Composition containing folic acid compound and near-infrared fluorescence capture system

Abstract

The invention provides a composition containing folic acid compounds and a near-infrared fluorescence capture system. The near-infrared fluorescence capture system comprises an imaging module, and the imaging module comprises a compound shown in the formula I or pharmaceutically acceptable salt of the compound. The compound shown in the formula I or the pharmaceutically acceptable salt of the compound can be used as a near-infrared fluorescence imaging agent, and is good in targeting property and clinical application prospect. # imgabs0 #

Description

[0001] This application claims the priority of Chinese Patent Application No. 2023110325244 filed on August 16, 2023. This application cites the entire text of the above Chinese Patent Application. Technical Field

[0002] The invention relates to a composition containing folic acid compounds and a near-infrared fluorescence capturing system. Background Art

[0003] Near-infrared fluorescence imaging technology, intraoperative near-infrared (NIR) fluorescence imaging helps surgeons make judgments and reduce the positive rate of surgical margins, and has become an effective solution for detecting intraoperative tumor margins. Fluorescence imaging intraoperative navigation is based on the enrichment of fluorescein in specific tissues, which can accurately display intraoperative blood vessels, lymph nodes, tumor tissues and other information. At the same time, it can specifically visualize specific molecular targets overexpressed in tumor tissues, thereby achieving the effect of high signal-to-noise ratio tumor imaging, further reducing the positive rate of surgical margins. Near-infrared light has a wavelength range of 650nm to 900nm, and because its penetration depth in tissues can reach 10mm, it is superior to visible light in intraoperative imaging. Since tissues only show limited autofluorescence in the NIR spectrum, the use of NIR fluorescent imaging agents can maximize the contrast between fluorescent signals in tumors and healthy tissues. In addition, near-infrared light does not affect the surgical field of view because near-infrared light is invisible to the human eye. Currently available imaging systems combine white light illumination of the surgical area with NIR fluorescence images to provide surgeons with anatomical information and fluorescence information at the same time.

[0004] Folate receptor alpha (FR-α), also known as FOLR1 or folate binding protein, is a glycoprotein anchored to the cell membrane by glycosylated phosphatidylinositol (GPI). It has a high affinity for folate and can transport folate through receptor-mediated endocytosis. FRα acts as a signaling molecule to promote tumor malignant growth. Similar to other glycosylated phosphatidylinositol family proteins, FRα activates the intracellular regulatory signaling network after binding to folate. FRɑ is mainly highly expressed in epithelial tumor tissues, not expressed or expressed at very low levels in normal tissues, has a high affinity for folate, and a low affinity for reduced folate.

[0005] FRα is known to be overexpressed on the surface of tumor cells in various cancers, including ovarian cancer, TNBC (triple negative breast cancer), endometrial cancer, mesothelioma and lung cancer. FRα is expressed at low levels in normal cells, but its expression level is significantly increased in certain cancer cells, so it has become an important target in cancer diagnosis and treatment in recent years.

[0006] Currently, the drugs that have been approved for clinical use in near-infrared fluorescence imaging include indocyanine green (ICG) and CYTALUX (Pafolacianine).

[0007] ICG can differentiate various types of adrenal lesions (pheochromocytoma, metastatic renal cell carcinoma (RCC), lymphangioma, adrenal cortical adenoma, adrenal hemorrhagic cyst, adrenal simple cyst, cystic lymphangioma) and perform safe adrenal-sparing surgery.

[0008] CYTALUX (Pafolacianine) is a fluorescent imaging agent targeting the folate receptor (FR) developed by On Target Laboratories. On November 29, 2021, the FDA (U.S. Food and Drug Administration) approved Pafolacianine sodium injection as an adjunct to intraoperative identification of malignant lesions in adult patients with ovarian cancer. On December 19, 2022, the FDA has approved a new indication for Pafolacianine to help surgeons detect lung cancer lesions in adult patients with known or suspected lung cancer. In clinical trials, Pafolacianine has achieved good results in combination with surgical robots. In a study of Pafolacianine combined with the da Vinci Xi system for robotic-assisted thoracic lung cancer surgery, tumor-specific fluorescence was identified in all (100%) subjects, and three nodules that could not be seen by robotic white light imaging were clearly located (DOI: 10.21037 / TLCR-21-1004). In a study of the safety and efficacy of Pafolacianine in patients undergoing robotic-assisted laparoscopic partial nephrectomy, patients were injected with a dose of 0.025 mg / kg of OTL38 before robotic-assisted laparoscopic partial nephrectomy. The da Vinci fluorescence imaging vision system was used to identify tumors and examine residual lesions after resection. Normal renal tissue expresses folate receptors (FR) while tumor tissue does not. The results showed that the tumor had no fluorescence, while the surrounding normal parenchyma did show fluorescence, which can improve the visualization and resection of renal tumors (DOI: 10.1080 / 21681805.2021.1933168).

[0009] OTL38 has the defects of weak targeting and poor tumor imaging effect. It is particularly important to develop fluorescent imaging agents with better targeting and better suitability for clinical applications. Summary of the invention

[0010] The technical problem to be solved by the present invention is to overcome the defect that existing near-infrared fluorescence imaging drugs have weak tumor differentiation ability. To this end, the present application provides a composition containing folic acid compounds and a near-infrared fluorescence capture system. The composition containing folic acid compounds provided by the present invention has strong tumor differentiation ability, is easy to prepare, and has good application prospects.

[0011] The present invention solves the above technical problems through the following solutions.

[0012] The present invention provides a near-infrared fluorescence capture system, which comprises an imaging module, wherein the imaging module contains a compound represented by Formula I or a pharmaceutically acceptable salt thereof;

[0013]

[0014] in,

[0015] R is

[0016] In one embodiment, the imaging module is used to provide the compound of Formula I or a pharmaceutically acceptable salt thereof to the targeted lesion area.

[0017] In a certain embodiment, the imaging module comprises an imaging agent, which comprises the compound represented by Formula I or a pharmaceutically acceptable salt thereof and the above-mentioned pharmaceutical excipients, wherein the pharmaceutical excipients are selected from one or more of pharmaceutically acceptable carriers, diluents, pH regulators, pH buffers, osmotic pressure regulators, cosolvents, metal ion chelators and antioxidants, for example, water for injection, osmotic pressure regulators, pH regulators and / or buffers, the osmotic pressure regulators are such as NaCl, the pH buffers are such as potassium dihydrogen phosphate / sodium and dipotassium hydrogen phosphate / sodium, citric acid and citrate; the pH regulators are such as hydrochloric acid and / or sodium hydroxide; the metal ion chelators are such as EDTA-2Na; the antioxidants are such as sodium sulfite.

