Azobenzene modified cyanine near-infrared photosensitizer as well as preparation method and application thereof
By modifying cyanin by azobenzene, two near-infrared photosensitizers o2CyO-AB and p2CyO-AB were developed, which solved the problem of poor effectiveness of existing photodynamic therapy and photothermal therapy in tumor treatment, achieved a significant improvement in the photothermal conversion efficiency and 1O2 generation ability, and had good biosafety and tumor suppression effect.
Patent Information
- Application Number
- CN202510319524.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2025-06-24
AI Technical Summary
Existing photodynamic therapy (PDT) and photothermal therapy (PTT) are not effective in tumor treatment, especially due to the lack of obvious results in tumor hypoxia environment, and the photostability and singlet oxygen yield of photothermal therapy are low.
By modifying cyanin by azobenzene, two near-infrared photosensitizers o2CyO-AB and p2CyO-AB are synthesized to improve their photothermal conversion efficiency and singlet oxygen generation ability.
It significantly improved the photothermal conversion efficiency and 1O2 production, enhanced the multimodal therapeutic effect of PTT and PDT, and significantly suppressed tumors on human tongue squamous cell carcinoma cells and tumor-bearing mice, and had low biotoxicity.
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Figure CN120192261A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of biomedical technologies, and particularly to a near-infrared photosensitizer based on azobenzene-modified cyanine and a preparation method thereof, as well as applications of the photosensitizer in tumor photothermal therapy (PTT) and photodynamic therapy (PDT). Background Art
[0002] Photodynamic therapy (PDT) is a non-invasive treatment method that uses a photosensitizer to generate reactive oxygen species (ROS) such as singlet oxygen ( 1 O2) under irradiation with specific wavelengths of light, thereby killing diseased cells. This method shows great potential in the fields of tumor treatment, antibacterial disinfection, and skin disease treatment. However, the tumor site often has an oxygen-deficient environment due to rapid cell growth, resulting in an unclear photodynamic therapy effect. At the same time, the photodynamic therapy process rapidly consumes oxygen, which will exacerbate the oxygen deficiency in tumor tissues and further affect the efficacy of photodynamic therapy. Photothermal therapy (PTT) is a new non-invasive tumor treatment method that uses a photosensitizer to convert light energy into heat energy under near-infrared light irradiation to kill tumor cells. Compared with single PDT or PTT, the combination of PTT and PDT has less trauma, higher selectivity, and lower side effects.
[0003] Cyanine dyes are commonly used near-infrared photosensitizers, which have a high molar extinction coefficient, but also have deficiencies such as poor photostability and low singlet oxygen ( 1 O2) quantum yield. As a photo-responsive molecular fragment, azobenzene has ultrafast non-radiative transitions and can be used to modify cyanine dyes to improve photoacoustic imaging performance. At the same time, the azobenzene group has a responsive property to azoreductase highly expressed in tumors. Modifying the cyanine parent nucleus with the azobenzene group is also expected to improve its PDT effect. The present invention synthesizes two derivatives by modifying cyanine with azobenzene, significantly improving 1 O2 generation and photothermal conversion efficiency, and having significantly enhanced PTT and PDT multimodal treatment effects in tumor-bearing mice. At the same time, the two photosensitizers have very low biological toxicity and have good application potential.
[0004] Based on this, the present application provides a near-infrared light-absorbing material based on azobenzene-modified cyanine, a preparation method thereof, and applications thereof. Summary of the Invention
[0005] The first object of the present invention is to provide two near-infrared light-absorbing materials with PTT / PDT effects. Generally speaking, azobenzene is introduced onto the cyanine parent nucleus to construct two azobenzene-modified cyanine derivatives o2CyO-AB and p2CyO-AB.
[0006] The second object of the present invention is to provide a preparation method of the above-mentioned azobenzene-modified cyanine derivatives o2CyO-AB and p2CyO-AB. Generally speaking, 2-(2-{2-chloro-3-[1,3,3-trimethyl-1,3(2H)-indol-2-ylidene)ethylidene]-1-cyclohexenyl}vinyl)-1,3,3-trimethylindole iodide (Cy-Cl) undergoes a substitution reaction with 2,2'-dihydroxyazobenzene or 4,4'-dihydroxyazobenzene respectively to obtain o2CyO-AB or p2CyO-AB.
