A near-infrared second-zone photosensitizer based on aza-fluoroborane dipyrrole, and preparation method and application thereof

Abstract

The present invention provides a near-infrared second-zone photosensitizer based on aza-fluoroboron dipyrrole, a preparation method and an application, and belongs to the technical field of photosensitizers. It utilizes the properties of Aza-BODIPY dyes, replaces the boron atoms in the parent with oxygen atoms, further increases the conjugated area of ​​the dye molecules and the flow of internal electrons, enhances the intersystem crossing ability of the molecules, and enables the molecules to have a PDT effect. At the same time, electron-donating groups (thiophene carbon chains) are introduced on the 2nd and 6th carbon atoms to enhance the vibrational relaxation of the photosensitizer molecules, enhance the ability of photothermal conversion, and enable them to have a PTT effect. Based on this, the designed Aza-BODIPY-like molecules have both photothermal and photodynamic properties, and can be used for phototherapy of tumor tissues.

Description

Technical Field

[0001] The present invention belongs to the technical field of photosensitizers, and particularly relates to a near-infrared II region photosensitizer based on azadipyrromethene boron difluoride, a preparation method thereof, and an application thereof. Background Art

[0002] As one of the advanced precision medicine means in tumor treatment, photodiagnosis and therapy has received extensive attention due to the comprehensive advantages of non-invasive real-time diagnosis and in-situ treatment triggered by light. Photothermal therapy (PTT) and photodynamic therapy (PDT) rely on photosensitizers (PS) to generate high temperature and reactive oxygen species respectively under the irradiation of light with a specific wavelength, and induce the death of tumor cells in a convenient and controllable manner. However, the single treatment method limits the treatment effect; the poor oxygenation and light transmittance in the tumor area result in poor PDT effect, while the overexpression of heat shock proteins (HSPs) will protect tumor cells from the thermal effect, leading to treatment failure and tumor recurrence. The combination of PDT and PTT can not only complement each other's disadvantages, but also achieve a synergistic effect in hypoxic tumors. The heat generated by PTT can promote oxygen perfusion and the penetration of nanoparticles into tumors, which is beneficial to the effective development of PDT. The reactive oxygen species (ROS), especially hydroxyl radicals, generated by type I PDT can inhibit the expression of HSPs induced by PTT and improve the treatment effect.

[0003] However, the short wavelength and low light energy of ultraviolet and visible light (200 - 600 nm) limit its application in photodiagnosis and therapy. Near-infrared II region (1000 - 1400 nm) dye molecules have great potential in biological applications due to their deep tissue penetration and high light energy. However, it is difficult to achieve synergistic photothermal and photodynamic therapy in the near-infrared II region. The reason is that the energy level bandgap of near-infrared II region dye molecules is relatively narrow, and the energy in the excited state is mainly generated as heat in a non-radiative form. It is difficult for energy to reach the T energy state of the dye molecule through intersystem crossing to generate energy transfer with the substrate or oxygen to produce ROS.

[0004] Therefore, there is a high demand for designing and inventing NIR-II PS with strong photothermal conversion efficiency and type I PDT for tumor ablation. Summary of the Invention

[0005] In order to overcome the disadvantages of the above-mentioned prior art, the object of the present invention is to provide a near-infrared second-region photosensitizer based on azadipyrromethene boron difluoride, its preparation method and application. By reasonably designing the molecular structure of the BODIPY-based dye molecule, the efficiency of intersystem crossing of the molecule is improved, so that the excited-state energy undergoes a rapid transition to the T state, generating effective ROS for effective PDT tumor treatment.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a near-infrared second-region photosensitizer based on azadipyrromethene boron difluoride, and the structural formula of the photosensitizer is as follows:

[0008] 。

[0009] The present invention provides a preparation method of the near-infrared second-region photosensitizer based on azadipyrromethene boron difluoride, comprising the following steps:

[0010] S1: Phosphorus oxychloride is added to N,N-dimethylformamide under an ice-salt bath condition to obtain a solution, and after stirring until a white solid is formed, a N,N-dimethylformamide solution of julolidine is added thereto and stirred, and then heated for the first reaction to obtain intermediate product I. Intermediate product I is poured into ice water and stirred until crystals are produced, and then the pH value is adjusted, and after suction filtration, intermediate product II is obtained;

[0011] S2: Intermediate product II, 2'-hydroxy-4'-methoxyacetophenone and ethanol are mixed, and then nitromethane is added, and the mixture is heated under reflux for the second reaction to obtain intermediate product III. Intermediate product III is poured into ice water to quench the reaction, and then extracted, dried, filtered, rotary evaporated and concentrated and purified to obtain intermediate product IV;

[0012] S3: Intermediate product IV is mixed with absolute ethanol, and under a protective gas, N,N-diisopropylethylamine and nitromethane are added, and the mixture is heated under reflux for the third reaction to obtain intermediate product V. Intermediate product V is poured into ice water to quench the reaction, and then extracted, dried, filtered, rotary evaporated and concentrated and purified to obtain intermediate product VI;

[0013] S4: Intermediate product VI, n-butanol and ammonium acetate are mixed and heated under reflux for the fourth reaction. After the fourth reaction is completed, suction filtration is carried out to obtain intermediate product VII;

[0014] S5: Intermediate product VII, dry dichloromethane and N,N-diisopropylethylamine are mixed, and under a protective gas, boron trifluoride diethyl etherate is added, and the mixture is reacted under light protection at room temperature for the fifth reaction to obtain intermediate product VIII. Intermediate product VIII is poured into saturated sodium chloride aqueous solution to quench the reaction, and then extracted, dried, filtered, rotary evaporated and concentrated and purified to obtain intermediate product OB;

[0015] S6: After mixing the intermediate product OB and dry dichloromethane, add N-bromosuccinimide dissolved in dry dichloromethane, and carry out the sixth reaction at room temperature in the dark to obtain the intermediate product IX. The intermediate product IX is concentrated and purified by rotary evaporation to obtain the intermediate product OB-2Br;

[0016] S7: The intermediate product OB-2Br, 2-(tributyltinyl)thiophene, tri(2-methylphenyl)phosphine, bis(dibenzylideneacetone)palladium and toluene were replaced for a set number of times under protective gas, and then heated for the seventh reaction. The solution after the reaction was concentrated and purified by rotary evaporation to obtain the near-infrared zone II photosensitizer OB5.

[0017] In the specific implementation process, the nano-processing step of the near-infrared zone II photosensitizer is also included:

[0018] S21: Dissolve the near-infrared zone II photosensitizer OB5 in tetrahydrofuran to obtain a mixed solution;

[0019] S22: Add the mixed solution to DSPE-PEG 5000 The solution was dissolved by ultrasonic and then placed at a set speed. After the treatment, it was filtered and centrifuged to obtain the nano-near infrared zone II photosensitizer OB5@NPs.

