A dental resin material with antibacterial properties, its preparation method and application

Abstract

This invention discloses an antimicrobial peptide, a dental resin material with antimicrobial effects, its preparation method, and its applications, belonging to the field of dental biomaterials technology. The dental resin material comprises a resin matrix, a modified antimicrobial nanofiller containing the antimicrobial peptide, a photoinitiator, and a promoter. The antimicrobial peptide is selected from SEQ ID NO.1, SEQ ID NO.2, or SEQ ID NO.3. This invention achieves slow release and long-lasting antimicrobial effect of the antimicrobial peptide through a core-shell carrier. Simultaneously, the polydopamine layer significantly improves the interfacial compatibility between the filler and the resin matrix, enabling the material to maintain excellent mechanical properties while exhibiting good biocompatibility.

Description

Technical Field

[0001] This invention relates to the field of dental biomaterials technology, specifically to a dental composite resin material with long-lasting antibacterial effects, its preparation method, and its application. Background Technology

[0002] Tooth defects are among the most common diseases in clinical dentistry. Factors such as caries, trauma, and abrasion can all lead to the loss of hard tooth tissue. Dental composite resins have become the preferred material for restoring tooth defects due to their aesthetic appeal, ease of application, and excellent biocompatibility. However, the unavoidable volume shrinkage during resin polymerization can create microleakage at the interface between the restoration and the tooth tissue. Oral pathogens (especially Streptococcus mutans) can colonize through these microleakages and form biofilms, leading to secondary caries. This is the leading cause of resin restoration failure, accounting for over 60% of all restoration failures.

[0003] To address this issue, researchers have attempted to add various antibacterial agents to the resin, including: antibiotics, which easily induce bacterial resistance and pose an allergy risk, limiting their clinical application; metal and metal oxide nanoparticles, such as silver nanoparticles and zinc oxide nanoparticles, which have problems such as cytotoxicity, tooth discoloration, and burst release of antibacterial agents; and quaternary ammonium salt antibacterial monomers, which are non-release antibacterial agents that can only kill bacteria that come into contact with the resin and have no inhibitory effect on bacteria far from the resin surface, and long-term use may induce bacterial resistance.

[0004] Antimicrobial peptides (AMPs) possess advantages such as broad-spectrum antimicrobial activity, low susceptibility to drug resistance, and good biocompatibility, making them ideal novel antimicrobial agents. However, directly adding antimicrobial peptides to resins has the following drawbacks: some antimicrobial peptides are easily degraded by proteases in the oral cavity, resulting in poor stability; the release rate is too rapid, making it impossible to maintain a long-term antimicrobial effect; and the poor compatibility between antimicrobial peptides and the resin matrix can significantly reduce the mechanical properties of the material.

[0005] Therefore, developing antimicrobial peptides that can be applied to dental resin materials, and developing novel dental antimicrobial resin materials that can stably load antimicrobial peptides, achieve long-term sustained release, and not affect the mechanical properties of the resin, has important clinical significance and application value. Summary of the Invention

[0006] To address the shortcomings of existing antibacterial dental resins, such as easy degradation of antibacterial agents, rapid release, and decreased mechanical properties, this paper provides an antimicrobial peptide with long-lasting efficacy, an antibacterial dental resin material, its preparation method, and its application.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The present invention first provides an antimicrobial peptide with antibacterial effect, wherein the antimicrobial peptide is selected from at least one of SEQ ID NO.1, SEQ ID NO.2 or SEQ ID NO.3.

[0008] The preferred antimicrobial peptides can be used to modify dental resin materials, thereby imparting antimicrobial properties to the dental resin materials.

[0009] This invention first provides a dental resin material with antibacterial properties, comprising the following components by weight: resin matrix: 60-80 parts; modified antibacterial nanofiller: 15-35 parts; photoinitiator: 0.5-2 parts; accelerator: 0.1-0.5 parts. The modified antibacterial nanofiller is prepared by loading antibacterial peptides onto mesoporous silica@polydopamine (mSiO2@PDA) core-shell nanoparticles.

[0010] Further, the antimicrobial peptide is selected from at least one of SEQ ID NO.1, SEQ ID NO.2, or SEQ ID NO.3. Preferably, the antimicrobial peptide has the amino acid sequence shown in SEQ ID NO.1.

