Near-infrared second-region small organic molecule compound with acid-base response capability as well as preparation method and application of near-infrared second-region small organic molecule compound

Abstract

The invention provides a near-infrared second-region small organic molecule compound with acid-base response capability and a preparation method and application thereof, the structural formula is shown in the formula (1): # imgabs0 #, and n is 0 or 1 or 2; r is # imgabs 1 # or # imgabs 2 # R1 is # imgabs 3 # m, and p is independently selected from integers from 0 to 5 respectively. The compound has very strong fluorescence / photoacoustic properties, the fluorescence emission wavelength of the compound is located in a near-infrared second region, and the compound is non-toxic, good in biocompatibility and easy to absorb and metabolize by organisms. And the compound has the characteristics of fluorescence / photoacoustic signal quenching in an alkaline environment and fluorescence / photoacoustic signal recovery in an acidic environment, is suitable for being applied to a weakly acidic tumor microenvironment, and has lower background noise and higher signal-to-noise ratio than other small organic molecules. After the compound is entrapped to obtain a probe with good biocompatibility, the probe can be used for near-infrared two-region fluorescence and photoacoustic tumor detection and the like, and has a wide application prospect.

Description

Technical Field

[0001] The patent of this invention relates to the field of medical material technology, and in particular refers to a near-infrared second zone organic small molecule compound with acid-base response ability and its preparation method and application. Background Art

[0002] Cancer (also known as malignant tumor) seriously threatens the health of the people and is a major cause of death worldwide. At present, traditional cancer detection methods include X-rays, CT, MRI and other imaging methods, but due to their low resolution, poor sensitivity, strong radioactivity, high background signal and other shortcomings, they have certain deficiencies in the diagnosis of early cancer. In recent years, the development of biomedical fluorescence imaging technology in the near-infrared second region (1000-1700nm) has provided a highly versatile platform for non-invasive exploration of biological tissues and organs by utilizing its higher penetration depth and higher imaging signal-to-noise ratio. It has the advantages of high sensitivity, deep penetration depth, high temporal and spatial resolution, less tissue background interference, and good biocompatibility. In recent years, in addition to the research on fluorescence imaging, photoacoustic imaging technology has begun to attract much attention. Compared with fluorescence imaging, photoacoustic imaging has higher resolution in deep tissue imaging and better penetration than pure optical imaging. Combined with fluorescence imaging, fluorescence imaging is used to determine the tumor contour, and then photoacoustic imaging is used to determine the tumor depth, which can achieve high-resolution tissue imaging. In tumor diagnosis, due to changes in the metabolic behavior of tumor cells, tumor tissue is weakly acidic compared to normal tissue. This difference is used to design acid-base responsive molecular probes or nanocarriers, which have excellent properties in improving tumor targeting and prolonging the duration of action.

[0003] Currently, there are very few reported fluorescent probes with acid-base responsiveness in the near-infrared region II, and there are almost no molecules with photoacoustic effects, which greatly limits the development and clinical application of near-infrared fluorescence imaging and photoacoustic imaging. Therefore, it is urgent to develop organic small molecule fluorescent / photoacoustic probes with acid-base responsiveness in the near-infrared region II, which has great scientific research, clinical and economic benefits. Summary of the invention

[0004] In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide a new type of near-infrared second-zone organic small molecule fluorescence / photoacoustic probe with acid-base responsiveness, high photostability and good biocompatibility, and use it as a photoacoustic and fluorescence imaging contrast agent for tumors to achieve early diagnosis of cancer.

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art to a certain extent. Therefore, in the first aspect of the present invention, the present invention provides a near-infrared region II organic small molecule compound having acid-base responsiveness, wherein the near-infrared region II organic small molecule compound having acid-base responsiveness has a structural formula as shown in formula (1):

[0006]

[0007] Where n is 0, 1 or 2; R is R1 is m and p are each independently selected from integers of 0-5.

