Aggregation-induced emission photosensitizer as well as preparation method and application thereof

Abstract

The aggregation-induced emission photosensitizer with a brand-new structure is designed and synthesized on the basis of benzothiadiazole, and has the following advantages that a cationic skeleton endows the aggregation-induced emission photosensitizer with cationic characteristics, for example, stable cationic free radicals are easily generated under illumination; oxygen family elements are introduced into a molecular skeleton, so that the absorption of molecules in a visible light region is improved, and meanwhile, the generation of active oxygen is also promoted; the periodontal dressing prepared on the basis of the aggregation-induced emission photosensitizer disclosed by the invention is easily used as a medical dressing in a gel form, and periodontitis treatment is convenient due to temperature-sensitive injectable property, so that the periodontal dressing is a matrix with huge photodynamic periodontitis treatment dressing development potential; when the compound is applied, the compound has remarkable inhibition activity on porphyromonas gingivalis under illumination and has huge potential for photodynamic therapy as a medical dressing.

Description

Technical Field

[0001] The invention relates to the field of aggregation-induced luminescence photosensitizers, and in particular to an aggregation-induced luminescence photosensitizer, a preparation method thereof, and application thereof in preparing injectable periodontal dressings. Background Art

[0002] Periodontitis is a very common bacterial infection in the oral cavity and is considered the sixth most prevalent disease in the world. It is reported that the prevalence of periodontitis in developed countries is about 20-50%. The global direct treatment cost of periodontal disease is about 298 billion US dollars each year, accounting for 4.6% of the global average health expenditure, which has caused a huge burden on health expenditure. Antibiotics, as a class of highly effective antibacterial drugs, have been widely used in the treatment of periodontitis. However, with the frequent use of antibiotics, the number of drug-resistant strains has also been rising. In response to this problem, researchers have developed a series of non-antibiotic treatment methods. For example, photodynamic therapy has become one of the most promising new antibacterial methods due to its advantages such as broad-spectrum antibacterial effect, little damage to normal tissues, high efficiency and low resistance to drug resistance. In recent years, it has attracted the attention of more and more scholars and has been successfully applied to the treatment of periodontitis, achieving remarkable results.

[0003] The organic small molecule photosensitizers that have been reported so far, such as porphyrin, methylene blue, and BODIPY, have weak light absorption ability, poor resistance to photobleaching, are harmful to healthy tissues, and have poor therapeutic effects.

[0004] Based on this, a new solution is needed. Summary of the invention

[0005] The technical solution adopted by the present invention to solve the technical problem is to provide an aggregation-induced luminescence photosensitizer, wherein the aggregation-induced luminescence photosensitizer has the following structure:

[0006]

[0007] Wherein, E is selected from one of O, S and Se, and R1 and R2 are selected from

[0008] ,

[0009] R3 is selected from R4 is one of Cl, Br, I or PF6.

[0010] The present invention also provides a method for preparing the aggregation-induced emission photosensitizer as described above, characterized in that it comprises the following steps:

[0011] Compound 1 is reacted with a boronic acid having an R1 substituent to obtain compound 2 through a Suzukii coupling reaction;

[0012] Compound 2 is reacted with a boronic acid having an R2 substituent to obtain compound 3 through Suzukii coupling reaction;

[0013] Compound 3 is reacted with a nitrile reagent having an R3 substituent to obtain a crude product, which is then separated by column chromatography to obtain the aggregation-induced luminescence photosensitizer;

[0014] Among them, the structural formulas of compounds 1, 2 and 3 are as follows:

[0015]

[0016] Wherein, E is selected from one of O, S and Se, and R1 and R2 are selected from

[0017] ,

[0018] R3 is selected from R4 is one of Cl, Br, I or PF6.

[0019] The present invention also provides a use of the above-mentioned aggregation-induced luminescence photosensitizer in the preparation of a periodontal dressing for periodontitis infection.