[0018] In one embodiment, the near-infrared fluorescence capture system further includes a light source module and a signal acquisition and display module.

[0019] The signal acquisition and display module is conventional in the art, and may include a near-infrared visual capture device with a near-infrared camera and a display device. The fluorescent signal emitted by the imaging agent is acquired by the near-infrared camera and displayed as a tracer on the display device.

[0020] The camera is conventional in the art, for example, the camera can receive visible light and near-infrared light at the same time.

[0021] The scope of the signal acquisition and display module is conventional in the art, such as an optical endoscope or an electronic endoscope, such as a flexible endoscope or a fiber endoscope.

[0022] The configuration of the near infrared camera is conventional in the art, for example, detecting visible light or near infrared light with absorption and emission maxima between about 400 nm and 900 nm.

[0023] The light source module is conventional in the art and can be used to provide visible light or near-infrared excitation light to the lesion area, which is the tissue cells targeted by the imaging agent. The wavelength of the near-infrared excitation light is conventional in the art, such as 776-805 nm.

[0024] The lesion area may be a tissue cell expressing folate receptor and / or a cancer tissue, and the tissue cell expressing folate receptor may be a cancer tissue, and the cancer tissue includes parenchymal tissue, interstitial tissue or marginal tissue. The cancer tissue is, for example, lung cancer, breast cancer (e.g., triple negative breast cancer (TNBC)), ovarian cancer, endometrial cancer or mesothelioma.

[0025] In one embodiment, the method for preparing the imaging agent comprises the following steps: mixing and dissolving the pharmaceutical excipient with the compound represented by Formula I or a pharmaceutically acceptable salt thereof (eg, filtering the solution), and sterilizing to obtain the imaging agent.

[0026] In one embodiment, the near-infrared fluorescence capture system further includes a power supply, which is used to supply power to the light source module, the imaging module and the signal acquisition and display module.

[0027] In one scheme, R is For example

[0028] In one embodiment, the compound represented by formula I is any of the following compounds:

[0029]

[0030] In one embodiment, the pharmaceutically acceptable salt of the compound represented by Formula I contains a pharmaceutically acceptable cation, the number of cations may be 1, 2, 3 or 4, and the cation may be K + 、Na + , Li + or NH4 + , for example, the tetrasodium salt of the compound represented by formula I.

[0031] In one embodiment, the pharmaceutically acceptable salt of the compound represented by Formula I is the compound represented by Formula II;

[0032]

[0033] Among them, M 1 、M 2 、M 3 and M 4Each is independently H or a pharmaceutically acceptable cation;

[0034] R is as described in any embodiment of the present invention.

[0035] In one embodiment, the pharmaceutically acceptable cation is K + 、Na + or Li + .

[0036] In one embodiment, the compound represented by formula II is

[0037]

[0038] Among them, M 1 、M 2 、M 3 and M 4 Independently K + 、Na + or Li + .

[0039] In one embodiment, the compound represented by formula II is

[0040]

[0041]

[0042] The present invention provides an application of the above-mentioned near-infrared fluorescence capture system in surgery guided by near-infrared fluorescence imaging.

[0043] The application may include the following steps: applying the above-mentioned imaging agent, providing near-infrared excitation light irradiation to the lesion area, using a signal acquisition and display module to acquire and display signals, and distinguishing and / or peeling off high-response areas based on the acquired signals.

[0044] The application may further include the following steps: preparing an imaging agent based on basic information of the target lesion area, wherein the basic information includes: lesion site, patient age, gender, vascular status, blood information, and blood supply status of the target area; applying the imaging agent, and after the fluorescent imaging agent completes targeted adsorption, providing near-infrared excitation light irradiation to the lesion area, using a signal acquisition and display module to acquire and display signals, and still acquiring signals to distinguish and / or peel off high response areas.

[0045] In the application, the imaging agent can be stored at -25°C to 15°C.

[0046] In such applications, the imaging agent may be a liquid preparation (eg, an injection).

[0047] In such applications, the imaging agent may be administered by injection (eg, intravenous injection).

[0048] In the application, the dosage of the imaging agent is conventional in the art, for example, it is administered according to the mass of the subject, calculated as the mass of the compound represented by Formula I or its pharmaceutically acceptable salt / unit mass of the subject: 0.005-1.5 mg / kg, for example 0.025 or 0.05 mg / kg.

[0049] The distance between the lens of the near-infrared fluorescence capture system and the tumor site is conventional in the art and can be selected according to needs, for example, 1-10 cm.

[0050] The near-infrared fluorescence capture system can be used for fluorescence-guided surgery or fluorescence-guided tumor resection of primary tumors, metastatic tumors, lymph nodes, synchronous lesions or tumor margins. The tumors are such as lung cancer, breast cancer (e.g., TNBC), ovarian cancer, endometrial cancer or mesothelioma.

[0051] The present invention provides an application of the compound represented by the above formula I or a pharmaceutically acceptable salt thereof, the application comprising:

[0052] (i) Used as an imaging agent for tissue cells expressing folate receptors;

[0053] (ii) for preparing imaging agents for tissue cells expressing folate receptors;

[0054] (iii) for use in the preparation of tumor imaging agents;

[0055]

[0056] Wherein, R is as described in any embodiment of the present invention.

[0057] In the application, the imaging agent may include (1) a compound represented by Formula I or a pharmaceutically acceptable salt thereof, and (2) a pharmaceutical excipient.

[0058] In the application, the tissue cells expressing folate receptors may be cancer tissues, which include parenchymal tissues, interstitial tissues or marginal tissues, such as lung cancer, breast cancer (such as TNBC), ovarian cancer, endometrial cancer or mesothelioma.

[0059] In the application, the tumor is, for example, lung cancer, breast cancer (eg, TNBC), ovarian cancer, endometrial cancer or mesothelioma.

[0060] In the application, the imaging agent may be a near-infrared fluorescent imaging agent, and the wavelength of the near-infrared light is 776-805 nm.