[0008] Preferably, the near-infrared second-zone organic small molecule compound having acid-base responsiveness has a structural formula as shown in formula (1a),

[0009]

[0010] In one or more technical solutions of the present invention, the fluorescence emission wavelength of the near-infrared second zone organic small molecule compound with acid-base response ability is 1000-1400nm, and the wavelength corresponding to the maximum photoacoustic intensity is 700-1100nm.

[0011] In the second aspect of the present invention, the present invention provides a method for preparing the near-infrared second zone organic small molecule compound with acid-base responsiveness as described in the first aspect of the present invention, wherein compound (1) is prepared from compound (17), and the reaction formula for preparing compound (1) from compound (17) is as follows:

[0012]

[0013] Wherein, the definition of n is the same as that in claim 1;

[0014] Preferably, the preparation of compound (1) from compound (17) comprises the following steps: mixing compound (17), acetic anhydride and compound (7) or compound (9), reacting at 80-90° C., and purifying to obtain compound (1).

[0015] In one or more technical solutions of the present invention, compound (17) is prepared from compound (14), and the reaction formula for preparing compound (17) from compound (14) is as follows:

[0016]

[0017] Preferably, the preparation of compound (17) from compound (14) comprises the following steps:

[0018] Step 1): Compound (15), tetrahydropyrrole and benzene are mixed uniformly, heated to reflux, reacted, and after the reaction is complete, the solvent is removed, and compound (14) and 1,4-dioxane are added, heated to reflux, reacted, and after the reaction is complete, purified to obtain compound (16);

[0019] Step 2): Compound (16) and diethyl ether are mixed evenly, and boron trifluoride diethyl ether and thioacetic acid are added, and the mixture is heated to reflux for reaction. After the reaction is complete, the mixture is purified to obtain compound (17);

[0020] In one or more technical solutions of the present invention, compound (14) is prepared from compound (10), and the reaction formula for preparing compound (14) from compound (10) is as follows:

[0021]

[0022] Preferably, the preparation of compound (14) from compound (10) comprises the following steps:

[0023] Step 1): Compound (10), potassium hydroxide aqueous solution and ethanol are mixed and reacted for 8-15 minutes, and then compound (11) is added, stirred and reacted. After the reaction is complete, the mixture is filtered, the filter cake is washed and dried to obtain compound (12);

[0024] Step 2): Compound (12), potassium carbonate and acetone are added and mixed, and compound (13) is added, and the mixture is heated under reflux to react to obtain compound (14).

[0025] In one or more technical solutions of the present invention, compound (9) is prepared from compound (2), and the reaction formula for preparing compound (9) from compound (2) is as follows:

[0026]

[0027] Wherein, the definition of n is the same as that in claim 1;

[0028] Preferably, the preparation of compound (9) from compound (2) comprises the following steps:

[0029] Step 1): Add N,N-dimethylformamide and chloroform into a reaction vessel, slowly add phosphorus tribromide dropwise, react, dissolve compound (2) in chloroform, add into the reaction system, react, after the reaction is complete, adjust the pH to 6.5-7.5, extract, and obtain compound (3);

[0030] Step 2): Add compound (3), cesium carbonate and N,N-dimethylformamide into a reaction container, then add compound (4) dissolved in N,N-dimethylformamide, mix well, react, filter after the reaction is complete, and purify the filter cake to obtain compound (5);

[0031] Step 3): Compound (5), compound (8), tris(dibenzylideneacetone)dipalladium, 2-dicyclohexylphosphine-2'-(N,N-dimethylamino)biphenyl, cesium carbonate and 1,4-dioxane are reacted under anaerobic conditions at 90-100° C. After the reaction is complete, purification is performed to obtain compound (9).

