A bodipy compound and application thereof

Abstract

The application discloses a BODIPY compound and application thereof. The BODIPY compound is constructed by taking a BODIPY dimer as a functional mother nucleus, covalently coupling PEG side chains with different chain lengths and different polar functional end groups at a specific alpha active site of a molecule, and is shown as formula (I). The structure-activity relationship research shows that the compound can regulate the absorption wavelength, has a mixed photosensitization mechanism of type I and type II, is free from the dependence on oxygen of a single type II, is adapted to a tumor hypoxic environment, can regulate the active oxygen yield, and is far superior to indocyanine green; the PEG side chain modification improves the water solubility, can self-assemble into nanoparticles in an aqueous phase, has excellent photothermal stability, and has good near-infrared absorption and emission performance. In-vitro cell experiments show that the compound has significant phototoxicity to tumor cells under laser irradiation, and opens up a new idea for efficient photodynamic therapy of tumors.

Description

Technical Field

[0001] This invention belongs to the field of organic molecular synthesis, specifically relating to a BODIPY-type compound and its applications. Background Technology

[0002] Malignant tumors have a high incidence and mortality rate, and have become a major disease that seriously threatens human life and health. Clinical tumor treatment still mainly relies on surgical resection, chemotherapy, and radiotherapy. However, traditional treatment methods are difficult to completely eliminate tiny residual tumor cells, and postoperative residues can easily induce recurrence in situ. At the same time, tumors are prone to developing multidrug resistance during chemotherapy, resulting in a low overall treatment response rate, limited prognostic effects, and difficulty in achieving complete tumor remission.

[0003] Photodynamic therapy (PDT) boasts advantages such as strong targeting, minimally invasive safety, rapid onset of action, and low side effects, demonstrating significant application potential in the field of precision oncology. It has become a key research area at the intersection of anti-tumor medical materials and minimally invasive treatment. Fluoroboropyrrole (BODIPY) photosensitizers (PS) possess advantages including good photostability, easily directional modification of their molecular structure, and mature and controllable synthesis processes, making them core photosensitizing materials with great industrialization prospects in the field of PDT.

[0004] Existing conventional BODIPY photosensitizers still suffer from numerous inherent technical defects, severely hindering their clinical application in vivo for antitumor treatment. On the one hand, existing BODIPY photosensitizers generally have short excitation wavelengths and insufficient tissue penetration depth, making them difficult to target deep solid tumor lesions. On the other hand, most BODIPY parent skeletons are highly hydrophobic and poorly water-soluble, easily agglomerating and precipitating under physiological conditions, resulting in poor in vivo circulation stability, low tumor accumulation efficiency, and suboptimal bioavailability. Furthermore, most commercially available and literature-reported BODIPY photosensitizers rely on type II photosensitization mechanisms to exert their tumor-suppressive effects. This mechanism is highly dependent on endogenous oxygen in the tumor microenvironment. During the photosensitization reaction, a large amount of local oxygen is continuously consumed, further exacerbating the inherent hypoxic microenvironment of solid tumors, thereby inducing tumor cells to develop anti-apoptotic and anti-photodamage tolerance characteristics, significantly reducing the overall efficacy of photodynamic therapy and resulting in poor actual antitumor effects.

[0005] To address the common industry challenge of poor water solubility and low solubility of existing BODIPY photosensitizers, conventional improvement methods mainly include nanocarrier encapsulation, molecular ionization hydrophilic modification, and supramolecular complex construction. Among these, using liposomes and polymer micelles as nanocarriers to encapsulate and load hydrophobic photosensitizers presents challenges such as complex preparation processes, poor batch-to-batch reproducibility, low drug loading capacity, and uncontrollable in vivo drug release. Furthermore, the carrier excipients pose potential biotoxicity risks, their in vivo metabolic behavior is unclear, and their safety for clinical translation is difficult to guarantee. Chemical modification of photosensitizers using ionized groups involves lengthy and complex synthetic routes, difficult intermediate separation and purification, and high preparation costs. Additionally, ionization modification can easily disrupt the conjugated structure of the BODIPY core, leading to deterioration of core photophysical parameters such as photosensitizer light absorption performance and reactive oxygen species production efficiency, directly weakening the core photodynamic antitumor activity. Summary of the Invention

[0006] In view of the problems of the prior art, the purpose of this invention is to provide a BODIPY-type compound and its application.

[0007] This invention is achieved through the following technical solution:

[0008] In a first aspect, the present invention provides a BODIPY-type compound, the structural formula of which is shown in formula (I).

[0009] (I)

[0010] in:

[0011] R1 is independently selected from C6-C10 aryl or C1-C6 alkyl-substituted C6-C10 aryl;

[0012] R2 and R3 may be the same or different, and each is independently selected from H and CH3-(CH2CH2O). n -O-、CH3-(CH2CH2O) n -NH-, CH3-(CH2CH2O) n -S-, n is 2-12.

