An aggregation-induced emission photosensitizer, and a preparation method and application thereof

Abstract

The application is based on benzothiadiazole, and a novel structure of an aggregation-induced emission photosensitizer is designed and synthesized, which has the following advantages: the cationic skeleton endows the cationic characteristics, such as the generation of stable cationic free radicals under light; the introduction of oxygen family elements into the molecular skeleton improves the absorption of the molecule in the visible light region, and also promotes the generation of active oxygen family; the periodontal dressing prepared based on the above-mentioned aggregation-induced emission photosensitizer has the gel form, which is easy to be used as a medical dressing, and the temperature-sensitive injectable is convenient for periodontitis treatment, so it is a kind of parent material with great development potential of photodynamic periodontitis treatment dressing; when the parent material is applied, the gingival porphyromonas has significant inhibitory activity under light, and has great potential as a medical dressing for photodynamic treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aggregation-induced emission photosensitizer, in particular to an aggregation-induced emission photosensitizer, a preparation method thereof and application of the preparation method in preparing injectable periodontal dressings. BACKGROUND

[0002] Periodontitis is a very common bacterial infectious disease in the oral cavity, and is considered to be the sixth most prevalent disease in the world. It is reported that the prevalence of periodontitis in developed countries is about 20-50%. The direct treatment cost of periodontal disease worldwide is about 298 billion US dollars per year, accounting for 4.6% of the average global health expenditure, which has caused a great burden of 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 is also rising. In view of 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 broad-spectrum antibacterial effect, little damage to normal tissues, high efficiency and difficulty in developing drug resistance, and has attracted more and more attention from scholars in recent years, and has been successfully applied to the treatment of periodontitis, and has achieved remarkable results.

[0003] Currently reported small organic molecule photosensitizers, such as porphyrin, methylene blue, BODIPY, have weak light absorption ability, poor anti-photobleaching ability, and harmfulness to healthy tissues, and have poor treatment effect.

[0004] Therefore, there is a need for a new solution. SUMMARY

[0005] The technical scheme adopted by the present application to solve its technical problems is to provide an aggregation-induced emission photosensitizer, which has the following structure:

[0006]

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

[0008]

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

[0010] The present application also provides a preparation method of the aggregation-induced emission photosensitizer, which comprises the following steps:

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

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

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

[0014] Compound 1, 2 and 3 have the following structural formulas, respectively:

[0015]

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

[0017]

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

[0019] The application further provides a use of the aggregation-induced emission photosensitizer in the preparation of a periodontal dressing for periodontitis infection.

[0020] In the use provided by the application, the periodontitis infection is a Porphyromonas gingivalis infection.

[0021] In the use provided by the application, the aggregation-induced emission photosensitizer is loaded in an injectable temperature-sensitive hydrogel

[0022] The application further provides a use of the aggregation-induced emission photosensitizer in the preparation of a medicament for photodynamic therapy.

[0023] In the use provided by the application, the medicament is used for inhibiting Porphyromonas gingivalis.

[0024] The application has the following beneficial effects:

[0025] The application designs and synthesizes a novel aggregation-induced emission photosensitizer based on benzothiadiazole, which has the following advantages: the cationic skeleton endows it with cationic characteristics, such as easy generation of stable cationic free radicals under light; the introduction of oxygen family 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 emission photosensitizer has a gel form which is easy to use as a medical dressing, and is temperature-sensitive and injectable, which is convenient for periodontitis treatment, and therefore, is a kind of mother substance with great development potential for photodynamic periodontitis treatment dressing; when it is applied, it has significant inhibitory activity on Porphyromonas gingivalis under light, and great potential for photodynamic therapy as a medical dressing. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on the provided drawings belong to the protection scope of the present application.

[0027] Figure 1 The synthesis route of the aggregation-induced emission photosensitizer provided by the present application is shown;

[0028] Figure 2 The active oxygen generation diagram of the present application is shown; 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 application under different conditions is shown; wherein a is the antibacterial activity coating result diagram, and b is the antibacterial activity statistical diagram;

[0030] Figure 4 The periodontal dressing display diagram of the present application and the rat photodynamic periodontitis treatment diagram are shown. DETAILED DESCRIPTION

[0031] In order to have a more clear understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments only represent some of the embodiments of the present application, but not all the embodiments. Based on the embodiments described in the present specification, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0032] The present application designs and synthesizes a new structure of aggregation-induced emission photosensitizer based on benzothiadiazole, and prepares a new type of aggregation-induced emission photosensitizer periodontal dressing based on the compound, and for the first time finds that the periodontal dressing has significant inhibitory activity on Porphyromonas gingivalis, and has the potential as an effective photodynamic therapy medical dressing.

[0033] Based on this, the present application improves an aggregation-induced emission photosensitizer, which has the following structure:

[0034]

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

[0036]

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

[0038] Meanwhile, the preparation method of the above-mentioned aggregation-induced emission photosensitizer is also provided, the synthetic route thereof is as shown in the figure, comprising the following steps: Figure 1

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

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

[0041] Compound 3 is reacted with a nitrile reagent with R3 substituent to obtain a crude product, and then the crude product is separated through column chromatography to prepare the aggregation-induced emission photosensitizer;

[0042] The structural formulae of compounds 1, 2 and 3 are as follows, respectively:

[0043]

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

[0045]

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

[0047] The prepared compound is loaded in injectable temperature-sensitive hydrogel to obtain a novel gel material with a photodynamic therapy effect.