[0007] The third object of the present invention is to provide the applications of the azobenzene-modified cyanine derivatives o2CyO-AB and p2CyO-AB. Specifically, o2CyO-AB and p2CyO-AB have low biotoxicity and are used for the PTT / PDT multimodal treatment of oral squamous cell carcinoma cells and tumor-bearing mice, with remarkable curative effects.
[0008] The object of the present invention can be achieved by the following technical methods:
[0009] In the first aspect, the present invention claims a near-infrared absorbing material based on azobenzene-modified cyanine, and the structural formula of the near-infrared absorbing material is shown as formula (Ⅰ) or (Ⅱ):
[0010]
[0011] Specifically, the above-mentioned near-infrared absorbing materials are 2,2'-di{6-[2-(1,3,3-trimethyl-1,3(2H)-indol-2-ylidene)ethylidene]-2-[2-(1,3,3-trimethyl-3(H)-indol-2-yl)vinyl]cyclohexyl-1-oxy}azobenzene diiodide (o2CyO-AB) and 2,2'-di{6-[2-(1,3,3-trimethyl-1,3(2H)-indol-2-ylidene)ethylidene]-2-[2-(1,3,3-trimethyl-3(H)-indol-2-yl)vinyl]cyclohexyl-1-oxy}azobenzene diiodide (p2CyO-AB), and the structural formulas of o2CyO-AB and p2CyO-AB are shown as formula (I) and (Ⅱ).
[0012] In the second aspect, the present invention claims the crystal of the above-mentioned near-infrared absorbing material. The single crystal structure parameters of the infrared absorbing material (p2CyO-AB) with the structural formula shown as formula (Ⅱ) are: monoclinic system, space group C2 / m, crystal axes The crystal face angle α = 90°, β = 90.09°, γ = 90°, and the unit lattice volume is The number of molecules in the lattice, and the lattice density is 0.887 g / cm 3 .
[0013] Third aspect, the present invention claims the preparation method of the above near-infrared absorbing material, and the method comprises the following steps:
[0014] 2-(2-{2-chloro-3-[1,3,3-trimethyl-1,3(2H)-indol-2-ylidene)ethylidene]-1-cyclohexenyl}vinyl)-1,3,3-trimethylindolium iodide (Cy-Cl) respectively undergoes substitution reactions with 2,2'-dihydroxyazobenzene or 4,4'-dihydroxyazobenzene to obtain near-infrared absorbing materials o2CyO-AB or p2CyO-AB shown in the structural formula of formula (Ⅰ) or (Ⅱ).
[0015] Furthermore, in the above preparation method, the substitution reaction is carried out in the presence of triethylamine and N,N-dimethylformamide.
[0016] Furthermore, the molar ratio of Cy-Cl, 2,2'-dihydroxyazobenzene, triethylamine, and N,N-dimethylformamide is 1:0.3-0.5:1.0-3.0:10-30; the molar ratio of Cy-Cl, 4,4'-dihydroxyazobenzene, triethylamine, and N,N-dimethylformamide is 1:0.3-0.5:1.0-3.0:10-30.
[0017] Furthermore, the specific steps of the above substitution reaction are: 2,2'-dihydroxyazobenzene or 4,4'-dihydroxyazobenzene is respectively mixed evenly with Cy-Cl, triethylamine, and N,N-dimethylformamide, and reacted at 20-50 °C to obtain near-infrared absorbing materials o2CyO-AB or p2CyO-AB shown in the structural formula of formula (Ⅰ) or (Ⅱ).
[0018] In the specific embodiments of the present invention, the preparation method of the near-infrared absorbing material specifically comprises the following steps:
[0019] (1) 2-(2-{2-chloro-3-[1,3,3-trimethyl-1,3(2H)-indol-2-ylidene)ethylidene]-1-cyclohexenyl}vinyl)-1,3,3-trimethylindolium iodide (Cy-Cl) undergoes a substitution reaction with 2,2'-dihydroxyazobenzene in the presence of triethylamine and N,N-dimethylformamide, and is mixed evenly according to the molar ratio of 1:0.3-0.5:1.0-3.0:10-30 and reacted at 20-50 °C to obtain the product o2CyO-AB.
[0020] (2) 2-(2-{2-chloro-3-[1,3,3-trimethyl-1,3(2H)-indol-2-ylidene)ethylidene]-1-cyclohexenyl}vinyl)-1,3,3-trimethylindolium iodide (Cy-Cl) reacts with 4,4'-dihydroxyazobenzene in the presence of triethylamine and N,N-dimethylformamide. They are mixed evenly according to a molar ratio of 1:0.3 - 0.5:1.0 - 3.0:10 - 30 and reacted at 20 - 50 °C to obtain the product p2CyO-AB.