[0013] In certain preferred embodiments of the invention, R1 is independently selected from phenyl or C1-C6 alkyl-substituted phenyl.

[0014] In some preferred embodiments of the present invention, R1 is a C1-C3 alkyl-substituted phenyl group.

[0015] In a preferred embodiment of the present invention, R1 is 2,4,6-trimethylphenyl.

[0016] In a preferred embodiment of the present invention, R2 and R3 are the same, each independently representing CH3-(CH2CH2O).n -S-.

[0017] In some preferred embodiments of the present invention, n is 2, 5 or 12.

[0018] In certain preferred embodiments of the present invention, the BODIPY-type compound is selected from any of the following compounds:

[0019] The method for synthesizing the above-mentioned BODIPY-type compounds of the present invention comprises the following reaction process:

[0020] R1 is independently selected from C6-C10 aryl or C1-C6 alkyl-substituted C6-C10 aryl;

[0021] R2 and R3 may be the same or different, and each is independently selected from H and CH3-(CH2CH2O). n -O-、CH3-(CH2CH2O) n -NH-, CH3-(CH2CH2O) n -S-, n is 2-12.

[0022] In some preferred embodiments of the present invention, the preparation method of the above-mentioned BODIPY-type compounds includes the following steps:

[0023] (1) The compound shown in Formula 1, hexa-n-butyltin, tris(dibenzylideneacetone)dipalladium, and tris(o-methylphenyl)phosphine were added to the first solvent and reacted at 50-70 °C for 1-3 h under argon protection to obtain the compound shown in Formula 2.

[0024] (2) Add the compound shown in Formula 2, copper chloride dihydrate, and potassium persulfate to the second solvent and react at 50~70 °C for 1~3 h to obtain the compounds shown in Formula 2Cl and 2Cl2;

[0025] (3) The compounds shown in formula 2Cl and 2Cl2 are added to a third solvent along with at least one compound selected from short-chain hydroxy ethers, methoxy polyethylene glycol amines or methoxy polyethylene glycol sulfur, and reacted at 110 °C for 1 to 3 h to obtain compound 2a-2h.

[0026] In some preferred embodiments of the present invention, in step (1), the molar ratio of the compound represented by Formula 1 to hexa-n-butyltin is 2:1 to 3:1.

[0027] In some preferred embodiments of the present invention, in step (1), the first solvent is toluene.

[0028] In some preferred embodiments of the present invention, in step (2), the molar ratio of the compound shown in Formula 2 to copper chloride dihydrate is 1:6 to 1:10; the molar ratio of the compound shown in Formula 2 to potassium persulfate is 1:2 to 1:6.

[0029] In some preferred embodiments of the present invention, in step (2), the second solvent is acetonitrile.

[0030] In some preferred embodiments of the present invention, in step (3), the molar ratio of the compound represented by formula 2Cl, 2Cl2 to the compound selected from diethylene glycol monomethyl ether, methoxy polyethylene glycol amine or methoxy polyethylene glycol sulfur is 1:2 to 1:10.

[0031] In some preferred embodiments of the present invention, in step (3), the third solvent is dichloroethane (DCE).

[0032] Secondly, the present invention provides nanoparticles comprising the aforementioned BODIPY-type compounds.

[0033] The nanoparticles described in this invention can be prepared by the following method:

[0034] The above-mentioned BODIPY compounds were dissolved in a solvent, water was added and stirred until homogeneous, dialyzed, and filtered through a filter membrane to obtain nanoparticles; the solvent was selected from any one of tetrahydrofuran, acetonitrile, methanol, ethanol, and dimethyl sulfoxide.

[0035] Thirdly, the present invention provides the application of the above-mentioned BODIPY-type compounds or nanoparticles as photosensitizers in the preparation of tumor photodynamic therapy.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] This invention uses BODIPY dimers as the functional core and covalently couples PEG side chains of different chain lengths and polar functional end groups (hydroxyl, amino, and thiol groups) at specific α-active sites of the molecule to construct BODIPY-like compounds as shown in formula (I). Structure-activity relationship studies show that these compounds can control the absorption wavelength, possess a mixed type I / II photosensitization mechanism, overcome the dependence on oxygen by a single type II mechanism, adapt to the hypoxic environment of tumors, and can control the reactive oxygen species yield, far exceeding indocyanine green; PEG side chain modification improves water solubility, allowing for self-assembly into nanoparticles in the aqueous phase, exhibiting excellent photothermal stability and good near-infrared absorption and emission properties. In vitro cell experiments show that these compounds have significant phototoxicity to tumor cells under laser irradiation, opening up new avenues for efficient photodynamic therapy of tumors. Attached Figure Description

[0038] Figure 1 The hydrogen spectrum of compound 2a is shown below.

[0039] Figure 2 The carbon spectrum of compound 2a;

[0040] Figure 3 The absorption and emission spectra of compounds 2a-2f in different solvents (excited at 640 nm);

[0041] Figure 4 The UV absorption and emission spectra of compounds 2 and 2f in toluene (excited at 640 nm).