[0061] In the application, the dosage of the compound of formula I or a pharmaceutically acceptable salt thereof is a conventional dosage in the art, for example, it is administered according to the mass of the subject, and the mass ratio of the compound of formula I or a pharmaceutically acceptable salt thereof to the subject may be 0.005-1.5 mg / kg, for example 0.025 mg / kg or 0.05 mg / kg.

[0062] In the application, the imaging agent is administered in a conventional manner in the art, preferably by injection.

[0063] In the application, the dosage form of the imaging agent is conventional in the art, such as a liquid preparation, preferably an injection.

[0064] In a certain embodiment, the pharmaceutical excipient is selected from one or more of a pharmaceutically acceptable carrier, a diluent, a pH regulator, a pH buffer, an osmotic pressure regulator, a cosolvent, a metal ion chelator and an antioxidant, for example, water for injection, an osmotic pressure regulator, a pH regulator and / or a buffer, the osmotic pressure regulator is such as NaCl, the pH buffer is such as potassium dihydrogen phosphate / sodium and dipotassium hydrogen phosphate / sodium, citric acid and citrate. The pH regulator is such as hydrochloric acid and / or sodium hydroxide. The metal ion chelator is such as EDTA-2Na. The antioxidant is such as sodium sulfite.

[0065] The present invention provides an imaging agent, which comprises a pharmaceutical excipient and a compound represented by the above formula I or a pharmaceutically acceptable salt thereof;

[0066]

[0067] Wherein, R is as described in any embodiment of the present invention.

[0068] In one embodiment, the imaging agent is a liquid preparation, such as an injection.

[0069] In a certain embodiment, the imaging agent is administered in a conventional manner in the art, preferably by injection.

[0070] In one embodiment, the dosage of the imaging agent is conventional in the art, and a suitable dosage can be selected according to actual needs, for example, according to the mass of the subject to be administered, and the mass ratio of the compound represented by Formula I or a pharmaceutically acceptable salt thereof to the subject to be administered can be 0.005-1.5 mg / kg, for example 0.025 mg / kg or 0.05 mg / kg.

[0071] In a certain embodiment, the pharmaceutical excipient is selected from one or more of a pharmaceutically acceptable carrier, a diluent, a pH regulator, a pH buffer, an osmotic pressure regulator, a cosolvent, a metal ion chelator and an antioxidant, for example, it contains water for injection, an osmotic pressure regulator, a pH regulator and / or a buffer, the osmotic pressure regulator is such as NaCl, the pH buffer is such as potassium dihydrogen phosphate / sodium and dipotassium hydrogen phosphate / sodium, citric acid and citrate; the pH regulator is such as hydrochloric acid and / or sodium hydroxide; the metal ion chelator is such as EDTA-2Na; the antioxidant is such as sodium sulfite.

[0072] In one embodiment, the imaging agent is a near-infrared fluorescent imaging agent, such as an imaging agent for folate receptor expressing tissue cells and / or cancer tissue, and the folate receptor expressing tissue cells may be cancer tissue. The cancer tissue may be lung cancer, breast cancer (such as TNBC), ovarian cancer, endometrial cancer or mesothelioma.

[0073] Terminology explanation:

[0074] The term "pharmaceutically acceptable" means relatively non-toxic, safe, and suitable for use by patients.

[0075] The term "pharmaceutically acceptable salt" refers to a salt obtained by reacting a compound with a pharmaceutically acceptable acid or base. When the compound contains a relatively basic functional group, an acid addition salt can be obtained by contacting the compound with a sufficient amount of a pharmaceutically acceptable acid in a suitable inert solvent. For details, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use (P. Heinrich Stahl, Camille G. Wermuth, 2011, 2nd Revised Edition).

[0076] The term "pharmaceutical excipients" refers to excipients and additives used in the production of drugs and the preparation of prescriptions. It is all substances contained in drug preparations except active ingredients. For details, please refer to the Pharmacopoeia of the People's Republic of China (2020 edition) or Handbook of Pharmaceutical Excipients (Raymond C Rowe, 2009).

[0077] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0078] The reagents and raw materials used in the present invention are commercially available.

[0079] The positive and progressive effects of the present invention are: the composition provided by the present invention has one or more of the following advantages:

[0080] (1) Good targeting, which helps to mark diseased tissues and identify tiny lesions and hidden lesions;

[0081] (2) It overcomes the disadvantage of fast clearance in cancer tissue. Generally, the half-life of ICG is 3-4 minutes. The short half-life leads to multiple perfusions during surgery, which seriously affects the quality of surgery and prolongs the operation time. The compound of the present invention can still detect fluorescence 24 hours after intravenous injection;

[0082] (3) Improved fluorescence quantum yield. The fluorescence quantum yield of ICG is usually between 0.01 and 0.1. Due to the low fluorescence quantum yield of ICG, a higher dose is required to maintain effective fluorescence intensity. The compound of the present invention is expected to provide an effective tumor-to-background ratio (TBR) at 0.005 mg / kg in clinical practice.

[0083] (4) Compared with OTL38, the compound of the present invention has more excellent pharmacokinetic properties, faster elimination rate in the blood, lower background, higher tumor background ratio (TBR), and can more clearly distinguish tumors from normal tissues.

[0084] (5) Based on the animal performance of the compound of the present invention and OTL38 at the same dose (the tumor-to-background ratio was better than that of OTL38 at each dose), it is expected that the compound of the present invention can provide the same or even better diseased tissue differentiation ability as OTL38 at a lower dose in clinical practice.

[0085] (6) The novel structure, good solubility, and small steric hindrance enable long-term enrichment of diseased tissues at low concentrations. The dynamic enrichment and elimination of diseased tissues and the elimination of background produce a significant contrast, and the diseased tissues are highlighted. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 1 nmol / mouse for 1 hour.

[0087] Figure 2 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 1 nmol / mouse for 2 hours.

[0088] Figure 3 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 1 nmol / mouse for 4 hours.

[0089] Figure 4 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 1 nmol / mouse for 8 hours.

[0090] Figure 5This is the near-infrared imaging image after compound 1 and OTL38 were administered at 1 nmol / mouse for 24 hours.

[0091] Figure 6 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 10 nmol / mouse for 1 hour.

[0092] Figure 7 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 10 nmol / mouse for 2 hours.

[0093] Figure 8 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 10 nmol / mouse for 4 hours.

[0094] Fig. 9 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 10 nmol / mouse for 8 hours.

[0095] Fig.10 This is the near-infrared imaging image after compound 1 and OTL38 were administered at 10 nmol / mouse for 24 hours.

