Fluoroboron compound and its preparation method, application, and mitochondrial targeted photosensitizer

Abstract

The present invention provides a fluoro-boron compound and a preparation method thereof. A novel fluoro-boron compound SBDP is obtained by using bis(benzothiazol-2-yl)methane, boron trifluoride diethyl etherate, triethylamine, and phosphorus oxychloride as raw materials. The fluoro-boron compound contains a cationic group. The present invention also provides a mitochondrion-targeted photosensitizer and a preparation method thereof. DSPE-PEG 2000 is used to wrap it, and nanoparticles with uniform particle size are prepared in an aqueous solution. After the nanoparticles are taken up by tumor cells, the fluoro-boron compound SBDP targets the mitochondria of tumor cells, and under white light illumination, the reactive oxygen species generated by the fluoro-boron compound SBDP cause oxidative damage to the mitochondria, thereby killing tumor cells.

Description

Technical Field

[0001] The present invention relates to the technical field of biomaterials, and in particular to a fluorine-boron compound and a preparation method and application thereof, and a mitochondrial-targeted photosensitizer. Background Art

[0002] Cancer is a major threat to human life and health, and finding effective cancer treatments has always been the focus of research by researchers around the world. At present, surgery, chemotherapy, and radiotherapy are the main means of cancer treatment, but these traditional treatments generally have many limitations, such as low efficiency and greater postoperative trauma. As an emerging tumor treatment method, phototherapy has broad prospects in basic research and clinical medicine due to its strong selectivity, few side effects, and high precision.

[0003] Phototherapy is divided into two categories: photodynamic therapy (PDT) and photothermal therapy (PTT). Photodynamic therapy mainly relies on photosensitizers to produce reactive oxygen species (ROS) under visible light or near-infrared light irradiation to induce tumor cell apoptosis and eliminate tumor cells. After absorbing photons, the photosensitizer transitions from the ground state (S0) to the singlet state (S1), and after converting to the triplet state (T1) with the help of intersystem crossing (ISC), it produces photochemical reactions with biological substrates through type I or type II pathways to produce ROS and kill tumor cells. In type I PDT, the main process of electron transfer between substances occurs. The photosensitizer in the T1 state transfers electrons to the biological substrate in the cell, causing the biological substrate to form free radicals. These free radicals can then interact with water and O2 to produce hydroxyl radicals (·OH) and superoxide anion radicals (O2 -· ), killing tumor cells. In type II PDT, it is an energy transfer mode, and the photosensitizer in the T1 state directly transfers energy to the surrounding O2, converting it into singlet oxygen ( 1 O2), killing tumor cells.

[0004] Photosensitizers are the most important part of photodynamic therapy. Organic small molecule photosensitizers have received more and more attention due to their advantages such as fixed molecular structure and easy adjustment of photophysical properties. Photosensitizers based on the boron dipyrrolidone (BODIPY) structure have become a hot material in the field of tumor phototherapy due to their high phototoxicity, high fluorescence quantum yield, and good optical stability. However, in practical applications, the use of BODIPY photosensitizers is often subject to disadvantages such as poor water solubility and non-targeting.

[0005] Therefore, while retaining the advantages of traditional BODIPY photosensitizers, new fluoroboron photosensitizers are developed to improve the water solubility and photostability of photosensitizers, especially to achieve tumor targeted therapy, which has very important practical application value for tumor photodynamic therapy. Summary of the invention

[0006] The purpose of the present invention is to provide a novel fluoroboron compound SBDP targeting mitochondria in view of the deficiencies of the prior art, and to apply the compound to an anti-tumor photosensitizer, which has the advantages of small molecular weight and excellent solubility, and contains indole salt groups in its molecules, so that the fluoroboron compound can pass through the lipid bilayer of mitochondria and be localized in mitochondria, thereby overcoming the shortcomings of poor water solubility and non-targeting of BODIPY photosensitizers during use.

[0007] According to the first aspect of the present invention, there is provided a fluorine-boron compound, which is denoted as SBDP and has a structural formula as shown in Formula I;

[0008]

[0009] According to a second aspect of the present invention, there is provided a method for preparing the aforementioned fluorine-boron compound, comprising the following steps:

[0010] Di(benzo[d]thiazol-2-yl)methane is reacted in toluene medium with boron trifluoride etherate and triethylamine as additives to obtain a first intermediate;

[0011] The first intermediate is reacted in 1,2-dichloroethane as a medium, with phosphorus oxychloride and N,N-dimethylformamide as additives, to generate a second intermediate through a Vilsmeier-Haack reaction;

[0012] 1,1,2-Trimethyl-1H-benz[e]indole in acetonitrile medium with iodoethane as additive to generate the third intermediate;

[0013] The second intermediate and the third intermediate are used to synthesize the fluoroboric compound SBDP in the medium of toluene and n-butanol.