[0032] In one or more technical solutions of the present invention, compound (7) is prepared from compound (2), and the reaction formula for preparing compound (7) from compound (2) is as follows:

[0033]

[0034] Wherein, the definition of n is the same as that in claim 1;

[0035] Preferably, the preparation of compound (7) from compound (2) comprises the following steps:

[0036] Step 1): Add N,N-dimethylformamide and chloroform into a reaction vessel, slowly add phosphorus tribromide dropwise, react, dissolve compound (2) in chloroform, add into the reaction system, react, after the reaction is complete, adjust the pH to 6.5-7.5, extract, and obtain compound (3);

[0037] Step 2): Compound (3), cesium carbonate and N,N-dimethylformamide are added to a reaction container, and then compound (6) dissolved in N,N-dimethylformamide is added, mixed, reacted, filtered after the reaction is complete, and the filter cake is purified to obtain compound (7).

[0038] In the third aspect of the present invention, the present invention provides a use of the near-infrared zone II organic small molecule compound with acid-base responsiveness described in the first aspect of the present invention in the preparation of a near-infrared zone II fluorescent imaging probe for in vivo imaging.

[0039] In the fourth aspect of the present invention, the present invention provides a near-infrared zone II fluorescent imaging probe, which is obtained by encapsulating the near-infrared zone II organic small molecule compound with acid-base responsiveness described in the first aspect of the present invention by polyethylene glycol, polyether F127, polypeptide, protein, and cell membrane.

[0040] In the fifth aspect of the present invention, the present invention provides a use of the near-infrared zone II fluorescent imaging probe described in the fourth aspect of the present invention in the preparation of tumor near-infrared zone II imaging contrast agents and / or tumor photoacoustic imaging contrast agents.

[0041] The beneficial effects of the present invention are:

[0042] 1. The near-infrared zone II organic small molecule compound with acid-base response ability of the present invention has strong fluorescence / photoacoustic properties, making it superior to other organic small molecules with only fluorescence properties.

[0043] 2. The near-infrared region II organic small molecule compound with acid-base response capability of the present invention is a new compound with dual properties of fluorescence / photoacoustic. Its fluorescence emission wavelength is located in the near-infrared region II, is non-toxic, has good biocompatibility, and is easily absorbed and metabolized by organisms. After encapsulation to obtain a probe with good biocompatibility, it can be used for tumor detection in the near-infrared region II fluorescence and photoacoustic.

[0044] 3. The near-infrared zone II organic small molecule compound with acid-base responsiveness of the present invention has the characteristics of fluorescence / photoacoustic signal quenching in an alkaline environment and fluorescence / photoacoustic signal recovery in an acidic environment. It is suitable for application in weakly acidic tumor microenvironments and has lower background noise and higher signal-to-noise ratio than other organic small molecules.

[0045] 4. The present invention provides a method for preparing the above-mentioned near-infrared zone II organic small molecule compound with acid-base responsiveness, which has a simple synthesis route, high reaction efficiency, high yield, and high industrial application prospects.

[0046] 5. The probe prepared from the near-infrared zone II organic small molecule compound with acid-base response ability in the present invention has excellent response ability and fluorescence / photoacoustic imaging effect in biomedical imaging experiments and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is the compound (1a) in Example 4 1 H spectrum;

[0048] Figure 2 is the compound (1a) in Example 4 13 C spectrum.

[0049] Figure 3 The absorption spectrum, emission spectrum and photoacoustic signal intensity spectrum of compound (1a), compound (1b), compound (1c) and compound (1d) in Example 4;

[0050] in, Figure 3 a is the absorption spectrum of compound (1a), compound (1b), compound (1c), and compound (1d); Figure 3 b is the emission spectra of compound (1a), compound (1b), compound (1c), and compound (1d); Figure 3 c is the photoacoustic signal intensity spectrum of compound 1a, compound (1b), compound (1c), and compound (1d);

[0051] Figure 4The absorption spectrum and emission spectrum of the acid-base response ability of compound (1a) in Example 5;

[0052] in, Figure 4 a is the absorption spectrum of the fluorescent probe HTPA after incubation with different concentrations of triethylamine; Figure 4 b is the emission spectrum of the fluorescent probe HTPA after incubation with different concentrations of triethylamine;