[0096] Fig.11 This is the near-infrared imaging of the organs of mice in the blank control group.

[0097] Fig.12 The near-infrared imaging images of mouse organs after administration of compound 1 at 1 nmol / mouse.

[0098] Fig.13 The near-infrared imaging images of mouse organs after administration of compound 1 at 10 nmol / mouse.

[0099] Fig.14 These are near-infrared images of mouse organs after administration of 1 nmol / mouse of OTL38.

[0100] Fig.15 These are near-infrared images of mouse organs after administration of 10 nmol / mouse OTL38. DETAILED DESCRIPTION

[0101] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0102]

[0103]

[0104]

[0105] Including but not limited to the following embodiments, including but not limited to the following embodiments: Refers to the carrier resin itself that does not participate in the reaction. eq refers to molar multiple. "V" represents the volume / mass ratio. 7V means that when the amount of chlororesin is 1g, the amount of the corresponding reagent is 7mL.

[0106] Example 1 Compound 1

[0107] Here M is Na + For example, for Li + , K + The situation can be realized in the same way.

[0108] Synthetic route

[0109] Step 1: B01 synthesis

[0110]

[0111] Weigh pteroic acid (600 mg) and Fmoc-ethylenediamine hydrochloride (643 mg), add to a 250 mL single-mouth bottle, add DMSO (24 mL) to dissolve; add HTAU (1.04 g) and DIEA (746 mg), stir for 2 h, add the reaction solution to MTBE after the reaction is completed, centrifuge, and dry to obtain B01 (1.1 g, yield 99%). LCMS: [M+H] + =577.2,2.78min.

[0112] Step 2: B02 Synthesis

[0113]

[0114] Weigh B01 (1.0 g) and add it into a 50 mL single-necked bottle, then add DMSO (20 mL) to dissolve it; add DBU (268 mg) and stir for 1 h. After the reaction is completed, add the reaction solution into MTBE, centrifuge and dry to obtain B02 (754 mg crude product, yield calculated as 100%).

[0115] Step 3: B03 Synthesis

[0116]

[0117] H-Tyr(tBu)-OtBu.HCl (490 mg) was weighed, and after being freed, it was added to a 50 mL single-mouth bottle. DMAP (7.2 mg) and DCM (10 mL) were added, and the temperature was lowered to 0-5°C under nitrogen protection; CDI (485 mg) was added, and the reaction was completed by HPLC monitoring, and 5 mL of water was added. The temperature was raised to 25°C and stirred for 1 h. The DCM layer was separated and concentrated; B02 (628 mg) and TEA (376 mg) were weighed and added to a 50 mL single-mouth bottle, DMSO (10 mL) was added to dissolve, and the above was added at 0-5°C to concentrate to obtain the intermediate, and stirred at 25°C overnight. The reaction solution was added dropwise to MTBE and centrifuged to dry to obtain B03 (809 mg, yield of about 85%).

[0118] LCMS: [M+H] + =674.4,2.92min.

[0119] Step 4: B04 Synthesis

[0120]

[0121] Weigh B03 (809 mg) and add it to a 50 mL single-mouth bottle, add 10 mL (90% TFA, 5% water, 5% triethylsilane), stir at 25°C, monitor the reaction by HPLC, and obtain B04 (403 mg, yield about 60%). LCMS [M+H] + =562.3,1.42min.

[0122] Preparation and purification of B04

[0123]

[0124]

[0125] Step 5: Synthesis of compound 1

[0126]

[0127] Weigh B04 (100 mg, 0.19 mmol) and add it to a 25 ml single-mouth bottle. Prepare a sodium carbonate aqueous solution (sodium carbonate: 134 mg, 1.26 mmol, purified water: 4 ml) and add it to the reaction bottle. Add int1 (237 mg, 0.27 mmol) and heat to 70 ～ 75℃, maintain the temperature for one hour.

[0128] Post-processing: Cool down to 20 ～ 25°C, prepared, freeze-dried to obtain 50 mg of blue solid compound 1, yield 19%, purity 96.30%), MS: [M-4Na+4H+2H] 2+=707.3,

[0129] 1 H NMR (400MHz, DMSO-d6 / D2O) δ8.63(s,1H),8.06(s,2H),7.78(d,J=14.0Hz,4H),7.65–7.58(m,8H),7.31(d,J=8.4 Hz,3H),7.18(d,J=8.5Hz,3H),7.00(d,J=8.5Hz,3H),6.91(t,J=6.1Hz,1H),6.61(d,J=8.7Hz,2H),6.28(s,1H),6 .19(d,J=14.2Hz,2H),6.01(d,J=7.0Hz,1H),4.46(d,J=5.9Hz,2H),4.25–4.04(m,6H),3.16–2.90(m,8H),2.78( dd,J=13.5,7.3Hz,1H),2.69(s,4H),1.90(s,3H),1.74(d,J=9.1Hz,10H),1.26(s,6H),1.23(s,2H),1.22(s,6H).

[0130] Preparation and purification of compound 1

[0131]

[0132]

[0133] Similarly, by using different raw materials, such as replacing the "Fmoc-ethylenediamine hydrochloride" in step 1 in Example 1 with "Fmoc-propylenediamine hydrochloride", "Fmoc-butylenediamine hydrochloride", or "Fmoc-pentanediamine hydrochloride", Compound 6, Compound 7, and Compound 8 can be obtained by the method of this embodiment. The specific process is described above and will not be repeated here.

[0134] Example 2

[0135] Preparation of compound 2

[0136] Here M is Na + For example, for Li + , K + The situation can be realized in the same way.

[0137] Synthesis route step 1: C03 solid phase synthesis

[0138]

[0139]

[0140]

[0141] Note: eq is the molar amount of chlororesin, V is the volume / mass ratio (mL / g), for example, 7V means that when the amount of chlororesin is 1g, the amount of the corresponding reagent is 7mL.

[0142] Step 2: Synthesis of compound 2

[0143]

[0144] Weigh CO3 (100 mg, 0.156 mmol) and add it to a 25 ml single-mouth bottle. Prepare a sodium carbonate aqueous solution (sodium carbonate: 100 mg, 0.946 mmol, purified water: 4 ml) and add it to the reaction bottle. Add int1 (152 mg, 0.156 mmol) and heat to 70 ～ 75℃, maintain the temperature for one hour.