[0042] Figure 5 The UV absorption and emission spectra of compounds 2f, 2g, and 2h are shown (excited at 640 nm).

[0043] Figure 6 The absorbance of compound 2 in toluene solution at DPBF (660 nm laser irradiation).

[0044] Figure 7 The absorbance of compound 2a-2f in toluene solution at DPBF (660 nm laser irradiation).

[0045] Figure 8 The absorbance of compound 2f-2h in toluene solution at DPBF (660 nm laser irradiation).

[0046] Figure 9 The fluorescence intensity changes of DHE at different time points (left) and under laser light source (730 nm, 300 mW / cm²). -2 The absorption spectra of ABDA at different time points after irradiation (right);

[0047] Figure 10 For nanoparticles NPs and ICG in 2h under continuous 660 nm laser (1.5 Wcm) -2 Light stability under illumination;

[0048] Figure 11 (a) at the same concentration (500 μg / mL) -1 (a) Photothermal curves of NPs at different optical densities over 2 hours; (b) Photothermal curves of NPs at the same 660 nm laser illumination power (1.5 W / cm²). -2 (c) Photothermal curves of NPs at different concentrations for 2 hours; (d) Laser turned off after 300 s of illumination, 2 hours of NPs (500 μg / mL) -1 (d) Photothermal curves of NPs after 2 hours (4 cycles);

[0049] Figure 12The absorbance and degradation spectrum of DPBF in ICG aqueous solution under 765 nm laser irradiation (414 nm).

[0050] Figure 13 The absorbance of DPBF in NPs aqueous solution and the degradation spectrum of DPBF (414 nm) under 765 nm laser irradiation for 2 h are shown.

[0051] Figure 14 The results of 2h NPS testing of nanoparticles on intracellular reactive oxygen species;

[0052] Figure 15 The toxicity of nanoparticles NPS to 4T1 cells over 2 hours. Detailed Implementation

[0053] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0054] The reagents and raw materials used in this invention are all commercially available.

[0055] Example 1: Synthesis of compound 2a

[0056]

[0057] (1) Synthesis of compound 2

[0058] Compound 1 (190 mg, 0.55 mmol), hexa-n-butyltin (65.5 μL, 0.131 mmol), tris(dibenzylacetone)palladium (13 mg, 0.02 mmol), tris(o-methylphenyl)phosphine (17 mg, 0.02 mmol), and 5 mL of toluene were added to a 50 mL Shrek tube. The reaction was carried out under argon protection at 50 °C for 1 h. The reaction was monitored by TLC. The reaction was quenched by adding 20 mL of saturated NaHCO3 aqueous solution and extracted with dichloromethane (3 × 50 mL). The organic phase was collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a purple-black solid. The solid was purified by silica gel column chromatography [eluent:v (petroleum ether):v (ethyl acetate) = 4:1] to obtain a purple-black solid (compound 2) in 82% yield.

[0059] (2) Synthesis of compounds 2Cl and 2Cl2

[0060] Compound 2 (500 mg, 0.8 mmol), copper chloride dihydrate (500 mg, 3 mmol), 100 mL of dichloromethane, and 100 mL of acetonitrile were added to a 500 mL round-bottom flask. The reaction was carried out at 40 °C for 1 h. The reaction was monitored by TLC. The reaction was quenched by adding 20 mL of saturated NaHCO3 aqueous solution and extracted with dichloromethane (3 × 50 mL). The organic phase was collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a purple-black solid. The solid was purified by silica gel column chromatography [V(petroleum ether):V(dichloromethane) = 2:1 as eluent] to obtain a purple-black solid (compounds 2Cl and 2Cl2) in 50% yield.

[0061] (3) Synthesis of compound 2a

[0062] In a thick-walled, pressure-resistant bottle, compounds 2Cl (33 mg, 0.05 mmol), diethylene glycol monomethyl ether (9 mg, 0.1 mmol), Cs₂CO₃ (49 mg, 0.15 mmol), and DCE (10.0 mL) were added, respectively. 110 o The reaction proceeded for 5 hours. The mixture was dried over anhydrous sodium sulfate, distilled under reduced pressure, and purified by silica gel column chromatography to give a green solid, which was compound 2a. The yield was 90%.

[0063] NMR spectroscopy was performed on compound 2a in the embodiments of the present invention, and the test results are as follows: Figure 1-2 As shown:

[0064] 1 H NMR (600 MHz, CDCl3) δ 7.78 (s, 1H), 7.49 (dd, J = 11.1, 4.4 Hz, 2H), 6.96 (d, J = 3.9 Hz, 4H), 6.74 (d, J = 4.8 Hz, 1H), 6.69 (d, J = 4.6 Hz,1H), 6.57 (d, J = 4.0 Hz, 1H), 6.45 (d, J = 4.3 Hz, 1H), 6.42 (dd, J = 4.1,1.9 Hz, 1H), 6.22 (d, J = 4.8 Hz, 1H), 4.51 (t, J = 4.9 Hz, 2H), 3.91 (t, J =4.8 Hz, 2H), 3.72-3.67 (m, 2H), 3.51-3.47 (m, 2H), 3.33 (s, 3H), 2.37 (d, J =5.3 Hz, 6H), 2.15 (d, J = 2.9 Hz, 12H).