[0021] In the specific implementation manner of the present invention, the above-mentioned near-infrared absorbing material crystal is obtained by the following method: Weigh the product p2CyO-AB prepared by the above method, dissolve it in dichloromethane, filter, add ethyl acetate, let it stand, and the solvent volatilizes to precipitate single crystals.
[0022] Fourthly, the present invention claims the application of the above-mentioned near-infrared absorbing material or the above-mentioned crystal as a photosensitizer in the preparation of a drug for treating tumors by photodynamic therapy.
[0023] Fifthly, the present invention claims a drug for treating tumors by photodynamic therapy, and the drug uses the above-mentioned near-infrared absorbing material or the above-mentioned crystal as a photosensitizer.
[0024] The tumor mentioned in the present invention is cancer, and the cancer is human tongue squamous cell carcinoma.
[0025] The research results of the present invention show that by modifying cyanine with azobenzene, the photothermal conversion ability can be enhanced. The photothermal conversion efficiencies of o2CyO-AB and p2CyO-AB are 51.75% and 54.50% respectively. By modifying cyanine with azobenzene, the 1 O2 generation ability can be enhanced. The 1 O2 quantum yields of o2CyO-AB and p2CyO-AB are 3.15% and 1.35% respectively, which are 15.7 and 6.75 times that of indocyanine green.
[0026] During the research process, HN6 cells and tumor-bearing nude mice were selected as the research objects for evaluating the efficacy of tumor growth inhibition, and the tumor inhibitory effects of the above materials were detected. The co-incubation method was used to evaluate the tumor inhibitory effects of the photosensitizer. When the tumor volume in the nude mice reached 100 mm 3When the anti-tumor effect test was carried out. The results showed that o2CyO-AB and p2CyO-AB under laser irradiation had obvious inhibitory effects on human tongue squamous carcinoma cells (HN6). o2CyO-AB and p2CyO-AB under laser irradiation had obvious inhibitory effects on the tumor growth of tumor-bearing (HN6) mice. It was shown that after treatment with o2CyO-AB and p2CyO-AB, the tumor growth was inhibited. Among them, o2CyO-AB had a better tumor inhibitory effect, and the above materials had basically no damage to mice in vivo and had good biosafety. In summary, the above near-infrared absorbing materials had good application prospects as photosensitizers in inhibiting the growth of tumor cells.
[0027] Compared with the prior art, the advantages of the present invention are as follows: The two photosensitizers developed in the present invention have a simple synthesis method and are easy to prepare on a large scale; The two azobenzene-modified cyanine derivatives o2CyO-AB and p2CyO-AB prepared have good photothermal conversion effects. 1 The O2 quantum yield is significantly improved; The two photosensitizers themselves have low toxicity and have excellent inhibitory effects on human tongue squamous carcinoma cells under laser irradiation, and can be used for multimodal treatment of tumors. Description of the Drawings
[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art.
[0029] Figure 1 It is a graph of the particle size (a) and potential (b) of the azobenzene-modified cyanine derivative.
[0030] Figure 2 It is a graph of the absorption spectrum (a) and fluorescence spectrum (b) of the azobenzene-modified cyanine derivative.
[0031] Figure 3 It is the change of the temperature of the azobenzene-modified cyanine derivative solution with the irradiation time (a) and the photothermal conversion efficiency (b) under laser irradiation.
[0032] Figure 4 It is the singlet oxygen quantum yield of the azobenzene-modified cyanine derivative.
[0033] Figure 5 It is the comparison of the cytotoxicity of the azobenzene-modified cyanine derivative before and after laser irradiation.
[0034] Figure 6 It is the intracellular reactive oxygen level of the azobenzene-modified cyanine derivative under laser irradiation; Among them, (a) is the intracellular reactive oxygen generation diagram; (b) is the fluorescence intensity diagram of the probe 2’,7’-dichlorofluorescein diacetate (detecting intracellular reactive oxygen generation).
[0035] Figure 7 Distribution map of azobenzene-modified cyanine derivatives in tumor-bearing mice.
[0036] Figure 8 Fluorescence imaging of major organs of tumor-bearing mice.
