Antibacterial and compression performance enhanced zinc oxide clove oil water gate valve stop composite material and preparation method thereof

Abstract

The application belongs to the technical field of new functional and structural materials, and specifically discloses a zinc oxide clove oil cement composite material with enhanced antibacterial and compression resistance and a preparation method thereof. The composite material takes ZOE as the main material of the composite material, and is prepared by blending PZnO@Cur, ZnONWs and ZOE, so as to achieve the purpose of enhancing the antibacterial and compression resistance of the raw material. The PZnO in the composite material can slowly degrade in the weak acidic environment where bacteria breed, release the loaded Cur, and realize the pH response controlled release effect of the drug, thereby improving the antibacterial effect, improving the bioavailability of the drug, and reducing the potential toxicity. Further, the ZnONWs are used as the reinforcing phase to improve the compression strength of the main material. By optimizing the proportion parameters of the components, the zinc oxide clove oil cement composite material with the best antibacterial and compression resistance is finally obtained. The preparation process of the application is simple, low in cost, safe and controllable, and has potential application prospect in the field of new functional and structural materials.

Description

Technical Field

[0001] This invention belongs to the field of novel functional and structural materials technology, and relates to the preparation of zinc oxide eugenol cement, a temporary sealing material for the treatment of oral diseases. Specifically, it relates to a zinc oxide eugenol cement composite material with enhanced antibacterial and compressive properties and its preparation method. Background Technology

[0002] Temporary sealing materials are an important class of materials widely used in clinical dentistry. They are mainly used in the treatment of common oral diseases such as dental caries, pulpitis, periapical periodontitis, and some periodontal diseases. Their core function is to temporarily seal the treated area during the intervals between treatments such as pulp devitalization, pulp chamber disinfection, root canal treatment, pulpotomy, and apexification. This provides a relatively sealed environment for medication and creates favorable conditions for subsequent treatment. Currently, commonly used temporary sealing materials include zinc oxide, glass ionomer, cement, and resin. Among them, zinc oxide eugenol cement (ZOE) is one of the most widely used short-term temporary sealing materials in China. ZOE is made by mixing zinc oxide powder and eugenol solution in a specific ratio: zinc oxide has antiseptic and astringent properties, protecting the wound surface; eugenol provides antiseptic and analgesic effects. This material offers significant advantages: excellent biocompatibility and pulp-soothing effects; rapid water-curing properties resulting in superior sealing performance in the moist oral environment; ease of use and low cost; long usable time after preparation; and convenient clinical application and removal. The antibacterial effect of ZOE primarily relies on its eugenol component, which possesses analgesic and antibacterial properties, inhibiting the growth of various oral bacteria, such as *Streptococcus mutans* and *Porphyromonas gingivalis*. However, ZOE is readily soluble in water and saliva, and the precipitation of eugenol may weaken its long-term antibacterial effect; furthermore, eugenol alone has limited antibacterial efficacy. Therefore, the development of novel ZOE composite materials is needed to balance its long-lasting antibacterial effect with biocompatibility and other properties.

[0003] The compressive strength of temporary filling materials is a key indicator affecting clinical efficacy, as it determines the material's deformation and risk of breakage under masticatory pressure. Once the material breaks due to insufficient compressive strength, its marginal sealing will completely fail (Zhao Shouliang, Zhang Shaofeng, Li Yun, et al. Stress analysis of tooth tissue after amalgam filling. 2003, 5: 474-476). However, the compressive strength of traditional ZOE is only 25-35 MPa, and that of reinforced ZOE is 45-55 MPa. When exposed to the moist environment of the oral cavity for a long time, its solubility (24-hour solubility rate of 1.5%) will further weaken its mechanical properties, making it difficult to withstand constant masticatory force (usually 1.5-3 MPa) (Jin Yifu, Feng Shanshan, Chen Huan, et al. Research progress of finite element analysis in the application of oral adhesive cement. Modern Stomatology Journal, 2023, 37(02): 105-109). Therefore, improving the antibacterial properties and compressive strength of temporary sealing materials (especially ZOE) is crucial for ensuring the effectiveness of clinical treatment. Current research focuses on optimizing the formulation of these materials to address their limitations in mechanical strength and maintaining the stability of antibacterial therapeutic effects. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a zinc oxide eugenol cement composite material with enhanced antibacterial and compressive strength properties. This composite material can enhance the antibacterial properties and compressive strength of temporary sealing materials (ZOE) in the context of oral infection and inflammation. Another objective of the present invention is to provide a method for preparing this composite material.

[0005] This invention is achieved through the following technical solution: A zinc oxide eugenol cement composite material with enhanced antibacterial and compressive properties, wherein the composite material uses ZOE as the main material and PZnO@Cur and ZnONWs as composite phases that enhance antibacterial and compressive properties, respectively, and is obtained by blending PZnO@Cur, ZnONWs and ZOE.