[0011] Furthermore, the mesoporous silica@polydopamine core-shell nanoparticles have a particle size of 50-200 nm, the polydopamine coating thickness is 5-20 nm, and the mesoporous silica pore size is 2-5 nm.

[0012] Furthermore, the mass ratio of the antimicrobial peptide to mesoporous silica@polydopamine core-shell nanoparticles is 1:5 to 1:20.

[0013] Furthermore, the resin matrix is ​​composed of bisphenol A dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) in a mass ratio of 3:7 to 7:3.

[0014] Furthermore, the photoinitiator is camphorquinone (CQ), and the accelerator is dimethylaminoethyl methacrylate (DMAEMA).

[0015] The present invention also provides a method for preparing the above-mentioned dental resin material with antibacterial effect, comprising the following steps: Mix the resin matrix, photoinitiator and accelerator according to the formula amount, and stir until completely dissolved under light-protected conditions to obtain the resin matrix prepolymer; Add modified antibacterial nanofiller to the resin matrix prepolymer, stir at high speed for 30-60 min under light-protected conditions, and then ultrasonically disperse for 15-30 min until the filler is uniformly dispersed. Pour the well-mixed slurry into a mold, degas it under vacuum at 40°C for 10-20 minutes, and then cure it by irradiation with blue light at a wavelength of 400-500nm for 20-60 seconds to obtain dental resin material.

[0016] Furthermore, the preparation method of the modified antibacterial nanofiller includes: synthesizing mesoporous silica nanoparticles and coating their surface with a polydopamine layer to obtain mSiO2@PDA core-shell nanoparticles; dispersing the core-shell nanoparticles in phosphate buffer, adding antibacterial peptides, and stirring the reaction at room temperature in the dark for 12-48 hours; collecting the product by centrifugation, washing, and then freeze-drying under vacuum to obtain the modified antibacterial nanofiller.

[0017] Optionally, the above-mentioned method for preparing dental resin materials with antibacterial properties can be achieved using light-curing 3D printing technology, which is suitable for the customized preparation of personalized tooth defect restorations, temporary crowns, denture bases, and orthodontic attachments, and specifically includes the following steps: a. Mix the resin matrix, photoinitiator, and accelerator according to the formula, and stir until completely dissolved under light-protected conditions to obtain the resin matrix prepolymer; add the modified antibacterial nanofiller to the prepolymer, stir at high speed for 30-60 minutes under light-protected conditions, and then ultrasonically disperse for 15-30 minutes until the filler is uniformly dispersed to obtain the 3D printing special resin slurry; the slurry viscosity can be controlled within the range of 100-10000 mPa·s by adjusting the mass ratio of Bis-GMA to TEGDMA according to the requirements of the printing equipment.

[0018] b. Pour the prepared resin slurry into the resin tank of a digital light processing (DLP) or stereolithography (SLA) 3D printer, import the three-dimensional digital model of the body to be printed, and set the printing parameters: layer thickness 25-100μm, exposure time 2-10s / layer, light source wavelength 400-500nm, and resin tank temperature controlled at 25-35℃.

[0019] c. Start the printing program to complete the layer-by-layer photocuring of the restoration; after printing, remove the molded part and ultrasonically clean it with anhydrous ethanol or isopropanol for 5-10 minutes to remove any uncured resin residue on the surface.

[0020] d. Place the cleaned molded part in a UV curing chamber and perform post-curing treatment at 40-60℃ for 15-30 minutes to finally obtain the 3D printed dental resin restoration.

[0021] The present invention further provides the application of the above-mentioned dental resin material in tooth defect repair, pit and fissure sealing, orthodontic bracket bonding and denture base modification.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) Long-lasting antibacterial performance: The mSiO2@PDA core-shell structure is used as the carrier of antimicrobial peptides. The mesoporous silica and polydopamine layer interact with the antimicrobial peptide molecules in multiple ways, realizing the slow and continuous release of antimicrobial peptides. In vitro release experiments show that the modified antimicrobial nanofiller of the present invention can continuously release antimicrobial peptides for more than 6 months, significantly prolonging the antimicrobial effective period and effectively preventing the occurrence of secondary caries.