[0065] 13C NMR (151 MHz, CDCl3) δ 151.34, 144.42, 142.01, 139.41, 138.69,137.19, 136.84, 133.74, 131.61, 130.40, 129.65, 128.23, 127.81, 124.39,122.51, 72.38, 72.01, 71.22, 69.33, 59.15, 21.30, 20.23.

[0066] Example 2: Synthesis of compound 2b

[0067]

[0068] The preparation of compound 2b was carried out in accordance with the synthesis in Example 1, except that 2Cl in step (3) was replaced with 2Cl2, and the rest of the steps were the same. The final green solid was obtained with a yield of 76%.

[0069] 1 H NMR. (600 MHz, CDCl3)δ 7.37 (d, J = 4.3 Hz, 2H), 6.94 (s, 4H), 6.63(d, J = 4.7 Hz, 2H), 6.44 (d, J = 4.3 Hz, 2H), 6.09 (d, J = 4.7 Hz, 2H), 4.45(t, J = 5.0 Hz, 4H), 3.90 (t, J = 5.0 Hz, 4H), 3.71-3.67 (m, 4H), 3.50 (dd, J= 5.6, 3.4 Hz, 4H), 3.33 (s, 6H), 2.36 (s, 6H), 2.14 (s, 12H).

[0070] 13 C NMR (151 MHz, CDCl3) δ 139.56, 138.43, 137.26, 135.94, 132.09,130.48, 130.06, 128.16, 125.47, 113.49, 105.15, 72.03, 71.20, 69.31, 59.15,21.29, 20.23.

[0071] Example 3: Synthesis of compound 2c

[0072]

[0073] The preparation of compound 2c was carried out in accordance with the synthesis in Example 1, except that the diethylene glycol monomethyl ether in step (3) was replaced with 1-(2-aminoethoxy)-2-methoxyethane, and the remaining steps were the same. The final result was a green solid with a yield of 82%.

[0074] 1 H NMR (600 MHz, CDCl3) δ 7.72 (s, 1H), 7.51 (s, 1H), 7.47 (s, 1H), 6.95 (d, J = 8.1 Hz, 4H), 6.78 (s, 1H), 6.69 (d, J = 2.7 Hz, 2H), 6.49 (s,1H), 6.38 (s, 1H), 6.24 (d, J = 3.9 Hz, 2H), 3.68 (s, 2H), 3.65-3.61 (m, 2H), 3.57 (d, J = 5.7 Hz, 2H), 3.53-3.49 (m, 2H), 3.34 (s, 3H), 2.37 (s, 3H), 2.36 (s, 3H), 2.15 (s, 6H), 2.14 (s, 6H).

[0075] 13 C NMR (151 MHz, CDCl3) δ 161.90, 151.53, 143.28, 139.94, 138.34,138.11, 137.92, 137.42, 137.07, 136.81, 135.73, 135.04, 134.64, 134.18,130.55, 130.44, 130.31, 130.03, 128.09, 128.03, 125.97, 124.04, 121.68,119.69, 116.91, 112.39, 71.93, 70.80, 69.77, 44.30, 21.15, 20.13.

[0076] Example 4: Synthesis of compound 2d

[0077]

[0078] The preparation of compound 2d was carried out in accordance with the synthesis in Example 1, except that 2Cl in step (3) was replaced with 2Cl2 and diethylene glycol monomethyl ether was replaced with 1-(2-aminoethoxy)-2-methoxyethane. The remaining steps were the same, and a green solid was finally obtained with a yield of 74%.

[0079] 1H NMR (600 MHz, CDCl3) δ 7.11 (d, J = 4.0 Hz, 2H), 6.92 (s, 4H), 6.59 (d, J = 4.8 Hz, 2H), 6.55 (d, J = 6.7 Hz, 2H), 6.23 (d, J = 4.0 Hz, 2H), 6.09 (d, J = 4.8 Hz, 2H), 3.65 (t, J = 5.5 Hz, 4H), 3.61 (dd, J = 5.6, 3.4Hz, 4H), 3.54-3.49 (m, 8H), 3.34 (s, 6H), 2.35 (s, 6H), 2.15 (s, 12H).

[0080] 13 C NMR (151 MHz, CDCl3) δ 161.38, 139.95, 137.83, 137.62, 137.34,134.58, 133.37, 133.30, 131.37, 130.84, 128.03, 120.37, 118.63, 109.73,72.05, 70.93, 70.12, 59.26, 44.60, 21.28, 20.27.