[0145] Post-processing: Cool down to 20 ～ 25°C, prepared, freeze-dried to obtain 84 mg of blue solid compound 2, yield 23%, purity 97.65%, MS: [M-4Na+4H+2H] 2+ = =743.9,

[0146] 1 H NMR (400MHz, DMSO-d6 / D2O) δ8.60(s,1H),7.77(d,J=13.8Hz,2H),7.59(dd,J=18.6,7.8Hz,6H),7.28(d,J=8.8Hz, 2H),7.18(d,J=8.4Hz,2H),6.97(d,J=8.4Hz,2H),6.59(d,J=8.7Hz,2H),6.14(d,J=14.2Hz,2H),4.45(s,2H),4.18 (s,2H),4.05(s,5H),3.54–3.38(m,6H),3.38–3.33(m,2H),3.30(d,J=5.3Hz,2H),2.95(s,1H),2.77(s,1H),2.64 (s,4H),2.56(t,J=6.7Hz,4H),2.20(d,J=5.8Hz,2H),1.86(s,2H),1.74(d,J=19.5Hz,9H),1.23(d,J=2.6Hz,12H).

[0147] Preparation and purification of compound 2

[0148]

[0149] Similarly, by using different raw materials, such as replacing the "Fmoc-PEG2-CH2CH2COOH" in step 1 in Example 2 with "Fmoc-PEG3-CH2CH2COOH", "Fmoc-PEG4-CH2CH2COOH", "Fmoc-PEG5-CH2CH2COOH", you can obtain compound 3, compound 4 and compound 5 by the method of this example. The specific process is described above and will not be repeated here.

[0150] Effect test example 1

[0151] 1. In vivo activity imaging of compound 1 (compared with OTL38, CAS: %1628858-03-6): lung cancer model

[0152] A subcutaneous HCC827 (human lung cancer cell line ATCC_CRL-2868) lung cancer tumor-bearing mouse model was established in BALB / c nude mice (athymic nude mice), and the average tumor volume reached about 300-400mm 3 The group dosing began at 1:00 pm. The mice in the drug-treated group were divided into 4 groups, with 3 mice in each group; there were 3 mice in the blank control group. Mice bearing HCC827 tumor xenografts were intravenously injected with 1 and 10 nmol / mouse of compound 1 and OTL38 (5% glucose solution, the same below), and the blank control group was injected with 5% glucose solution (see Table 1 below). Then, whole-body imaging studies were performed using a small animal in vivo imaging system (IVIS Lumina LT serier III). The imaging equipment contains a near-infrared fluorescence imaging system. Imaging was performed at 1h, 2h, 4h, 8h, and 24h (the blank control group was imaged at 1h and 24h), and the tumor and background parts were circled with the same diameter to obtain the fluorescence value, and the tumor-to-background ratio (TBR) was calculated. The average value was calculated. The larger the value, the more it tends to provide a clearer tumor boundary, and it is expected to provide a better surgical field during surgery. See below for specific results. Figure 1-10 (The left image in the figure is the test data of compound 1, and the right image is the test data of OTL38. Radiant Efficiency is the radiation efficiency (p / sec / cm 2 / sr) / (μw / cm 2 ) and Table 2.

[0153] Table 1 Grouping of in vivo imaging

[0154]

[0155] In the four drug-treated groups, there was some fluorescence enrichment in the tumor part at 1 hour, and the tumor and non-tumor parts could be roughly distinguished from the image. The boundaries became obvious at subsequent time points and continued until the last time point of the experiment, 24 hours.

[0156] All four dosing groups can provide a certain tumor-to-background ratio at 1 hour and later (except for the 1 hour point of the OTL38 1nmol / group). In terms of compound dimension, the TBR value of compound 1 at each time point in both doses is better than that of OTL38; at different dose levels, the compound 1 10nmol / group is better than the 1nmol / group at each time point, and there is no difference in the tumor-to-background ratio (TBR) value between the OTL38 1nmol / group and the 10nmol / group, and the imaging boundary is not clearer due to the increase in dose. Compound 1 is expected to provide better tumor background data in subsequent dose optimization studies.

[0157] The results showed that compound 1 combined with a near-infrared fluorescence imaging system could distinguish tumors from background in mice in as fast as 1 hour. The TBR peaks of 1 nmol / mouse and 10 nmol / mouse were at 8 hours and 24 hours, respectively, and its performance in mice was significantly better than that of OTL38.

[0158] Table 2 Comparison of tumor-to-background ratio data of OTL38 and compound 1 in vivo imaging

[0159]

[0160] 2. In vitro tissue imaging-tissue distribution research

[0161] A subcutaneous HCC827 (human lung cancer cell line) lung cancer tumor-bearing mouse model was established in BALB / c nude (athymic nude mice), and the average tumor volume reached about 300-400mm 3 The mice in the drug-treated group were divided into 4 groups, with 3 mice in each group, and 3 mice in the blank control group (the grouping was the same as the above-mentioned in vivo live imaging study). Mice bearing HCC827 tumor xenografts were intravenously injected with 1 and 10 nmol / mouse compound 1 and OTL38 (5% glucose solution, the same below), and the blank control group was injected with 5% glucose solution. Then, whole-body imaging studies were performed using a small animal live imaging system. The imaging equipment contained a near-infrared fluorescence imaging system. Imaging was performed at 1h, 2h, 4h, 8h, and 24h (the blank control group was imaged at 1h and 24h). After 24h of live fluorescence imaging, the mice were euthanized, and the organs of the mice (tumors, heart, liver, spleen, lungs, kidneys, stomach, muscles, skin, ovaries, pancreas, colon, and small intestine) were collected for measurement by the live imaging system. The results of the study are shown in Figure 11-15 At the same time, the fluorescence ratios of mouse tumors to muscle tissue, ovarian tissue, and lung tissue were calculated, see Table 3 below.

[0162] The results showed that at the 24h time point, in the 1nmol / group, the fluorescence of compound 1 and OTL38 was not fully displayed in the tumor site, but due to the low uptake in other tissues, this dose group showed a more obvious distinction between tumor / muscle and tumor / lung (see Table 3 for details); in the 10nmol / group, both compound 1 and OTL38 could be observed to have obvious fluorescence in the tumor, and this dose group showed a better distinction between tumor / muscle and tumor / lung than the 1nmol / group (see Table 3 for details), and is expected to distinguish positive resection margins in clinical use.