[0023] (2) Excellent mechanical properties: The polydopamine layer contains abundant catechol and amino groups, which can form stable bonds with antimicrobial peptide molecules on the one hand, and covalent and hydrogen bonds with methacrylate groups in the resin matrix on the other hand, acting as a molecular bridge and significantly improving the interfacial compatibility between the hydrophilic antimicrobial peptide filler and the hydrophobic resin matrix. Compared with the control group with direct addition of free antimicrobial peptides, the dental resin material of the present invention has an increased flexural strength of about 25% and an increased compressive strength of about 30%, exhibiting excellent mechanical properties that meet the requirements of oral mastication function.

[0024] (3) Broad-spectrum antibacterial activity: The antimicrobial peptides selected in this invention have good inhibitory effects on a variety of oral pathogens such as Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces naeslundii. The minimum inhibitory concentration (MIC) is 1-8 μg / mL, which has strong antibacterial activity. Moreover, due to its physical membrane destruction mechanism, it is not easy to induce bacteria to develop drug resistance.

[0025] (4) Good biocompatibility: Both the antimicrobial peptide and the mesoporous silica carrier material have excellent biocompatibility. The cytotoxicity test showed that the material had a survival rate of more than 90% against human gingival fibroblasts (HGF) and no obvious cytotoxicity, which met the safety requirements of dental biomaterials.

[0026] (5) Simple preparation process: The preparation method of the present invention is simple to operate, mild, requires no special equipment, and is easy to industrialize and clinically promote. Attached Figure Description

[0027] The product, method, and their beneficial effects of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Figure 1 The images shown are transmission electron microscope (TEM) images of the mSiO2@PDA core-shell nanoparticles prepared in Example 2 of this invention, where Figure A shows mSiO2 and Figure B shows mSiO2 coated with PDA.

[0029] Figure 2Bar chart showing the survival rate of human gingival fibroblasts (HGF-1) after treatment with different concentrations of antimicrobial peptides. The horizontal axis represents the concentration of antimicrobial peptides (μg / mL), and the vertical axis represents the cell survival rate (%). Data are expressed as mean ± standard deviation (n=3), and different letters indicate significant differences between groups (p<0.05).

[0030] Figure 3 The bar chart shows the antibacterial properties of different samples. The horizontal axis represents soaking time, and the vertical axis represents the inhibition rate (%). The data are expressed as mean ± standard deviation (n=3). Different letters indicate significant differences between groups (p<0.05).

[0031] Figure 4 The bar charts show the mechanical properties of different samples. Figure A represents the flexural strength (MPa), and Figure B represents the compressive strength (MPa). Data are expressed as mean ± standard deviation (n=5), and different letters indicate significant differences between groups (p<0.05).

[0032] Figure 5 This is a bar chart showing the cell viability of samples treated with extracts of different dental resin materials. The horizontal axis represents different sample groups, and the vertical axis represents cell viability (%). Data are expressed as mean ± standard deviation (n=3). Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0035] Example 1: Screening and Identification of Antimicrobial Peptides 1.1 Sample collection: Collect 5 mL of non-irritating saliva samples from healthy and carious patients and place them on ice.

[0036] 1.2 Extraction of total microbial protein: The saliva sample was centrifuged at 12,000 rpm for 10 minutes at 4°C, the supernatant was removed, and the precipitate was collected. Protein extraction buffer (containing 8M urea, 2M thiourea, 4% CHAPS, and 1% protease inhibitor) was added, the cells were sonicated to disrupt the protein, and the mixture was extracted by shaking at 4°C for 2 hours. Then, it was centrifuged at 15,000 rpm for 30 minutes, and the supernatant was collected, which was the total microbial protein extract.

[0037] 1.3 Peptideomics Analysis: Protein concentration was determined using the Bradford method. 100 μg of protein was digested with trypsin, followed by peptide separation and identification using liquid chromatography-tandem mass spectrometry (LC-MS / MS). MaxQuant software was used to analyze the mass spectrometry data, identifying 127 peptides with significant abundance differences between the two groups (fold change > 2, p < 0.05).

