adding 12.6 mg of cerium nitrate hexahydrate into 10 mL of ethylene glycol, and mixing by ultrasonication to obtain solution J;

[0065] Step 11, mix 10 mL of solution I and 10 mL of solution J, and stir vigorously at room temperature for 4 h to obtain solution K;

[0066] Step 12, transfer solution K to a 60°C oil bath, continue stirring for 10 min, dropwise add 80 μL of 28%-30% ammonia water, continue stirring for 3 h, and obtain solution L;

[0067] Step 13: Centrifuge the solution L to collect the precipitate, and wash the precipitate several times with deionized water to obtain a temperature difference-controlled heterojunction with antibacterial and anti-inflammatory effects.

[0068] like Figure 1 As shown in the transmission electron microscope image of the heterojunction prepared in Example 1, the size of the heterojunction is about 100 to 150 nm, in an irregular flake shape, and obvious cerium oxide particles can be observed on its surface. Figure 2 As shown: The elemental analysis diagram of the heterojunction prepared in Example 1 shows that Bi, Cu, Se, Ce, and O are uniformly distributed in the material.

[0069] Example 2

[0070] This embodiment provides a method for preparing a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory effects, the steps of which are as follows:

[0071] Step 1: Mix equal volumes of absolute ethanol and deionized water to prepare Solution A.

[0072] Step 2: Add bismuth nitrate pentahydrate to Solution A and stir magnetically for 10 min to obtain Solution B.

[0073] Step 3: Add selenourea to Solution B and stir magnetically for 1 min to obtain Solution C.

[0074] Step 4: Add PVP (polyvinylpyrrolidone) to Solution C and stir magnetically for 1 min to obtain Solution D.

[0075] Step 5: Add copper nitrate trihydrate to Solution D and stir magnetically for 1 min to obtain Solution E.

[0076] Step 6: Add potassium hydroxide to Solution E and stir magnetically for 1 min to obtain Solution F.

[0077] Step 7: Add sodium hydroxide to Solution F and stir magnetically for 1 min to obtain Solution G.

[0078] Step 8: Transfer the above Solution G to a reaction kettle, heat it at a high temperature, and cool it to room temperature to obtain Solution H.

[0079] Step 9: Centrifuge the above Solution H to collect the precipitate, wash the precipitate several times, and resuspend it with deionized water to obtain Solution I.

[0080] Step 10: Add cerium nitrate hexahydrate to ethylene glycol and mix it evenly by ultrasonic to obtain Solution J.

[0081] Step 11: Mix equal volumes of Solution I and J evenly and stir vigorously at room temperature to obtain Solution K.

[0082] Step 12: Transfer Solution K to an oil bath, continue stirring for 10 min, add ammonia water dropwise, and continue stirring to obtain Solution L.

[0083] Step 13: Centrifuge the above Solution L to collect the precipitate, wash the precipitate several times, and obtain a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory effects.

[0084] Among them, in step 1, the volumes of absolute ethanol and deionized water are both 5 mL. In step 2, the concentration of bismuth nitrate pentahydrate is 9.5 mg / mL. In step 3, the concentration of selenourea is 2.6 mg / mL. In step 4, the concentration of polyvinylpyrrolidone is 12 mg / mL. In step 5, the concentration of copper nitrate trihydrate is 5 mg / mL. In step 6, the concentration of potassium hydroxide is 12 mg / mL. In step 7, the concentration of sodium hydroxide is 32 mg / mL. In step 8, the heating temperature of solution G is 180 °C and the heating time is 24 h. In step 9, the precipitate is washed alternately with ethanol and deionized water. In step 10, the concentration of cerium nitrate hexahydrate is 6.3 mg / mL and the volume of ethylene glycol is 10 mL. In step 11, the concentration of solution I is 2 mg / mL, the volume is 10 mL, and the stirring time is 4 h. In step 12, the heating temperature is 60 °C and the continuous stirring time is 3 h. In step 13, the precipitate is washed several times with deionized water.

[0085] In this example, a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions is obtained.

[0086] Comparative Example 1:

[0087] This comparative example provides a preparation method of nanosheets, and the steps are as follows:

[0088] Step 1: Mix 5 mL of absolute ethanol and 5 mL of deionized water to prepare solution A;

[0089] Step 2: Dissolve 95 mg of bismuth nitrate pentahydrate in solution A and stir magnetically for 10 min to obtain solution B;

[0090] Step 3: Dissolve 26 mg of selenourea in solution B and stir magnetically for 1 min to obtain solution C;

[0091] Step 4: Dissolve 100 mg of polyvinylpyrrolidone in solution C and stir magnetically for 1 min to obtain solution D;

[0092] Step 5: Dissolve 50 mg of copper nitrate trihydrate in solution D and stir magnetically for 1 min to obtain solution E;

[0093] Step 6: Dissolve 120 mg of potassium hydroxide in solution E and stir magnetically for 1 min to obtain solution F;

[0094] Step 7: Dissolve 320 mg of sodium hydroxide in solution F and stir magnetically for 1 min to obtain solution G;

[0095] Step 8: Transfer the above solution G to a reaction kettle, heat it at 180 °C for 24 h, and cool it to room temperature to obtain solution H;

[0096] Step 9: Centrifuge the above solution H to collect the precipitate, wash the precipitate several times alternately with ethanol and water, and then resuspend it with deionized water to obtain a nanosheet solution.