[0014] In an optional embodiment, when synthesizing the first intermediate, the molar ratio of di(benzo[d]thiazol-2-yl)methane, triethylamine, and boron trifluoride etherate is 1:(2-5):(5-10).

[0015] In an optional embodiment, the reaction conditions for synthesizing the first intermediate are as follows:

[0016] The reaction is carried out at a temperature of 80-110° C. for 10-20 hours. After the reaction is completed, the solvent is removed, and the mixture is washed and filtered to obtain a first intermediate.

[0017] In an optional embodiment, when synthesizing the second intermediate, the molar ratio of the first intermediate, N,N-dimethylformamide, and phosphorus oxychloride is 1:(2-5):(4-10).

[0018] In an optional embodiment, the reaction conditions for synthesizing the second intermediate are as follows:

[0019] After stirring at room temperature for 10-30 minutes, the mixture is reacted at 80-100° C. for 3-10 hours. After the reaction is completed, dichloromethane is used for extraction, and the solvent is removed under reduced pressure to obtain a second intermediate.

[0020] In an optional embodiment, when synthesizing the third intermediate, the molar ratio of 1,1,2-trimethyl-1H-benzo[e]indole to ethyl iodide is 1:(10-15);

[0021] The reaction conditions are: reacting at a temperature of 60-80° C. for 12-48 hours, extracting with dichloromethane after the reaction is completed, and removing the solvent under reduced pressure to obtain the third intermediate.

[0022] In an optional embodiment, when the second intermediate and the third intermediate are used to synthesize fluoroboric compounds in a medium of toluene and n-butanol, the molar ratio between the second intermediate and the third intermediate is 1:(1-1.5), the volume ratio of toluene and n-butanol is 3:(7-10), the reaction temperature is 100-135°C, the reaction time is 12-48 hours, and pink solid SBDP is obtained by column chromatography.

[0023] According to a third aspect of the present invention, there is provided a use of the aforementioned fluoroboron compound in the preparation of an anti-tumor photosensitizer.

[0024] According to a fourth aspect of the present invention, a method for preparing a mitochondrial targeted photosensitizer is provided, wherein the fluoroborane compound is dissolved in tetrahydrofuran, and a DSPE-PEG-containing solution is added under ultrasonic conditions. 2000 After the reaction is completed, the tetrahydrofuran is removed by stirring in ultrapure water, and the solution is filtered to obtain a pink clear SBDP nanoparticle solution, which is a mitochondrial targeted photosensitizer.

[0025] In an alternative embodiment, SBDP and DSPE-PEG 2000 The mass ratio is 1:(10-20), and stirred at room temperature for 24-48 hours.

[0026] According to a fifth aspect of the present invention, a mitochondrial-targeted photosensitizer prepared by the aforementioned method is provided.

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

[0028] The fluoroboron compound SBDP of the present invention contains a cationic group, which is easy to bind to the negatively charged mitochondrial membrane in the cell, so that it can target the cell mitochondria; using DSPE-PEG 2000The nanoparticles are encapsulated and prepared in aqueous solution to obtain nanoparticles with uniform particle size. The nanoparticles have high stability and good biocompatibility in aqueous solution. After the nanoparticles are taken up by tumor cells, the fluoroboron compound SBDP targets the mitochondria of tumor cells, localizes in the mitochondria, and generates a large amount of ROS in the tumor cells under white light conditions, causing oxidative damage to the mitochondria, thereby killing the tumor cells.

[0029] The fluoroboron compound SBDP of the present invention has a clear chemical structure, a simple synthesis process, is easy to purify, and has a high yield; and the novel photosensitizer of the present invention has good photophysical properties, and the maximum absorption wavelength of the ultraviolet absorption spectrum in a dichloromethane solution is 616nm, and the maximum emission peak is 603nm. At the same time, the novel photosensitizer of the present invention has the advantages of small molecular weight, excellent solubility, etc., and has great application prospects in biological imaging, fluorescent labeling, photodynamic therapy, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is a synthetic route diagram of the fluoroboron compound SBDP of the present invention.

[0031] Figure 2 is the compound SBDP in the example of the present invention 1 H-NMR spectrum.