[0020] In the application provided by the present invention, the periodontitis infection is Porphyromonas gingivalis infection.

[0021] In the application provided by the present invention, the aggregation-induced luminescence photosensitizer is loaded in an injectable thermosensitive hydrogel.

[0022] The present invention also provides a use of the aggregation-induced luminescence photosensitizer as described above in the preparation of a drug for photodynamic therapy.

[0023] In the application provided by the present invention, the drug is used to inhibit Porphyromonas gingivalis.

[0024] The implementation of the present invention can achieve the following beneficial effects:

[0025] The present invention designs and synthesizes a novel aggregation-induced luminescence photosensitizer based on benzothiadiazole, which has the following advantages: the cationic skeleton gives it cationic characteristics, such as easy generation of stable cationic free radicals under light; the introduction of oxygen group elements into the molecular skeleton improves the absorption of the molecule in the visible light region, and also promotes the generation of active oxygen species; the periodontal dressing prepared based on the above-mentioned aggregation-induced luminescence photosensitizer of the present invention is easy to be used as a medical dressing in the form of a gel, and is thermosensitive and injectable, which is convenient for the treatment of periodontitis. Therefore, it is a matrix with great potential for the development of photodynamic periodontitis treatment dressings; when it is used, it has significant inhibitory activity against Porphyromonas gingivalis under light and has great potential for photodynamic therapy as a medical dressing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work:

[0027] Figure 1 Shown is the synthesis route of the aggregation-induced luminescence photosensitizer provided by the present invention;

[0028] Figure 2 is the active oxygen generation diagram of the present invention; wherein a is the total active oxygen generation diagram, and b is the singlet oxygen generation diagram;

[0029] Figure 3 The antibacterial effect diagram of the dressing of the present invention under different conditions; wherein a is a diagram of antibacterial activity coating results, and b is a diagram of antibacterial activity statistics;

[0030] Figure 4 This is a display diagram of the periodontal dressing of the present invention and a diagram of photodynamic periodontitis treatment in rats. DETAILED DESCRIPTION

[0031] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments described in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The present invention designs and synthesizes a novel aggregation-induced luminescence photosensitizer based on benzothiadiazole, and prepares a novel aggregation-induced luminescence photosensitizer-type periodontal dressing based on this type of compound. It is found for the first time that this periodontal dressing has significant inhibitory activity against Porphyromonas gingivalis, and has the potential to be used as a medical dressing for effective photodynamic therapy.

[0033] Based on this, the present invention provides an aggregation-induced luminescence photosensitizer, wherein the aggregation-induced luminescence photosensitizer has the following structure:

[0034]

[0035] Wherein, E is selected from one of O, S and Se, and R1 and R2 are selected from

[0036] ,

[0037] R3 is selected from R4 is one of Cl, Br, I or PF6.

[0038] At the same time, a preparation method of the above-mentioned aggregation-induced luminescence photosensitizer is also provided, and its synthesis route is as follows Figure 1 As shown, the following steps are included:

[0039] Compound 1 is reacted with a boronic acid having an R1 substituent to obtain compound 2 through a Suzukii coupling reaction;

[0040] Compound 2 is reacted with a boronic acid having an R2 substituent to obtain compound 3 through Suzukii coupling reaction;

[0041] Compound 3 is reacted with a nitrile reagent having an R3 substituent to obtain a crude product, which is then separated by column chromatography to obtain the aggregation-induced luminescence photosensitizer;

[0042] Among them, the structural formulas of compounds 1, 2 and 3 are as follows:

[0043]

[0044] Wherein, E is selected from one of O, S and Se, and R1 and R2 are selected from

[0045] ,

[0046] R3 is selected from R4 is one of Cl, Br, I or PF6.

[0047] The prepared compound is loaded into an injectable thermosensitive hydrogel to obtain a novel gel material with photodynamic therapy effect.

