Periodontal local drug delivery system with antioxidant, anti-inflammatory and antibacterial synergistic effect and preparation method thereof

Abstract

The application discloses a periodontal local drug delivery system with antioxidant, anti-inflammatory and antibacterial synergistic effect and a preparation method thereof, and belongs to the technical field of pharmaceutical preparations.The preparation method comprises the following steps: first, preparing an organic phase by using DSPC, cholesterol, SA and resveratrol, and preparing a cationic liposome by using PBS as an aqueous phase; then, preparing an aqueous phase by using AlgMA and LAP, preparing an oil phase by using a surfactant solution, and preparing polydopamine hydrogel microspheres by surface modification through PDA; and finally, preparing the periodontal local drug delivery system by physical adsorption loading.The synergistic effect of resveratrol, the cationic liposome and polydopamine comprehensively intervenes in a periodontitis pathological chain, realizes synergistic treatment, has excellent antibacterial performance, anti-inflammatory effect and antioxidant effect, improves the drug retention rate, and solves the problems that traditional treatment drugs cannot simultaneously realize antibacterial, inflammation regulation and oxidative stress synergistic treatment, the drug has a short retention time in a periodontal pocket, and frequent drug administration is required.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pharmaceutical preparations, in particular to a periodontal local drug delivery system with synergistic effects of antioxidation, anti-inflammation and antibiosis and a preparation method thereof. BACKGROUND

[0002] Periodontitis is a chronic infectious disease caused by plaque biofilm, and its pathological process involves complex interactions between plaque microorganisms and the host immune system. When plaque accumulates, bacterial metabolites activate the host innate immune system, causing a large number of inflammatory cells to infiltrate and release excessive reactive oxygen species (ROS), forming a characteristic oxidative stress microenvironment, ultimately leading to periodontal attachment loss and alveolar bone resorption, which is the leading cause of tooth loss in adults.

[0003] The current clinical routine subgingival scaling and root planing (SRP) faces significant technical limitations: on the one hand, due to the complex anatomical structure of the periodontal pocket (such as deep and narrow pocket type, irregular root surface morphology), instruments are difficult to completely remove deep plaque; on the other hand, simple mechanical debridement cannot regulate excessive host immune response. Although local drug adjuvant therapy (such as minocycline hydrochloride ointment and other antibiotic preparations) can partially compensate for the above deficiencies, there are still deficiencies - only targeting antibacterial single link, unable to simultaneously solve the key pathological processes such as oxidative stress and excessive inflammatory response.

[0004] Therefore, there is an urgent clinical need to develop a new multifunctional synergistic treatment system. SUMMARY

[0005] To solve the above technical problems, the purpose of the present application is to provide a periodontal local drug delivery system with synergistic effects of antioxidation, anti-inflammation and antibiosis and a preparation method thereof, in order to solve the problem that the existing treatment strategies and local treatment products only have single treatment effect (such as simple antibiosis), and cannot comprehensively cope with the complex pathological processes involved in the development of periodontitis, such as oxidative stress and excessive inflammatory response.

[0006] The technical solution of the present application to solve the above technical problems is as follows:

[0007] In a first aspect of the present application, a preparation method of a periodontal local drug delivery system with synergistic effects of antioxidation, anti-inflammation and antibiosis is provided, comprising the following steps:

[0008] S1: Preparation of cationic liposomes

[0009] First, dissove distearoylphosphatidylcholine, cholesterol, stearylamine and resveratrol in an organic solvent to obtain a lipid-organic phase solution, and use a phosphate buffer solution as an aqueous phase solution; then mix the lipid-organic phase solution and the aqueous phase solution for molecular self-assembly to obtain a liposome suspension; finally, remove the solvent to prepare cationic liposomes;

[0010] S2: Preparation of polydopamine hydrogel microspheres

[0011] First, the aqueous solution of methacrylated sodium alginate and the photoinitiator are mixed to prepare an aqueous phase solution, and a surfactant solution is used as an oil phase solution; then the aqueous phase solution and the oil phase solution are mixed for photocuring crosslinking to obtain hydrogel microspheres; finally, the hydrogel microspheres are stirred and reacted in a dopamine hydrochloride solution to obtain polydopamine hydrogel microspheres.

[0012] S3: Preparation of a periodontal local drug delivery system

[0013] The polydopamine hydrogel microspheres obtained in S2 are mixed with the cationic liposome solution obtained in S1 for physical adsorption loading to obtain a periodontal local drug delivery system.

[0014] The periodontal local drug delivery system prepared by the method has the advantages that: the cationic liposome is composed of distearoylphosphatidylcholine, cholesterol and stearylamine, and has a positive charge on the surface, thereby imparting antibacterial activity to the system; resveratrol, as a drug, is combined with the cationic liposome, and is encapsulated in the cationic liposome to play an anti-inflammatory and antioxidant role; the polydopamine modified hydrogel microspheres are used as a carrier to provide a three-dimensional network structure, and the drug-loaded cationic liposome is wrapped to impart adhesion to the microspheres by surface modification of the polydopamine, so that the microspheres can adhere to the surface of the periodontal pocket tissue to prolong the local retention time; through the synergistic effect of the above multiple systems, the periodontal local drug delivery system prepared by the method realizes the synergistic effect of multiple functions such as antibacterial, anti-inflammatory and antioxidant, can precisely act on the periodontal pocket, and realizes synergistic treatment.

[0015] Further, the mass ratio of distearoylphosphatidylcholine, cholesterol and stearylamine in S1 is (30-60):(10-20):(5-10), and the organic solvent includes anhydrous ethanol; the drug includes resveratrol.

[0016] Preferably, the mass ratio of distearoylphosphatidylcholine, cholesterol and stearylamine in S1 is 45:15:8, and the organic solvent is anhydrous ethanol.

[0017] Further, the mass ratio of resveratrol and stearylamine is (5-10):(5-10).

[0018] Preferably, the mass ratio of resveratrol and stearylamine is 8:8.

[0019] Further, the pH of the phosphate buffer solution in S1 is 7.4.

[0020] Further, the lipid-organic phase solution and the aqueous phase solution in S1 are simultaneously injected into the microfluidic chip for mixing in the microfluidic channel; the flow rate ratio of the lipid-organic phase solution and the aqueous phase solution simultaneously injected is (0.5-1.5):(2-4).

[0021] The beneficial effects of the above further technical solutions are: the present application realizes controllable mixing of two-phase fluid in the microfluidic channel by microfluidic assembly, and the two-phase fluid forms a monolayer liposome structure at the interface through molecular self-assembly, wherein resveratrol is loaded in the hydrophobic cavity of the liposome, and the cationic groups provided by the stearylamine are distributed on the surface of the liposome.