[0038] 1.4 Bioinformatics Prediction: Differential peptide sequences were evaluated using antimicrobial peptide prediction software to predict their antimicrobial activity. Based on the prediction results, three candidate peptides with excellent antimicrobial potential were screened and named AMP-1 (SEQ ID NO.1), AMP-2 (SEQ ID NO.2), and AMP-3 (SEQ ID NO.3), respectively.

[0039] The amino acid sequence of SEQ ID NO.1 is: IHKLVGLVIFAALVIFGLSA The amino acid sequence of SEQ ID NO.2 is: AGLIFSVVNSVLKPIVTILA The amino acid sequence of SEQ ID NO.3 is: GLLIACVGVVWYKPMSLLKK 1.5 Chemical synthesis of antimicrobial peptides: The above three candidate peptides were synthesized using solid-phase peptide synthesis method, with a purity >95%.

[0040] 1.6 Antimicrobial assay of peptides: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of antimicrobial peptides against major cariogenic bacteria were determined by the micro-broth dilution method.

[0041] (1) Experimental strains: Streptococcus mutans ATCC 25175, Lactobacillus acidophilus ATCC 4356, and Actinomyces naeslundii ATCC12104.

[0042] (2) Preparation of bacterial culture: Each strain was inoculated into brain heart and brain extract (BHI) medium and cultured at 37°C and 5% CO2 until the logarithmic growth phase. The bacterial culture concentration was adjusted to 1×10⁻⁶ using fresh BHI medium. 6 CFU / mL.

[0043] (3) Preparation of antimicrobial peptide solution: The synthesized antimicrobial peptide was dissolved in sterile physiological saline to prepare a stock solution with a concentration of 1024 μg / mL. Then, it was serially diluted with BHI medium to obtain working solutions with concentrations of 512, 256, 128, 64, 32, 16, 8, 4, 2, and 1 μg / mL.

[0044] (4) Experimental Grouping: Experimental group: 100 μL of antimicrobial peptide working solution and 100 μL of bacterial culture of different concentrations were added respectively. Positive control group: Add 100 μL of chloramphenicol solution with a concentration of 10 μg / mL and 100 μL of bacterial culture. Negative control group: Add 100 μL of sterile saline and 100 μL of bacterial culture. Blank control group: Add 200 μL of BHI culture medium (5) Incubation and Measurement: The 96-well plate was incubated at 37℃ and 5% CO2 for 24 hours, and the absorbance at 600 nm was measured using a microplate reader. The lowest concentration of antimicrobial peptide at which no bacterial growth was observed was taken as the MIC. Then, 10 μL of bacterial culture was taken from each well with no bacterial growth and spread onto a BHI agar plate, and incubated for another 24 hours. The lowest concentration of antimicrobial peptide at which no colony growth was observed was taken as the MBC. Each experiment was repeated 3 times, and the average value of the results was taken.

[0045] (6) Experimental results: Table 1. MIC and MBC values ​​(μg / mL) of different antimicrobial peptides against major cariogenic bacteria. The results showed that the three antimicrobial peptides of the present invention all had significant antimicrobial activity against major cariogenic bacteria, among which AMP-2 had the strongest antimicrobial activity, comparable to the positive control chloramphenicol.

[0046] 1.7 Cytotoxicity assay of antimicrobial peptides The cytotoxicity of antimicrobial peptides against human gingival fibroblasts (HGF-1) was determined using the CCK-8 assay.

[0047] (1) Cell culture: HGF-1 cells were seeded in DMEM medium containing 10% fetal bovine serum, 100 U / mL penicillin and 100 μg / mL streptomycin and cultured at 37℃ and 5% CO2. The cells were passaged every 2-3 days.