[0020] In the specific implementation process, in S1, the volume ratio of phosphorus oxychloride to N,N-dimethylformamide in the solution is 4.5:3.75; the temperature of the first reaction is 85-95°C, the time of the first reaction is 3-5h; the pH value is 7.

[0021] In the specific implementation process, in S2, the molar ratio of the intermediate product II, 2'-hydroxy-4'-methoxyacetophenone and nitromethane is 1:1:1.5; the temperature of the second reaction is 75-80°C, and the time of the second reaction is 12-24h.

[0022] In the specific implementation process, in S3, the molar ratio of the intermediate product IV to N,N-diisopropylethylamine is 1:5; the temperature of the third reaction is 85-95°C, and the time of the third reaction is 36-48h.

[0023] In the specific implementation process, in S4, the molar ratio of the intermediate product VI to ammonium acetate is 1:10; the temperature of the fourth reaction is 110-120°C, and the time of the fourth reaction is 3-5h.

[0024] In the specific implementation process, in S5, the molar ratio of the intermediate product VII, N,N-diisopropylethylamine and boron trifluoride etherate is 1:10:15. ​​

[0025] In the specific implementation process, in S6, the molar ratio of the intermediate OB to N-bromosuccinimide is 1:2.2; in S7, the molar ratio of the intermediate OB-2Br to tris(2-methylphenyl)phosphine is 1:1.5; the temperature of the seventh reaction is 95-105 °C, and the time of the seventh reaction is 12-24 h.

[0026] The present invention also provides an application of the near-infrared second-region photosensitizer based on azaboron dipyrrole in the preparation of photothermal therapy drugs.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention provides a near-infrared second-region photosensitizer based on azaboron dipyrrole. By utilizing the properties of Aza-BODIPY dyes, the boron atom in the parent body is replaced with an oxygen atom, further increasing the conjugated area of the dye molecule and the flow of internal electrons, enhancing the intersystem crossing ability of the molecule, and enabling the molecule to have a PDT effect; at the same time, an electron-donating group (thiophene carbon chain) is introduced at the 2,6-carbon atoms to enhance the vibrational relaxation of the photosensitizer molecule and the ability of photothermal conversion, making it have a PTT effect. The designed Aza-BODIPY-like molecule has both photothermal and photodynamic properties and can be used for the phototherapy of tumor tissues.

[0029] Furthermore, the emission peak of the emission spectrum of the photosensitizer of the present invention is in the near-infrared second region and has excellent photothermal conversion efficiency (45.4%) and strong intersystem crossing ability (ΔE st , S 1 -T 1， 0.084 eV). The photosensitizer can be used for photothermal and photodynamic therapy, effectively ablating subcutaneous tumors in mice and differentially expressing heat shock proteins in the tumor site.

[0030] Furthermore, the photosensitizer has good biocompatibility after being complexed with DSPE-PEG 5000 , has small toxic and side effects on organisms, can be biodegraded, and has certain potential for biological applications.

[0031] Furthermore, azaboron dipyrrole (Aza-BODIPY) is a class of BODIPY analogs in which the 8-carbon atom in the BODIPY dye family is replaced by a nitrogen atom. The main peak of the emission spectrum of Aza-BODIPY is located in the near-infrared second region, has a deep tissue penetration depth and a large molar extinction coefficient, and is an excellent photosensitizer for PTT and PDT. Description of the Drawings

[0032] Figure 1Structural formula and photophysical property test diagrams of the photosensitizer molecule OB5 of the present invention. Among them, Figure (a) is a schematic diagram of the spatial configuration and HOMO-LUMO energy level bandgap of the photosensitizer molecule OB5 determined by time-dependent density function theory (TD-DFT); Figure (b) is an energy level diagram of OB5; Figure (c) is an ultraviolet-visible-near-infrared absorption (UV-vis-NIR) spectrum diagram of the photosensitizer molecule in different solvents; Figure (d) is a single-photon emission (FL) spectrum diagram of the photosensitizer molecule in different solvents; Figure (e) is a photostability test diagram of the photosensitizer molecule.

[0033] Figure 2 Photophysical property test diagrams of the nanosized photosensitizer molecule OB5@NPs of the present invention. Among them, Figure (a) is a schematic diagram of the morphology and size of OB5@NPs; Figure (b) is a comparison diagram of the UV-vis-NIR spectrum and single-photon emission (FL) spectrum of OB5@NPs; Figure (c) is a concentration-dependent test diagram of the photothermal performance of OB5@NPs; Figure (d) is a schematic diagram of the photothermal conversion efficiency of OB5@NPs; Figure (e) is a schematic diagram of the ability of OB5@NPs to generate ROS; Figure (f) is a quantification diagram of the ROS generated by OB5@NPs;

[0034] Figure 3 In vitro cell experiment diagrams of OB5@NPs of the present invention; Figure (a) is a test diagram of the photothermal stability of OB5@NPs; Figure (b) is a time stability test diagram of the solution of OB5@NPs; Figure (c) is a comparison diagram of the viability of HeLa cells before and after laser irradiation treatment; Figure (d) is a schematic diagram of the cell viability and death staining of HeLa cells after treatment with OB5@NPs; Figure (e) is a quantification diagram of Figure (d); Figure (f) is a cell apoptosis diagram of HeLa cells after treatment with OB5@NPs+Laser; Figure (g) is a quantification diagram of Figure (f); Figures (h) and (i) are schematic diagrams of the cell cycle of HeLa cells after treatment with OB5@NPs+Laser.

[0035] Figure 4 In vivo animal experiment diagrams of OB5@NPs of the present invention; Figure (a) is a schematic diagram of the tumor ablation of mice injected with OB5@NPs via the tail vein; Figure (b) is a schematic diagram of the tumor mass of each group of mice; Figure (c) is a schematic diagram of the pathological effects of the internal organs and tumor sites of mice injected with OB5@NPs via the tail vein; Figure (d) is a schematic diagram of the expression of HSP protein in the tumor tissue of mice injected with OB5@NPs via the tail vein;

[0036] Figure 5 Structural formula of the near-infrared second-region photosensitizer OB5 of the present invention;

[0037] Figure 6 Schematic diagram of the preparation method of the near-infrared second-region photosensitizer OB5 of Example 1 of the present invention. Detailed implementation manners

[0038] To enable those skilled in the art to understand the characteristics and effects of the present invention, the following provides a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art regarding the present invention. In case of conflict, the definition in this specification shall prevail.

[0039] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not in any way limit the scope of the present invention, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0040] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual values within the range (including integers and fractions).

[0041] In this article, unless otherwise specified, "comprising", "including", "containing", "having" or similar terms cover the meanings of "consisting of" and "mainly consisting of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A only comprises a".

[0042] In this article, for the sake of concise description, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as the scope described in this specification.

[0043] The present invention provides a near-infrared second-region photosensitizer based on azadipyrromethene boron difluoride, a preparation method thereof, and an application thereof.