[0022] Preferably, the flow rate ratio of the simultaneous injection of the lipid-organic phase solution and the aqueous phase solution is 1:3.

[0023] Further, the injection flow rate of the lipid-organic phase solution is 7.5 mL / h, and the injection flow rate of the aqueous phase solution is 22.5 mL / h.

[0024] Further, the way of removing the solvent in S1 is: using a rotary evaporator to remove the organic solvent under the condition of 30℃ and reduced pressure.

[0025] Further, the mass concentration of the methacrylated sodium alginate in the aqueous phase solution in S2 is 5%-10%, and the mass concentration of the photoinitiator is 0.5%-2%.

[0026] Preferably, the mass concentration of the methacrylated sodium alginate in the aqueous phase solution in S2 is 7.5%, and the mass concentration of the photoinitiator is 1%.

[0027] Further, the surfactant in S2 includes T154, and the solvent of the surfactant solution includes n-tetradecane with a concentration of 1 w / v %-3 w / v %.

[0028] Preferably, the surfactant in S2 is T154, the solvent of the surfactant solution is n-tetradecane, and the concentration is 2 w / v %.

[0029] Further, the aqueous phase solution and the oil phase solution are simultaneously injected into the microfluidic chip to mix in the microfluidic channel, and a UV light source is aimed at the microfluidic channel for photocuring crosslinking; the flow rate ratio of the simultaneous injection of the aqueous phase solution and the oil phase solution is (0.5-1.5):(10-20).

[0030] The beneficial effects of the above further technical solutions are: the present application injects the hydrogel precursor solution (aqueous phase solution) and the oil phase solution into two inlets of the microfluidic chip respectively, and by adjusting the flow rate, the aqueous phase forms monodisperse droplets under the shearing force of the oil phase in the microfluidic channel, when the droplets flow through the ultraviolet light irradiation area, the photoinitiator absorbs ultraviolet light, and initiates the crosslinking reaction of the hydrogel precursor, and finally forms solid hydrogel microspheres.

[0031] Preferably, the flow rate ratio of the simultaneous injection of the aqueous phase solution and the oil phase solution is 1:16.

[0032] Furthermore, the injection flow rate of the aqueous phase solution is 0.5 mL / h, and the injection flow rate of the oil phase solution is 8 mL / h.

[0033] Furthermore, the wavelength of the ultraviolet light source is 405 nm.

[0034] Furthermore, the concentration of dopamine hydrochloride solution in S2 was 5-20 mmol / L, and the solvent was Tris-HCl buffer; the reaction was carried out under light-protected conditions with stirring, at room temperature, for 20-30 h.

[0035] Preferably, the concentration of dopamine hydrochloride solution in S2 is 10 mmol / L, and the solvent is Tris-HCl buffer; the reaction is carried out under light-protected conditions with stirring, at room temperature, for 24 h.

[0036] Furthermore, the pH of the Tris-HCl buffer is 8.5.

[0037] Furthermore, the concentration of the cationic liposome solution in S3 was 1-10 mg / mL; the conditions for physical adsorption loading were: shaking incubation at 35-40℃ for 10-15 h.

[0038] Preferably, the concentration of the cationic liposome solution in S3 is 5 mg / mL; the conditions for physical adsorption loading are: shaking incubation at 37°C for 12 h.

[0039] Furthermore, after loading was completed, the composite microspheres were collected by centrifugation and washed with PBS to remove unadsorbed free liposomes.

[0040] In a second aspect, the present invention provides a periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory and antibacterial effects, which is prepared by the above-described preparation method.

[0041] A third aspect of the present invention provides the application of the above-described periodontal local drug delivery system in the preparation of periodontitis treatment drugs.

[0042] The present invention has the following beneficial effects:

[0043] This invention provides a method for preparing a periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory, and antibacterial effects. Through the synergistic effect of resveratrol, cationic liposomes, and polydopamine, it comprehensively intervenes in the pathological chain of periodontitis, achieving synergistic treatment. It possesses excellent antibacterial properties, anti-inflammatory effects, and antioxidant effects, improving the drug retention rate (by approximately 55.9%) and ensuring that the drug can continuously exert its effects at the lesion site. It solves the problems of traditional treatment drugs being unable to simultaneously achieve synergistic treatment of antibacterial, anti-inflammatory, and oxidative stress, having a short drug retention time in the periodontal pocket, and requiring frequent drug administration, and has broad application prospects. Attached Figure Description

[0044] Figure 1 This is a schematic diagram illustrating the working principle of the periodontal local drug delivery system prepared according to the present invention;

[0045] Figure 2 Figure 1 shows the characterization results of the cationic liposomes in Experiment Example 1. (a) is a schematic diagram of liposome preparation, (b) is a photographic image of the preparation process, (c) is a particle size distribution diagram, (d) is the Zeta potential, and (e) is a transmission electron microscope image.

[0046] Figure 3 Figure 1 shows the characterization results of the hydrogel microspheres in Experiment Example 2. (a) is the particle size distribution diagram, (b) is the infrared spectrum, (c) is the microscopic image, (d) and (e) are the adhesion characterization results, and (f) is the electron microscopic image.

[0047] Figure 4 The following diagram shows the biocompatibility characterization results in Experiment Example 3, where (a) shows the hemolysis test results, (b) shows the cell viability, and (c) shows the live / dead cell staining results.

[0048] Figure 5 The results show the anti-inflammatory properties of the drug-loaded cationic liposomes in Experiment 4, where (a)-(d) represent the mRNA expression levels of TNF-α, IL-1β, IL-6, and IL-10, respectively.

[0049] Figure 6 Figure 5 shows the results of the free radical scavenging ability and the ability to alleviate oxidative stress damage of the drug-loaded cationic liposomes in Experiment Example 5. In the figure, (a)-(c) show the scavenging ability of ABTS, DPPH and hydroxyl radicals, respectively; (d) shows the ability to alleviate oxidative stress damage; and (e) shows the ROS fluorescence staining results.

[0050] Figure 7 The figure shows the characterization results of the ability of drug-loaded cationic liposomes to scavenge intracellular reactive oxygen species in Experiment Example 6.

[0051] Figure 8 The figure shows the characterization results of the antibacterial experiment in Experiment Example 7, where (a) is the result of the minimum inhibitory concentration determination, and (b) is the result of bacterial live / dead staining.

[0052] Figure 9 The results of the microcomputed tomography analysis in Experiment Example 8 are shown in the figure. (a) is the maxillary bone scan of different experimental groups, and (b)-(d) are the bone volume fraction, alveolar bone height and trabecular bone thickness, respectively.