[0037] Figure 9 Tumor volume changes of tumor-bearing mice in different treatment groups over treatment time. Detailed implementation
[0038] All raw materials used in this invention were purchased from Aladdin Reagent Co., Ltd. Fluorescence emission spectra were measured at room temperature using an FS 5 fluorescence spectrometer from Edinburgh Instruments, with an excitation wavelength of 720 nm and a scanning wavelength range of 740 - 860 nm; particle size was measured by dynamic light scattering using a Malvern Zetasizer; ultraviolet absorption spectra were measured at room temperature using a Cary 5000 UV-Vis spectrophotometer from Agilent Technologies, with a scanning wavelength range of 500 - 1000 nm. The room temperature was 25 ± 5 °C, but not limited to this.
[0039] Example 1 Preparation and characterization of azobenzene-modified cyanine derivatives
[0040] (1) Preparation:
[0041] Into a 50 mL three-necked flask, 1.22 g (20 mmol) of Cy-Cl (purchased from Aladdin Reagent Co., Ltd.), 0.21 g (10 mmol) of 4,4'-dihydroxyazobenzene, 0.40 g (40 mmol) of triethylamine, and 20 mL (260 mmol) of N,N-dimethylformamide were successively added, and the mixture was stirred at room temperature for 24 h. 10 mL of water was added to precipitate a solid. The solid was filtered, dried under vacuum, and recrystallized from dichloromethane / ethyl acetate to obtain brown crystals with a yield of 75.2%. 1 H NMR (400 MHz, DMSO-d 6 ) δ (ppm): 7.98 (d, J = 4.0 Hz, 4H), 7.85 (d, J = 8.0 Hz, 4H), 7.85 (d, J = 4.0 Hz, 4H), 7.39 - 7.36 (m, 12H), 7.22 - 7.11 (m, 4H), 6.22 (d, J = 8.0 Hz, 4H), 3.64 (s, 12H), 2.78 (br, 8H), 2.00 (br, 4H), 1.25 (s, 24H).
[0042] Weigh 10 mg of p2CyO-AB and dissolve it in 10 mL of dichloromethane, filter, add 10 mL of ethyl acetate, and let it stand at room temperature. The solvent evaporates to precipitate single crystals. The single crystal structure parameters are: monoclinic system, space group C2 / m, crystal axes The included angle of crystal planes α = 90°, β = 90.09°, γ = 90°, and the unit lattice volume is the number of molecules in the lattice, and the lattice density is 0.887 g / cm 3 .
[0043] In a 50 mL three-necked flask, 1.22 g (20 mmol) of Cy-Cl, 0.21 g (10 mmol) of 2,2'-dihydroxyazobenzene, 0.40 g (40 mmol) of triethylamine, and 20 mL (260 mmol) of N,N-dimethylformamide were successively added, and the reaction was stirred at room temperature for 24 h. 10 mL of water was added to precipitate a solid. The solid was filtered, dried under vacuum, and recrystallized from chloroform to obtain a red-brown crystal with a yield of 67.8%. 1 HNMR (400 MHz, DMSO-d 6 ) δ (ppm): 7.98 (d, J = 4.0 Hz, 4H), 7.85 (d, J = 4.0 Hz, 2H), 7.55 (t, J = 8.0 Hz, 2H), 7.39 (t, J = 8.0 Hz, 8H), 7.31 - 7.23 (m, 6H), 7.18 - 7.13 (m, 6H), 6.26 (d, J = 8.0 Hz, 4H), 3.65 (s, 12H), 2.80 (s, 8H), 2.00 (br, 4H), 1.44 (s, 12H), 1.10 (s, 12H).
[0044] (2) Preparation and characterization of nanoparticles: The photosensitizers Cy-Cl, o2CyO-AB, and p2CyO-AB were respectively dissolved in dimethyl sulfoxide to prepare stock solutions of 1 mg / mL. Pure water was added to obtain nanoparticle solutions with corresponding concentrations of 5, 10, and 100 μg / mL. A nanoparticle size and Zeta potential analyzer was used to measure the particle size and potential of Cy-Cl, o2CyO-AB, and p2CyO-AB nanoparticles (10 μg / mL), as Figure 1 shown.
[0045] Example 2: Absorption spectrum and fluorescence spectrum tests
[0046] An ultraviolet spectrometer was used to test the absorption peaks of Cy-Cl, o2CyO-AB, and p2CyO-AB nanoparticles, and a fluorescence spectrometer was used to test the emission peaks of Cy-Cl, o2CyO-AB, and p2CyO-AB, as Figure 2 shown.