[0081] Example 5: Synthesis of compound 2e

[0082]

[0083] The preparation of compound 2e was carried out in accordance with the synthesis in Example 1, except that the diethylene glycol monomethyl ether in step (3) was replaced with 2-(2-methoxyethoxy)ethanethiol, and the remaining steps were the same. The final result was a green solid with a yield of 81%.

[0084] 1H NMR (600 MHz, CDCl3) δ 7.81 (s, 1H), 7.51 (d, J = 4.4 Hz, 2H), 6.96 (d, J = 3.3 Hz, 4H), 6.69 (dd, J = 8.1, 4.5 Hz, 2H), 6.61 (d, J = 4.1Hz, 1H), 6.53 (dd, J = 4.6, 1.5 Hz, 2H), 6.44 (dd, J = 4.2, 1.8 Hz, 1H), 3.80(t, J = 6.8 Hz, 2H), 3.65-3.62 (m, 2H), 3.53 (dd, J = 5.6, 3.6 Hz, 2H), 3.36(s, 3H), 3.31 (t, J = 6.9 Hz, 2H), 2.37 (d, J = 5.0 Hz, 6H), 2.15 (s, 12H).

[0085] 13 C NMR (151 MHz, CDCl3) δ 150.06, 145.11, 144.01, 143.00, 139.77,138.83, 138.81, 138.23, 138.05, 137.50, 118.81, 118.48, 118.46, 77.37, 76.95,72.01, 70.83, 69.80, 59.26, 29.47, 21.31, 20.30.

[0086] Example 6: Synthesis of compound 2f

[0087]

[0088] The preparation of compound 2f was carried out in accordance with the synthesis in Example 1, except that 2Cl in step (3) was replaced with 2Cl2 and diethylene glycol monomethyl ether was replaced with 2-(2-methoxyethoxy)ethanethiol, and the remaining steps were the same. The final green solid was obtained with a yield of 75%.

[0089] 1H NMR (600 MHz, CDCl3) δ 7.47 (d, J = 4.4 Hz, 2H), 6.95 (s, 4H), 6.61 (d, J = 4.5 Hz, 2H), 6.51 (d, J = 4.4 Hz, 2H), 6.47 (d, J = 4.5 Hz, 2H), 3.79(t, J = 6.9 Hz, 4H), 3.65-3.62 (m, 4H), 3.54-3.50 (m, 4H), 3.36 (s, 6H), 3.28(t, J = 6.9 Hz, 4H), 2.36 (s, 6H), 2.14 (s, 12H).

[0090] 13 C NMR (151 MHz, CDCl3) δ 158.76, 144.80, 138.23, 137.47, 136.27,136.16, 135.93, 128.94, 128.78, 127.09, 125.99, 116.79, 70.83, 69.60, 69.47,68.68, 58.07, 31.03, 20.13, 19.13.

[0091] Example 7: Synthesis of 2g of compound

[0092]

[0093] The preparation of compound 2g was carried out in accordance with the synthesis in Example 1, except that 2Cl in step (3) was replaced with 2Cl2 and diethylene glycol monomethyl ether was replaced with m-PEG5-SH. The remaining steps were the same, and the final green solid was obtained with a yield of 85%.

[0094] 1 H NMR (600 MHz, CDCl3) δ 7.47 (d, J = 4.4 Hz, 2H), 6.94 (s, 4H), 6.61 (d, J = 4.5 Hz, 2H), 6.50 (d, J = 4.4 Hz, 2H), 6.47 (d, J = 4.5 Hz, 2H), 3.79(t, J = 6.9 Hz, 4H), 3.65 – 3.59 (m, 28H), 3.52 (t, J = 4.7 Hz, 4H), 3.35 (s,6H), 3.27 (t, J = 6.9 Hz, 4H), 2.36 (s, 6H), 2.14 (s, 12H).

[0095] 13 C NMR (151 MHz, CDCl3) δ 158.85, 144.78, 138.17, 137.47, 136.26,136.16, 135.92, 128.94, 128.77, 127.09, 125.96, 122.38, 116.81, 70.89, 69.70,69.62, 69.56, 69.53, 69.47, 68.62, 58.00, 31.10, 20.14, 19.14.

[0096] HR-MS (ESI) m / z: calcd for C 58 H 76 B2F4N4O 10 S2Na + [M+Na] + 1173.5023, found1173.5023.

[0097] Example 8: Synthesis of compound 2h

[0098]

[0099] The preparation of compound 2h was carried out in accordance with the synthesis in Example 1, except that 2Cl in step (3) was replaced with 2Cl2 and diethylene glycol monomethyl ether was replaced with m-PEG12-SH. The remaining steps were the same, and the final green solid was obtained with a yield of 84%.