[0053] Figure 5 is the absorption spectrum of the acid-base response recovery ability of the compound (1a) of Example 5;

[0054] Figure 6 Schematic diagram of the preparation of the near-infrared second-region fluorescence imaging probe HTPA in Example 6;

[0055] Figure 7 This is a TEM image of the near-infrared second-zone fluorescence imaging probe HTPA in Example 6 to verify the acid-base response ability;

[0056] Figure 8 This is a fluorescence intensity diagram of the near-infrared second-zone fluorescence imaging probe HTPA in Example 6 in buffer solutions with different pH values ​​(6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.4);

[0057] Fig. 9 Fluorescence imaging diagram of the near-infrared second-zone fluorescence imaging probe HTPA in Example 7 on an orthotopic breast cancer mouse model;

[0058] Fig.10 This is the photoacoustic imaging image of the in situ breast cancer mouse model using the near-infrared second-zone fluorescence imaging probe HTPA in Example 7. DETAILED DESCRIPTION

[0059] The present invention will be further described below in conjunction with specific examples and accompanying drawings, but the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. In the following examples, if specific conditions are not specified, they are carried out according to normal conditions or conditions recommended by the manufacturer. The methods used are conventional methods known in the art unless otherwise specified, and the consumables and reagents used are commercially available unless otherwise specified. Unless otherwise specified, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the recorded content may also be applied to the present invention.

[0060] The present invention provides a near-infrared region II organic small molecule compound having acid-base responsiveness, wherein the near-infrared region II organic small molecule compound having acid-base responsiveness has a structural formula as shown in formula (1):

[0061]

[0062] Where n is 0, 1 or 2; R is R1 is m and p are independently selected from integers of 0-5.

[0063] The preparation route of the above-mentioned near-infrared zone II organic small molecule compound with acid-base response ability is as follows:

[0064]

[0065] The following is a description of the synthesis method of compound (1) using compound (1a) as an example: The preparation route of compound (1a) is as follows:

[0066]

[0067] Example 1: Preparation of Compound 3a

[0068] Take N,N-dimethylformamide (12mL, 155mol) and chloroform (50mL) and add them into the reaction container, slowly add phosphorus tribromide (9mL, 94.7mmol). After 1h of reaction, dissolve compound 2a (4mL, 39mmol) in chloroform (10mL), add it into the reaction system, and react at room temperature for 18h. After the reaction is completed, add sodium bicarbonate in an ice bath until the pH is equal to 7, and extract with dichloromethane to obtain 17g of colorless oily liquid, which is compound 3a, with a yield of 60%;

[0069] The structural detection results of compound 3a are as follows:

[0070] 1 H NMR (400MHz, CDCl3) δ10.05 (s, 1H), 2.77 (s, 2H), 2.30 (s, 2H), 1.79 (s, 2H), 1.72 (d, J = 6.0Hz, 2H).

[0071] 13 C NMR (101MHz, DMSO-d6) δ188.9,138.9,130.4,34.1,20.2,19.4,16.3.

[0072] Example 2: Preparation of Compound 5a

[0073] Compound 3a (0.26g 1.26mmol), cesium carbonate (1.2g, 3.68mmol) and N,N-dimethylformamide were added to a reaction vessel (10mL), and compound 4a (0.49g, 2.56mmol) was dissolved in N,N-dimethylformamide (1mL) and slowly added to mix the two thoroughly. The mixture was reacted at room temperature for 24h, and after the reaction was completed, the filter cake was filtered and purified by column silica gel to obtain 186mg of yellow solid, which was compound 2a, with a yield of 51%;

[0074] The structural detection results of compound 5a are as follows:

[0075] 1 H NMR (400MHz, CDCl3) δ10.25 (s, 1H), 7.22–7.13 (m, 2H), 6.99 (d, J = 8.0Hz, 1H), 6.58 (d,J=7.2Hz,1H),2.54(td,J=7.2,3.4Hz,2H),2.40(q,J=6.2Hz,2H),1.70(m,2H).