[0048] (2) Experimental Groups: Experimental group: HGF-1 cells in logarithmic growth phase were injected with 1×10⁻⁶ cells. 4 Antimicrobial peptide solutions were inoculated at a density of 1000 cells / well in 96-well plates and cultured for 24 hours. Then, different final concentrations (1, 2, 4, 8, 16, 32, and 64 μg / mL) of antimicrobial peptide solution were added. Positive control group: Mitomycin C solution was added to a final concentration of 10 μg / mL. Negative control group: Add an equal volume of sterile saline. Blank control group: Add an equal volume of DMEM culture medium. (3) Culture and Measurement: After culturing for another 24 hours, 10 μL of CCK-8 solution was added to each well, and the cells were incubated at 37°C for 2 hours. The absorbance at 450 nm was measured using a microplate reader. The cell viability was calculated as follows: Cell viability (%) = (Absorbance of experimental group - Absorbance of blank control group) / (Absorbance of negative control group - Absorbance of blank control group) × 100%. Each experiment was repeated 3 times, and the results were taken as the mean ± standard deviation.

[0049] (4) Experimental results: such as Figure 2 As shown, when the concentration of the antimicrobial peptide was below 16 μg / mL, the survival rate of HGF-1 cells was above 90%; when the concentration reached 32 μg / mL, the cell survival rate was still above 80%; and when the concentration reached 64 μg / mL, the cell survival rate dropped to about 60%. The results indicate that the antimicrobial peptide of the present invention exhibits good biocompatibility and low cytotoxicity within the effective antimicrobial concentration range.

[0050] Example 2: Preparation of dental resin materials with antibacterial properties 2.1 Preparation of mSiO2@PDA core-shell nanoparticles (1) Synthesis of mesoporous silica (mSiO2) nanoparticles: 0.5 g of cetyltrimethylammonium bromide (CTAB) was dissolved in 240 mL of deionized water, and 1.75 mL of ammonia (28 wt%) was added. After stirring evenly in a water bath at 40 °C, 2.5 mL of tetraethyl orthosilicate (TEOS) was slowly added dropwise, and the reaction was continued with stirring for 2 h. After the reaction was completed, the product was collected by centrifugation, washed three times alternately with ethanol and deionized water, dried at 60 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 6 h to remove the template agent CTAB, yielding white powdery mSiO2 nanoparticles. Characterized by transmission electron microscopy (TEM) and nitrogen adsorption-desorption, the mSiO2 nanoparticles were spherical with a particle size of approximately 80-120 nm, an average pore size of approximately 3 nm, and a BET specific surface area of ​​approximately 850 m². 2 / g.

[0051] (2) Polydopamine (PDA) coating: 0.2 g of the above mSiO2 nanoparticles were dispersed in 200 mL of Tris-HCl buffer (10 mM, pH=8.5) and ultrasonically dispersed for 30 min to ensure complete dispersion of the particles. 0.08 g of dopamine hydrochloride was added, and the mixture was stirred at room temperature in the dark for 12 h. During the reaction, the solution color gradually changed from white to light gray, and finally to dark brown, indicating that dopamine underwent an oxidative self-polymerization reaction on the mSiO2 surface, forming a polydopamine coating. After the reaction, the product was collected by centrifugation, washed three times each with deionized water and ethanol, and vacuum dried at 40 °C for 24 h to obtain mSiO2@PDA core-shell nanoparticles. TEM characterization results showed that the PDA shell thickness was approximately 5 nm (10 nm increase relative to the mSiO2 particle size) (see...). Figure 1 ).

[0052] 2.2 Loading of antimicrobial peptides (1) Take three 0.1g mSiO2@PDA core-shell nanoparticles and disperse them in 10mL phosphate buffer (PBS, 0.01M, pH=7.4), sonicate for 15min, and prepare a dispersion with a concentration of 10mg / mL.

[0053] (2) Add 10 mg of SEQ ID NO.1, SEQ ID NO.2 and SEQ ID NO.3 antimicrobial peptides (the mass ratio of antimicrobial peptides to nanoparticles is 1:10) to the above three dispersions respectively, and stir at room temperature in the dark for 24 h.

[0054] (3) After the reaction was completed, the product was collected by centrifugation at 12000 rpm for 15 min. The unloaded free antimicrobial peptides were removed by washing with PBS three times. The product was then freeze-dried in vacuum (-50℃, <10Pa) for 24 h to obtain modified antimicrobial nanofillers loaded with SEQ ID NO.1, SEQ ID NO.2 and SEQ ID NO.3, respectively, and were named F1, F2 and F3.