[0047] Example 3: Photothermal effect evaluation
[0048] Prepare 100 μg / mL of o2CyO-AB and p2CyO-AB nanoparticles according to Example 1, at a wavelength of 808 nm and a power density of 1.0 W / cm2 Under laser irradiation, a thermal imager was used to record the temperature changes at 1-min intervals. Figure 3 As shown, the photothermal effects of the two are comparable. After calculation, the photothermal conversion efficiencies of o2CyO-AB and p2CyO-AB are 51.75% and 54.50%, respectively.
[0049] Example 4: Singlet oxygen quantum yield test
[0050] Diphenylisobenzofuran (DPBF) was used as 1 O2 indicator, evaluation of two photosensitizers o2CyO-AB and p2CyO-AB (concentration 5μg / mL) 1 The generation of O2 was performed by 808 nm laser (0.5 W / cm 2 ) irradiation, the absorbance change of DPBF at 420nm was tested by UV spectrophotometer, and the near-infrared photosensitizer indocyanine green (ICG) used in clinic was used as the benchmark to calculate and compare its 1 O2 quantum yield, such as Figure 4 As shown, o2CyO-AB and p2CyO-AB 1 The O2 quantum yields are 3.15% and 1.35%, which are 15.7 and 6.75 times that of indocyanine green, respectively.
[0051] Example 5: Cell assay
[0052] Human tongue squamous cell carcinoma cells (HN6) were selected as the research object of the cell experiment.
[0053] CCK-8 kit was used to detect cell viability and evaluate the cytotoxicity of the materials. First, HN6 cells were cultured at 1×10 4 The cells were inoculated at a density of 100 μg / mL in a 96-well plate and cultured in a standard cell culture incubator for 24 h. The cells were washed three times with PBS and treated with different concentrations of material solutions. After further incubation for 12 h, the cells were washed three times with PBS and the cell metabolic activity was detected using CCK-8. The results showed good biocompatibility.
[0054] To detect laser toxicity, HN6 cells were cultured at 1 × 10 4 The cells were seeded in a 96-well plate at a density of 1.50 μg / cm2 and cultured for 24 h. The culture medium was discarded and replaced with cell culture medium containing different concentrations of Cy-Cl, o2CyO-AB and p2CyO-AB and incubated for 12 h. The cells were then cultured at 37 °C with a wavelength of 808 nm and a power density of 1 W / cm2. 2 After 24 h of incubation, the cells were washed three times with PBS and cell viability was detected using CCK-8. Figure 5As shown, under laser irradiation, o2CyO-AB has the strongest killing ability against HN6 cells.
[0055] Using 2’,7’-dichlorofluorescein diacetate as an indicator of intracellular reactive oxygen species. HN6 cells were seeded in culture dishes at a density of 1.0×10 5 cells per dish and cultured for 24 h, and then incubated overnight with the above material solutions. After removing the culture medium and washing with PBS, the cells were then incubated with 2’,7’-dichlorofluorescein diacetate (10 μM, 1 mL) for 20 min, and then irradiated with a laser at a wavelength of 808 nm and a power density of 1 W / cm 2 for 5 min at room temperature, and then fluorescence images were taken using a laser confocal microscope. The results are as Figure 6 shown. Compared with Cy-Cl, the generation of intracellular reactive oxygen species was significantly increased in o2CyO-AB and p2CyO-AB, and o2CyO-AB had the strongest ability to generate intracellular reactive oxygen species.
[0056] Example 5: Animal experiments
[0057] Immunodeficient nude mice were used in the experiment. HN6 human tongue squamous carcinoma cells were subcutaneously injected into the nude mice to establish a tumor model. When the tumor volume reached 100 mm 3 , an anti-tumor effect test was carried out. The nude mice were randomly divided into different experimental groups.
[0058] By injecting the materials into the tail vein of the nude mice, small animal in vivo imaging was performed. As Figure 7 shown, the materials had tumor targeting. After 40 min, the nude mice were sacrificed and the important organs (heart, liver, spleen, lung, kidney) were dissected. As Figure 8 shown, the liver was the main metabolic organ of Cy-Cl, o2CyO-AB and p2CyO-AB.