[0044] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0045] In the following examples, conventional instruments and equipment in the art are used. For the experimental methods without specific conditions noted in the following examples, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. In the following examples, various raw materials are used. Unless otherwise stated, commercially available products are used, and their specifications are the conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0046] The present application provides a method for preparing a near-infrared second-region photosensitizer based on azadifluoroboron dipyrrole, comprising the following steps:

[0047] Step 1: Phosphorus oxychloride (POCl 3 ) was slowly added dropwise to a 100 mL round-bottom flask containing N,N-dimethylformamide (DMF) under an ice-salt bath condition. The volume ratio of phosphorus oxychloride to N,N-dimethylformamide was 4.5:3.75. After the addition was completed, stirring was continued for half an hour until a white solid was formed. Then, a DMF solution of julolidine was slowly added dropwise thereto. After the addition was completed, stirring was continued at room temperature for half an hour. Subsequently, the water bath was removed and the temperature was raised to 85-95 °C. After reacting for 3-5 h, intermediate product I was obtained. The reaction solvent was poured into 200 mL of ice water and stirred for half an hour until a large amount of crystals were produced. The pH of the solution was adjusted to 7, and suction filtration was carried out to finally obtain a light yellow solid intermediate product II.

[0048] Step 2: Intermediate product II (1.0 equiv.), 2'-hydroxy-4'-methoxyacetophenone (1.0 equiv.), and ethanol (100 mL) were added to a 250 mL round-bottom flask. Nitromethane (1.5 equiv.) was added thereto. The mixture was refluxed at 75-80 °C for 12-24 h to obtain intermediate product III. Finally, the reaction solution was poured into ice water to quench the reaction, and it was extracted 3 times with dichloromethane. Then, anhydrous sodium sulfate was added for drying, filtration, rotary evaporation and concentration, and column chromatography purification. Finally, a red solid intermediate product IV was obtained. The molar ratio of the above intermediate product II, 2'-hydroxy-4'-methoxyacetophenone to nitromethane was 1:1:1.5.

[0049] Step 3: Add the intermediate Ⅳ (1 equiv.) to 50 mL of anhydrous ethanol in a 250 mL two-necked flask. Under nitrogen protection, add N,N-diisopropylethylamine (DIPEA, 5 equiv.) and nitromethane (10 mL). Stir and heat under reflux at 85 - 95 °C for 36 - 48 h to obtain the intermediate Ⅴ. Pour the reaction solution into ice water to quench the reaction. Extract with dichloromethane three times, then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography. Finally, a yellow solid intermediate Ⅵ is obtained. The molar ratio of the above intermediate Ⅳ to N,N-diisopropylethylamine is 1:5.

[0050] Step 4: Add the intermediate Ⅵ (1 equiv.), n-butanol (20 mL), and ammonium acetate (10 equiv.) to a 25 mL round-bottom flask. Stir and reflux at 110 - 120 °C for 3 - 5 h, and then filter to obtain the blue-black solid intermediate Ⅶ. The molar ratio of the above intermediate Ⅵ to ammonium acetate is 1:10.

[0051] Step 5, Preparation of OB: Add the intermediate Ⅶ (1 equiv.), dry dichloromethane, and DIPEA (10.0 equiv.) to a 25 mL two-necked flask. Under N 2 protection, slowly add BF 3 .Et 2 O (15 equiv.). React under light protection at room temperature for 24 h to obtain the intermediate Ⅷ. Pour the reacted substance into a saturated sodium chloride aqueous solution to quench the reaction, and then extract with dichloromethane. Then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography. Finally, a black-green solid intermediate OB is obtained. The molar ratio of the above intermediate Ⅶ, N,N-diisopropylethylamine to boron trifluoride diethyl etherate is 1:10:15.

[0052] Step 6, Preparation of OB-2Br: Add OB (1 equiv.), dry dichloromethane (10 mL) to a 50 mL round-bottom flask. Slowly add N-bromosuccinimide (NBS, 2.2 equiv.) dissolved in dry dichloromethane (10 mL). React under light protection at room temperature for 1 h to obtain the intermediate Ⅸ. Concentrate the reacted substance by rotary evaporation and purify by column chromatography. Finally, a blue-green solid OB-2Br is obtained. The molar ratio of the intermediate OB to N-bromosuccinimide is 1:2.2.

[0053] Step 7, Preparation of OB5: Add the compound OB-2Br (1 equiv.), 2-(tributylstannyl)thiophene (200 )), tris(2-methylphenyl)phosphine (1.5 equiv.), and bis(dibenzylideneacetone)palladium Pd(dba)2 (10 mg), toluene (15 mL), and the protective gas N 2 was replaced three times under an atmosphere, and then the reaction was heated to 95 - 105 °C for 12 - 24 h. The reaction solution was concentrated by rotary evaporation and purified by column chromatography, and finally a blue-green solid near-infrared second-region photosensitizer OB5 was obtained.

[0054] Step eight, preparation of OB5@NPs: Weigh OB5 and dissolve it in tetrahydrofuran (THF), and then add it to the DSPE-PEG 5000 aqueous solution, dissolve it by ultrasonic treatment, treat it overnight at 500 rpm, filter, and after centrifugation, obtain OB5@NPs, and measure the concentration of the OB5@NPs aqueous solution by the absorbance method.

[0055] This application also provides the near-infrared second-region photosensitizer OB5 prepared by the above preparation method, and the structural formula is as follows:

[0056] .

[0057] Application of the near-infrared second-region photosensitizer prepared by the above preparation method in the preparation of photothermal therapy drugs. Specifically, when applying, the near-infrared second-region photosensitizer OB5 is nano-sized to generate OB5@NPs for application in the field of tumor tissue phototherapy technology.

[0058] As Figure 3 shown, Figure 3In vitro cell experiment images of OB5@NPs. As shown in Fig. (a) of the photothermal stability of OB5@NPs, the maximum temperature increase of the nanoparticles remained basically unchanged within 5 heating and cooling cycles; as shown in Fig. (b) of the time stability of the OB5@NPs solution, the particle size of OB5@NPs remained unchanged within 15 days, showing good time stability and being conducive to long-term storage; Fig. (c) shows the viability of HeLa cells before and after laser irradiation treatment, indicating that OB5@NPs has low dark toxicity and strong phototoxicity; Fig. (d) shows the live / dead cell staining of HeLa cells after treatment with OB5@NPs. Green represents live cells and red represents dead cells. It can be seen from the figure that more cells died in the OB5@NPs+Laser group (1: PBS+Laser, 2: OB5@NPs, 3: OB5@NPs+Laser); Fig. (e) is the quantification graph of (d). It can be seen from the figure that there is a significant difference between group 1 and group 3 ****P<0.0001; Fig. (f) shows the apoptosis of HeLa cells after treatment with OB5@NPs+Laser. It can be seen from the figure that apoptosis of HeLa cells was successfully induced after laser irradiation of OB5@NPs; Fig. (g) is the quantification graph of (f). It can be seen from the figure that there is a significant difference between group 1 and group 3 ****P<0.0001; Figs. (h, i) show the cell cycle of HeLa cells after treatment with OB5@NPs+Laser. It can be seen from the figure that OB5@NPs+Laser induced changes in the cell cycle of HeLa cells, and the cell cycle was arrested at the G2 / M phase.