[0053] Figure 10 The image shows the histological analysis results of Experiment Example 8, where (a) is the H&E staining result and (b) is the Masson staining result.

[0054] Figure 11 The histological staining results are from Experiment Example 8. Detailed Implementation

[0055] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0056] Example 1:

[0057] A method for preparing a periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory, and antibacterial effects includes the following steps:

[0058] S1: Preparation of cationic liposomes

[0059] This embodiment uses microfluidic technology to construct cationic liposomes loaded with resveratrol, specifically including the following steps:

[0060] (1) Preparation of lipid-organic phase solution

[0061] Distearate phosphatidylcholine (DSPC), cholesterol, stearamine (SA), and the loaded drug resveratrol were dissolved together in anhydrous ethanol to form a homogeneous lipid-organic phase solution.

[0062] The mass ratio of DSPC, cholesterol, SA and resveratrol was 45:25:8:8, and the amount of anhydrous ethanol used was 10 mL.

[0063] (2) Preparation of aqueous solution

[0064] Prepare a phosphate-buffered saline (PBS) solution with a pH of 7.4 as the aqueous phase solution.

[0065] (3) Microfluidic assembly

[0066] The lipid-organic phase solution obtained in step (1) and the aqueous phase solution obtained in step (2) are injected into two independent inlets of the microfluidic chip, respectively. The flow rate ratio of the two phases is controlled to be 1:3 by a tight injection pump (where the flow rate of the organic phase is 7.5 mL / h and the flow rate of the aqueous phase is 22.5 mL / h), so that the two phase fluids can be controlled to mix in the microfluidic channel.

[0067] (4) Liposome formation

[0068] In the microfluidic channel, two-phase fluids form a monolayer liposome structure at the interface through molecular self-assembly, in which resveratrol is encapsulated in the hydrophobic cavity of the liposome, and cationic groups provided by stearamine are distributed on the surface of the liposome.

[0069] (5) Post-processing

[0070] The liposome suspension at the outlet was collected, and the residual organic solvent was removed by rotary evaporation at 30°C under reduced pressure, finally obtaining drug-loaded cationic liposomes with uniform particle size.

[0071] S2: Preparation of polydopamine hydrogel microspheres

[0072] This embodiment uses microfluidic technology to construct hydrogel microspheres, specifically including the following steps:

[0073] (1) Preparation of aqueous solution

[0074] Sodium alginate methacrylate (AlgMA) was dissolved in deionized water to prepare a 7.5% (w / w) solution. Then, 1% (w / w) of photoinitiator (LAP) was added and stirred until dissolved to obtain an aqueous solution.

[0075] (2) Preparation of oil phase solution

[0076] First, the surfactant T154 (Guangzhou Ruishengyan Chemical Technology Co., Ltd.) was dissolved in n-tetradecane to prepare a 2 w / v % solution as the oil phase solution.

[0077] (3) Crosslinking curing

[0078] The microfluidic chip was fixed on the microscope stage, and a syringe pump and fluid lines were connected. A UV light source (405 nm) was aimed at the cross-linking region of the microfluidic chip. The hydrogel precursor solution (aqueous phase) and oil phase solution were injected into the two inlets of the microfluidic chip, respectively. The flow rate ratio of the two phases was precisely controlled to 1:16 by adjusting the syringe pump (0.5 mL / h for the aqueous phase and 8 mL / h for the oil phase). Within the microfluidic channels, the aqueous phase formed monodisperse droplets under the shear force of the oil phase. When the droplets flowed through the UV-irradiated region, the photoinitiator absorbed the UV light, initiating a cross-linking reaction in the hydrogel precursor, ultimately forming solid hydrogel microspheres.

[0079] (4) Polydopamine (PDA) surface modification

[0080] First, dopamine hydrochloride was dissolved in Tris-HCl buffer (pH=8.5) and ultrasonically dispersed to obtain a 10 mmol / L solution. Then, the hydrogel microspheres obtained in step (3) were added and stirred at room temperature in the dark for 24 h to allow PDA to be uniformly deposited on the surface of the microspheres. Finally, the microspheres were collected by centrifugation and washed until the eluent was colorless and transparent to obtain polydopamine hydrogel microspheres.

[0081] S3: Construction of a local periodontal drug delivery system

[0082] The periodontal local drug delivery system (liposome-loaded hydrogel microspheres) was constructed using a physical adsorption method, specifically including the following steps:

[0083] The polydopamine hydrogel microspheres obtained in S2 were mixed with drug-loaded cationic liposomes obtained in S1 at a concentration of 5 mg / mL, and incubated at 37°C with constant temperature and shaking for 12 h to allow the liposomes to be fully adsorbed into the microsphere matrix. After loading, the composite microspheres were collected by centrifugation and washed with PBS to remove unadsorbed free liposomes, finally obtaining liposome-loaded hydrogel microspheres (RSV@Lipo@PMS). The working principle of this periodontal local drug delivery system is as follows: Figure 1 As shown.

[0084] Example 2:

[0085] A method for preparing a periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory, and antibacterial effects includes the following steps:

[0086] S1: Preparation of cationic liposomes

[0087] This embodiment uses microfluidic technology to construct cationic liposomes loaded with resveratrol, specifically including the following steps:

[0088] (1) Preparation of lipid-organic phase solution

[0089] Distearate phosphatidylcholine (DSPC), cholesterol, stearamine (SA), and the loaded drug resveratrol were dissolved together in anhydrous ethanol to form a homogeneous lipid-organic phase solution.

[0090] The mass ratio of DSPC, cholesterol, SA and resveratrol is 30:10:5:5, and the amount of anhydrous ethanol used is 10 mL.

[0091] (2) Preparation of aqueous solution

[0092] Prepare a phosphate-buffered saline (PBS) solution with a pH of 7.4 as the aqueous phase solution.

[0093] (3) Microfluidic assembly

[0094] The lipid-organic phase solution obtained in step (1) and the aqueous phase solution obtained in step (2) are injected into two independent inlets of the microfluidic chip, respectively. The flow rate ratio of the two phases is controlled to be 1:3 by a tight injection pump (where the flow rate of the organic phase is 7.5 mL / h and the flow rate of the aqueous phase is 22.5 mL / h), so that the two phase fluids can be controlled to mix in the microfluidic channel.

[0095] (4) Liposome formation

[0096] In the microfluidic channel, two-phase fluids form a monolayer liposome structure at the interface through molecular self-assembly, in which resveratrol is encapsulated in the hydrophobic cavity of the liposome, and cationic groups provided by stearamine are distributed on the surface of the liposome.