[0076] 13 C NMR (151MHz, CDCl3) δ188.0,159.7,152.4,130.4,127.7,127.1,125.9,123.1,120.4,118.8,30.2,21.5,20.3.

[0077] Example 3: Preparation of Compound 9a

[0078] Compound 5a (375.7 mg, 1.3 mmol), compound 8a (137 mg, 0.9 mmol), tris(dibenzylideneacetone)dipalladium, 2-dicyclohexylphosphine-2'-(N,N-dimethylamino)biphenyl, cesium carbonate (880 mg, 2.70 mmol) and 1,4-dioxane (1 mL) were added to a reaction vessel and reacted at 95 ° C for 18 h under anaerobic conditions. After the reaction was completed, it was cooled to room temperature and separated and purified by column silica gel to obtain 200 mg of an orange-yellow solid, which was compound 9a, with a yield of 35%.

[0079] The structural detection results of compound 9a are as follows:

[0080] 1H NMR (400MHz, CDCl3) δ10.20 (s, 1H), 7.12 (d, J = 8.4Hz, 4H), 6.92 (dd, J = 20.9, 8.4Hz, 5H), 6. 60(d,J=9.3Hz,2H),3.84(s,6H),2.57(t,J=6.1Hz,2H),2.45(t,J=6.0Hz,2H),1.72(m,2H).

[0081] 13 C NMR (151MHz, CDCl3) δ187.6,156.9,153.4,150.9,139.7,127.6,127.4,127. 1,125.6,115.1,115.2,114.7,113.9,112.2,104.8,55.6,30.1,21.7,20.7.

[0082] Example 4: Preparation of Compound 1a

[0083] The method and preparation steps of compound 10a for preparing compound 17a are the same as those in CN109369633B. Compound 17a (160 mg, 0.46 mmol) and compound 8a (242 mg, 0.55 mmol) were dissolved in 5 mL of acetic anhydride and reacted at 85°C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, ether was added to precipitate, and the filter cake was obtained by filtration. The purple-black solid was separated and purified by column silica gel to obtain 298 mg of compound 1a with a yield of 76%.

[0084] The structural detection results of compound 1a are as follows:

[0085] 1 H NMR (400MHz, CD3CN) δ7.59–7.45(m,9H),7.40(d,J=1.6Hz,1H),7.35–7.30(m,2H),7.04(d,J=8.5Hz,4H),6.97–6.93( m,2H),6.87(d,J=8.7Hz,4H),6.76–6.72(m,2H),4.75(d,J=2.4Hz,2H),3.73(s,6H),2.66–2.49(m,4H),2.22(s,2H).

[0086] 13C NMR(126MHz,CD3CN)δ162.4,162.0,159.9,157.9,155.4,153.2,146.4,145.4 ,144.9,138.1,137.8,132.3,129.1,129.0,128.3,128.2,127.9,127.8,127. 7,126.5,126.1,119.0,116.9,116.4,115.5,115.1,101.3,78.0,76.8,55.9,55.2,31.6,30.9,30.3,29.4,29.3,29.2,29.0,28.9,28.2,26.8,20.6,13.2.

[0087] Compound (1b), compound (1c) and compound (1d) were prepared by a method similar to that of compound (1a), wherein n of compound (1b) is 0 and R is m is 0; n of compound (1c) is 1, and R is m is 0; n of compound (1d) is 2, and R is m is 0.

[0088] Figure 1 is the compound (1a) in Example 4 1 H spectrum.

[0089] Figure 2 is the compound (1a) in Example 4 13 C spectrum.

[0090] Figure 3 are the absorption spectra, emission spectra and photoacoustic signal intensity spectra of compound (1a), compound (1b), compound (1c) and compound (1d) in Example 4; wherein, Figure 3 a is the absorption spectrum of compound (1a), compound (1b), compound (1c), and compound (1d), Figure 3 b is the emission spectra of compound (1a), compound (1b), compound (1c), and compound (1d); Figure 3 c is the photoacoustic signal intensity spectrum of compound (1a), compound (1b), compound (1c) and compound (1d).