[0055] (4) Loading capacity and encapsulation efficiency were detected using the BCA protein quantification method. The results are shown in Table 2 below: Table 2. Test results of load capacity and encapsulation efficiency 3.1 Preparation of dental resin materials Prepare dental resin materials according to the formulations shown in Table 3.

[0056] Table 3. Dental Resin Material Formulation (Parts by Weight) Preparation steps: (1) Mix Bis-GMA, TEGDMA, camphorquinone and DMAEMA according to the formula amount, and stir at 400 rpm for about 15 min under light-protected conditions until completely dissolved to obtain resin matrix prepolymer. (2) Add the appropriate filler to the resin matrix prepolymer, stir at 1200 rpm for 45 min under light-protected conditions, and then ultrasonically disperse for 20 min under a power of 250 W until the filler is uniformly dispersed. (3) The well-mixed slurry was vacuum degassed at 40°C for 15 minutes, then poured into a mold, and heated with a wavelength of 450 nm and a power density of 1000 mW / cm². 2 The sample was cured by blue light irradiation for 40 seconds to obtain a dental resin material sample.

[0057] 3.2 Antibacterial performance test The antibacterial properties of the material against Streptococcus mutans (S. mutans UA159) were tested using the plate count method. (1) Prepare the resin sample into a circular disc with a diameter of 10 mm and a thickness of 2 mm, and sterilize it with ultraviolet light for 30 min; (2) 100 μL of solution with a concentration of 1×10 6 A CFU / mL Streptococcus mutans bacterial suspension was dropped onto the sample surface and incubated at 37℃ and 5% CO2 for 24 h. (3) Rinse the sample with PBS, then spread the rinse solution onto brain heart and brain immersion (BHI) agar plates after gradient dilution and incubate for 48 h before counting the number of colonies. (4) Calculate the antibacterial rate: The resin without any filler was used as the blank control group. The antibacterial rate (%) = (number of colonies in the blank control group - number of colonies in the experimental group) / number of colonies in the blank control group) × 100%.

[0058] (5) The antibacterial properties of the materials were simultaneously tested after soaking in PBS (pH=7.4) for 1 month, 3 months, and 6 months. Each experiment was repeated 3 times, and the results were taken as mean ± standard deviation. The results are shown in Table 4 and... Figure 3 As shown: Table 4. Antibacterial properties of different samples (inhibition rate / %) From Table 4 and Figure 3As can be seen, Comparative Example 3 (pure mSiO2@PDA) exhibited certain inherent antibacterial activity, with an initial inhibition rate of 35.2%, proving that polydopamine itself has antibacterial effects, but the antibacterial activity is limited and not long-lasting. Example 3-1 had an initial inhibition rate as high as 99.2%, and maintained an inhibition rate of 85.3% after immersion for 6 months, demonstrating excellent long-lasting antibacterial performance. The antibacterial performance of Example 3-3 was the second best. The antibacterial performance of Example 3-2 was the worst, indicating that different combinations of peptides and nanomaterials can change the antibacterial performance. In Comparative Example 2, free antibacterial peptides were directly added. Although the initial inhibition rate was high, it dropped sharply to 45.2% after immersion for 1 month, and almost lost its antibacterial effect after 6 months, proving the sustained-release effect of the carrier system of the present invention.

[0059] 3.3 Mechanical Performance Testing The flexural and compressive strength of the material were tested according to ISO 4049 standard: Bending strength test: The sample was made into a cuboid of 25mm×2mm×2mm and tested using the three-point bending method with a span of 20mm and a loading speed of 0.5mm / min. Compressive strength test: The sample is made into a cuboid of 4mm×4mm×6mm and the loading speed is 1mm / min.

[0060] Each experiment was repeated 5 times, and the results were taken as mean ± standard deviation.

[0061] The results are shown in Table 5 and Figure 4 As shown: Table 5 Mechanical properties of different samples From Table 5 and Figure 4 As can be seen, compared with Comparative Example 1 (with added pure mSiO2), the flexural strength and compressive strength of Examples 1 and 3 are improved. This is because the polydopamine layer improves the interfacial bonding between the filler and the resin matrix. However, in Comparative Example 2, free antimicrobial peptides were directly added, resulting in a significant decrease in the mechanical properties of the material due to the poor compatibility between the antimicrobial peptides and the resin matrix.