[0097] (5) Post-processing

[0098] The liposome suspension at the outlet was collected, and the residual organic solvent was removed by rotary evaporation at 30°C under reduced pressure, finally obtaining drug-loaded cationic liposomes with uniform particle size.

[0099] S2: Preparation of polydopamine hydrogel microspheres

[0100] This embodiment uses microfluidic technology to construct hydrogel microspheres, specifically including the following steps:

[0101] (1) Preparation of aqueous solution

[0102] Sodium alginate methacrylate (AlgMA) was dissolved in deionized water to prepare a 5% (w / w) solution. Then, 1% (w / w) of photoinitiator (LAP) was added and stirred until dissolved to obtain an aqueous solution.

[0103] (2) Preparation of oil phase solution

[0104] First, the surfactant T154 was dissolved in n-tetradecane to prepare a 1.5 w / v % solution as the oil phase solution.

[0105] (3) Crosslinking curing

[0106] The microfluidic chip was fixed on the microscope stage, and a syringe pump and fluid lines were connected. A UV light source (405 nm) was aimed at the cross-linking region of the microfluidic chip. The hydrogel precursor solution (aqueous phase) and oil phase solution were injected into the two inlets of the microfluidic chip, respectively. The flow rate ratio of the two phases was precisely controlled to 1:16 by adjusting the syringe pump (0.5 mL / h for the aqueous phase and 8 mL / h for the oil phase). Within the microfluidic channels, the aqueous phase formed monodisperse droplets under the shear force of the oil phase. When the droplets flowed through the UV-irradiated region, the photoinitiator absorbed the UV light, initiating a cross-linking reaction in the hydrogel precursor, ultimately forming solid hydrogel microspheres.

[0107] (4) Polydopamine (PDA) surface modification

[0108] First, dopamine hydrochloride was dissolved in Tris-HCl buffer (pH=8.5) and ultrasonically dispersed to obtain an 8 mmol / L solution. Then, the hydrogel microspheres obtained in step (3) were added and stirred at room temperature in the dark for 24 h to allow PDA to be uniformly deposited on the surface of the microspheres. Finally, the microspheres were collected by centrifugation and washed until the eluent was colorless and transparent to obtain polydopamine hydrogel microspheres.

[0109] S3: Construction of a local periodontal drug delivery system

[0110] The periodontal local drug delivery system (liposome-loaded hydrogel microspheres) was constructed using a physical adsorption method, specifically including the following steps:

[0111] The polydopamine hydrogel microspheres obtained in S2 were mixed with drug-loaded cationic liposomes obtained in S1 at a concentration of 5 mg / mL and incubated at 37 °C under constant temperature shaking for 12 h to allow the liposomes to be fully adsorbed into the microsphere matrix. After loading was completed, the composite microspheres were collected by centrifugation and washed with PBS to remove unadsorbed free liposomes, and finally liposome-loaded hydrogel microspheres were obtained.

[0112] Example 3:

[0113] A method for preparing a periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory, and antibacterial effects includes the following steps:

[0114] S1: Preparation of cationic liposomes

[0115] This embodiment uses microfluidic technology to construct cationic liposomes loaded with resveratrol, specifically including the following steps:

[0116] (1) Preparation of lipid-organic phase solution

[0117] Distearate phosphatidylcholine (DSPC), cholesterol, stearamine (SA), and the loaded drug resveratrol were dissolved together in anhydrous ethanol to form a homogeneous lipid-organic phase solution.

[0118] The mass ratio of DSPC, cholesterol, SA and resveratrol is 60:20:10:10, and the amount of anhydrous ethanol used is 10 mL.

[0119] (2) Preparation of aqueous solution

[0120] Prepare a phosphate-buffered saline (PBS) solution with a pH of 7.4 as the aqueous phase solution.

[0121] (3) Microfluidic assembly

[0122] The lipid-organic phase solution obtained in step (1) and the aqueous phase solution obtained in step (2) are injected into two independent inlets of the microfluidic chip, respectively. The flow rate ratio of the two phases is controlled to be 1:3 by a tight injection pump (where the flow rate of the organic phase is 7.5 mL / h and the flow rate of the aqueous phase is 22.5 mL / h), so that the two phase fluids can be controlled to mix in the microfluidic channel.

[0123] (4) Liposome formation

[0124] In the microfluidic channel, two-phase fluids form a monolayer liposome structure at the interface through molecular self-assembly, in which resveratrol is encapsulated in the hydrophobic cavity of the liposome, and cationic groups provided by stearamine are distributed on the surface of the liposome.

[0125] (5) Post-processing

[0126] The liposome suspension at the outlet was collected, and the residual organic solvent was removed by rotary evaporation at 30°C under reduced pressure, finally obtaining drug-loaded cationic liposomes with uniform particle size.

[0127] S2: Preparation of polydopamine hydrogel microspheres

[0128] This embodiment uses microfluidic technology to construct hydrogel microspheres, specifically including the following steps:

[0129] (1) Preparation of aqueous solution

[0130] Sodium alginate methacrylate (AlgMA) was dissolved in deionized water to prepare a 10% (w / w) solution. Then, 1% (w / w) of photoinitiator (LAP) was added and stirred until dissolved to obtain an aqueous solution.

[0131] (2) Preparation of oil phase solution

[0132] First, the surfactant T154 was dissolved in n-tetradecane to prepare a 2.5 w / v % solution as the oil phase solution.

[0133] (3) Crosslinking curing

[0134] The microfluidic chip was fixed on the microscope stage, and a syringe pump and fluid lines were connected. A UV light source (405 nm) was aimed at the cross-linking region of the microfluidic chip. The hydrogel precursor solution (aqueous phase) and oil phase solution were injected into the two inlets of the microfluidic chip, respectively. The flow rate ratio of the two phases was precisely controlled to 1:16 by adjusting the syringe pump (0.5 mL / h for the aqueous phase and 8 mL / h for the oil phase). Within the microfluidic channels, the aqueous phase formed monodisperse droplets under the shear force of the oil phase. When the droplets flowed through the UV-irradiated region, the photoinitiator absorbed the UV light, initiating a cross-linking reaction in the hydrogel precursor, ultimately forming solid hydrogel microspheres.

[0135] (4) Polydopamine (PDA) surface modification

[0136] First, dopamine hydrochloride was dissolved in Tris-HCl buffer (pH=8.5) and ultrasonically dispersed to obtain a 12 mmol / L solution. Then, the hydrogel microspheres obtained in step (3) were added and stirred at room temperature in the dark for 24 h to allow PDA to be uniformly deposited on the surface of the microspheres. Finally, the microspheres were collected by centrifugation and washed until the eluent was colorless and transparent to obtain polydopamine hydrogel microspheres.