[0091] Example 5: Verification of the acid-base response ability of compound 1a

[0092] Compound 1a was dissolved in N,N-dimethylformamide to a concentration of 400 μM. Triethylamine was dissolved in N,N-dimethylformamide to concentrations of 1600 μM, 1200 μM, 800 μM, 400 μM, 200 μM, 100 μM, 50 μM, and 25 μM. Compound 1a solution was mixed with triethylamine solutions of different concentrations in equal volumes, and the absorption and emission spectra were measured after co-incubation. Figure 4 The absorption spectrum and emission spectrum of the acid-base response ability of compound (1a) in Example 5; wherein, Figure 4 a is the absorption spectrum of the fluorescent probe HTPA after incubation with different concentrations of triethylamine; Figure 4 b is the emission spectrum of the fluorescent probe HTPA after co-incubation with different concentrations of triethylamine. It can be seen from the figure that with the increase of triethylamine concentration, the absorption and emission spectra of compound 1a both decrease significantly, reaching the lowest when the ratio is 1:4. Figure 5 The absorption spectrum of the acid-base response recovery ability of compound (1a). It can be seen from the figure that in each cycle, after the compound 1a solution was incubated with the same concentration of triethylamine solution, trifluoroacetic acid was added for neutralization to restore the fluorescence signal of compound 1a to the level before incubation, indicating that compound 1a has the properties of absorption and fluorescence quenching under alkaline conditions and fluorescence recovery under acidic conditions.

[0093] Example 6: Compound 1a was prepared as a near-infrared second-zone fluorescence imaging probe HTPA, and its acid-responsive release performance was detected. The preparation reaction formula of polymer 1 is shown below:

[0094]

[0095] The specific steps are as follows:

[0096] Carboxyl-polyethylene glycol-carboxyl (8 g, 1.6 mmol) and TEA (1.3 mL, 9.6 mmol) were dissolved in 250 mL of dichloromethane. In an ice bath, 2-bromoisobutyryl bromide (1 mL, 8 mmol) dissolved in 10 mL of dichloromethane was added dropwise. After stirring for 24 hours, the mixture was washed with 1M NaOH (3×50 mL), 1M HCl (3×50 mL) and deionized water (3×50 mL). After drying over anhydrous MgSO4, the solution was concentrated and ether was added to precipitate the product. After three more precipitations and vacuum drying, intermediate 1 was obtained. 2-(Diisopropylamino)ethyl methacrylate, intermediate 1 (0.75 g, 0.15 mmol), pentamethyldiethylenetriamine (31.5 μL, 0.15 mmol) were dissolved in DMF (3 mL) and 2-propanol (3 mL). Vacuum the mixture and add CuBr (21.6 mg, 0.15 mmol) under nitrogen atmosphere. After reacting at 40°C for 24 hours, add tetrahydrofuran (THF) to dilute the product, and then remove the catalyst through a neutral alumina column. The obtained tetrahydrofuran solution is concentrated and then dialyzed with deionized water. After vacuum drying, polymer 1 is obtained.