[0006] A further improvement to the present invention is as follows: A method for preparing a zinc oxide eugenol cement composite material with enhanced antibacterial and compressive properties includes the following steps: (1) Dissolve Zn(NO3)2·6H2O and polyvinylpyrrolidone in urea aqueous solution, stir, and carry out high pressure reaction. After the reaction, centrifuge, wash with deionized water, and dry. Then transfer the product to a muffle furnace and calcine at high temperature for a period of time to obtain porous zinc oxide material, denoted as PZnO. (2) PZnO was added to curcumin solution, stirred in the dark for a period of time, centrifuged, washed with methanol and water in sequence, and vacuum dried to obtain PZnO sample loaded with curcumin, denoted as PZnO@Cur; (3) Dissolve Zn(CH3COO)2·2H2O, NaOH and sodium dodecyl sulfate in PEG400 ethanol solution, stir, and carry out high pressure reaction. After the reaction, the product is centrifuged, washed with deionized water and ethanol, dried, and annealed at high temperature for a period of time to obtain ZnO nanowires, denoted as ZnONWs. (4) PZnO@Cur, ZnONWs, ZnO powder and clove oil liquid are mixed and stirred evenly, and after standing for a period of time to form, PZnO@Cur / ZnONWs / ZOE composite material is obtained.

[0007] A further improvement of the present invention is as follows: In step (1), the ratio of Zn(NO3)2·6H2O, polyvinylpyrrolidone, and urea aqueous solution is 1-2g:1-3g:150-200mL; the concentration of the urea aqueous solution is 40-60mmol·L. -1 The stirring time is 1-3 hours.

[0008] Furthermore, in step (1), the high-pressure reaction temperature is 100-130℃ and the time is 12-24h; the drying temperature is 60-80℃ and the time is 12-24h.

[0009] Furthermore, in step (1), the high-temperature calcination temperature is 300-400℃ and the time is 3-4h.

[0010] Furthermore, in step (2), the ratio of PZnO to curcumin solution is 1-1.5g:250-500mL; the concentration of curcumin solution is 50-100ppm, and the solvent is methanol; the stirring time in the dark is 3-5h.

[0011] Furthermore, in step (3), the ratio of Zn(CH3COO)2·2H2O, NaOH, sodium dodecyl sulfate and PEG400 ethanol solution is 2-3g:10-15g:0.5-1g:50-200mL; the volume concentration of PEG400 ethanol solution is 40-50%; and the stirring time is 1-2h.

[0012] Furthermore, in step (3), the high-pressure reaction is carried out at a temperature of 120-150°C for 12-24 hours.

[0013] Furthermore, in step (3), the annealing temperature is 400-500℃ and the time is 3-4h.

[0014] Furthermore, in step (4), the ratio of the amount of PZnO@Cur, ZnONWs, ZnO powder and clove oil liquid is 0.5-1g:0.5-1g:3.5-5g:1mL; and the molding time is 1-2h.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention prepares a PZnO@Cur / ZnONWs / ZOE composite material by blending PZnO@Cur and ZnONWs with ZOE to enhance the antibacterial and compressive strength properties of the raw materials. The porous structure of PZnO in the composite material provides ample adsorption sites for the electrostatic adsorption of curcumin. The PZnO prepared in this invention has a rich irregular pore structure with a pore size of ~500 nm; the prepared ZnONWs have a diameter of ~2 μm. PZnO slowly degrades in a weakly acidic environment conducive to bacterial growth, releasing the curcumin it supports, achieving controlled drug release, improving drug bioavailability, and reducing potential toxicity; the zinc oxide nanowires (ZnONWs), as a reinforcing phase, can improve the compressive strength of the main material, ultimately achieving a synergistic enhancement of antibacterial and compressive strength properties. Attached Figure Description

[0016] Figure 1 A photograph of the PZnO@Cur / ZnONWs / ZOE composite material prepared in Example 1; Figure 2 A scanning electron microscope image of the PZnO material prepared in Example 1; Figure 3 A scanning electron microscope image of the ZnONWs material prepared in Example 1; Figure 4 The pH-responsive Cur release curve of the PZnO@Cur / ZnONWs / ZOE composite material is shown in the graph. Detailed Implementation

[0017] The present invention will now be described in detail with reference to specific embodiments.