[0059] As Figure 4 shown, Figure 4 Fig. (a) in shows the tumor ablation of mice injected with OB5@NPs via the tail vein. Laser irradiation treatment was performed on the tumor site of the mice on the second day after tail vein injection, once every other day for a total of 5 times. On the 14th day, the tumors of the mice were dissected. It can be seen from the figure that the tumors of the mice in the OB5@NPs+Laser group were smaller and even ablated; Fig. (b) shows the tumor masses of the mice in each group. It can be seen from the figure that the tumor mass in the OB5@NPs+Laser group was significantly lower than that in the PBS+Laser group, indicating that it had an inhibitory effect on tumor growth; (c) shows the pathological effects of the internal organs and tumor sites of the mice injected with OB5@NPs via the tail vein. As shown in the figure, there was no significant difference in the heart, liver, pancreas, lungs, and kidneys between the OB5@NPs+Laser group and the PBS+Laser group, indicating that OB5@NPs did not cause damage to other tissues of the mice under laser irradiation. However, compared with the tumor site, the number of cell nuclei in the OB5@NPs+Laser group decreased, the cell gap became larger, showing the characteristics of large-area necrosis, which was consistent with the result of the smaller tumor volume; Fig. (d) shows the expression of HSP proteins in the tumor tissues of the mice injected with OB5@NPs via the tail vein. It can be seen from the figure that the OB5@NPs+Laser group induced the high expression of HSP40.

[0060] Example 1

[0061] Step 1: Slowly add POCl 3 (4.5 mL) dropwise to a 100 mL round-bottom flask containing N,N-dimethylformamide (DMF, 3.75 mL) under an ice-salt bath condition. After the addition is complete, continue stirring for half an hour until a white solid is formed. Then slowly add a DMF solution of julolidine (3 g, 17.3 mmol) to it. After the addition is complete, continue stirring at room temperature for half an hour. Subsequently, remove the water bath and heat to 90 °C. After reacting for 4 hours, pour the reaction solvent into 200 mL of ice water and stir for half an hour until a large amount of crystals are produced. Adjust the pH of the solution to 7, and finally obtain a light yellow solid by suction filtration (yield: 98%). 1 HNMR (400 MHz, CDCl 3 ) δ / ppm: 9.61 (s, 1H), 7.31 (s, 2H), 3.36 – 3.25 (m, 4H),2.78 (t, J = 6.3 Hz, 4H), 1.99 (dt, J = 12.4, 6.1 Hz, 4H).

[0062] Step 2: Add the above product (4.54 g, 27 mmol, 1.0 equiv.), 2'-hydroxy-4'-methoxyacetophenone (5 g, 25 mmol, 1.0 equiv.), and ethanol (100 mL) to a 250 mL round-bottom flask. Add nitromethane (2.5 g, 36.7 mmol, 1.5 equiv.) to it. Reflux at 78 °C for 24 hours. Finally, pour the reaction solution into ice water to quench the reaction. Extract it 3 times with dichloromethane, then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography. Finally, obtain a red solid (yield: 85%). 1 H NMR (400 MHz, CDCl 3 ) δ / ppm: 13.91 (s, 1H), 7.81(dd, J = 18.9, 12.4 Hz, 2H), 7.52 – 7.18 (m, 1H), 7.12 (s, 2H), 6.61 – 6.24 (m,2H), 3.84 (s, 3H), 3.45 – 3.11 (m, 4H), 2.76 (t, J = 6.3 Hz, 4H), 1.97 (dt, J =12.0, 6.1 Hz, 4H). 1313C NMR (100 MHz, CDCl 3 ) δ / ppm: 190 (s), 166.43 (s), 165 (s), 145.95 (s), 145 (s), 130.87 (s), 128.40 (s), 121 (s), 121.02 (s), 114.14 (s), 113.28 (s), 107.22 (s), 101.00 (s), 55.51 (s), 49.98 (s), 7.70 (s), 21.53 (s).

[0063] Step 3: Add the above product (3 g, 8.5 mmol, 1 equiv.) to 50 mL of anhydrous ethanol in a 250 mL two-necked flask. Under nitrogen protection, add N,N-diisopropylethylamine (DIPEA, 3 mL, 44 mmol, 5 equiv.) and nitromethane (10 mL). Stir and heat under reflux at 90 °C for 48 hours. Pour the reaction solution into ice water to quench the reaction. Extract with dichloromethane three times, then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography. Finally, obtain a yellow solid (yield: 62%). 1 1H NMR (400 MHz, CDCl 3 ) δ / ppm: 12.57 (s, 1H), 7.62 (d, J = 8.8 Hz, 1H), 6.64 (s, 2H), 6.42 (dt, J = 7.4, 2.4 Hz, 2H), 4.71 (dd, J = 12.3, 7.0 Hz, 1H), 4.59 (dd, J = 12.3, 7.7 Hz, 1H), 4.03 - 3.92 (m, 1H), 3.83 (s, 3H), 3.30 (ddd, J = 24.8, 17.1, 7.0 Hz, 3H), 3.13 - 3.08 (m, 4H), 2.71 (t, J = 6.5 Hz, 4H), 2.00 - 1.85 (m, 5H). 13 13C NMR (100 MHz, CDCl 3) δ / ppm: 201.35 (s), 166.27 (s), 165.46 (s), 142.52 (s), 131.37 (s), 125.32 (s), 121.81 (s), 113.42 (s), 107.91 (s), 100.98 (s), 80.07 (s), 55.64 (s), 49.87 (s), 41.13 (s), 38.68 (s), 27.68 (s), 21.92 (s).

[0064] Step 4: Add the above product (40 mg, 1 mmol, 1 equiv.), n-butanol (20 mL), and ammonium acetate (0.77 g, 10 mmol, 10 equiv.) to a 25 mL round-bottom flask, stir and reflux at 115 °C for 4 hours, and then perform suction filtration to obtain a blue-black solid (yield: 68%). 1 H NMR (400 MHz, CDCl 3 ) δ / ppm: 7.68 (s, 1H), 7.37 (d, J = 8.8 Hz, 1H), 7.02 (s, 1H), 6.24 (s, 1H), 6.10 (d, J = 8.5 Hz, 1H), 3.31 (s, 1H), 3.28 - 3.19 (m, 2H), 2.78 (t, J = 6.0 Hz, 1H), 2.04 - 1.94 (m, 2H). 13 C NMR (400 MHz, CDCl 3 ) δ / ppm: 163.37 (s), 158.34 (s), 147.90 (s), 144.13 (s), 143.72 (s), 141.81 (s), 128.10 (s), 127.23 (s), 124.39 (s), 123.51 (s), 121.09 (s), 120.38 (s), 112.92 (s), 108.97 (s), 107.58 (s), 103.85 (s), 55.49 (s), 50.09 (s), 31.53 (s), 30.15 (s), 29.73 (s), 29.35 (s), 28.07 (s), 21.83 (s), 14.16 (s).