[0097] Figure 6 The schematic diagram of the preparation of the near-infrared second-zone fluorescence imaging probe HTPA is as follows: polymer 1 is dissolved in N,N-dimethylformamide to a concentration of 20 mg / mL. Compound 1a is dissolved in N,N-dimethylformamide to prepare a 5 mg / mL solution, polymer 1 and compound 1a solution are mixed at a ratio of 25:1 (w / w), and the mixture is added dropwise to 18 mL of deionized water under vigorous stirring (1000 rpm). The formed nanoparticle dispersion is transferred to an ultrafiltration device (EMDMillipore, MWCO 100K) and centrifuged to remove organic solvents and free compounds. The near-infrared second-zone fluorescence imaging probe HTPA is obtained. After washing with phosphate buffered saline (PBS, pH 7.4) solution (3×5 mL), the obtained nanoparticles are dispersed in 1 mL of PBS buffer. HTPA is dissolved in buffer solutions of different pH values ​​to a concentration of 200 μM. Figure 7 This is a TEM image of the near-infrared zone II fluorescence imaging probe HTPA nanoparticles to verify the acid-base response ability. It can be seen from the figure that when the pH value is 7.4, HTPA maintains a stable nanoparticle morphology of approximately 100 nm; when the pH value is 6.0, the nanoparticle morphology is destroyed due to the depolymerization of polymer 1. Figure 8This is the fluorescence intensity diagram of the near-infrared second zone fluorescence imaging probe HTPA nanoparticles in buffer solutions with different pH values ​​(6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.4); it can be seen from the figure that as the pH value of the buffer solution decreases, the fluorescence intensity of the HTPA nanoparticles gradually increases, indicating that HTPA has the ability to restore fluorescence under acidic conditions.

[0098] Example 7: Fluorescence / photoacoustic imaging of subcutaneous breast cancer-bearing mice using near-infrared second-zone fluorescence imaging probe HTPA

[0099] The near-infrared zone II fluorescence imaging probe HTPA (200μM, PBS, 200μL) was injected into subcutaneous breast cancer tumor-bearing mice through the tail vein, and near-infrared zone II in vivo fluorescence imaging and photoacoustic imaging were performed at different time points. Fig. 9 This is the fluorescence imaging image of the near-infrared second-zone fluorescence imaging probe HTPA on an orthotopic breast cancer mouse model; Fig.10 This is the photoacoustic imaging of the near-infrared zone II fluorescence imaging probe HTPA on the in situ breast cancer mouse model. As can be seen from the figure, with the passage of time after the injection of the probe, the enrichment of the probe in the tumor site of the model mouse increased significantly, reaching the maximum at 96 hours, indicating that the probe HTPA has good targeting for subcutaneous breast cancer tumors and can be used for near-infrared zone II fluorescence / photoacoustic imaging of in vivo breast cancer.

[0100] Experiments have confirmed that compounds (1b), (1c) and (1d) can also be used for near-infrared second-zone fluorescence / photoacoustic imaging of in vivo breast cancer.

[0101] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention, which shall all be included in the scope of protection of the present invention.

Claims

1. A near-infrared second-zone organic small molecule compound with acid-base response ability, characterized in that: The structural formula of the near-infrared second-zone organic small molecule compound with acid-base response capability is shown in formula (1): Where n is 0, 1 or 2; R is R1 is m and p are independently selected from integers of 0-5.

2. The near-infrared second region organic small molecule compound with acid-base responsiveness according to claim 1, characterized in that: The fluorescence emission wavelength of the near-infrared second zone organic small molecule compound with acid-base response ability is 1000-1400nm, and the wavelength corresponding to the maximum photoacoustic intensity is 700-1100nm.

3. A method for preparing a near-infrared second-region organic small molecule compound with acid-base responsiveness according to claim 1 or 2, characterized in that: Compound (1) is prepared from compound (17). The reaction formula for preparing compound (1) from compound (17) is as follows: Wherein, n and R are defined as in claim 1; Preferably, the preparation of compound (1) from compound (17) comprises the following steps: mixing compound (17), acetic anhydride and compound (7) or compound (9), reacting at 80-90° C., and purifying to obtain compound (1).

4. The method for preparing a near-infrared second-region organic small molecule compound with acid-base responsiveness according to claim 3, characterized in that: Compound (17) is prepared from compound (14). The reaction formula for preparing compound (17) from compound (14) is as follows: Preferably, the preparation of compound (17) from compound (14) comprises the following steps: Step 1): Compound (15), tetrahydropyrrole and benzene are mixed uniformly, heated to reflux, reacted, and after the reaction is complete, the solvent is removed, and compound (14) and 1,4-dioxane are added, heated to reflux, reacted, and after the reaction is complete, purified to obtain compound (16); Step 2): Compound (16) and diethyl ether are mixed evenly, and boron trifluoride diethyl ether and thioacetic acid are added, and the mixture is heated to reflux for reaction. After the reaction is complete, the mixture is purified to obtain compound (17).