[0137] S3: Construction of a local periodontal drug delivery system

[0138] The periodontal local drug delivery system (liposome-loaded hydrogel microspheres) was constructed using a physical adsorption method, specifically including the following steps:

[0139] The polydopamine hydrogel microspheres obtained in S2 were mixed with drug-loaded cationic liposomes obtained in S1 at a concentration of 5 mg / mL and incubated at 37 °C under constant temperature shaking for 12 h to allow the liposomes to be fully adsorbed into the microsphere matrix. After loading was completed, the composite microspheres were collected by centrifugation and washed with PBS to remove unadsorbed free liposomes, and finally liposome-loaded hydrogel microspheres were obtained.

[0140] Comparative Example 1:

[0141] A method for preparing a periodontal local drug delivery system includes the following steps:

[0142] The preparation method is the same as in Example 1, except that stearamine (SA) is not added in step (1) of S1, while the other steps remain unchanged. The resulting periodontal local drug delivery system is named No SA Lipo.

[0143] Experimental Example 1: Liposome Characterization

[0144] I. Experimental Methods

[0145] The drug-loaded cationic liposomes obtained in S1 of Example 1 were characterized, specifically including the following:

[0146] (1) Liposome particle size distribution test

[0147] The liposome particle size distribution was determined using dynamic light scattering technology (Malvern Zetasizer Nano ZS90). The specific procedure is as follows:

[0148] Sample pretreatment: Dilute the liposome suspension with phosphate-buffered saline (PBS) at a ratio of 1:4 (v / v);

[0149] Test parameter settings: equilibrium temperature 25±0.1℃, equilibrium time 60 s, each sample was measured 3 times consecutively.

[0150] (2) Liposome Zeta potential analysis

[0151] The zeta potential of the prepared liposomes was measured using dynamic light scattering (DLS). Specifically, the liposome solution was diluted 5-fold with PBS and placed in a zeta potential sample cell to measure its surface potential. Each sample was measured in triplicate.

[0152] (3) Morphological characterization of liposomes

[0153] The morphology and microstructure of the prepared liposome samples were characterized using transmission electron microscopy.

[0154] II. Experimental Results and Analysis

[0155] A schematic diagram of liposome preparation using a microfluidic chip in Example 1 is shown below. Figure 2 As shown in Figure (a), the controllable preparation of liposomes can be achieved by precisely controlling the two-phase fluid dynamics parameters. High-speed camera recordings show a clear parallel streamline interface between the organic and aqueous phases at the junction of the microfluidic channels (e.g., ...). Figure 2 As shown in Figure (b), this stable laminar flow state provides an ideal hydrodynamic environment for the uniform self-assembly of liposomes. Figure 2 As shown in Figure (c), the liposome solution prepared in Example 1 exhibits typical colloidal characteristics, with a pale blue opalescence, obvious Tyndall effect, and a narrow, single-peaked particle size distribution. Figure 2 The Zeta potential results in Figure (d) show that the surface of the unmodified liposomes (liposomes prepared in Comparative Example 2) is close to electroneutrality, while the surface positive charge of the SA-modified liposomes is significantly increased, confirming that amino protonation successfully imparts a positive charge to the surface. Transmission electron microscopy characterization results show that the prepared liposomes exhibit a typical spherical morphology, a relatively smooth surface, and a distinct bilayer structure (e.g., ...). Figure 2 (Figure e)

[0156] Experimental Example 2: Characterization of Hydrogel Microspheres

[0157] I. Experimental Methods

[0158] The hydrogel microspheres prepared in Example 1 were characterized, specifically including the following:

[0159] (1) Particle size analysis of hydrogel microspheres

[0160] The morphological characteristics of AlgMA microspheres without PDA modification were characterized using an inverted optical microscope. The diameter of at least 100 microspheres was randomly measured using Image-J software, and the uniformity of particle size distribution was evaluated by the coefficient of variation (CV) (CV = standard deviation / mean × 100%).

[0161] (2) Infrared characterization

[0162] The chemical structure of the microspheres was characterized using Fourier transform infrared spectroscopy (FTIR). Freeze-dried AlgMA and PDA@AlgMA microspheres were ground into fine powders, mixed with KBr powder at a ratio of 1:100 (w / w), and compressed into tablets. The tablets were then analyzed using Fourier transform infrared spectroscopy at 4000–400 cm⁻¹. -1 Scanning is performed within the beam range.

[0163] (3) Adhesion test

[0164] The tissue adhesion properties of microspheres were evaluated using an extracted tooth model. The specific method was as follows: AlgMA microspheres were stained with Rhodamine B for observation. AlgMA and PDA@AlgMA microspheres were applied to the surface of the extracted tooth, and the tooth was continuously rinsed with 1 mL of water. Images were acquired before and after rinsing. Image-J software was used to quantitatively analyze the microsphere coverage area before and after rinsing, and the microsphere retention rate was calculated (retention rate = microsphere coverage area after rinsing / microsphere coverage area before rinsing × 100%).

[0165] II. Experimental Results and Analysis

[0166] Experimental results are as follows Figure 3 As shown in the figure. The results show that AlgMA hydrogel microspheres with uniform particle size were successfully prepared. Particle size analysis showed that they exhibited a narrow unimodal distribution with a coefficient of variation (CV) of less than 5%, indicating that the microspheres have excellent monodispersity (e.g., ...). Figure 3 (Figure (a)). Infrared spectral characterization results show that, compared with unmodified AlgMA microspheres, the polydopamine-modified microspheres have a higher spectral density at 1528 cm⁻¹. -1 The appearance of a characteristic absorption peak (corresponding to the bending vibration of NH in polydopamine) confirms that polydopamine has been successfully coated onto the surface of microspheres (e.g., Figure 3 (Figure b) shows that the coating uniformly covers the surface of the microspheres under an industrial microscope (e.g., Figure 3 (Figure c)). In vitro adhesion experiments showed that polydopamine-modified microspheres exhibited significantly enhanced adhesion properties on extracted tooth surfaces (e.g., Figure 3 (Figures (d) and (e)).

[0167] Experiment Example 3: Biocompatibility Experiment

[0168] I. Experimental Methods

[0169] (a) Hemolysis test

[0170] (1) Red blood cell preparation: Centrifuge fresh rabbit blood (3000 rpm, 20 min), wash with PBS until the upper PBS becomes colorless, and collect red blood cells.