[0163] Obvious fluorescence was observed in the kidney, which may be related to drug excretion through urine. A small amount of fluorescence was also observed in the healthy lung, liver, stomach, and ovary in the 10 nmol group, which may be related to the fact that FRα is also slightly expressed in these tissues. During data processing, since ovarian cancer also overexpresses FRα, the tumor / ovary comparison values ​​were calculated. The 10 nmol / group of the two compounds was significantly different from the control group, indicating the application value of the two compounds in ovarian cancer.

[0164] Table 3 Fluorescence ratio of subcutaneous tumor to normal tissue in dissected tissues 24 hours after tumor-bearing mice were injected with 1 and 10 nmol / mouse compound 1 and OTL38

[0165] Grouping Tumor / Muscle Tumor / lung Tumor / ovarian Blank control group 3.51 1.48 2.18 OTL38 1nmol / each 7.04 1.60 2.78 OTL38 10nmol / each 19.21 2.80 5.43 Compound 1 1nmol / 6.64 2.09 2.89 Compound 1 10nmol / mouse 27.80 5.01 5.60 .

[0166] Effect test example 2

[0167] In vivo live imaging studies

[0168] HCC827 (human lung cancer cell line, Jicui Yaokang) and A549 (folate receptor α-negative cell line, Jicui Yaokang) lung cancer subcutaneous tumor-bearing mouse models were constructed on BALB / c nude (athymic nude mice), and the average tumor volume reached about 300-400mm 3 The group dosing began at 1h (grouping is shown in Table 4 below). Mice bearing tumor xenografts were intravenously injected with 0.025 and 0.05 mg / kg of compound 1, compound 2 and OTL38 (5% glucose solution, the same below), and the blank control group was injected with 5% glucose solution. Then, whole-body imaging studies were performed using a small animal in vivo imaging system. The imaging equipment contained a near-infrared fluorescence imaging system. Imaging was performed at 1h, 2h, 4h, 8h, and 24h, respectively. The tumor and background parts were circled with the same diameter, the fluorescence value was obtained, and the ratio of tumor to background was calculated. The larger the value, the more it tends to provide a clearer tumor boundary, which is expected to provide a better surgical field during surgery. The specific results are shown in Table 5 below.

[0169] Table 4 Grouping of in vivo imaging

[0170]

[0171]

[0172] In the six drug-treated groups, there was some fluorescence enrichment in the tumor part at 1 hour, and the tumor and non-tumor parts could be roughly distinguished from the image. The boundaries became obvious at subsequent time points and continued until the last time point of the experiment, 24 hours.

[0173] All six dosing groups can provide a certain tumor-to-background ratio (TBR) at 1 hour and thereafter. At different dose levels, there is no significant difference in TBR values ​​at each time point for OTL38, compound 1 and compound 2 0.025mg / kg and 0.05mg / kg dose groups. The 0.05mg / kg dose groups of compound 1 and compound 2 are superior to their low dose groups, suggesting that: 1) increasing the dose is expected to increase the tumor-to-background ratio of compound 1 and compound 2; 2) the difference in the 2-fold dose interval is not significant, and the dose interval needs to be increased in the future to investigate the dose-relatedness. Compound 1 and compound 2 are expected to provide better tumor background data in subsequent dose optimization studies. In terms of compound dimensions, compound 1 has a clear advantage in tumor background ratio, followed by compound 2, and OTL38 has the lowest, suggesting that the structural changes of compound 1 and compound 2 have brought about changes in pharmacokinetic properties. This conclusion is also reflected in the background fluorescence values ​​of the three compounds. The specific data are shown in Table 6: At the same dose level, the background fluorescence value is: OTL38>Compound 1>Compound 2. Part of the background fluorescence comes from the blood vessels throughout the tissue, suggesting that the elimination rate in the blood should be: OTL38<Compound 1<Compound 2. It can be seen that the superior tumor background ratio of compound 1 and compound 2 should come from a certain tumor accumulation and lower background interference, which also widens the gap with OTL38. Good pharmacokinetic properties are not easy to obtain, and it is even more difficult to find changes in pharmacokinetic properties caused by structural changes. Compounds that are eliminated too quickly in the blood generally have unsatisfactory tissue accumulation due to their short distribution time; while compounds that are eliminated too slowly from the blood, on the one hand, take longer to reach a low background, which usually means a longer waiting time before surgery. On the other hand, if there is no higher tumor accumulation, a high background means a low tumor background ratio, and the tumor boundary provided will be more unclear. How to achieve a balance: that is, a certain blood elimination rate can bring about a lower background while allowing the target tissue to have a certain accumulation that meets the time window.

[0174] The compound protected by this patent is a small molecule compound targeting folate receptors. To confirm its targeting, another It's In vivo imaging test of folate receptor negative cell line A549, there was no difference between the 6 drug-treated groups and the control group, confirming its receptor specificity. The tumor-to-background ratio data are shown in Table 7 below.

[0175] Table 5 Comparison of tumor-to-background ratio (TBR) data of OTL38, compound 1 and compound 2 in vivo imaging (HCC827 group)

[0176]

[0177] Table 6 Comparison of background fluorescence values ​​(unit: [p / s / cm^2 / sr] / [μW / cm^2]) of in vivo imaging OTL38, compound 1 and compound 2 (HCC827 group)

[0178]

[0179] Table 7 Comparison of tumor-to-background ratio (TBR) data of OTL38, compound 1 and compound 2 in vivo imaging (A549 group)

[0180]

[0181] In vitro tissue imaging--tissue distribution studies

[0182] A subcutaneous tumor-bearing mouse model of HCC827 (human lung cancer cell line, Jicui Yaokang) lung cancer was constructed on BALB / c nude mice (athymic nude mice), and the average tumor volume reached about 300-400mm 3 The group administration started at 14:00. The mice bearing HCC827 tumor xenografts were intravenously injected with 0.025mg / kg and 0.05mg / kg of compound 1, compound 2 and OTL38 (5% glucose solution, the same below), and the blank control group was injected with 5% glucose solution (the grouping was the same as the HCC827 group in the in vivo imaging study). 2h after administration, the mice in the 7 groups were euthanized as a whole. After euthanasia, the tumor, heart, liver, spleen, lung, kidney, stomach, back muscle, back skin, ovary, pancreas, colon and small intestine and other organs were taken for fluorescence imaging. The fluorescence ratio of mouse tumor to muscle tissue, ovarian tissue and lung tissue was calculated, as shown in Table 8 below.