[0032] Figure 3 is the compound SBDP in the examples of the present invention 13 C-NMR spectrum.

[0033] Figure 4 It is the mass spectrum of the compound SBDP in the example of the present invention.

[0034] Figure 5 This is a dynamic light scattering particle size distribution test chart of the compound SBDP nanoparticles in the example of the present invention.

[0035] Figure 6 The size of the SBDP nanoparticles dissolved in different solvents changes over time in the examples of the present invention.

[0036] Figure 7 It is the ultraviolet absorption spectrum of the compound SBDP in the example of the present invention in dichloromethane solvent.

[0037] Figure 8 It is the fluorescence emission spectrum of the compound SBDP in the example of the present invention in dichloromethane solvent.

[0038] Fig. 9 This is a graph showing the change in absorption intensity of hydroxyphenyl fluorescein under white light irradiation conditions after SBDP nanoparticles and hydroxyphenyl fluorescein are mixed in an example of the present invention.

[0039] Fig.10 The relative survival rates of mouse breast cancer cells (4T1) incubated with SBDP nanoparticles of different concentrations for 24 hours under light or dark conditions in the present invention.

[0040] Fig.11 This is a laser confocal imaging image of SBDP nanoparticles and mitochondrial commercial dye Mito-tracker after incubation with tumor cells in an example of the present invention.

[0041] Fig.12 1 is a correlation curve between mouse tumor volume and time after different treatments in the examples of the present invention.

[0042] Fig.13 These are H&E staining images of various organs of mice after 14 days of different treatments in the present invention. Scale bar length: 100 μm. DETAILED DESCRIPTION

[0043] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0044] Various aspects of the invention are described in this disclosure with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways.

[0045] Mitochondria, as organelles that provide energy, are closely related to the metabolism, apoptosis, and increase of reactive oxygen species in tumor cells.

[0046] Therefore, the photosensitizer based on the boron dipyrrole (BODIPY) structure of the present invention has the advantages of high phototoxicity, high fluorescence quantum yield, good optical stability, etc., and a mitochondrial-targeted boron photosensitizer is designed. The mitochondria are used as the target of tumor treatment, and selective targeting is performed to produce reactive oxygen species under light, promote tumor cell death, and improve the effect of tumor treatment.

[0047] As an exemplary fluorine-boron compound in the implementation of the present invention, the compound is denoted as SBDP, and the structural formula is shown in Formula I;

[0048]

[0049] In another exemplary embodiment of the present invention, a method for preparing the aforementioned fluorine-boron compound is provided, using di(benzo[d]thiazol-2-yl)methane, boron trifluoride etherate, triethylamine, and phosphorus oxychloride as raw materials, according to Figure 1 The reaction route is used for reaction preparation.

[0050] In a specific embodiment, the preparation method of fluorine-boron compounds comprises the following steps:

[0051] Di(benzo[d]thiazol-2-yl)methane is reacted in toluene medium with boron trifluoride etherate and triethylamine as additives to obtain a first intermediate;

[0052] The first intermediate is reacted in 1,2-dichloroethane as a medium, with phosphorus oxychloride and N,N-dimethylformamide as additives, to generate a second intermediate through a Vilsmeier-Haack reaction;

[0053] 1,1,2-Trimethyl-1H-benz[e]indole in acetonitrile medium with iodoethane as additive to generate the third intermediate;

[0054] The second intermediate and the third intermediate are used to synthesize the fluoroboric compound SBDP in the medium of toluene and n-butanol.

[0055] In an optional embodiment, the preparation method of the first intermediate is as follows:

[0056] Di(benzo[d]thiazol-2-yl)methane and triethylamine are fully dissolved in anhydrous dry toluene in a nitrogen atmosphere to obtain a first mixed solution. Boron trifluoride etherate is slowly added dropwise to the first mixed solution, and the mixture is stirred, heated and reacted. After the reaction is completed, the solvent is removed, and the mixture is washed and filtered to obtain a first intermediate.

[0057] In an optional embodiment, the molar ratio of di(benzo[d]thiazol-2-yl)methane, triethylamine and boron trifluoride etherate is 1:(2-5):(5-10).

[0058] In an optional embodiment, the temperature is raised to 80-110° C. with stirring and heating, and the reaction is carried out for 10-20 hours. Afterwards, the solvent is removed by distillation under reduced pressure, and the mixture is fully washed with methanol and filtered to obtain a bright yellow solid compound 1, i.e., the first intermediate.