[0059] (1) Blank control group (each nude mouse was injected with 100 μL of normal saline and not irradiated with laser)
[0060] (2) Nanoparticle (Cy-Cl) + laser treatment group: Each nude mouse was injected with 100 μL of 100 μg / mL Cy-Cl nanoparticles via the tail vein, and the tumor area was irradiated with an 808 nm 1 W / cm 2 laser for 10 min.
[0061] (3) Nanoparticle (o2CyO-AB) + laser treatment group: Each nude mouse was injected with 100 μL of 100 μg / mL o2CyO-AB nanoparticles via the tail vein, and the tumor area was irradiated with an 808 nm 1 W / cm 2 laser for 10 min.
[0062] (4) Nanoparticle (p2CyO-AB) + Laser Treatment Group: Each nude mouse was intravenously injected with 100 μL of 100 μg / mL p2CyO-AB nanoparticles, and the tumor area was irradiated with 808 nm 1 W / cm 2 laser for 10 min.
[0063] All nude mice were treated once every four days. No treatment was carried out in the last 6 days of the experiment. The tumor volume was measured every 2 days during the treatment. The following formula was used to calculate the tumor volume: Volume = length × width × height × π / 6.
[0064] By Figures 7-9 The results showed that:
[0065] ① The tumor volume in the control group increased rapidly;
[0066] ② The tumor growth in the azobenzene-modified cyanine derivative material + laser treatment group was inhibited, resulting in a significant reduction in tumor volume. Among them, o2CyO-AB had the best effect on inhibiting tumor growth.
[0067] It should be noted that the above examples are only used to illustrate the specific implementation manners of the present invention and do not limit the technical solutions of the present invention; for professionals in the technical field, it should be understood that the present invention allows corresponding modifications or equivalent replacements; in short, all technical solutions and their improvements that do not deviate from the core concept and protection scope of the present invention should be regarded as being included in the scope claimed by the present invention.
Claims
1. A near-infrared absorbing material based on azobenzene-modified anthocyanin, characterized in that: The structural formula of the near infrared absorbing material is shown in formula (I) or (II):
2. The crystal of near infrared absorbing material according to claim 1, characterized in that: The single crystal structural parameters of the infrared absorbing material shown in formula (II) are: monoclinic system, space group C2 / m, crystal axis The crystal plane angles α = 90°, β = 90.09°, γ = 90°, and the unit lattice volume is The number of molecules in the lattice, the lattice density is 0.887g / cm 3 .
3. The method for preparing the near infrared absorbing material according to claim 1, characterized in that: The method comprises the following steps: 2-(2-{2-chloro-3-[1,3,3-trimethyl-1,3(2H)-indol-2-methylene)ethylidene]-1-cyclohexenyl}vinyl)-1,3,3-trimethylindole iodide (Cy-Cl) undergoes a substitution reaction with 2,2'-dihydroxyazobenzene or 4,4'-dihydroxyazobenzene to obtain a near-infrared absorbing material o2CyO-AB or p2CyO-AB having a structural formula as shown in formula (I) or (II).
4. The preparation method according to claim 3, characterized in that: The substitution reaction is carried out in the presence of triethylamine and N,N-dimethylformamide.
5. The preparation method according to claim 4, characterized in that: The molar ratio of Cy-Cl, 2,2'-dihydroxyazobenzene, triethylamine and N,N-dimethylformamide is 1:0.3-0.5:1.0-3.0:10-30; The molar ratio of Cy-Cl, 4,4'-dihydroxyazobenzene, triethylamine and N,N-dimethylformamide is 1:0.3-0.5:1.0-3.0:10-30.
6. The preparation method according to claim 4, characterized in that: The specific steps of the substitution reaction are: 2,2'-dihydroxyazobenzene or 4,4'-dihydroxyazobenzene are respectively mixed with Cy-Cl, triethylamine and N,N-dimethylformamide, and reacted at 20-50°C to obtain a near-infrared absorbing material o2CyO-AB or p2CyO-AB having a structural formula as shown in formula (I) or (II).
7. Use of the near-infrared absorption material according to claim 1 or the crystal according to claim 2 as a photosensitizer in the preparation of a drug for treating tumors using photodynamic therapy.
8. The use according to claim 7, characterized in that: The tumor is human tongue squamous cell carcinoma.
9. A drug for treating tumors using photodynamic therapy, characterized in that: The drug uses the near-infrared absorbing material according to claim 1 or the crystal according to claim 2 as a photosensitizer.