[0097] Comparative Example 2:

[0098] This comparative example provides a method for preparing nanoparticles, and the steps are as follows:

[0099] Step 1: Dissolve 100 mg of cerium nitrate hexahydrate in 10 mL of ethylene glycol to prepare solution A;

[0100] Step 2: Add 10 mL of deionized water to solution A, and stir vigorously for 4 h to obtain solution B;

[0101] Step 3: Transfer solution B to an oil bath at 60 °C, stir for 15 min, add 80 μL of 28% - 30% ammonia water dropwise thereto, and continue to stir for 3 h to obtain solution C;

[0102] Step 4: Centrifuge solution C to collect the precipitate, wash it several times with deionized water, and then resuspend it with deionized water to obtain an aqueous solution of nanoparticles.

[0103] To prove the beneficial effects of the present invention, the following test experiments were specifically conducted:

[0104] Test Experiment 1: Thermoelectric effect of BiCuSeO-CeO2 HJ

[0105] Detect the ability of the two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions prepared in Example 1 and the nanosheets with antibacterial effects prepared in Comparative Example 1 to generate singlet oxygen. The specific steps are as follows: First, prepare suspensions of 50 μg / mL of the heterojunction prepared in Example 1 and the nanosheets prepared in Comparative Example 1. Immediately take 3 mL of the suspension of the heterojunction and add it to a cuvette, and then add 50 μL of a 1 mg / mL solution of 1,3-diphenylisobenzofuran in N,N-dimethylformamide. Measure its ultraviolet spectrum in the range of 300 - 600 nm with a UV spectrophotometer. Irradiate it with a 1064 nm laser emitter at a power of 1.0 W / cm2 for 8 min, and cool for 12 min, which is one cycle. Test 5 cycles and observe the downward trend at a wavelength of 420 nm. Repeat the same operation for the nanosheet suspension. From Figure 3 It can be concluded that the decrease in the absorption peak at 420 nm in Example 1 is significantly higher than that in Comparative Example 1. From this, it can be proved that the formation of the nanoheterojunction significantly enhances its thermoelectric performance and improves its antibacterial ability.

[0106] Test Experiment 2: Ability of BiCuSeO-CeO2 HJ to generate hydroxyl radicals

[0107] To further prove the antibacterial ability of the heterojunction obtained in Example 1, the ability of the heterojunction to catalyze peroxides to generate hydroxyl radicals, i.e., peroxidase-like activity (POD activity), was measured. The specific steps are as follows: The heterojunction was configured into an aqueous solution with a concentration of 100 μg / mL. 1 mL of this solution was added to a cuvette, and at the same time, 500 μL of a 1 mg / mL aqueous solution of 3,3',5,5'-tetramethylbenzidine (TMB) and 500 μL of 4 mM hydrogen peroxide were added thereto. The ultraviolet spectrum in the range of 500 - 800 nm was measured, and the measurement was taken every 1 min to observe the rise of the absorption peak at 650 nm. From Figure 4 It can be seen that the nanoheterojunction obtained in Example 1 has good POD enzyme activity, thus proving its good antibacterial activity.

[0108] Test Experiment 3: Determination of SOD Enzyme Activity of BiCuSeO-CeO2 HJ

[0109] To prove the anti-inflammatory ability of BiCuSeO-CeO2 HJ, taking the ability to scavenge superoxide anions in ROS as an example, it was compared with pure CeO2 nanoparticles. The specific steps are as follows: 6 mg of riboflavin was dissolved in 2 ml of PBS buffer solution. 1 ml of the solution was diluted to 10 ml, and then 2 ml of the solution was diluted to 20 ml. 5 mg of nitroblue tetrazolium chloride (NBT) was dissolved in 20 ml of PBS; 150 mg of methionine (Met) was dissolved in 20 ml of PBS. In the control group experiment, 500 μL of methionine solution, 500 μL of riboflavin solution, and 500 μL of nitroblue tetrazolium chloride solution were added, and finally 500 μL of PBS buffer solution was added; in the experimental group, the heterojunction was dissolved in PBS buffer solution to prepare a 100 μg / mL solution. A total of 500 μL of the material solution and PBS were added to the methionine, riboflavin, and nitroblue tetrazolium chloride mixture, so that the final concentrations of the heterojunction were 1.0 μg / mL, 1.5 μg / mL, 2.0 μg / mL, and 2.5 μg / mL. After illumination for several minutes, when the solution of the control group turned dark blue, the absorbance of the sample at 515 nm was measured under dark conditions, and the scavenging rate of superoxide anions in the solution was calculated. The SOD enzyme activity test of CeO2Np in Comparative Example 2 was the same as above. From Figure 5 It can be seen that BiCuSeO-CeO2 HJ shows excellent SOD enzyme activity and has strong anti-inflammatory ability.