[0018] Example 1: The PZnO@Cur / ZnONWs / ZOE composite material provided in this example uses ZOE as the main material in the composite material. PZnO@Cur and ZnONWs are blended with ZOE. The specific preparation method is as follows: (1) Dissolve 1.2g of Zn(NO3)2·6H2O and 2g of polyvinylpyrrolidone in 160mL of 50mmol·L⁻¹ -1The mixture was stirred in a urea aqueous solution for 1 hour. It was then transferred to a high-pressure reactor and maintained at 130°C for 12 hours. The resulting product was washed three times with water and dried at 70°C for 12 hours. Finally, it was calcined in a muffle furnace at 350°C for 3 hours to obtain porous zinc oxide (PZnO) nanosheets. (2) Add 1g of PZnO to 250mL of curcumin methanol solution (50ppm), stir for 3h in the dark, centrifuge, wash three times with water, and vacuum dry to obtain curcumin-loaded PZnO sample (PZnO@Cur). (3) 2.2 g of Zn(CH3COO)2·2H2O, 12.5 g of NaOH and 0.5 g of sodium dodecyl sulfate were dissolved in 100 mL of 50% (V / V) PEG400 ethanol solution. After stirring for 1 h, the solution was transferred to an autoclave and heated at 140 °C for 16 h. The product was then centrifuged, washed with deionized water and ethanol respectively, dried at 60 °C for 24 h, and annealed at 500 °C for 3 h to obtain ZnO nanowires (ZnONWs). (4) Mix 0.5g of PZnO@Cur, 0.5g of ZnONWs, 3.5g of ZnO powder and 1mL of clove oil liquid until homogeneous. After standing for 1 hour, the PZnO@Cur / ZnONWs / ZOE composite material is obtained. The actual object is shown in the figure below. Figure 1 As shown.

[0019] The microstructure of the PZnO prepared in Example 1 was characterized, and the results are as follows: Figure 2 As shown, this nanomaterial possesses a rich porous structure with a pore size of approximately 500 nm. The abundant porous structure of PZnO material can increase its specific surface area, playing a crucial role in promoting the electrostatic adsorption of curcumin.

[0020] The microstructure of the ZnONWs prepared in Example 1 was characterized, and the results are as follows: Figure 3 As shown, this nanomaterial exhibits a typical fibrous structure with a fiber diameter of approximately 2 µm. The fibrous structure of the ZnONWs material plays a positive role in enhancing the compressive strength of the composite material.

[0021] Example 2

[0022] The difference between this embodiment and embodiment 1 is that in step (4), the amounts of PZnO@Cur, ZnONWs, ZnO powder and clove oil liquid are 0.3g, 0.3g, 3.9g and 1mL, respectively. Other operations are roughly the same as in embodiment 1, and will not be repeated here.

[0023] Example 3

[0024] The difference between this embodiment and embodiment 1 is that in step (4), the amounts of PZnO@Cur, ZnONWs, ZnO powder and clove oil liquid are 0.7g, 0.7g, 3.1g and 1mL, respectively. Other operations are roughly the same as in embodiment 1, and will not be repeated here.

[0025] Comparative Example 1: Preparation of ZOE matrix material (1) Mix 3.5g of ZnO powder and 1mL of clove oil liquid evenly, and follow the same steps (4) as in Example 1 to obtain ZOE sample.

[0026] Comparative Example 2: Preparation of PZnO@Cur / ZOE composite materials (1) The PZnO@Cur composite material was prepared using the same method as in Example 1; (2) Mix 0.5g of PZnO@Cur, 3.5g of ZnO powder and 1mL of clove oil liquid, stir evenly, and let stand for 1h to obtain PZnO@Cur / ZOE sample.

[0027] Comparative Example 3: The ZnONWs / ZOE composite material prepared in this study (1) Preparation of ZnONWs nanomaterials, the method is the same as in Example 1; (2) Mix 0.5g of ZnONWs, 3.5g of ZnO powder and 1mL of clove oil liquid evenly, let stand for 1h, and obtain ZnONWs@Cur / ZOE sample.

[0028] Example 4: Performance testing of the materials prepared in the examples and comparative examples. 1. pH-responsive Cur release: To assess the pH-responsive Cur release performance of Examples 1, 2, 3, Comparative Examples 1, 2, and 3, the samples were immersed in aqueous media at different pH values ​​(5.8, 7.4, and 8.0). Supernatants were collected at specific time points (0, 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, and 90 minutes), and measurements were taken using a UV-Vis spectrophotometer. The amount of Cur released was evaluated based on the absorbance at λ = 430 nm.

[0029] like Figure 4 As shown, in Examples 1, 2, 3 and Comparative Example 2, the amount of Cur released gradually increased with increasing ZnONWs@Cur doping, while in Comparative Examples 1 and 2, there was no Cur release due to the absence of ZnONWs@Cur doping. Importantly, the amount of Cur released from the sample groups increased significantly with decreasing pH, exhibiting a clear pH-responsive Cur release performance.