[0059] In an optional embodiment, the preparation method of the second intermediate is as follows:

[0060] Under nitrogen atmosphere and ice-water bath conditions, the first intermediate and N,N-dimethylformamide are added to 1,2-dichloroethane to obtain a second mixed solution. After phosphorus oxychloride is slowly added dropwise to the second mixed solution, stirring is continued in an ice-water bath, and then stirred at room temperature, and then the temperature is raised to react. After the reaction is completed, the reaction solution is cooled to room temperature, the pH value is adjusted, and extraction is performed with a saturated sodium chloride solution and dichloromethane. The organic solvent is removed and purified by column chromatography to obtain a second intermediate.

[0061] In an optional embodiment, the molar ratio of the first intermediate, N,N-dimethylformamide, and phosphorus oxychloride is 1:(2-5):(4-10).

[0062] In an optional embodiment, phosphorus oxychloride is slowly added dropwise to the second mixed solution, and then stirred in an ice-water bath for 15 minutes, stirred at room temperature for 10-30 minutes, and then heated to 80-100°C for reaction for 3-10 hours. The reaction solution is cooled to room temperature, poured into a saturated K2CO3 solution, the pH value is adjusted to 7.0, extracted with a saturated sodium chloride solution and dichloromethane, and the organic solvent is removed by vacuum distillation, and purified by column chromatography (ethyl acetate: petroleum ether = 1:4) to obtain a yellow solid compound 2, i.e., the second intermediate.

[0063] In an optional embodiment, the preparation method of the third intermediate is as follows:

[0064] 1,1,2-trimethyl-1H-benzo[e]indole and iodoethane are added to acetonitrile, and the temperature is raised to the desired temperature under nitrogen conditions, and the reaction is refluxed. After the reaction is completed, extraction is performed and the solvent is removed to obtain a third intermediate.

[0065] In an optional embodiment, the molar ratio of 1,1,2-trimethyl-1H-benzo[e]indole to ethyl iodide is 1:(10-15);

[0066] The reaction conditions are: reacting at a temperature of 60-80° C. for 12-48 hours, extracting with dichloromethane after the reaction, and removing the solvent under reduced pressure to obtain a gray solid powder 3, i.e., the third intermediate.

[0067] In an optional implementation manner, the specific process of step S3 is as follows:

[0068] The second intermediate and the third intermediate are added to a mixed solvent of toluene and n-butanol to obtain a third mixed solution. The third mixed solution is heated and refluxed to separate the produced water until the reaction is complete. The product is cooled to room temperature and the organic solvent is removed to obtain a crude product. The crude product is purified by column chromatography and washed to obtain the fluoroboron compound SBDP.

[0069] In an optional embodiment, when the second intermediate and the third intermediate are used to synthesize fluoroboric compounds in a medium of toluene and n-butanol, the molar ratio between the second intermediate and the third intermediate is 1:(1-1.5), the volume ratio of toluene and n-butanol is 3:(7-10), the reaction temperature is 100-135°C, the reaction time is 12-48 hours, and pink solid SBDP is obtained by column chromatography.

[0070] In another exemplary embodiment of the present invention, there is also provided a use of the aforementioned fluoroboron compound in the preparation of an anti-tumor photosensitizer.

[0071] In another exemplary embodiment of the present invention, a method for preparing a mitochondrial targeted photosensitizer is provided. The fluoroborane compound is dissolved in tetrahydrofuran, and a DSPE-PEG-containing solution is added under ultrasonic conditions. 2000 The reaction was stirred in ultrapure water. 2000 After encapsulating the fluoroboric compounds, nanoparticles with uniform particle size can be formed in the aqueous solution. After the reaction is completed, tetrahydrofuran is removed and filtered to obtain a pink clear SBDP nanoparticle solution, which is a mitochondrial targeted photosensitizer.

[0072] In an alternative embodiment, SBDP and DSPE-PEG 2000 The mass ratio is 1:(10-20), and stirred at room temperature for 24-48 hours.

[0073] In another exemplary embodiment of the present invention, a mitochondrial-targeted photosensitizer prepared by the aforementioned method is also provided. After being taken up by tumor cells, the photosensitizer can be localized in mitochondria and, under white light irradiation, produce a large amount of ROS in tumor cells and kill tumor cells.

[0074] In an alternative embodiment, the particle size of the mitochondria-targeted photosensitizer is 73±6.5 nm.

[0075] The mitochondrial targeted photosensitizer of the present invention has a simple preparation method and good use effect, and is particularly conducive to the construction and application of a mitochondrial targeted optical diagnosis and treatment system, and can accurately act on tumor mitochondria to achieve efficient tumor treatment, and has strong practicality and wide applicability.