[0048] The present invention uses an in vitro antibacterial activity test to evaluate the antibacterial activity of the above compounds. The aggregation-induced luminescence photosensitizer-based periodontal dressing involved in the present invention has obvious inhibitory activity against Porphyromonas gingivalis and has great potential as an antibacterial medical dressing for photodynamic therapy. The application of this type of periodontal dressing as an antibacterial medical dressing has significant inhibitory activity against Porphyromonas gingivalis.

[0049] Example 1 Preparation of Aggregation-Induced Luminescence Photosensitizer

[0050] 4,7-Dibromo-5,6-difluorobenzo[c][1,2,5]thiadiazole (4.5mmol), boronic acid with different substituents R1 (4.5mmol), potassium carbonate (18mmol) and tetrakistriphenylphosphine palladium (0.17mmol) were added to a 500mL two-necked round-bottom flask, and 150mL of distilled toluene and 50mL of water were added. The mixture was then heated to reflux for 10h under nitrogen, cooled to room temperature, poured into water, and extracted three times with dichloromethane. The organic phase was washed with saturated sodium chloride solution and dried over anhydrous magnesium sulfate. After filtration and solvent evaporation, it was purified by silica gel column chromatography to obtain compound 2, and then compound 3 was obtained through the above steps. Sodium hydride (2mmol) was dissolved in dry N,N-dimethylformamide solution, added to R3 (1mmol) at 0℃ and reacted for 30min, then carbon disulfide (2mmol) was added and reacted at room temperature for 2h. Compound 3 (0.2 mmol) was dissolved in dry N,N-dimethylformamide and added to the mixture. The mixture was stirred at 70°C overnight. After cooling to room temperature, the mixture was poured into water and extracted three times with dichloromethane. The organic phase was washed with saturated sodium chloride solution and dried over anhydrous magnesium sulfate. After filtration and solvent evaporation, it was purified by silica gel column chromatography to obtain compound 4.

[0051] The following are the names, numbers, physical states, and NMR data of the aggregation-induced luminescence photosensitizers synthesized using the above method.

[0052] Compound 4: yield 23%, solid powder. 1 H NMR (600MHz, MeOD): δ8.76-8.74(d,2H),8.23-8.21(d,2H),7.97-7.93(q,4 H),7.75-7.74(d,2H),7.34-7.31(m,4H),7.16-7.12(m,10H),4.33(s,3H). 13 C NMR (150MHz, DMSO-d6): δ193.6,183.7,183.0,175.6,171.0,167.6,162.2,157.2,147.2,146.8,145.2,145.1,142.1,129.7,129.6,129 .5,129.4,129.3,129.2,124.9,124.3,123.9,123.4,120.5,119.6,119.1,118.5,117.8,117.7,117.4,116.4,103.3,96.9,65.8,43.3.

[0053] Example 2 Preparation of Aggregation-Induced Luminescence Photosensitizer-Based Periodontal Dressing

[0054] 300 mg of PLGA-PEG-PLGA block polymer was added to 2 mL of deionized water and stirred at room temperature until the polymer was evenly dispersed in the water to form a viscous transparent milky white liquid. Compound 4 was dissolved in dimethyl sulfoxide and diluted to 1 uM with the polymer solution and stored in a 4°C refrigerator. Before use, the syringe was drawn up and placed in a 37°C incubator for 15 minutes, and further tested after gelation.

[0055] Example 3 Antibacterial activity of periodontal dressings based on aggregation-induced luminescence photosensitizers

[0056] 1. Test bacteria:

[0057] Porphyromonas gingivalis (P.gingivalis).

[0058] 2. Sample preparation:

[0059] Accurately weigh a certain amount of the test compound into a centrifuge tube, add 1 mL of sterile water to make a 1 μmol / L solution, and use 0.9% NaCl as a blank control.