5. The method for preparing a near-infrared second-region organic small molecule compound with acid-base responsiveness according to claim 4, characterized in that: Compound (14) is prepared from compound (10). The reaction formula for preparing compound (14) from compound (10) is as follows: Preferably, the preparation of compound (14) from compound (10) comprises the following steps: Step 1): Compound (10), potassium hydroxide aqueous solution and ethanol are mixed and reacted for 8-15 minutes, and then compound (11) is added, stirred and reacted. After the reaction is complete, the mixture is filtered, the filter cake is washed and dried to obtain compound (12); Step 2): Compound (12), potassium carbonate and acetone are added and mixed, and compound (13) is added, and the mixture is heated under reflux to react to obtain compound (14).

6. The method for preparing the near-infrared second region organic small molecule compound with acid-base responsiveness according to claim 3, characterized in that: Compound (9) is prepared from compound (2). The reaction formula for preparing compound (9) from compound (2) is as follows: Wherein, n and R are defined as in claim 1; Preferably, the preparation of compound (9) from compound (2) comprises the following steps: Step 1): Add N,N-dimethylformamide and chloroform into a reaction vessel, slowly add phosphorus tribromide dropwise, react, dissolve compound (2) in chloroform, add into the reaction system, react, after the reaction is complete, adjust the pH to 6.5-7.5, extract, and obtain compound (3); Step 2): Add compound (3), cesium carbonate and N,N-dimethylformamide into a reaction container, then add compound (4) dissolved in N,N-dimethylformamide, mix well, react, filter after the reaction is complete, and purify the filter cake to obtain compound (5); Step 3): Compound (5), compound (8), tris(dibenzylideneacetone)dipalladium, 2-dicyclohexylphosphine-2'-(N,N-dimethylamino)biphenyl, cesium carbonate and 1,4-dioxane are reacted under anaerobic conditions at 90-100° C. After the reaction is complete, purification is performed to obtain compound (9).

7. The method for preparing a near-infrared second region organic small molecule compound with acid-base responsiveness according to claim 3, characterized in that: Compound (7) is prepared from compound (2). The reaction formula for preparing compound (7) from compound (2) is as follows: Wherein, n and R are defined as in claim 1; Preferably, the preparation of compound (7) from compound (2) comprises the following steps: Step 1): Add N,N-dimethylformamide and chloroform into a reaction vessel, slowly add phosphorus tribromide dropwise, react, dissolve compound (2) in chloroform, add into the reaction system, react, after the reaction is complete, adjust the pH to 6.5-7.5, extract, and obtain compound (3); Step 2): Compound (3), cesium carbonate and N,N-dimethylformamide are added to a reaction container, and then compound (6) dissolved in N,N-dimethylformamide is added, mixed, reacted, filtered after the reaction is complete, and the filter cake is purified to obtain compound (7).

8. Use of the near-infrared region II organic small molecule compound with acid-base responsiveness as claimed in claim 1 or 2 in the preparation of a near-infrared region II fluorescent imaging probe for in vivo imaging.

9. A near-infrared second-zone fluorescence imaging probe, characterized in that: The near-infrared zone II fluorescent imaging probe is obtained by encapsulating the near-infrared zone II organic small molecule compound with acid-base response ability as claimed in claim 1 or 2 by polyethylene glycol, polyether F127, polypeptide, protein, or cell membrane.

10. Use of the near-infrared zone II fluorescence imaging probe according to claim 9 in the preparation of tumor near-infrared zone II imaging contrast agent and / or tumor photoacoustic imaging contrast agent.

Images