[0076] The following will be combined with specific examples and experiments to conduct exemplary experiments and comparisons on the preparation of the above-mentioned compounds and photosensitizers and their effects. Of course, the embodiments of the present invention are not limited thereto.

[0077] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following embodiments can be obtained from commercial sources unless otherwise specified.

[0078] Example 1

[0079] [Synthesis of the First Intermediate]

[0080] Compound di(benzo[d]thiazol-2-yl)methane (1.13 g, 4 mmol), triethylamine (1.0 mL, 14 mmol), and anhydrous dry toluene (50 mL) were added to a dry 250 mL double-necked flask. After being fully stirred under a nitrogen atmosphere until the compound was completely dissolved, boron trifluoride-ether complex (1.7 mL, 20 mmol) was slowly added dropwise. The mixed solution was stirred and heated to 80°C. After reacting for 16 hours, the solvent was removed by distillation under reduced pressure. The solution was fully washed with methanol and filtered to obtain a bright yellow solid compound 1 (0.93 g, 71.2%).

[0081] 1 H NMR (400MHz, CDCl3): δ (ppm) = 8.06 (d, J = 8.0Hz, 2H), 7.60 (d, J = 8.0Hz, 2H), 7.49 (t, J = 8.0Hz, 2H), 7.28 (t, J = 8.0Hz, 2H), 6.06 (s, 1H).

[0082] 13 C NMR (100MHz, CDCl3): δ (ppm) = 161.01, 142.66, 127.03, 126.63, 123.82, 121.24, 116.68, 81.24.; Its chemical structure is shown in Formula II:

[0083]

[0084] [Synthesis of the Second Intermediate]

[0085] In a nitrogen atmosphere and ice-water bath, compound 1 (1.32 g, 4 mmol), N,N-dimethylformamide (DMF, 1.7 mL, 19.5 mmol), 1,2-dichloroethane (70 mL) were added to a 250 mL two-necked bottle, phosphorus oxychloride (POCl3, 1.5 mL, 16.0 mmol) was slowly added dropwise, and the mixture was stirred in an ice-water bath for 15 minutes. After stirring at room temperature for 10 minutes, the mixture was heated to 80 °C and reacted for 3 hours. The reaction solution was cooled to room temperature, poured into a saturated K2CO3 solution, the pH value was adjusted to 7.0, extracted with a saturated sodium chloride solution and dichloromethane (3×100 mL), the organic solvent was removed by vacuum distillation, and purified by column chromatography (ethyl acetate: petroleum ether = 1:4) to obtain a yellow solid compound 2 (1.03 g, 72.1%).

[0086] 1 H NMR (400MHz, CDCl3): δ (ppm) = 10.01 (s, 1H), 8.22 (s, 2H), 7.87 (d, J = 8.0Hz, 2H), 7.61 (t, J = 4.0Hz, 2H), 7.47 (d, J = 12.0Hz, 2H).

[0087] 13 C NMR (100MHz, CDCl3): δ (ppm) = 180.24, 128.04, 127.77, 125.98, 125.53, 122.13, 121.77, 118.20, 117.88.

[0088] Its chemical structure is shown in Formula III:

[0089]

[0090] [Synthesis of the Third Intermediate]

[0091] 1,1,2-Trimethyl-1H-benzo[e]indole (2.09 g, 10 mmol), iodoethane (7.80 g, 50 mmol), and acetonitrile (50 mL) were added to a 100 mL dry two-necked bottle, heated to 85°C under N2 conditions, and refluxed for 16 hours. After the reaction, dichloromethane was used for extraction, and the solvent was removed under reduced pressure to obtain a gray solid powder compound 3.

[0092] 1 H NMR (400MHz, CDCl3): δ (ppm) = 8.10 (m, 3H), 7.85 (d, J = 8.0Hz, 1H), 7.73 (m, 2H), 4.90 (m, 2H), 1.87 (m, 6H), 1.69 (m, 3H).