[0065] Step 5, Preparation of OB: Add the above product (20 mg, 0.0273 mmol, 1 equiv.), dry dichloromethane (7 mL), DIPEA (0.05 mL, 0.286 mmol, 10.0 equiv.) into a 25 mL two-necked flask. Under N 2 protection, slowly add BF 3 .Et 2 O (0.07 mL, 0.572 mmol, 15 equiv.). React under dark at room temperature for 24 h. Pour the reacted material into saturated sodium chloride aqueous solution to quench the reaction, and then add dichloromethane for extraction. Then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, purify by column chromatography, and finally obtain a black-green solid (yield: 77%). 1 H NMR (400 MHz, CDCl 3 ) δ / ppm: 7.70 (s, 1H), 7.67 (d, J = 8.7 Hz, 1H), 6.86 (s, 1H), 6.64 (dd, J = 8.7, 2.4 Hz, 1H), 6.52 (d, J = 2.4 Hz, 1H), 3.79 (s, 3H), 3.30 - 3.24 (m, 3H), 2.80 (t, J = 6.2 Hz, 3H), 2.04 - 1.94 (m, 4H). 13 C NMR (400 MHz, CDCl 3 ) δ / ppm: 163.37 (s), 158.34 (s), 147.90 (s), 144.13 (s), 143.72 (s), 141.81 (s), 128.10 (s), 127.23 (s), 124.39 (s), 123.51 (s), 121.09 (s), 120.38 (s), 112.92 (s), 108.97 (s), 107.58 (s), 103.85 (s), 55.49 (s), 50.09 (s), 31.53 (s), 30.15 (s), 29.73 (s), 29.35 (s), 28.07 (s), 21.83 (s), 14.16 (s). Found: 739.68.

[0066] Step 6, Preparation of OB-2Br: Add OB (20 mg, 0.0270 mmol, 1 equiv.) and dry dichloromethane (10 mL) to a 50 mL round-bottom flask. Slowly add N-bromosuccinimide (NBS, 10.57 mg, 0.0594 mmol, 2.2 equiv.) dissolved in dry dichloromethane (10 mL). React under dark at room temperature for 1 h. Concentrate the reaction mixture by rotary evaporation and purify by column chromatography to obtain a blue-green solid (yield: 30%). 1 H NMR (400 MHz, CDCl 3 ) δ / ppm: 8.44 (d, J = 8.9 Hz, 1H), 7.55 (s, 2H), 6.70 (dd, J = 8.9, 2.5 Hz, 1H), 6.49(d, J = 2.5 Hz, 1H), 3.82 (d, J = 10.8 Hz, 3H), 3.26 - 3.22 (m, 3H), 2.80 (t, J = 6.1Hz, 4H), 2.03 - 1.95 (m, 4H). 13 C NMR (500 MHz, CDCl 3 ) δ / ppm: 163.37 (s), 158.34(s), 147.90 (s), 144.13 (s), 143.72 (s), 141.81 (s), 128.10 (s), 127.23 (s),124.39 (s), 123.51 (s), 121.09 (s), 120.38 (s), 112.92 (s), 108.97 (s),107.58 (s), 103.85 (s), 55.49 (s), 50.09 (s), 31.53 (s), 30.15 (s), 29.73(s), 29.35 (s), 28.07 (s), 21.83 (s), 14.16 (s). Found: 897.48.

[0067] Step 7, OB5: Add compound OB-2Br (20 mg, 0.0223 mmol, 1 equiv.), 2-(tributylstannyl)thiophene (200 ), tris(2-methylphenyl)phosphine (10 mg, 0.0328 mmol, 1.5 equiv.), Pd(dba)2 (10 mg), toluene (15 mL), N 2 The atmosphere was replaced three times, and then the reaction was heated to 100 °C and reacted for 24 h. The reaction solution was concentrated by rotary evaporation and purified by column chromatography to finally obtain a blue-green solid (yield: 74%). 1 1H NMR (500 MHz, CDCl 3 ) δ / ppm: 7.48 (d, J J = 5.1 Hz, 1H), 7.31 (s, 2H), 7.20 - 7.10 (m, 2H), 7.06 (d, J J = 2.8 Hz, 1H), 6.48 (s, 1H), 6.38 (d, J J = 8.8 Hz, 1H), 3.74 (s, 3H), 3.18 (t, J J = 5.3 Hz, 4H), 2.59 (t, J J = 6.2 Hz, 4H), 1.98 - 1.83 (m, 5H). 13 13C NMR (500 MHz, CDCl 3 ) δ / ppm: 201.35 (s), 166.27 (s), 165.46 (s), 142.52 (s), 131.37(s), 125.55 (d, J J = 45.2 Hz), 125.25 - 124.70 (m), 121.81 (s), 113.42 (s), 107.91(s), 100.98 (s), 80.07 (s), 77.34 (d, J J = 11.3 Hz), 76.92 (d, J J = 32.0 Hz), 76.49 - 76.13 (m), 55.63 (s), 49.87 (s), 41.13 (s), 38.67 (s), 27.68 (s), 21.92(s), 1.06 (s). Found: 909.92.

[0068] Step 8: Preparation of OB5@NPs: Weigh 1.0 mg of OB5 and dissolve it in 1 mL of THF, and then add it to 9 mL of an aqueous solution of DSPE-PEG 5000 with a concentration of 0.5 mg / mL. Ultrasonic dissolution was carried out for 5 min, and it was treated overnight at 500 rpm. After filtration and centrifugation, the concentration of the OB5@NPs aqueous solution was determined by the absorbance method.

[0069] Example 2

[0070] Step 1: Slowly add POCl 3 (4.5 mL) dropwise to a 100 mL round-bottom flask containing N,N-dimethylformamide (DMF, 3.75 mL) under an ice-salt bath condition. After the addition, continue stirring for half an hour until a white solid is formed. Then, slowly add a DMF solution of julolidine (3 g, 17.3 mmol) dropwise. After the addition, continue stirring at room temperature for half an hour. Subsequently, remove the water bath and heat to 85 °C. After reacting for 3 hours, pour the reaction solvent into 200 mL of ice water and stir for half an hour until a large amount of crystals are produced. Adjust the pH of the solution to 7, and finally obtain a light yellow solid by suction filtration.