[0171] (2) Add 20 μL of blood cells to each tube and 1 mL of material prepared with physiological saline. At the same time, set up a negative control group (1 mL NaCl) and a positive control group (1 mL H2O).

[0172] (3) Incubate at 37℃ for 30 min, centrifuge at 3000 rpm for 20 min, and measure the absorbance of the supernatant at a wavelength of 540 nm.

[0173] (4) Calculate the hemolysis rate. The calculation formula is: Hemolysis rate = (experimental group - negative control group) / (positive control group - negative control group) × 100%.

[0174] (II) Cell viability assay

[0175] (1) Cell seeding: Take RAW264.7 cells in good condition and seed them evenly in 96-well plates, 100 μL per well.

[0176] (2) Drug administration: After the cells were completely attached to the wall, the culture medium was replaced with antibiotic-free culture medium containing different concentrations of RSV (resveratrol), Lipo (SA-modified liposomes loaded with resveratrol) and LPMS (cationic liposome hydrogel microspheres RSV@Lipo@PMS) extract. Each group was set up with 3 replicates, and blank group and control group were also set up.

[0177] (3) After culturing for 24 h, the old culture medium was discarded, and after gentle rinsing with sterile PBS, 100 μL of antibiotic-free culture medium containing 10 μL of CCK-8 reagent was added to each well. The cells were incubated at 37°C in the dark for 1 h. The absorbance value at 450 nm was detected using an ELISA reader, and the cell viability was calculated.

[0178] (iii) Staining of live / dead cells

[0179] (1) Cell seeding: Take RAW264.7 cells in good condition and seed them evenly in 6-well plates, 2 mL per well.

[0180] (2) Drug administration: After the cells have completely adhered to the wall, the culture medium is replaced with a complete culture medium containing different concentrations of RSV, Lipo and LPMS extracts.

[0181] (3) After co-culturing for 24 h, the old culture medium was discarded, and the cells were rinsed with PBS. 1 mL of Calcein-AM working solution (Beyotime) was added to each well, and the cells were incubated at 37°C in the dark for 20 min. The old culture medium was then discarded, and the cells were rinsed with PBS. 1 mL of PI working solution (Beyotime) was added to each well, and the cells were incubated at room temperature in the dark for 5 min. The old culture medium was then discarded, and the cells were rinsed with PBS. The cells were photographed using an inverted fluorescence microscope. Live cells were stained green by Calcein-AM, and dead cells were stained red by PI.

[0182] II. Experimental Results and Analysis

[0183] Experimental results are as follows Figure 4 As shown, after treatment with different concentrations of RSV, Lipo, and LPMS extracts, the hemolysis rate of cells in each group was less than 5%, the cell survival rate was greater than 85%, and almost no red fluorescence was observed, demonstrating good biocompatibility.

[0184] Experimental Example 4: Anti-inflammatory properties of drug-loaded cationic liposomes

[0185] I. Experimental Methods

[0186] The anti-inflammatory effect of the drug-loaded cationic liposomes (RSV@Lipo) prepared in Example 1 was detected by RT-qPCR. The specific method included the following steps:

[0187] (1) Cell seeding and starvation treatment: RAW264.7 cells in good condition were evenly seeded into 6-well plates, 2 mL per well. After the cells were completely attached, the medium was replaced with serum-free medium and starved for one day to synchronize the cell state.

[0188] (2) Inflammation induction and drug intervention: An inflammation model was established by stimulating cells with 1 μg / mL LPS. The experimental groups were treated with free RSV and different concentrations of RSV@Lipo, respectively. Untreated cells were used as the control group and cultured for 24 hours.

[0189] (3) RNA extraction and quality testing: Cells from each group were collected, and total RNA was extracted by lysing the cells using Trizol reagent (Invitrogen). RNA purity was tested using Nanodrop to ensure that RNA was of acceptable quality. 260 / A 280 The ratio is between 1.8 and 2.0, which meets the requirements for subsequent experiments.

[0190] (4) cDNA synthesis and qPCR amplification: 1 μg of total RNA was reverse transcribed according to the PrimerScript™ RT kit instructions to synthesize cDNA. The qPCR reaction system used was SYBR Green Mix (Shanghai Yisen Biotechnology Co., Ltd.). The target gene was amplified in a quantitative PCR instrument. Primers were synthesized by Beijing TsingKe. GAPDH was used as an internal control gene, and the amplification was performed using 2... −ΔΔCt The relative expression levels of target gene mRNA were calculated, and the data were normalized before analyzing the regulatory effect of RSV@Lipo on the expression of inflammatory factors.

[0191] II. Experimental Results and Analysis

[0192] Experimental results are as follows Figure 5 As shown, the results indicate that RSV@Lipo exhibits significant anti-inflammatory effects. With increasing RSV@Lipo concentration, the mRNA expression levels of pro-inflammatory factors TNF-α, IL-1β, and IL-6 showed a significant dose-dependent decrease, while the expression of the anti-inflammatory factor IL-10 was significantly upregulated.

[0193] Example 5: Antioxidant properties of drug-loaded cationic liposomes

[0194] I. Experimental Methods

[0195] The antioxidant properties of the drug-loaded cationic liposomes (RSV@Lipo) prepared in Example 1 were characterized, specifically including the following:

[0196] (1) ABTS free radical scavenging ability

[0197] The free radical scavenging activity of liposomes was determined using the ABTS free radical scavenging assay kit (Solarbio). 50 µL of diluted sample was added to 950 µL of ABTS working solution and reacted at room temperature in the dark for 6 min. The absorbance of the mixture was measured at 405 nm.

[0198] (2) DPPH free radical scavenging ability

[0199] The free radical scavenging activity of liposomes was determined using a DPPH free radical scavenging assay kit (Solarbio). 50 µL of the diluted sample was added to 950 µL of DPPH ethanol solution and reacted at room temperature in the dark for 30 min. The absorbance of the mixture at 515 nm was measured.

[0200] (3) Hydroxyl radical scavenging ability

[0201] The hydroxyl radical scavenging ability was determined by the salicylic acid capture method. Hydroxyl radicals were generated using the Fenton reaction system: 50 μL of 2.4 mmol / L hydrogen peroxide solution and 50 μL of 4 mmol / L ferrous sulfate solution were mixed and shaken, followed by the addition of 50 μL of RSV@Lipo solutions of different concentrations and reacting for 1 min, and then 50 μL of 4 mmol / L salicylic acid solution was added. The salicylic acid reacted with the residual hydroxyl radicals to generate the purple product 2,3-dihydroxybenzoic acid, and the absorbance was measured at 510 nm.