[0100] 1 H NMR (600 MHz, CDCl3) δ 7.47 (d, J = 4.4 Hz, 2H), 6.94 (s, 4H), 6.61 (d, J = 4.5 Hz, 2H), 6.50 (d, J = 4.4 Hz, 2H), 6.47 (d, J = 4.5 Hz, 2H),3.79 (t, J = 6.9 Hz, 4H), 3.65-3.59 (m, 28H), 3.52 (t, J = 4.7 Hz, 4H), 3.35(s, 6H), 3.27 (t, J = 6.9 Hz, 4H), 2.36 (s, 6H), 2.14 (s, 12H).

[0101] 13C NMR (151 MHz, CDCl3) δ 158.85, 144.78, 138.17, 137.47, 136.26,136.16, 135.92, 128.94, 128.77, 127.09, 125.96, 122.38, 116.81, 70.89, 69.70,69.62, 69.56, 69.53, 69.47, 68.62, 58.00, 31.10, 20.14, 19.14.

[0102] Example 9: Preparation of Nanoparticles

[0103] Weigh approximately 1 mg of compound 2h, dissolve it in 1 mL of tetrahydrofuran, place the solution in a 50 mL round-bottom flask, stir, slowly add 5 mL of water, dialyze, and filter to obtain the nanoparticle solution (2h NPs).

[0104] Experimental Example 1: Basic Spectrum of the Compounds of the Invention

[0105] This experiment tested the UV and fluorescence spectra of compounds 2a-2f in different polar organic solvents, such as... Figure 3 As shown, the maximum absorption peaks of compounds 2a-2f in toluene are located at 678, 676, 686, 662, 709, and 739 nm, respectively, with shoulder peaks at 466, 466, 454, 466, 484, and 500 nm, respectively. Among them, compound 2f exhibits a wavelength effectively red-shifted by more than 63 nm compared to compound 2. Figure 4 As shown, NIR light exhibits stronger tissue penetration compared to UV / Vis light and can significantly reduce the risk of photodamage to surrounding healthy tissue. This indicates that the absorption characteristics of 2f within the 700–900 nm NIR window are crucial for phototransformation (PDT). Furthermore, 2f shows a significant redshift in toluene, with its strongest fluorescence emission peak reaching 792 nm and a Stokes shift of 53 nm, suggesting its potential for NIR I region fluorescence imaging.

[0106] As shown in Table 1, the fluorescence quantum yields of compounds 2a-2f in toluene were 0.33, 0.32, 0.03, 0.22, 0.25 and 0.22, respectively, indicating that the molecular structure of the compounds of the present invention has a regulatory effect on the luminescence properties.

[0107] Table 1. Basic spectral data of compounds 2a, 2b, 2c, 2d, 2e, and 2f

[0108] To further investigate the effect of side chain length on photophysical properties, based on compound 2f, the UV and fluorescence spectra of 2f, 2g, and 2h in different polar organic solvents were tested, such as... Figure 5 As shown in Table 2, the maximum absorption wavelengths of 2f, 2g, and 2h in toluene solution are 739 nm, 738 nm, and 738 nm, respectively, with highly overlapping absorption peaks. Their corresponding emission peaks are 792 nm, 788 nm, and 787 nm, respectively, with Stokes shifts of approximately 50 nm (53, 50, and 49 nm), indicating no significant deviation in spectral properties. The data suggest that within the tested carbon chain length range, the elongation of the thiol ether side chain did not cause a significant shift in absorption or emission wavelengths.

[0109] Table 2. Basic spectral data of compounds 2f, 2g, and 2h

[0110] [a] All values ​​have been corrected for changes in the solvent refractive index.

[0111] Experimental Example 2: ROS generation capacity of the compounds of the present invention in different solvents

[0112] 1,3-Diphenylisobenzofuran (DPBF) was used as a reactive oxygen species (ROS) indicator probe to evaluate the ROS yield of the compound in different solvents. In the presence of ROS, DPBF is oxidized, exhibiting a significant decrease in its characteristic absorption peak at 414 nm. Therefore, the ROS yield can be calculated by measuring the rate of decrease in absorbance. Compound ICG was used as a reference compound for ROS yield. The testing and calculation procedures are as follows: the ROS yield of ICG in methanol solution is known to be 0.008. Toluene and methanol were used as test solvents. The absorbance of DPBF at 414 nm was controlled within the range of 1.0–1.2, while the absorbance of the reference compound ICG and the sample at 730 nm was controlled between 0.15–0.25. Subsequently, a 730nm laser was used to irradiate the cuvette, and the decrease in absorbance of DPBF at 414 nm was monitored by selecting an appropriate irradiation time. The relevant data were saved, and the data were processed using Origin plotting software to calculate the degradation slope. The reactive oxygen species yield of the relevant compounds was calculated using the following formula.

[0113] Φ △(x) =Φ △S(std)· ( )·( )

[0114] In this system, the subscript X represents the sample tested, S represents the reference compound ICG, Ф represents the singlet oxygen production, S is the slope of a straight line obtained by linearly fitting irradiation time as the x-axis and the absorbance of DPBF at 414 nm after the corresponding irradiation time as the y-axis, and F represents the absorption correction factor, calculated using the formula F = 1 - 10. -0D OD represents the ultraviolet absorption value of the compound at the corresponding wavelength of the laser irradiation (in this test, it was uniformly set to 730nm).