[0071] Step 2: Add the above product (4.54 g, 27 mmol, 1.0 equiv.), 2'-hydroxy-4'-methoxyacetophenone (5 g, 25 mmol, 1.0 equiv.), and ethanol (100 mL) to a 250 mL round-bottom flask. Add nitromethane (2.5 g, 36.7 mmol, 1.5 equiv.) to it. Reflux at 75 °C for 12 hours. Finally, pour the reaction solution into ice water to quench the reaction, extract it 3 times with dichloromethane, then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography to finally obtain a red solid.

[0072] Step 3: Add the above product (3 g, 8.5 mmol, 1 equiv.) to 50 mL of absolute ethanol in a 250 mL two-necked flask. Under nitrogen protection, add N,N-diisopropylethylamine (DIPEA, 3 mL, 44 mmol, 5 equiv.) and nitromethane (10 mL). Stir and heat under reflux at 85 °C for 36 hours. Pour the reaction solution into ice water to quench the reaction, extract it 3 times with dichloromethane, then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography to finally obtain a yellow solid.

[0073] Step 4: Add the above product (40 mg, 1 mmol, 1 equiv.), n-butanol (20 mL), and ammonium acetate (0.77 g, 10 mmol, 10 equiv.) to a 25 mL round-bottom flask. Stir and reflux at 110 °C for 3 hours, and then obtain a blue-black solid by suction filtration.

[0074] Step 5, Preparation of OB: Add the above product (20 mg, 0.0273 mmol, 1 equiv.), dry dichloromethane (7 mL), and DIPEA (0.05 mL, 0.286 mmol, 10.0 equiv.) to a 25 mL two-necked flask. N 2Slowly add BF under protection 3 .Et 2 O (0.07 mL, 0.572 mmol, 15 equiv.), react for 24 h at room temperature in the dark. Pour the reacted material into saturated sodium chloride aqueous solution to quench the reaction, then add dichloromethane for extraction. Then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, purify by column chromatography, and finally obtain a black-green solid.

[0075] Step six, prepare OB-2Br: Add OB (20 mg, 0.0270 mmol, 1 equiv.) to a 50 mL round-bottom flask, dry dichloromethane (10 mL), slowly add N-bromosuccinimide (NBS, 10.57 mg, 0.0594 mmol, 2.2 equiv.) dissolved in dry dichloromethane (10 mL), react for 1 h at room temperature in the dark, concentrate the reacted material by rotary evaporation, purify by column chromatography, and finally obtain a blue-green solid.

[0076] Step seven, OB5: Add compound OB-2Br (20 mg, 0.0223 mmol, 1 equiv.), 2-(tributylstannyl)thiophene (200 ), tris(2-methylphenyl)phosphine (10 mg, 0.0328 mmol, 1.5 equiv.), Pd(dba) 2 (10 mg), toluene (15 mL) to a 50 mL round-bottom flask, displace with N 2 atmosphere for 4 times, then heat the reaction to 95 °C and react for 12 h. Concentrate the reacted solution by rotary evaporation, purify by column chromatography, and finally obtain a blue-green solid.

[0077] Step eight, prepare OB5@NPs: Weigh 1.0 mg of OB5 and dissolve it in 1 mL of THF, then add it to 9 mL of 0.5 mg / mL DSPE-PEG 5000 aqueous solution, ultrasonically dissolve for 10 min, treat overnight at 500 rpm, filter, after centrifugation, measure the concentration of OB5@NPs aqueous solution by absorbance method.

[0078] Example 3

[0079] Step one: Add POCl 3(4.5 mL) was slowly added dropwise to a 100 mL round-bottom flask containing N,N-dimethylformamide (DMF, 3.75 mL) under an ice-salt bath. After the addition was complete, stirring was continued for half an hour until a white solid was formed. Then, a DMF solution of julolidine (3 g, 17.3 mmol) was slowly added dropwise thereto. After the addition was complete, stirring was continued at room temperature for half an hour. Subsequently, the water bath was removed and the temperature was raised to 95 °C. After reacting for 5 hours, the reaction solvent was poured into 200 mL of ice water and stirred for half an hour until a large amount of crystals were produced. The pH of the solution was adjusted to 7, and suction filtration was performed to finally obtain a light yellow solid.

[0080] Step 2: Add the above product (4.54 g, 27 mmol, 1.0 equiv.), 2'-hydroxy-4'-methoxyacetophenone (5 g, 25 mmol, 1.0 equiv.), and ethanol (100 mL) to a 250 mL round-bottom flask. Add nitromethane (2.5 g, 36.7 mmol, 1.5 equiv.) thereto. Reflux at 80 °C for 24 hours. Finally, pour the reaction solution into ice water to quench the reaction. Extract with dichloromethane 4 times. Then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography to finally obtain a red solid.

[0081] Step 3: Add the above product (3 g, 8.5 mmol, 1 equiv.) to 50 mL of anhydrous ethanol in a 250 mL two-necked flask. Under nitrogen protection, add N,N-diisopropylethylamine (DIPEA, 3 mL, 44 mmol, 5 equiv.) and nitromethane (10 mL). Stir and heat under reflux at 95 °C for 48 hours. Pour the reaction solution into ice water to quench the reaction. Extract with dichloromethane 4 times. Then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography to finally obtain a yellow solid.

[0082] Step 4: Add the above product (40 mg, 1 mmol, 1 equiv.), n-butanol (20 mL), and ammonium acetate (0.77 g, 10 mmol, 10 equiv.) to a 25 mL round-bottom flask. Stir and reflux at 120 °C for 5 hours. Suction filtration can obtain a blue-black solid.

[0083] Step 5, Preparation of OB: Add the above product (20 mg, 0.0273 mmol, 1 equiv.), dry dichloromethane (7 mL), and DIPEA (0.05 mL, 0.286 mmol, 10.0 equiv.) to a 25 mL two-necked flask. Under N 2 protection, slowly add BF 3 .Et 2O (0.07 mL, 0.572 mmol, 15 equiv.), react for 24 h at room temperature in the dark. Pour the reacted material into saturated sodium chloride aqueous solution to quench the reaction, then add dichloromethane for extraction. After that, add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, purify by column chromatography, and finally obtain a black-green solid.

[0084] Step 6: Preparation of OB-2Br: Add OB (20 mg, 0.0270 mmol, 1 equiv.) to a 50 mL round-bottom flask, dry dichloromethane (10 mL), slowly add N-bromosuccinimide (NBS, 10.57 mg, 0.0594 mmol, 2.2 equiv.) dissolved in dry dichloromethane (10 mL), react for 1 h at room temperature in the dark. Concentrate the reacted material by rotary evaporation, purify by column chromatography, and finally obtain a blue-green solid.