[0110] Test Experiment 4: Photothermal Performance of BiCuSeO-CeO2 HJ

[0111] Due to the strong penetration of near-infrared light, we use light irradiation to provide heat, thereby stimulating the thermoelectric performance of the heterojunction and exerting its antibacterial effect. The specific steps are as follows: Disperse the material in water to prepare dispersion liquids with different ratios, and the concentrations are 50 μg / mL, 100 μg / mL, 150 μg / mL, and 200 μg / mL respectively. Irradiate the material dispersion liquid with a 1064 nm laser emitter, and at the same time use a FOTRIC thermal imaging camera to record the corresponding temperature changes. The results are as Figure 6 shown. Taking the aqueous solution as a control, the temperature change of BiCuSeO-CeO2 HJ expands with the increase of its concentration, indicating that its photothermal performance gradually strengthens with the increase of its concentration.

[0112] Test Experiment 5: Photothermal Stability Test of BiCuSeO-CeO2 HJ

[0113] To test the photothermal stability of the BiCuSeO-CeO2 HJ prepared in Example 1, the specific steps are as follows: First, prepare a dispersion liquid of the BiCuSeO-CeO2 HJ prepared in Example 1 with a concentration of 200 μg / mL, and irradiate the solution with a 1064 nm laser emitter with a power density of 1.5 W / cm 2 for 7 minutes, then cool for 7 minutes, and repeat this cycle 4 times. The results are as Figure 7 shown. During the four cycles, the temperature increase of BiCuSeO-CeO2 HJ fluctuates little, indicating that this heterojunction has good photothermal stability.

[0114] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions, characterized in that, It includes the following steps: Mix absolute ethanol, deionized water, bismuth nitrate pentahydrate, selenourea, polyvinylpyrrolidone, copper nitrate trihydrate, potassium hydroxide, and sodium hydroxide, and then carry out a high-temperature reaction to generate BiCuSeO nanosheets, and resuspend the BiCuSeO nanosheets with deionized water; Add cerium nitrate hexahydrate to ethylene glycol and mix it with the BiCuSeO nanosheets resuspended with deionized water. Using the BiCuSeO nanosheets as seeds and cerium nitrate hexahydrate as raw materials, prepare a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions through a hydrothermal synthesis method.

2. The preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions according to claim 1, characterized in that Specifically, it includes the following steps: Step 1: Mix equal volumes of absolute ethanol and deionized water to prepare solution A; Step 2: Add bismuth nitrate pentahydrate to solution A and stir to obtain solution B; Step 3: Add selenourea to solution B and stir to obtain solution C; Step 4: Add polyvinylpyrrolidone to solution C and stir to obtain solution D; Step 5: Add copper nitrate trihydrate to solution D and stir to obtain solution E; Step 6: Add potassium hydroxide to solution E and stir to obtain solution F; Step 7: Add sodium hydroxide to solution F and stir to obtain solution G; Step 8: Transfer solution G to an autoclave for high-temperature heating, and cool it to room temperature to obtain solution H; Step 9: Centrifuge solution H to collect the precipitate, wash the precipitate several times, and then resuspend it with deionized water to obtain solution I; Step 10: Add cerium nitrate hexahydrate to ethylene glycol and ultrasonically mix it evenly to obtain solution J; Step 11: Mix equal volumes of solution I and J evenly and stir vigorously at room temperature to obtain solution K; Step 12: Transfer solution K to an oil bath, continue stirring, add ammonia water dropwise, and continue stirring to obtain solution L; Step 13: Centrifuge the above solution L to collect the precipitate, and after washing the precipitate several times, obtain a heterojunction with antibacterial and anti-inflammatory effects controlled by temperature difference.

3. The preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions according to claim 2, characterized in that, In step 2, the concentration of bismuth nitrate pentahydrate in solution B is 9 - 10 mg / mL.

4. The preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions according to claim 2, characterized in that, In step 3, the concentration of selenourea is 2.5 - 3.0 mg / mL.

5. The preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions according to claim 2, wherein, In step 4, the molecular weight of polyvinylpyrrolidone is 40000, and the concentration of polyvinylpyrrolidone is 10 mg / mL.

6. The preparation method of a two-dimensional nanoheterojunction with spatio-temporal antibacterial and anti-inflammatory functions according to claim 2, characterized in that, In step 9, in solution I, the precipitate is BiCuSeO nanosheets (BiCuSeO Ns).

7. The preparation method of a two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions according to claim 2, characterized in that, The concentration of cerium nitrate hexahydrate in step 10 is 1.2 - 1.5 mg / mL.

8. A two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions, characterized in that, Obtained based on the preparation method described in any one of the above claims 1 - 7.

9. Use of the two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions described in claim 8 in the preparation of antibacterial and anti-inflammatory materials.

10. The application according to claim 9, wherein Use of the two-dimensional nanoheterojunction with spatiotemporal antibacterial and anti-inflammatory functions in the preparation of infectious bone defect materials.

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