[0115] This experimental example evaluated the ROS generation capacity of compounds 2 and 2a-2f under 660 nm laser irradiation in toluene solvent. Figure 6-7 As shown, all tested compounds could rapidly degrade DPBF under 660 nm laser irradiation, indicating that all tested compounds could generate ROS. The relative ROS yields of the compounds were calculated to be: 2f (0.19) > 2b (0.16) > 2 (0.12) > 2a (0.11) > 2e (0.10) > 2d (0.08) > 2c (0.03) (Table 3). The thiol-disubstituted product 2f showed the best performance.

[0116] Table 3. Reactive oxygen species production of compounds 2a, 2b, 2c, 2d, 2e, and 2f

[0117] To investigate the effect of the number of ether chain segments (2, 5, 12) in PEG on the ROS efficiency of dithiol compounds (2f, 2g, 2h), this experiment measured the ability of these three compounds to generate ROS in toluene. Figure 8 As shown, the ROS of 2f, 2g, and 2h were all 0.18 (Table 4). When the ether chain length in the side chain increased from 2 to 12, the ROS yield did not change significantly. Under the premise of maintaining a constant ROS yield, other properties (such as solubility and biocompatibility) can be optimized by lengthening the PEG chain without worrying about reducing photodynamic activity.

[0118] Table 4. Reactive oxygen species production of compounds 2f, 2g, and 2h

[0119] Subsequently, using commercially available ICG as a control, the ROS generation capabilities of compounds 2g and 2h after 730 nm LED irradiation were compared under the same conditions. As shown in Table 5, under 730 nm laser irradiation, the ROS yields of 2g and 2h were approximately 15 times that of ICG, indicating that both have excellent PDT potential.

[0120] Table 5. Relative reactive oxygen species production of compound 2g, 2h compared with ICG

[0121] To determine the type of ROS generated by compound 2h, this invention uses the singlet oxygen probe ABDA and the superoxide anion probe DHE for characterization. For example... Figure 9 As shown, after phototreatment, compound 2h exhibits a decrease in the absorbance of ABDA at 378 nm, indicating the generation of singlet oxygen. Simultaneously, the DHE probe shows a significant increase in fluorescence intensity at 610 nm, confirming the generation of superoxide anion radicals. Based on these results, compound 2h belongs to a type I / II mixed PS.

[0122] Experimental Example 3: Photostability of Nanoparticles (NPs) after 2 hours

[0123] The maximum absorption and emission peaks of the 2h nanoparticles (NPs) in aqueous solution are located at 690 nm and 784 nm, respectively. Figure 10 As shown, at a power density of 1.5 Wcm -2 After continuous irradiation with a 660 nm laser for 6 minutes, the absorption spectrum of the NPs in DMF remained almost unchanged for 2 hours, demonstrating their excellent photostability. In contrast, the commonly used phototherapy reagent ICG showed minimal change after only 6 minutes (1.5 W / cm²) of irradiation with a 660 nm light source. -2 It then rapidly degraded.

[0124] Experimental Example 4: Photothermal Capacity of the Nanoparticles of the Present Invention

[0125] This experimental example evaluated the photothermal capability of 2-hour nanoparticles (NPs) using photothermal imaging technology. The photothermal performance of the nanoparticles was assessed using a nanoparticle dispersion (500 μg / mL). -1 The material was irradiated with a 660 nm laser to investigate the effect of different power densities on its heating behavior. Subsequently, nanoparticles of different concentrations were irradiated at 1.5 W / cm². -2 The material was irradiated at a power density for 5 min to investigate the effect of different nanoparticle concentrations on the material's heating behavior. To evaluate the photothermal stability of the nanoparticles, 500 μg / mL... -1 The aqueous solution of nanoparticles was obtained using a 660 nm laser (1.5 W cm⁻¹). -2 Irradiate for 5 minutes, then allow to cool naturally to room temperature. Repeat this cycle four times.