[0062] 3.4 Cytotoxicity test The cytotoxicity of the material against human gingival fibroblasts (HGF) was tested using the CCK-8 assay. 3.1 Prepare the resin sample into a circular disc with a diameter of 10 mm and a thickness of 1 mm, and sterilize it with ultraviolet light for 30 min; 3.2 Place the sample in a 24-well plate, add 1 mL of DMEM medium containing 10% fetal bovine serum, and extract for 24 h at 37°C and 5% CO2. 3.3 Add the extract to a 96-well plate inoculated with HGF cells and continue culturing for 24 h; The negative control group was incubated with DMEM complete medium without the sample for 24 h under the same conditions; The positive control group was incubated with DMEM complete medium containing mitomycin C (10 μg / mL) for 24 h under the same conditions.

[0063] 3.4 Add CCK-8 solution, incubate for 2 hours, and then measure the absorbance at 450 nm using an ELISA reader to calculate the cell viability.

[0064] The results are as follows Figure 5 As shown, the cell viability rates of Examples 3-1, 3-2, and 3-3 were 92.3%, 93.5%, and 92.8%, respectively, all greater than 90%, indicating that the material has good biocompatibility.

[0065] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to the above embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An antimicrobial peptide, characterized in that, The antimicrobial peptide is selected from at least one of SEQ ID NO.1, SEQ ID NO.2 or SEQ ID NO.

3.

2. A dental resin material with antibacterial properties, characterized in that, By weight, it comprises the following components: resin matrix: 60-80 parts; modified antibacterial nanofiller: 15-35 parts; photoinitiator: 0.5-2 parts; accelerator: 0.1-0.5 parts; The modified antibacterial nanofiller is prepared by loading antibacterial peptides onto mesoporous silica@polydopamine core-shell nanoparticles.

3. The dental resin material as described in claim 2, characterized in that, The antimicrobial peptide is selected from at least one of SEQ ID NO.1, SEQ ID NO.2 or SEQ ID NO.

3.

4. The dental resin material as described in claim 2, characterized in that, The mesoporous silica@polydopamine core-shell nanoparticles have a particle size of 50-200 nm, the polydopamine coating thickness is 5-20 nm, and the mesoporous silica pore size is 2-5 nm.

5. The dental resin material as described in claim 2, characterized in that, The mass ratio of the antimicrobial peptide to mesoporous silica@polydopamine core-shell nanoparticles is 1:(5-20).

6. The dental resin material according to claim 2, characterized in that, The resin matrix is ​​composed of bisphenol A dimethacrylate glycidyl acrylate and triethylene glycol dimethacrylate in a mass ratio of (3-7):(7-3).

7. The dental resin material according to claim 2, characterized in that, The photoinitiator is camphorquinone, and the accelerator is dimethylaminoethyl methacrylate.

8. A method for preparing a dental resin material with antibacterial properties as described in any one of claims 2-7, characterized in that, Includes the following steps: a. Mix the resin matrix, photoinitiator and accelerator according to the formula amount, and stir under light-protected conditions until completely dissolved to obtain the resin matrix prepolymer; b. Add modified antibacterial nanofiller to the resin matrix prepolymer, stir at high speed for 30-60 min under light-protected conditions, and then ultrasonically disperse for 15-30 min; c. After vacuum degassing the uniformly mixed slurry, it is cured by blue light irradiation to obtain dental resin material.

9. The preparation method according to claim 8, characterized in that, The preparation method of the modified antibacterial nanofiller includes the following steps: a. Synthesize mesoporous silica nanoparticles, and then coat their surface with a polydopamine layer to obtain mesoporous silica@polydopamine core-shell nanoparticles; b. Disperse the core-shell nanoparticles in phosphate buffer, add antimicrobial peptides, and stir at room temperature in the dark for 12-48 hours; c. Collect the product by centrifugation, wash it, and freeze-dry it under vacuum to obtain the modified antibacterial nanofiller.

10. The use of the antimicrobial peptide of claim 1 or the dental resin material with antimicrobial effect as described in any one of claims 2-7 in tooth defect repair, pit and fissure sealing, orthodontic bracket bonding, temporary braces and denture base modification.

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