[0093] 13 C NMR (100MHz, CDCl3) δ (ppm) = 195.46, 138.44, 137.36, 134.25, 131.94, 129.67, 128.67, 127.36, 123.05, 112.69, 55.62, 45.88, 22.31, 17.35, 14.00. Its structural formula is shown in Formula IV:

[0094]

[0095] [Synthesis of Compound of Formula (I)]

[0096] Under nitrogen atmosphere, compound 2 (0.36 g, 1 mmol), compound 3 (0.37 g, 1 mmol), toluene: n-butanol (v / v = 3:7) mixed solvent (20 mL) was added to a 100 mL double-necked flask, the mixed solution was heated to 135 ° C and refluxed, the reaction was separated by an oil-water separator, and the reaction was completed, cooled to room temperature, and the organic solvent was removed by vacuum distillation. The crude product was purified by column chromatography (dichloromethane: methanol = 40: 1) and washed with petroleum ether (3 × 10 mL) to obtain a pink solid powder SBDP (0.39 g, 44.1%).

[0097] like Figure 2 As shown, 1 H NMR (400MHz, d6-DMSO): δ (ppm) = 8.44 (d, J = 8.45Hz, 1H), 8.38 (t, J = 8.0Hz, 3H), 8.31 (d, J = 12.0Hz, 1H), 8.22 (t, J = 8.0Hz, 3H), 8. 13(d,J=8.0Hz,1H),7.83(t,J=7.2Hz,3H),7.22(m,3H),7.07(d,J=16.0Hz,1H),4.72(m,2H),2.10(s,6H),1.66(t,J=7.2Hz,3H).

[0098] like Figure 3 As shown, 13 C NMR (100MHz, CDCl3) δ (ppm) = 195.03, 137.96, 137.29, 133.83, 131.70, 130.22 ,128.82,127.99,127.80,122.91,112.40,55.98,45.82,22.74,16.63,13.73.

[0099] like Figure 4 As shown, MALDI-TOF Mass (m / z): Calcd for C 33 H 27 BF2N3S2[M] + :578.431,found578.301.

[0100] Its chemical structure is shown in Formula I:

[0101]

[0102] Example 2

[0103] [Preparation of mitochondrial-targeted photosensitizer]

[0104] 2 mg of the compound SBDP prepared in Example 1 was dissolved in 2 mL of tetrahydrofuran and injected into the DSPE-PEG 2000 The SBDP nanoparticles (10 mg) were added to ultrapure water (10 mL) and stirred for 36 hours to remove tetrahydrofuran in the solution. The solution was filtered through a 200 μm filter to obtain a pink clear SBDP nanoparticle solution.

[0105] like Figure 5 As shown in the figure, the dynamic light scattering particle size distribution test results of the organic nanomaterial SBDP nanoparticles show that the hydrated particle size is about 73nm. Nanoparticles of this size can be effectively enriched in tumor cells through the enhanced permeability and retention (EPR) effect.

[0106] Example 3

[0107] [Stability test of compound SBDP]

[0108] SBDP nanoparticles were dissolved in water, PBS, and 10% FBS, and the size of the particles was measured every three days. Figure 6 As shown, the diameters of the nanoparticles in the three solvents hardly changed within two weeks, confirming that the SBDP nanoparticles had excellent size stability and better water solubility.

[0109] Example 4

[0110] [Photophysical properties test of compound SBDP]

[0111] The SBDP dichloromethane solution (2.5 mL) prepared in Example 1 was added to a quartz cuvette for UV testing at a concentration of 1×10 -5 mol / L, tested its UV absorption spectrum, the results are as follows Figure 7 shown.

[0112] from Figure 7 It can be seen that the maximum ultraviolet absorption peak wavelength of the compound SBDP is 616nm.

[0113] A dichloromethane solution (2.5 mL) of compound SBDP was added to a quartz cuvette for fluorescence testing at a concentration of 1×10 -5 mol / L, and tested its fluorescence emission spectrum. The results are as follows Figure 8 shown.

[0114] from Figure 8 It can be seen that the maximum fluorescence emission wavelength of the compound SBDP is 603 nm.

[0115] It can be seen from the above results that the compound SBDP prepared in the present invention has good photophysical properties.

[0116] Example 5

[0117] [Photodynamic performance test of SBDP nanoparticles]

[0118] The SBDP nanoparticle aqueous solution (0.25 mM, 2 mL) prepared in Example 2 was added to the cuvette, and then 40 μL of a 1 mM aqueous solution of hydroxyphenylfluorescein (HPF) was added dropwise (HPF reacts with hydroxyl radicals, resulting in a decrease in the characteristic absorption peak of HPF, and thus can be used as a hydroxyl radical probe). The cuvette was irradiated with white light intermittently for 1 minute each time, and the change in fluorescence intensity at the HPF characteristic peak of 515 nm was monitored. The results are shown in FIG. Fig. 9 shown.