[0030] 2. Compression resistance test The compressive strength of each sample was tested using a universal testing machine. As shown in Table 1, the compressive strength of Examples 1, 3 and 2 gradually decreased. That is, the compressive strength of the composite material was optimal when the ratio of PZnO@Cur, ZnONWs, ZnO powder and clove oil liquid was 0.5g:0.5g:3.5g:1mL.

[0031] Table 1. Compressive strength test results of materials prepared in the examples and comparative examples. Compressive strength (MPa) 52 40 43 33 35 48 3. Antibacterial test: Escherichia coli and Staphylococcus aureus were used as experimental strains in the antibacterial experiment. The revived bacteria were placed in liquid culture medium and shaken overnight at 37°C. Samples from Examples 1, 2, 3, Comparative Examples 1, 2, and 3 were placed in 12-well plates, and 100 µL of bacterial suspension was added to the sample surface for each. After 24 hours, 1 mL of PBS solution was added to each sample, and after sonication, 50 μL of bacterial suspension was plated and incubated overnight at 37°C. The number of bacterial colonies was then observed.

[0032] Table 2. Bacterial survival rate results of materials prepared in the examples and comparative examples. E. coli 8.4 20.2 4.1 28.1 12.0 29.1 Staphylococcus aureus 9.3 22.1 5.0 26.5 10.9 26.8 The statistical data of plate colonies in the in vitro antibacterial experiment are shown in Table 2 above. The results show that Examples 1, 2, 3, Comparative Examples 1, 2, and 3 all exhibited certain antibacterial effects against Escherichia coli and Staphylococcus aureus. Among them, Examples 3 and 1 showed more significant antibacterial efficiencies.

[0033] The above description of the embodiments is only for illustrating the technical concept and features of the present invention. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. Those skilled in the art can obviously easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the above embodiments should not be used to limit the scope of protection of the present invention. All improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a zinc oxide eugenol cement composite material with enhanced antibacterial and compressive strength properties, characterized in that, Includes the following steps: (1) Dissolve Zn(NO3)2·6H2O and polyvinylpyrrolidone in urea aqueous solution, stir, and then carry out high pressure reaction. After the reaction, centrifuge, wash with deionized water, and dry. The product is then transferred to a muffle furnace and calcined at high temperature for a period of time to obtain porous zinc oxide material, denoted as PZnO; the high temperature calcination is 300-400℃ and the time is 3-4h. (2) PZnO was added to curcumin solution, stirred in the dark for a period of time, centrifuged, washed with methanol and water in sequence, and vacuum dried to obtain PZnO sample loaded with curcumin, denoted as PZnO@Cur; the stirring time in the dark was 3-5h. (3) Dissolve Zn(CH3COO)2·2H2O, NaOH and sodium dodecyl sulfate in PEG400 ethanol solution, stir and carry out high pressure reaction. After the reaction, the product is centrifuged, washed with deionized water and ethanol, dried and annealed at high temperature for a period of time to obtain ZnO nanowires, denoted as ZnONWs; the annealing temperature is 400-500℃ and the time is 3-4h. (4) PZnO@Cur, ZnONWs, ZnO powder and clove oil liquid are mixed and stirred evenly, and after standing for a period of time, the PZnO@Cur / ZnONWs / ZOE composite material is obtained; the ratio of the amount of PZnO@Cur, ZnONWs, ZnO powder and clove oil liquid is 0.5-1g:0.5-1g:3.5-5g:1mL; the molding time is 1-2h.

2. The preparation method according to claim 1, characterized in that: In step (1), the ratio of Zn(NO3)2·6H2O, polyvinylpyrrolidone, and urea aqueous solution is 1-2g:1-3g:150-200mL; the concentration of the urea aqueous solution is 40-60mmol·L. -1 The stirring time is 1-3 hours.

3. The preparation method according to claim 1, characterized in that: In step (1), the high-pressure reaction is carried out at a temperature of 100-130℃ for 12-24 hours; the drying process is carried out at a temperature of 60-80℃ for 12-24 hours.

4. The preparation method according to claim 1, characterized in that: In step (2), the ratio of PZnO to curcumin solution is 1-1.5g:250-500mL; the concentration of curcumin solution is 50-100ppm, and the solvent is methanol.

5. The preparation method according to claim 1, characterized in that: In step (3), the ratio of Zn(CH3COO)2·2H2O, NaOH, sodium dodecyl sulfate and PEG400 ethanol solution is 2-3g:10-15g:0.5-1g:50-200mL; the volume concentration of PEG400 ethanol solution is 40-50%; and the stirring time is 1-2h.

6. The preparation method according to claim 1, characterized in that: In step (3), the high-pressure reaction is carried out at a temperature of 120-150°C for 12-24 hours.

7. A zinc oxide eugenol cement composite material with enhanced antibacterial and compressive strength properties, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.

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