[0085] Step 7: OB5: Add compound OB-2Br (20 mg, 0.0223 mmol, 1 equiv.), 2-(tributylstannyl)thiophene (200 ), tris(2-methylphenyl)phosphine (10 mg, 0.0328 mmol, 1.5 equiv.), Pd(dba) 2 (10 mg), toluene (15 mL) into a 50 mL round-bottom flask, displace with N 2 atmosphere for 4 times, then heat the reaction to 105 °C and react for 24 h. Concentrate the reacted solution by rotary evaporation, purify by column chromatography, and finally obtain a blue-green solid.

[0086] Step 8: Preparation of OB5@NPs: Weigh 1.0 mg of OB5 and dissolve it in 1 mL of THF, then add it to 9 mL of an aqueous solution of DSPE-PEG 5000 with a concentration of 0.5 mg / mL, ultrasonically dissolve for 15 min, treat overnight at 500 rpm, filter, after centrifugation, determine the concentration of the OB5@NPs aqueous solution by absorbance method.

[0087] Example 4

[0088] Step 1: Add POCl 3(4.5 mL) was slowly added dropwise to a 100 mL round-bottom flask containing N,N-dimethylformamide (DMF, 3.75 mL) under an ice-salt bath. After the addition was complete, stirring was continued for half an hour until a white solid was formed. Then, a DMF solution of julolidine (3 g, 17.3 mmol) was slowly added dropwise thereto. After the addition was complete, stirring was continued at room temperature for half an hour. Subsequently, the water bath was removed and the temperature was raised to 85 °C. After reacting for 4 hours, the reaction solvent was poured into 200 mL of ice water and stirred for half an hour until a large amount of crystals were produced. The pH of the solution was adjusted to 7, and suction filtration was carried out to finally obtain a light yellow solid.

[0089] Step 2: Add the above product (4.54 g, 27 mmol, 1.0 equiv.), 2'-hydroxy-4'-methoxyacetophenone (5 g, 25 mmol, 1.0 equiv.), and ethanol (100 mL) to a 250 mL round-bottom flask. Add nitromethane (2.5 g, 36.7 mmol, 1.5 equiv.) thereto. Reflux at 80 °C for 24 hours. Finally, pour the reaction solution into ice water to quench the reaction. Extract with dichloromethane 3 times. Then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography to finally obtain a red solid.

[0090] Step 3: Add the above product (3 g, 8.5 mmol, 1 equiv.) to 50 mL of anhydrous ethanol in a 250 mL two-necked flask. Under nitrogen protection, add N,N-diisopropylethylamine (DIPEA, 3 mL, 44 mmol, 5 equiv.) and nitromethane (10 mL). Stir and heat under reflux at 85 °C for 48 hours. Pour the reaction solution into ice water to quench the reaction. Extract with dichloromethane 3 times. Then add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, and purify by column chromatography to finally obtain a yellow solid.

[0091] Step 4: Add the above product (40 mg, 1 mmol, 1 equiv.), n-butanol (20 mL), and ammonium acetate (0.77 g, 10 mmol, 10 equiv.) to a 25 mL round-bottom flask. Stir and reflux at 115 °C for 4 hours. Suction filtration can obtain a blue-black solid.

[0092] Step 5, Preparation of OB: Add the above product (20 mg, 0.0273 mmol, 1 equiv.), dry dichloromethane (7 mL), and DIPEA (0.05 mL, 0.286 mmol, 10.0 equiv.) to a 25 mL two-necked flask. Under N 2 protection, slowly add BF 3 .Et 2O (0.07 mL, 0.572 mmol, 15 equiv.), react for 24 h at room temperature in the dark. Pour the reacted material into saturated sodium chloride aqueous solution to quench the reaction, then add dichloromethane for extraction. After that, add anhydrous sodium sulfate for drying, filter, concentrate by rotary evaporation, purify by column chromatography, and finally obtain a black-green solid.

[0093] Step 6: Preparation of OB-2Br: Add OB (20 mg, 0.0270 mmol, 1 equiv.) and dry dichloromethane (10 mL) to a 50 mL round-bottom flask. Slowly add N-bromosuccinimide (NBS, 10.57 mg, 0.0594 mmol, 2.2 equiv.) dissolved in dry dichloromethane (10 mL). React for 1 h at room temperature in the dark. Concentrate the reacted material by rotary evaporation and purify by column chromatography to finally obtain a blue-green solid.

[0094] Step 7: OB5: Add compound OB-2Br (20 mg, 0.0223 mmol, 1 equiv.), 2-(tributylstannyl)thiophene (200 ), tris(2-methylphenyl)phosphine (10 mg, 0.0328 mmol, 1.5 equiv.), Pd(dba) 2 (10 mg), and toluene (15 mL) to a 50 mL round-bottom flask. Replace the atmosphere with N 2 for 3 times, then heat the reaction to 105 °C and react for 24 h. Concentrate the reacted solution by rotary evaporation and purify by column chromatography to finally obtain a blue-green solid.

[0095] Step 8: Preparation of OB5@NPs: Weigh 1.0 mg of OB5 and dissolve it in 1 mL of THF, then add it to 9 mL of an aqueous solution of DSPE-PEG 5000 with a concentration of 0.5 mg / mL. Ultrasonically dissolve for 5 min, treat overnight at 500 rpm, filter, and after centrifugation, determine the concentration of the OB5@NPs aqueous solution by absorbance method.

[0096] As Figure 1 shown, Figure 1It is the structural formula of photosensitizer molecule OB5 and the test chart of its photophysical properties. Among them, in Figure (a), the spatial configuration and HOMO-LUMO energy level bandgap of photosensitizer molecule OB5 are determined by time-dependent density function theory (TD-DFT); it can be seen from the figure that the energy level bandgap of OB5 molecule is 1.65 eV; in the LUMO orbital, electrons are concentrated on the BODIPY matrix, and the electron cloud is discretely distributed on the HOMO orbital; the calculated energy levels and possible ISC channels from the S1 state to higher or lower triplet states (T5) shown in Figure (b), the triplet state on the left is the energy level higher than ES1 + 0.37 eV or lower than ES1 - 0.37 eV. The triplet states marked on the right contain the same transition configuration combinations as the S1 state, and T3, T4, and T5 are transition-forbidden. Figure (c) is the ultraviolet-visible-near-infrared absorption (UV-vis-NIR) spectrum of the photosensitizer molecule in different solvents; OB5 molecule has a relatively wide absorption wavelength (600 - 1050 nm), and the solvation effect of OB5 molecule is obvious; Figure (d) is the single-photon emission (FL) spectrum of the photosensitizer molecule in different solvents. Under the excitation light of 808 nm, OB5 molecule has a strong emission peak at 1090 nm; Figure (e) shows the schematic diagram of the photostability of the photosensitizer molecule. After being irradiated by an 808 nm laser for 100 min, the fluorescence intensity of OB5 molecule does not change significantly, indicating that the molecule is not easily photo-bleached.