[0060] 3. Preparation of solid culture medium:

[0061] Tryptic soy broth, supplemented with yeast extract (5 g L -1 ), l-cysteine ​​(0.5 g L -1) , Vitamin K1 (1mgL -1 ), hemoglobin (5 mg L -1 ), agar powder (15 g L -1 ) and 5% fiber-free sheep blood, adjusted to pH 7.3.

[0062] 4. Determination of antibacterial activity:

[0063] The antibacterial activity was determined by plate colony counting method. 9 CPU / mL of bacterial solution was mixed and coated on the solid culture medium, and the aggregation-induced luminescence photosensitizer-based periodontal dressing was attached to the culture medium and irradiated under white light (50 mW / cm 2 ) for 3 minutes and then cultured in an anaerobic constant temperature and humidity incubator at 37°C. Each treatment was repeated three times. After culturing for 16 hours, the number of colonies was counted and the antibacterial rate of each test compound was calculated according to the following formula.

[0064]

[0065] C is the colony count of the test group; C0 is the colony count of the blank control group.

[0066] The test results can be found in Figure 2 to Figure 4, that is, the inhibitory activity of the aggregation-induced luminescence photosensitizer-based periodontal dressing on P.gingivalis (1.25 μM). The results showed that under photoelectric stimulation, at a concentration of 1.25 μM, the aggregation-induced luminescence photosensitizer-based periodontal dressing showed a certain inhibitory activity on Porphyromonas gingivalis. It can be seen that the aggregation-induced luminescence photosensitizer-based periodontal dressing involved in the present invention has a strong antibacterial activity against Porphyromonas gingivalis and has a potential use for preparing medical dressings for photodynamic therapy.

[0067] Specifically, Figure 2 The results showed that the material had a good effect in generating reactive oxygen species in vitro. Both the results of total reactive oxygen species generation and singlet oxygen showed that the material had good photodynamic therapy potential. Figure 3 The results showed that after 3 minutes of low-power white light irradiation, the material showed a significant inhibitory effect on Porphyromonas gingivalis, with an inhibition rate of more than 95%. The prepared dressing also showed a gelling effect, and the gel loaded with compound 4 had a good thermosensitive effect. After gelling at 37°C, it could be injected into the rat periodontal pocket through a syringe for photodynamic therapy.

[0068] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many modifications without departing from the scope of protection of the present invention and the claims, all of which belong to the scope of protection of the present invention.

Claims

1. An aggregation-induced emission photosensitizer, characterized in that: The aggregation-induced emission photosensitizer has the structure shown below: Wherein, E is selected from one of O, S and Se, and R1 and R2 are selected from ， R3 is selected from R4 is one of Cl, Br, I or PF6.

2. A method for preparing the aggregation-induced emission photosensitizer according to claim 1, characterized in that: The following steps are involved: Compound 1 is reacted with a boronic acid having an R1 substituent to obtain compound 2 through a Suzukii coupling reaction; Compound 2 is reacted with a boronic acid having an R2 substituent to obtain compound 3 through Suzukii coupling reaction; Compound 3 is reacted with a nitrile reagent having an R3 substituent to obtain a crude product, which is then separated by column chromatography to obtain the aggregation-induced luminescence photosensitizer; Among them, the structural formulas of compounds 1, 2 and 3 are as follows: Wherein, E is selected from one of O, S and Se, and R1 and R2 are selected from ， R3 is selected from R4 is one of Cl, Br, I or PF6.

3. Use of the aggregation-induced emission photosensitizer according to claim 1 in the preparation of a periodontal dressing for periodontitis infection.

4. The use according to claim 3, characterized in that The periodontitis infection is Porphyromonas gingivalis infection.

5. The use according to claim 3, characterized in that The aggregation-induced emission photosensitizer is loaded into an injectable thermosensitive hydrogel.

6. Use of the aggregation-induced emission photosensitizer according to claim 1 in the preparation of drugs for photodynamic therapy.

7. The drug according to claim 6, characterized in that The drug is used for inhibiting Porphyromonas gingivalis.

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