[0202] (4) Alleviate oxidative stress damage

[0203] To evaluate the antioxidant protective effect, a H2O2-induced cellular oxidative stress model was first established: logarithmic growth phase RAW264.7 cells were divided into groups of 5 × 10⁻⁶ cells. 3 Cells were seeded at 100 µL / well in 96-well plates and treated with H2O2 solutions at concentration gradients of 400–800 μmol / L for 24 h after adhesion. Cell viability was assessed using the CCK-8 assay to determine the optimal concentration for modeling. Cells were then divided into a negative control group, an H2O2-damaged group, and an H2O2+RSV@Lipo-protected group. After co-culturing for 24 h, cell proliferation activity was assessed using the CCK-8 assay to evaluate the repair effect of drug-loaded liposomes on oxidative damage.

[0204] (5) Intracellular reactive oxygen species (ROS) scavenging effect

[0205] Cell seeding and starvation treatment: RAW264.7 cells in good growth condition were evenly seeded into 6-well plates, 2 mL per well. After the cells were completely adhered, the medium was replaced with serum-free medium, and the cells were starved for one day to synchronize their state.

[0206] Establishment of oxidative stress model and drug intervention: Cells were stimulated with 300 μmol / L H2O2 solution to establish a high ROS model, and RSV group, RSV@Lipo group and control group without drug treatment were set up and cultured together for 3 h.

[0207] ROS fluorescence staining and detection: Discard the culture medium, gently wash cells three times with pre-cooled PBS, add 10 μmol / L DCFH-DA fluorescent probe (diluted with serum-free medium), incubate at 37°C in the dark for 20 min, and wash thoroughly with PBS again to remove uninternalized probe. Detect cell ROS levels using an inverted fluorescence microscope and flow cytometry, with excitation wavelength at 488 nm and emission wavelength at 525 nm.

[0208] II. Experimental Results and Analysis

[0209] Experimental results are as follows Figure 6 and Figure 7 As shown in the figure. The results indicate that RSV@Lipo has good free radical scavenging ability, with an ABTS free radical scavenging rate of over 95%, a DPPH free radical scavenging rate of approximately 60%, and a hydroxyl free radical scavenging rate of approximately 40%. Simultaneously, RSV@Lipo can improve cell survival under oxidative stress conditions and effectively remove intracellular reactive oxygen species.

[0210] Test Example 6: Antibacterial Properties

[0211] I. Experimental Methods

[0212] The antibacterial properties of the liposomes prepared by the method of Example 1 and Comparative Example 1 were characterized. The cationic liposome of Example 1 was named SA-Lipo, and the liposome prepared by Comparative Example 1 was named Lipo. The concentration was uniformly adjusted to 2.5 mg / mL.

[0213] (1) Determination of minimum inhibitory concentration (MIC)

[0214] The liposomes were serially diluted using TSB medium to prepare liposome solutions with concentrations of 1000, 500, 250, 200, 125, and 62.5 μg / mL. (All were 2× working concentrations, to be used when mixed with an equal volume of bacterial culture to achieve the target final concentration).

[0215] Porphyromonas gingivalis (ATCC 33277) was cultured in vitro, and the bacterial culture was pre-adjusted to 10⁻⁶ with culture medium. 7 CFU / mL (final concentration after mixing with drug solution is 5×10⁻⁶) 6 (CFU / mL) Add 50 μL of bacterial culture and an equal volume (50 μL) of the above-mentioned liposome solutions to each well of a 96-well plate. The first column is inoculated with 50 µL of bacterial culture + 50 µL of culture medium as a negative control, and the second column is inoculated with 100 µL of culture medium as a blank control. Incubate at 37℃ for 48 h in an anaerobic incubator, and measure the absorbance at 600 nm using a microplate reader.

[0216] (2) Staining of live / dead bacteria

[0217] To further evaluate the antibacterial activity of liposomes, the DMAO / PI live / dead bacteria double staining assay (Beyotime) was used to further verify the antibacterial effect of liposomes. A liposome solution with a concentration near the MIC value (62.5 μg / mL) was co-cultured with *Porphyromonas gingivalis* under anaerobic conditions at 37℃ for 48 h. An appropriate amount of bacterial culture was centrifuged at 10000×g at room temperature for 5 min, the supernatant was discarded, and the solution was washed once with physiological saline. The bacterial concentration was then adjusted to approximately 10% with physiological saline. 8 Bacteria / mL. Staining was performed by adding 1 µL of staining working solution (100×) to every 100 µL of bacterial culture. Incubation was carried out at 37°C in the dark for 15 min. After staining, a 10 μL smear of the bacterial culture was taken and observed and images were acquired under an inverted fluorescence microscope. Live bacteria showed green fluorescence after DMAO staining, while dead bacteria showed red fluorescence after PI staining, thus distinguishing and quantifying bacterial viability.

[0218] Experimental results are as follows Figure 8 As shown, the bacterial survival rate of SA-Lipo at a concentration of 62.5 μg / mL was approximately 56.8%, which further decreased to 22.9% at 100 μg / mL; while conventional Lipo required a concentration of 250 μg / mL to exhibit significant antibacterial activity. Within the concentration range of 62.5-125 μg / mL, the antibacterial performance of SA-modified cationic liposomes was significantly superior to that of conventional liposomes, indicating that SA modification effectively enhanced its antibacterial efficacy. Live / dead bacterial staining results showed that the number of dead bacteria in the SA-Lipo group was significantly higher than that in the unmodified liposome group, further confirming from a morphological perspective that cationic liposomes possess superior antibacterial properties, consistent with the aforementioned quantitative antibacterial results.

[0219] Experiment 7: Animal Experiment

[0220] I. Modeling and Microcomputed Tomography Analysis

[0221] (1) Six-week-old male SD rats were randomly divided into five groups (healthy group, periodontitis group, RSV group (10% ethanol as solvent), RSV@Lipo group (drug-loaded cationic liposomes not loaded on hydrogel microspheres) and RSV@Lipo@PMS group). Except for the healthy group, the experimental group rats were anesthetized with 1.25% tribromoethanol in the peritoneum, and the bilateral second molars were ligated with 4-0 suture soaked in Pg bacterial solution. Bacterial solution was applied to the ligated area every 3 days to maintain infection.

[0222] (2) Ten days after ligation, the treatment drugs of each group were precisely injected into the periodontal pocket using an insulin needle. The drugs were administered once every 4 days for 20 days. The control group and the periodontitis group were injected with saline.