[0183] From the data analysis in Table 8, it can be seen that, except for the two dose groups of OTL38, the ratios of tumor and muscle, healthy lung and ovary of compound 1 and compound 2 are statistically different, indicating that positive tumor tissue and muscle, healthy lung and ovary can be clearly distinguished, and it is expected to distinguish positive resection margins in clinical surgery of lung cancer and ovarian cancer. The reason for evaluating ovarian cancer here is that the folate receptor FRα is overexpressed in most ovarian cancers and lung cancers. This experiment is a subcutaneous tumor-bearing model constructed by human lung cancer cell line, which overexpresses folate receptor α. To a certain extent, its possible application in ovarian cancer can be speculated through the ratio of tumor expressing folate receptor to healthy ovarian tissue.

[0184] The ratio of tumor to healthy lung tissue in the two dose groups of OTL38 failed to distinguish from the blank control group, probably because of the slow elimination in the blood. The accumulation of tumor at the 2h time point was less than the interference of the background. It is expected that the time point shift may bring better results. Compared with OTL38, compounds 1 and 2 are expected to meet surgical requirements in a shorter time after clinical administration, and combined with the results of in vivo live imaging (the tumor-to-background ratio showed an upward trend, and the peak appeared at 24h), the distinction between tumors and tissues at subsequent time points will be clearer. Considering the two together, compounds 1 and 2 are expected to provide a wider surgical time window.

[0185] Table 8 Fluorescence ratio of subcutaneous tumor to normal tissue in dissected tissue 2h after tumor-bearing mice were injected with 0.025 and 0.05 mg / kg compound 1, compound 2, and OTL38

[0186]

[0187] Effect Test Example 3 (Ovarian Cancer)

[0188] The SKOV3 (Shanghai Cell Bank) ovarian cancer subcutaneous tumor-bearing mouse model was established on NCG mice, with an average tumor volume of about 300-400 mm 3 The group dosing started at 1h. Mice bearing SKOV3 tumor xenografts were intravenously injected with 0.025mg / kg and 0.05mg / kg of compound 1, compound 2 and OTL38 (5% glucose solution, the same below), and the blank control group was injected with 5% glucose solution (see Table 9 below). Then, whole-body imaging studies were performed using a small animal in vivo imaging system, and the imaging equipment contained a near-infrared fluorescence imaging system. Imaging was performed at 1h, 2h, 4h, 8h, and 24h, respectively. The tumor and background parts were circled with the same diameter, the fluorescence value was obtained, and the tumor-to-background ratio (TBR) was calculated. The larger the value, the more it tends to provide a clearer tumor boundary, which is expected to provide a better surgical field during surgery. The specific results are shown in Table 10 below.

[0189] Table 9 Grouping of in vivo imaging

[0190]

[0191]

[0192] Except for the OTL38 0.025 mg / kg dose group, the other five dosing groups had partial fluorescence enrichment in the tumor part at 1 hour. The tumor and non-tumor parts could be roughly distinguished from the image. The boundaries became obvious at subsequent time points and continued until the last time point of the experiment, 24 hours.

[0193] From the perspective of different dose levels, the two dose groups of OTL38 can provide a certain tumor-to-background ratio after 2 hours, and the other four dosing groups can provide a certain tumor-to-background ratio at 1 hour and thereafter. At different dose levels, there is little difference between high and low doses of the three compounds, and the TBR of the high-dose group is slightly higher than that of the low-dose group, suggesting that increasing the dose in the later stage may have greater application value.

[0194] Among the different compounds, compound 1 has the most obvious advantage, followed by compound 2, and OTL38 is weaker, but it can still distinguish tumors after 2 hours and provide clear surgical margins.

[0195] Table 10 Comparison of tumor-to-background ratio (TBR) data of SKOV3 tumor-bearing mice injected with 0.025 and 0.05 mg / kg of compound 1, compound 2, and OTL38

[0196]

Claims

1. A near-infrared fluorescence capture system, characterized in that: It comprises an imaging module, wherein the imaging module comprises a compound represented by formula I or a pharmaceutically acceptable salt thereof; in, R is 2. The near-infrared fluorescence capture system according to claim 1, characterized in that: It meets one or more of the following conditions: (1) The imaging module is used to provide the compound of formula I or a pharmaceutically acceptable salt thereof to a targeted lesion area, wherein the lesion area is, for example, a tissue cell expressing folate receptor and / or a cancer tissue; (2) The imaging module comprises an imaging agent, wherein the imaging agent comprises the compound of Formula I or a pharmaceutically acceptable salt thereof and a pharmaceutical excipient, wherein the pharmaceutical excipient is selected from one or more of a pharmaceutically acceptable carrier, a diluent, a pH regulator, a pH buffer, an osmotic pressure regulator, a cosolvent, a metal ion chelator and an antioxidant, and comprises, for example, water for injection, an osmotic pressure regulator, a pH regulator and / or a buffer, wherein the osmotic pressure regulator is, for example, NaCl, the pH buffer is, for example, potassium dihydrogen phosphate / sodium and dipotassium hydrogen phosphate / sodium, citric acid and citrate; the pH regulator is, for example, hydrochloric acid and / or sodium hydroxide; the metal ion chelator is, for example, EDTA-2Na; the antioxidant is, for example, sodium sulfite; (3) The near-infrared fluorescence capture system also includes a light source module and a signal acquisition and display module; (4) The method for preparing the imaging agent comprises the following steps: mixing and dissolving the pharmaceutical excipient and the compound represented by Formula I or a pharmaceutically acceptable salt thereof, and sterilizing to obtain the imaging agent; (5) R is For example (6) The pharmaceutically acceptable salt of the compound of Formula I contains a pharmaceutically acceptable cation, and the number of cations is 1, 2, 3 or 4; Preferably, the pharmaceutically acceptable salt of the compound represented by formula I is the compound represented by formula II; Among them, M 1 、M 2 、M 3 and M 4 Each is independently H or a pharmaceutically acceptable cation; R as described in claim 1.

3. The near-infrared fluorescence capture system according to claim 1 or 2, characterized in that: It meets one or more of the following conditions: (1) The signal acquisition and display module includes a near-infrared visual capture device with a near-infrared camera and a display device, and the fluorescent signal emitted by the imaging agent is collected by the near-infrared camera and displayed on the display device; (2) The light source module is used to provide visible light or near-infrared excitation light to the lesion area, and the lesion area is the tissue cells that target the imaging agent; (3) The tissue cells expressing folate receptors are cancer tissues, and the cancer tissues include parenchymal tissues, interstitial tissues or marginal tissues; (4) The near-infrared fluorescence capture system further includes a power supply, which is used to power the light source module, the imaging module and the signal acquisition and display module; (5) The cation is K + 、Na + , Li + or NH4 + .