[0097] As Figure 2 shown, it can be seen from Figure 2 Figure (a) in the figure that the nano-particle size is about 100 nm and the morphology is relatively uniform; as shown in the UV-vis-NIR spectrum (black) and single-photon emission (FL) spectrum (red) of OB5@NPs in Figure (b), the absorption and emission spectra of OB5 molecule before and after nano-formation do not change significantly. OB5@NPs have absorption in the range of 600 - 1000 nm. When the nano-particles are irradiated with an excitation light of 808 nm, the emission wavelength is 1080 nm, which is located in the second near-infrared region; the concentration dependence of the photothermal performance of OB5@NPs shown in Figure (c), the temperature-time change curves of OB5@NPs with different concentrations irradiated by an 808 nm laser with a power density of 0.2 W / cm2, indicating that OB5@NPs have excellent photothermal performance; the ability of OB5@NPs to generate ROS shown in Figures (d) and (e). Using DCFH-DA as an indicator for ROS generation, it can be seen from the figure that as the irradiation time of the laser gradually increases, the fluorescence value at 528 nm gradually increases, indicating that OB5@NPs can generate a large amount of ROS under the irradiation of an 808 nm laser; (f) The quantification chart of ROS generation by OB5@NPs.

[0098] The present invention utilizes the properties of Aza-BODIPY dyes. By replacing the boron atom in the parent body with an oxygen atom, the conjugation area of the dye molecule and the flow of internal electrons are further increased, enhancing the intersystem crossing ability of the molecule and endowing the molecule with PDT effect. At the same time, electron-donating groups (thiophene carbon chains) are introduced at the 2,6-carbon atoms to enhance the vibrational relaxation of the photosensitizer molecule and the ability of photothermal conversion, endowing it with PTT effect. Based on this, the designed Aza-BODIPY-like molecules have both photothermal and photodynamic properties and can be used for phototherapy of tumor tissues.

[0099] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A near-infrared second zone photosensitizer based on aza-fluoro-boron dipyrrole, characterized in that: The structural formula of the photosensitizer is as follows: 。 2. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoro-boron dipyrrole according to claim 1, characterized in that: The following steps are involved: S1: adding phosphorus oxychloride to N,N-dimethylformamide in an ice-salt bath to obtain a solution and stirring until a white solid is formed, adding a solution of julolidine in N,N-dimethylformamide and stirring, then heating for a first reaction to obtain an intermediate product I, pouring the intermediate product I into ice water and stirring until crystals are generated, then adjusting the pH value, and filtering to obtain an intermediate product II; S2: Mix the intermediate product II, 2′-hydroxy-4′-methoxyacetophenone and ethanol, then add nitromethane, heat under reflux for a second reaction, and obtain the intermediate product III. Pour the intermediate product III into ice water to quench the reaction, then extract, dry, filter, concentrate by rotary evaporation and purify to obtain the intermediate product IV. S3: Mix the intermediate product IV with anhydrous ethanol, add N,N-diisopropylethylamine and nitromethane under protective gas, heat and reflux for a third reaction to obtain an intermediate product V, pour the intermediate product V into ice water to quench the reaction, then extract, dry, filter, concentrate by rotary evaporation and purify to obtain an intermediate product VI; S4: mixing the intermediate product VI, n-butanol and ammonium acetate and heating them under reflux for a fourth reaction, and filtering to obtain an intermediate product VII after the fourth reaction is completed; S5: After mixing the intermediate product VII, dry dichloromethane and N,N-diisopropylethylamine, boron trifluoride etherate was added under protective gas, and the reaction was carried out for the fifth time at room temperature in the dark to obtain the intermediate product VIII. The intermediate product VIII was poured into a saturated sodium chloride aqueous solution to quench the reaction, followed by extraction, drying, filtration, rotary evaporation and purification to obtain the intermediate product OB; S6: After mixing the intermediate product OB and dry dichloromethane, N-bromosuccinimide dissolved in dry dichloromethane was added, and the reaction was carried out for the sixth time at room temperature in the dark to obtain the intermediate product IX. The intermediate product IX was concentrated and purified by rotary evaporation to obtain the intermediate product OB-2Br; S7: The intermediate product OB-2Br, 2-(tributyltinyl)thiophene, tri(2-methylphenyl)phosphine, bis(dibenzylideneacetone)palladium and toluene were replaced for a set number of times under protective gas, and then heated for the seventh reaction. The solution after the reaction was concentrated and purified by rotary evaporation to obtain the near-infrared second zone photosensitizer OB5.

3. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoroborane dipyrrole according to claim 2, characterized in that: It also includes the nano-sizing step of near-infrared zone II photosensitizer: S21: dissolving the near-infrared II photosensitizer OB5 in tetrahydrofuran to obtain a mixed solution; S22: Add the mixed solution to DSPE-PEG 5000 The solution was dissolved by ultrasonic and then allowed to stand at a set speed. After the treatment, it was filtered and centrifuged to obtain the nano-near-infrared zone II photosensitizer OB5@NPs.

4. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoroborane dipyrrole according to claim 2, characterized in that: In S1, the volume ratio of phosphorus oxychloride to N,N-dimethylformamide in the solution is 4.5:3.75; the temperature of the first reaction is 85-95° C., the time of the first reaction is 3-5 h; and the pH value is 7.

5. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoroborane dipyrrole according to claim 2, characterized in that: In S2, the molar ratio of the intermediate product II, 2′-hydroxy-4′-methoxyacetophenone and nitromethane is 1:1:1.5; the temperature of the second reaction is 75-80° C., and the time of the second reaction is 12-24 hours.

6. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoroborane dipyrrole according to claim 2, characterized in that: In S3, the molar ratio of the intermediate product IV to N,N-diisopropylethylamine is 1:5; the temperature of the third reaction is 85-95° C., and the time of the third reaction is 36-48 hours.

7. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoroborane dipyrrole according to claim 2, characterized in that: In S4, the molar ratio of the intermediate product VI to ammonium acetate is 1:10; the temperature of the fourth reaction is 110-120° C., and the time of the fourth reaction is 3-5 h.

8. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoroborane dipyrrole according to claim 2, characterized in that: In S5, the molar ratio of the intermediate product VII, N,N-diisopropylethylamine and boron trifluoride etherate is 1:10:

15.

9. The method for preparing the near-infrared second zone photosensitizer based on aza-fluoroborane dipyrrole according to claim 2, characterized in that: In S6, the molar ratio of the intermediate product OB to N-bromosuccinimide is 1:2.2; in S7, the molar ratio of the intermediate product OB-2Br to tri(2-methylphenyl)phosphine is 1:1.5; the temperature of the seventh reaction is 95-105° C., and the time of the seventh reaction is 12-24 h.

10. Use of the near-infrared second-zone photosensitizer based on azafluoroboron dipyrrole according to claim 1 in the preparation of photothermal therapy drugs.

Images