[0223] (3) At the end of the experiment, the animals were anesthetized and euthanized. The maxilla and major internal organs (heart, liver, spleen, lungs and kidneys) were completely removed and fixed in 4% paraformaldehyde solution for 24 h. Then, they were rinsed with 75% alcohol for further analysis.

[0224] (4) The maxillary bone sample was scanned by Micro-CT and the following indicators were quantitatively analyzed in the specified area using the matching analysis software: alveolar bone height (CEJ-ABC distance), bone volume fraction (BV / TV), and trabecular bone thickness (Tb.Th).

[0225] Experimental results are as follows Figure 9 As shown, the results indicated that the alveolar bone morphology and structure in the second molar region of healthy rats remained intact, and the ridge height was maintained at a normal level. In contrast, the periodontitis group showed significant bone resorption in this area, manifested as exposure of the root bifurcation region and obvious local bone destruction. After RSV@Lipo treatment, the CEJ-ABC distance was somewhat restored, but the bone volume fraction (BV / TV) and trabecular bone thickness (Tb.Th) showed no statistically significant difference compared to the periodontitis group. It is speculated that this may be because although the liposome carrier improves drug bioavailability, its local retention performance is still insufficient, limiting the therapeutic effect. The RSV@Lipo@PMS composite treatment group prepared in Example 1 of this invention showed a more significant alveolar bone repair effect: the CEJ-ABC distance was significantly reduced, and the trabecular bone thickness was significantly increased. These results indicate that RSV@Lipo@PMS has excellent ability to inhibit bone resorption and promote bone repair in vivo.

[0226] II. Histological Analysis

[0227] (1) Sample pretreatment: After the Micro-CT scan, the maxillary bone sample was decalcified with 10% EDTA for 6 weeks, dehydrated, and embedded in paraffin.

[0228] (2) Sectioning, staining and imaging: Paraffin-embedded samples were sectioned to a thickness of 5 μm and subjected to H&E staining and Masson staining, respectively. Images were acquired using a full-slice scanning system (Yijingtong, VS200) to observe the histological features such as alveolar bone morphology and collagen fiber arrangement, and to assess the degree of alveolar bone resorption.

[0229] Experimental results are as follows Figure 10 As shown, the results indicated that in the normal group, the gingival junctional epithelium of the rats was tightly attached to the tooth surface, with no apical recession, and the alveolar ridge height remained normal, with no obvious bone resorption. In contrast, the periodontitis group showed destruction of the interdental papilla structure, reduced alveolar ridge height, and significant bone resorption and destruction. Compared to this, treatment with RSV@Lipo@PMS prepared in Example 1 of this invention significantly improved periodontal tissue regeneration and repair, restored alveolar bone height, and significantly improved bone resorption. The RSV@Lipo treatment group also showed some degree of periodontal tissue healing and regeneration, but its efficacy was weaker than that of the RSV@Lipo@PMS group.

[0230] III. Histological Staining

[0231] The collected vital organs were dehydrated and paraffin-embedded. The embedded samples were then sectioned at a thickness of 5 μm and stained with H&E. Images were acquired using a full-slice scanning system (E-Speed ​​VS200). By observing the tissue structure, cell morphology, and inflammatory infiltration of each organ, the potential systemic toxicity of the drug delivery system was systematically evaluated.

[0232] Experimental results are as follows Figure 11 As shown, the results indicated that the morphology and structure of tissue sections from important organs such as the heart, liver, spleen, lungs, and kidneys of rats treated with RSV, RSV@Lipo, and RSV@Lipo@PMS were normal, and no obvious pathological changes (such as cell necrosis, inflammatory cell infiltration, congestion, or fibrosis) were observed. This suggests that the three drug preparations have good biosafety in vivo and did not cause significant systemic toxicity.

[0233] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory, and antibacterial effects, characterized in that, Includes the following steps: S1: Preparation of cationic liposomes First, distearate phosphatidylcholine, cholesterol, stearamine, and resveratrol were dissolved together in an organic solvent to obtain a lipid-organic phase solution, with phosphate buffer as the aqueous phase solution. Then, the lipid-organic phase solution and the aqueous phase solution were mixed to perform molecular self-assembly, resulting in a liposome suspension. Finally, the solvent was removed to obtain cationic liposomes. S2: Preparation of polydopamine hydrogel microspheres First, an aqueous solution of sodium alginate methacrylate and a photoinitiator were mixed to prepare an aqueous solution, and a surfactant was used as an oil solution. Then, the aqueous solution and the oil solution were mixed and photocured to obtain hydrogel microspheres. Finally, the hydrogel microspheres were stirred and reacted in a dopamine hydrochloride solution to obtain polydopamine hydrogel microspheres. S3: Preparation of a periodontal local drug delivery system The polydopamine hydrogel microspheres obtained in S2 were mixed with the cationic liposome solution obtained in S1 for physical adsorption loading to prepare a periodontal local drug delivery system. In S1, the mass ratio of distearate phosphatidylcholine, cholesterol and stearamine is (30-60):(10-20):(5-10), and the organic solvent includes anhydrous ethanol; In S1, the lipid-organic phase solution and the aqueous phase solution are simultaneously injected into the microfluidic chip and mixed in the microfluidic channel; the flow rate ratio of the lipid-organic phase solution and the aqueous phase solution injected simultaneously is 1:3; In the S2 aqueous solution, the mass concentration of sodium alginate methacrylate is 5%-10%, and the mass concentration of photoinitiator is 0.5%-2%. The surfactant in S2 includes T154, and the solvent of the surfactant solution includes n-tetradecane with a concentration of 1 w / v%-3 w / v%. In step S2, the aqueous solution and the oil solution are simultaneously injected into the microfluidic chip and mixed in the microfluidic channel. The ultraviolet light source is then directed at the microfluidic channel for photocuring and crosslinking. The flow rate ratio of the aqueous solution to the oil solution during simultaneous injection is (0.5-1.5):(10-20). The concentration of dopamine hydrochloride solution in S2 is 5-20 mmol / L, and the solvent is Tris-HCl buffer. The reaction is carried out under light-protected conditions with stirring, at room temperature, for 20-30 h.

2. The method for preparing the periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory, and antibacterial effects according to claim 1, characterized in that, The concentration of the cationic liposome solution in S3 is 1-10 mg / mL; the conditions for physical adsorption loading are: shaking incubation at 35-40℃ for 10-15 h.

3. A periodontal local drug delivery system with synergistic antioxidant, anti-inflammatory, and antibacterial effects, characterized in that, It is prepared by the preparation method described in claim 1 or 2.

4. The use of the periodontal local drug delivery system according to claim 3 in the preparation of periodontitis treatment drugs.

Images