4. The near-infrared fluorescence capture system according to claim 3, characterized in that: It meets one or more of the following conditions: (1) The scope of the signal acquisition and display module is an optical endoscope or an electronic endoscope; (2) the near infrared camera is configured to detect visible light or near infrared light having absorption and emission maxima between about 400 nm and 900 nm; (3) The wavelength of the near-infrared excitation light is 776-805 nm; (4) The cancer tissue is lung cancer, breast cancer, ovarian cancer, endometrial cancer or mesothelioma, and the breast cancer is, for example, triple-negative breast cancer; (5) The camera can receive visible light and near-infrared light simultaneously.

5. The near-infrared fluorescence capture system according to claim 1 or 2, characterized in that: The compound represented by formula I is any of the following compounds: Alternatively, the compound represented by formula II is any of the following compounds; 6. Use of the near-infrared fluorescence capture system according to any one of claims 1 to 5 in surgery guided by near-infrared fluorescence imaging; Preferably, the application satisfies one or more of the following conditions: (1) The application comprises the following steps: applying the imaging agent, providing near-infrared excitation light irradiation to the lesion area, using a signal acquisition and display module to acquire and display signals, and distinguishing and / or peeling off high-response areas based on the acquired signals; (2) In the application, the imaging agent is stored at -25°C to 15°C; (3) In the application, the imaging agent is an injectable agent; (4) In the application, the imaging agent is administered by injection; (5) In the above application, the dosage of the imaging agent is based on the weight of the subject, calculated as the weight of the compound represented by Formula I or its pharmaceutically acceptable salt / unit weight of the subject: 0.005-1.5 mg / kg, for example 0.025 or 0.05 mg / kg; (4) The lens of the near-infrared fluorescence capture system is 1-10 cm away from the tumor site; (5) The near-infrared fluorescence capture system is used for fluorescence-guided surgery or fluorescence-guided tumor resection of primary tumors, metastatic tumors, lymph nodes, synchronous lesions or tumor margins; the tumors are, for example, lung cancer, breast cancer, ovarian cancer, endometrial cancer or mesothelioma.

7. A use of the compound of formula I or a pharmaceutically acceptable salt thereof as claimed in any one of claims 1 to 5, comprising: (i) Used as an imaging agent for tissue cells expressing folate receptors; (ii) for preparing imaging agents for tissue cells expressing folate receptors; (iii) for use in the preparation of tumor imaging agents; R is as described in any one of claims 1-5.

8. The use of the compound of formula I or a pharmaceutically acceptable salt thereof according to claim 7, characterized in that: It meets one or more of the following conditions: (1) In the application, the imaging agent comprises (1) the compound represented by Formula I or a pharmaceutically acceptable salt thereof, and (2) a pharmaceutical excipient; Preferably, the pharmaceutical excipients contain one or more selected from pharmaceutically acceptable carriers, diluents, pH regulators, pH buffers, osmotic pressure regulators, cosolvents, metal ion chelators and antioxidants, for example, water for injection, osmotic pressure regulators, pH regulators and / or buffers, the osmotic pressure regulators are such as NaCl, the pH buffers are such as potassium dihydrogen phosphate / sodium and dipotassium hydrogen phosphate / sodium, citric acid and citrate; the pH regulators are such as hydrochloric acid and / or sodium hydroxide; the metal ion chelators are such as EDTA-2Na; the antioxidants are such as sodium sulfite; (2) In the application, the tissue cells expressing folate receptors are cancer tissues, and the cancer tissues include parenchymal tissues, interstitial tissues or marginal tissues, such as lung cancer, breast cancer, ovarian cancer, endometrial cancer or mesothelioma, and the breast cancer is, for example, triple-negative breast cancer; (3) In the application, the tumor is lung cancer, breast cancer, ovarian cancer, endometrial cancer or mesothelioma, and the breast cancer is, for example, triple-negative breast cancer; (4) In the application, the imaging agent is a near-infrared fluorescent imaging agent, and the wavelength of the near-infrared light is 776-805 nm; (5) In the application, the dosage of the compound of Formula I or its pharmaceutically acceptable salt is a mass ratio of the compound of Formula I or its pharmaceutically acceptable salt to the subject of administration of 0.005-1.5 mg / kg, for example 0.025 mg / kg or 0.05 mg / kg; (6) In the application, the imaging agent is administered by injection; (7) In the application, the imaging agent is in the form of a liquid preparation, such as an injection.

9. An imaging agent, characterized in that It comprises pharmaceutical excipients and a compound of formula I as claimed in any one of claims 1 to 5 or a pharmaceutically acceptable salt thereof; R is as described in any one of claims 1-5.

10. The imaging agent according to claim 9, characterized in that It meets one or more of the following conditions: (1) The imaging agent is administered by injection; (2) The imaging agent is in the form of a liquid preparation, such as an injection; (3) The dosage of the imaging agent is a mass ratio of the compound of Formula I or a pharmaceutically acceptable salt thereof to the subject of administration of 0.005-1.5 mg / kg, for example 0.025 mg / kg or 0.05 mg / kg; (4) The pharmaceutical excipients include one or more selected from pharmaceutically acceptable carriers, diluents, pH regulators, pH buffers, osmotic pressure regulators, cosolvents, metal ion chelators and antioxidants, for example, water for injection, osmotic pressure regulators, pH regulators and / or buffers, the osmotic pressure regulators are such as NaCl, the pH buffers are such as potassium dihydrogen phosphate / sodium and dipotassium hydrogen phosphate / sodium, citric acid and citrate; the pH regulators are such as hydrochloric acid and / or sodium hydroxide; the metal ion chelators are such as EDTA-2Na; the antioxidants are such as sodium sulfite; (5) The imaging agent is a near-infrared fluorescent imaging agent, for example, an imaging agent for tissue cells expressing folate receptors and / or cancer tissues. The tissue cells expressing folate receptors may be cancer tissues, for example, lung cancer, breast cancer, ovarian cancer, endometrial cancer or mesothelioma, and the breast cancer may be, for example, triple-negative breast cancer.

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