[0048] The above-mentioned compound is subjected to antibacterial activity evaluation through in-vitro bacteriostatic activity test. The periodontal dressing of the aggregation-induced emission photosensitizer involved in the present application has obvious inhibitory activity on Porphyromonas gingivalis, and has great potential as an antibacterial medical dressing for photodynamic therapy. The application of the periodontal dressing as a preparation of antibacterial medical dressing has significant inhibitory activity on Porphyromonas gingivalis.

[0049] Example 1 Preparation of aggregation-induced emission photosensitizer

[0050] ​A 500 mL two-necked round bottom flask was charged with 4,7-dibromo-5,6-difluorobenzo[c][l,2,5]thiadiazole (4.5 mmol), boronic acid with different substituent R1(4.5 mmol), potassium carbonate (18 mmol) and tetrakis triphenylphosphine palladium (0.17 mmol), 150 mL of distilled toluene and 50 mL of water were added. The mixture was then heated under reflux for 10 h 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, compound 2 was purified by column chromatography on silica gel and compound 3 was obtained by following the above procedure. Sodium hydride (2 mmol) was dissolved in dry N,N-dimethylformamide and R3(1 mmol) was added at 0°C for 30 min, then carbon disulfide (2 mmol) was added and the reaction was carried out at room temperature for 2 h. 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, compound 4 was purified by column chromatography on silica gel.

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

[0052] Compound 4: yield 23%, solid powder. 1 H NMR (600 MHz, MeOD): δ 8.76-8.74 (d, 2H), 8.23-8.21 (d, 2H), 7.97-7.93 (q, 4H), 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 (150 MHz, DMSO-d6): δ 193.6, 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 an aggregation-induced emission photosensitizer-based periodontal dressing

[0054] Add 300 mg PLGA-PEG-PLGA block polymer into 2 mL deionized water, stir at room temperature until the polymer is uniformly dispersed in water to form a relatively viscous transparent milky white liquid. Compound 4 is dissolved in dimethyl sulfoxide and diluted with the polymer solution to 1 uM for storage at 4°C refrigerator. Before use, the syringe is taken out and placed in a 37°C incubator for 15 minutes after gelling, and further tested.

[0055] Example 3 Anti-bacterial activity of the aggregation-induced emission photosensitizer-based periodontal dressing

[0056] 1. Test bacteria:

[0057] P. gingivalis.

[0058] 2. Sample preparation:

[0059] Accurately weigh a certain mass of the test compound in a centrifuge tube, add 1 mL of sterile water to prepare a 1 umol / L drug solution. Use 0.9% NaCl as a blank control.

[0060] 3. Preparation of solid culture medium:

[0061] Trypsin soy broth, add yeast extract (5 g / L -1 ), l-cysteine (0.5 g / L -1) , vitamin K1 (1 mg / L -1 ), hemin (5 mg / L -1 ), agar powder (15 g / L -1 ) and 5% non-fiber sheep blood, adjust the pH to 7.3.

[0062] 4. Determination of anti-bacterial activity:

[0063] The anti-bacterial activity was determined by plate colony counting method. 10 9 CPU / mL of bacterial solution was mixed and coated on the solid culture medium, the aggregation-induced emission photosensitizer-based periodontal dressing was attached to the culture medium and irradiated under white light (50 mW / cm 2 ) for 3 minutes, and then placed in a 37°C anaerobic constant temperature and humidity incubator for culture. Each treatment was repeated three times. After 16 h of culture, the number of colonies was counted, and the inhibition rate of each test compound was calculated according to the following formula.

[0064]

[0065] C is the number of colonies in the test group; C0is the number of colonies in the blank control group.

[0066] The test results are shown in Figures 2 to 4The inhibition activity of the aggregation-induced emission photosensitizer periodontal dressing on P.gingivalis (1.25 μM) is obtained. The results show that the aggregation-induced emission photosensitizer periodontal dressing has certain inhibition activity on P.gingivalis under photoelectric stimulation at a concentration of 1.25 μM. It can be seen that the aggregation-induced emission photosensitizer periodontal dressing has strong antibacterial activity on P.gingivalis, and has potential use for preparing medical dressings for photodynamic therapy.

[0067] Specifically, Figure 2 The results show that the material has good active oxygen production effect in vitro, whether it is total active oxygen production or singlet oxygen. The results show that the material has good photodynamic therapy potential. Figure 3 The results show that after 3 minutes of low-power white light irradiation, the material exhibits significant inhibition effect on P.gingivalis, and the inhibition rate is more than 95%. The prepared dressing also has good gelation effect. The gel loaded with compound 4 has good temperature sensitivity effect, and can be injected into the rat periodontal pocket for photodynamic therapy through a syringe after gelation at 37℃.

[0068] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative but not restrictive. Those skilled in the art can make many modifications under the guidance of the present application without departing from the purpose of the present application and the scope protected by the claims, and these all belong to the protection scope of the present application.

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, 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 through a Suzukii coupling reaction to obtain compound 2; Compound 2 is reacted with a boronic acid having an R2 substituent through a Suzukii coupling reaction to obtain compound 3; Compound 3 is reacted with a nitrile reagent having an R3 substituent and carbon disulfide to obtain a crude product, which is then separated by column chromatography to obtain the aggregation-induced emission 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, 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 a drug 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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