[0119] from Fig. 9 It can be seen that the emission value at the characteristic peak of hydroxyphenylfluorescein (515 nm) increases continuously with the increase of irradiation time, indicating that SBDP nanoparticles have good hydroxyl radical generation ability.

[0120] Example 6

[0121] [Cytotoxicity experiment of SBDP nanoparticles]

[0122] 4T1 cells were seeded in two 96-well cell culture plates at a density of 5.0×10 3 cells per well and cultured and incubated at 37° C., 5% CO 2 , and dark light for 24 hours.

[0123] Using the SBDP nanoparticles prepared in Example 2, different concentrations of SBDP nanoparticles (0, 1, 2, 5, 10, 15, 20, 30, 40, 50 μg / mL, respectively) were prepared and added to the well plate for incubation for 12 hours. After the incubation was completed, one of the well plates was illuminated with white light for 10 minutes at room temperature, and the other well plate was protected from light to test the dark cytotoxicity of the SBDP nanoparticles. After the illumination was completed, the well plates continued to be cultured under dark light conditions for 12 hours, and 20 μL of MTT solution was added to each well for treatment for 4 hours. The well plate culture medium was removed, 150 μL of dimethyl sulfoxide (DMSO) was added to dissolve the blue-purple formazan crystals, and the absorbance data at 490 nm was read with an enzyme reader to calculate the survival rate of 4T1 cells under different concentrations of photosensitizer. The calculation formula for cell survival rate is: average absorbance of the treatment group / average absorbance of the control group × 100%. It was calculated that the half-inhibitory concentration (IC50) of SBDP nanoparticles was 44 μg / mL. The results are as follows Fig.10 shown.

[0124] from Fig.10It can be seen that the cell survival rate is inversely concentration-dependent. The higher the drug concentration, the lower the cell survival rate. 50 The value is approximately 27.3μg / mL.

[0125] Example 7

[0126] [SBDP nanoparticle organelle localization experiment]

[0127] 4T1 cells were inoculated into confocal dishes, cultured for 24 hours, and 1 μM SBDP nanoparticles diluted in RPMI-1640 cell culture medium were added, incubated in a cell culture incubator at 37°C for 4 hours, the culture medium was discarded, the cells were washed three times with phosphate buffer, stained with the commercial mitochondrial dye Mito-Tracker, fixed with 4% formaldehyde, and observed and photographed under a confocal microscope. Since the photosensitizer exhibits red fluorescence and MitoTracker Green exhibits green fluorescence, the overlap of red fluorescence and green fluorescence (yellow fluorescence) was observed with the help of a laser confocal microscope to determine whether the photosensitizer was localized in the mitochondria after being taken up by tumor cells. Fig.11 Confocal images of the photosensitizer localized in mitochondria.

[0128] from Fig.11 It can be seen that the SBDP photosensitizer is targeted to mitochondria.

[0129] Example 8

[0130] [SBDP nanoparticle tumor treatment experiment]

[0131] Balb / c mice injected with 4T1 tumor cells into the axilla were selected as the tumor model, and 16 nude mice were randomly divided into 4 groups.

[0132] When the tumor volume is about 100 mm 3 At the same time, the mice in group 1 (normal saline) were injected with normal saline through the tail vein; the mice in group 2 (normal saline + light) were injected with normal saline through the tail vein; the mice in group 3 (SBDP nanoparticle solution) were injected with SBDP nanoparticle solution (preparation method is the same as that of SBDP nanoparticles, 100μg / mL, 100μL) through the tail vein; the mice in group 4 (SBDP nanoparticle solution + light) were injected with SBDP nanoparticle solution (100μg / mL, 100μL) through the tail vein. Twelve hours after injection, the tumors of mice in groups 3 and 4 were illuminated by white light (20mW / cm 2 ) for 10 minutes, and groups 1 and 2 were not exposed to light.

[0133] The above process was repeated for 14 days, and the tumor size was measured every 2 days. Fig.12 shown.

[0134] from Fig.12 It can be seen that in Group 1 and Group 2, the tumor volume of mice increased over time, while in Group 4, the tumor volume of mice grew slowly after treatment and light exposure. The growth trend of the tumor volume of mice in Group 3 without light exposure was similar to that of the control group (Group 1 and Group 2), which fully demonstrated that SBDP nanoparticles have excellent photodynamic therapy effects.

[0135] Example 9

[0136] After 14 days of treatment, the tumors and major organs of each group of mice were dissected, and the tumor sections and major organs were pathologically stained with hematoxylin and eosin (H&E). Fig.13 shown.

[0137] from Fig.13 It can be seen that H&E staining of major organs in all groups showed almost no dead cells, further confirming the biocompatibility of the nanoparticles to healthy tissues.

[0138] From the above, it can be seen that the present invention successfully prepared the fluoroboron compound SBDP, and the obtained mitochondrial targeted photosensitizer can actively target mitochondria, and under white light irradiation, the reactive oxygen species produced by the fluoroboron compound SBDP cause oxidative damage to mitochondria, thereby killing tumor cells, and the use effect is good, which is especially beneficial to the construction and application of mitochondrial targeted photodiagnosis and treatment system, accurately acting on tumor mitochondria to achieve efficient tumor treatment, and has strong practicality and wide applicability.

[0139] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A fluorine-boron compound, which is denoted as SBDP and has a structural formula as shown in Formula I; Formula Ⅰ.

2. A method for preparing the fluorine-boron compound according to claim 1, characterized in that: The following steps are involved: Di(benzo[d]thiazol-2-yl)methane is reacted in a toluene medium with boron trifluoride etherate and triethylamine as additives to obtain a first intermediate; wherein the structural formula of the first intermediate is shown in Formula II; Formula II; The first intermediate is reacted in 1,2-dichloroethane as a medium, with phosphorus oxychloride and N,N-dimethylformamide as additives, through Vilsmeier-Haack reaction to generate a second intermediate; wherein the structural formula of the second intermediate is as shown in Formula III; Formula III; 1,1,2-trimethyl-1H-benz[e]indole is reacted in acetonitrile with iodoethane as an additive to generate a third intermediate; wherein the structural formula of the third intermediate is shown in Formula IV; Formula IV; The second intermediate and the third intermediate are used to synthesize the fluoroboric compound SBDP in the medium of toluene and n-butanol.

3. The preparation method according to claim 2, characterized in that: When synthesizing the first intermediate, the molar ratio of di(benzo[d]thiazol-2-yl)methane, triethylamine and boron trifluoride ether is 1:(2-5):(5-10).

4. The preparation method according to claim 2, characterized in that: The reaction conditions for synthesizing the first intermediate are as follows: The reaction is carried out at a temperature of 80-110° C. for 10-20 hours. After the reaction is completed, the solvent is removed, and the mixture is washed and filtered to obtain a first intermediate.

5. The preparation method according to claim 2, characterized in that: When synthesizing the second intermediate, the molar ratio of the first intermediate, N,N-dimethylformamide and phosphorus oxychloride is 1:(2-5):(4-10).

6. The preparation method according to claim 2, characterized in that: The reaction conditions for synthesizing the second intermediate are as follows: After stirring at room temperature for 10-30 minutes, the mixture is reacted at a temperature of 80-100° C. for 3-10 hours. After the reaction is completed, the mixture is extracted with dichloromethane and the solvent is removed under reduced pressure to obtain a second intermediate.

7. The preparation method according to claim 2, characterized in that: When synthesizing the third intermediate, the molar ratio of 1,1,2-trimethyl-1H-benzo[e]indole to ethyl iodide is 1:(10-15); The reaction conditions are: reacting at a temperature of 60-80° C. for 12-48 hours, extracting with dichloromethane after the reaction is completed, and removing the solvent under reduced pressure to obtain a third intermediate.

8. The preparation method according to claim 2, characterized in that: When the second intermediate and the third intermediate are used to synthesize fluoroboric compounds in a medium of toluene and n-butanol, the molar ratio between the second intermediate and the third intermediate is 1:(1-1.5), the volume ratio of toluene and n-butanol is 3:(7-10), the reaction temperature is 100-135°C, the reaction time is 12-48 hours, and pink solid SBDP is obtained by column chromatography.

9. Use of the fluorine boron compound according to claim 1 in the preparation of an anti-tumor photosensitizer.

10. A method for preparing a mitochondrial targeted photosensitizer, characterized in that: The fluorine-boron compound of claim 1 is dissolved in tetrahydrofuran, and DSPE-PEG is added under ultrasonic conditions. 2000 After the reaction is completed, the tetrahydrofuran is removed by stirring in ultrapure water, and the solution is filtered to obtain a pink clear SBDP nanoparticle solution, which is a mitochondrial targeted photosensitizer.

11. The method for preparing a mitochondrial-targeted photosensitizer according to claim 10, characterized in that: SBDP and DSPE-PEG 2000 The mass ratio is 1:(10-20), and stirred at room temperature for 24-48 hours.

12. A mitochondrial-targeted photosensitizer prepared by the method according to any one of claims 10-11.

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