[0126] like Figure 11 As shown in Figure ab, when the laser optical density is 1.5 W / cm², -2 Under the conditions, the concentration is 500 μg / mL -1 After 2h NPs were continuously exposed to light, their temperature rose rapidly. After 5 minutes of light exposure, the temperature of the 2h NPs increased from 20.9°C. oC rose to 42.6 o C. Meanwhile, the 2h NPs solution exhibited power-temperature dependence. This increased the laser optical density from 0.6 W / cm². -2 Up to 1.5 Wcm -2 Its highest temperature also increased from 23.5°C to 42.6°C. For example... Figure 11 As shown in Figure b, the concentration-temperature dependence of 2h NPs was also observed. Under laser irradiation with the same optical density, the temperature of a 1000 µM 2h NPs solution rapidly increased to 55.9 °C, while the temperature only increased to 34.4 °C when the concentration was 200 µM. In stark contrast, the blank control group containing PBS showed almost no temperature increase. Figure 11 The image shows the photothermal curve of an aqueous dispersion of ICG NPs (500 μg / mL) under 1.5 W / cm² laser irradiation: After laser activation, the temperature rises rapidly, reaching a peak at approximately 300 s, with a temperature increase exceeding 20°C; after laser deactivation, the temperature steadily returns to room temperature, demonstrating the material's excellent photothermal conversion performance. Generally, small organic molecule dyes have poor photothermal stability and may decompose significantly after a single treatment in vivo; therefore, photothermal stability evaluation is an important criterion. The initial temperature of ICG NPs was approximately 19°C, and it rapidly increased after laser irradiation, reaching a maximum of approximately 29°C. During the second irradiation, the maximum temperature of ICG NPs only rose to approximately 22°C, with a significant decrease in the temperature increase. After multiple laser irradiation cycles, the photothermal conversion efficiency of ICG NPs rapidly decreased, exhibiting significant photobleaching and failing to maintain a stable temperature rise. (500 μg / mL) -1 The 2-hour aqueous solution of NPs was subjected to four photothermal cycles (660 nm, 1.5 W / cm²). -2 After laser irradiation for 5 minutes followed by a 15-minute pause, and repeated four times, the nanoparticles still maintained their heating capacity well. This indicates that 2hNPs possess excellent photothermal stability. Figure 11 (d).

[0127] Experimental Example 5: ROS generation capacity of the nanoparticles of this invention in water

[0128] Using DPBF as an indicator, the ROS efficiency of NPs over 2 hours was evaluated under 765 nm laser irradiation. Figure 12-13 As shown, calculations show that 2h NPs have approximately 121 times the ROS generation capacity of ICG in water.

[0129] Experimental Example 6: ROS generation capacity of the nanoparticles of the present invention in cells

[0130] To verify the reactive oxygen species (ROS) generation capacity of nanoparticles (2h NPs) at the cellular level, this study used a DCFH-DA probe combined with flow cytometry and inverted fluorescence microscopy for characterization. Flow cytometry results ( Figure 14 As shown in (a), compared with the PBS control group and the 2h NPs-only treatment group, the fluorescence intensity of 4T1 cells in the 2h NPs plus light irradiation group (2h NPs+L) was significantly increased after 1 min of laser irradiation (p < 0.0001), indicating a significant upregulation of ROS levels in 4T1 cells under light-induced stimulation. Inverted fluorescence microscopy imaging results ( Figure 14 b) further verified this phenomenon: the PBS control group and the 2h NPs treatment group had almost no green fluorescence signal, while the 2h NPs combined with light irradiation group showed strong DCF green fluorescence in the cells, which directly proved that nanoparticles can effectively induce intracellular ROS generation under light conditions and have the potential for photodynamic therapy.

[0131] Experimental Example 7: Phototoxicity of the Nanoparticles of the Present Invention to Cells

[0132] To assess the effect of 2h NPs on cell viability, the cell survival rate after treatment with different concentrations of 2h NPs was detected using the CCK-8 / MTT assay. The results are as follows: cytotoxic effect of 2h NPs ( Figure 15 a) Compared with the control group (0 μM), 2hNPs showed no significant inhibitory effect on cell viability in the concentration range of 0-4 μM, and cell viability remained above 90%. When the concentration increased to 8 μM, cell viability decreased significantly to about 18%, and with further increases in concentration to 16 μM and above, cell viability approached 0, exhibiting a clear dose-dependent cytotoxic effect. The IC50 of the test drug... 50 Value measurement results are as follows Figure 15 As shown in Figure b, based on the above experimental data, the half-inhibitory concentration (IC50) of 2hNPs was calculated by fitting the dose-response curve using nonlinear regression. 50 The concentration was 6.129 μM. This result indicates that NPs at micromolar concentrations significantly inhibited cell proliferation in 2 hours, demonstrating strong in vitro cytotoxicity. Changes in cell viability in the control group were as follows: Figure 15 As shown in Figure c, in the control group, cell viability decreased slowly with increasing concentration at a concentration gradient of 0-128 μM, but the cell survival rate remained above 65% at the highest concentration (128 μM), showing no obvious cytotoxicity. This confirms that the cell-killing effect of 2h NPs is specific, rather than non-specific cell death caused by solvent or experimental environmental factors. The above cell experiment results indicate that 2h NPs have the potential for phototherapy in cancer treatment.

Claims

1. A BODIPY-type compound, characterized in that, The structural formula of the compound is shown in formula (Ⅰ). ； （Ⅰ） Wherein: R1 is 2,4,6-trimethylphenyl; R2 and R3 may be the same or different, and each is independently selected from CH3-(OCH2CH2). n -S-, n is 2-12.

2. The BODIPY-type compound according to claim 1, characterized in that, R2 and R3 are the same, each independently representing CH3-(OCH2CH2). n -S-.

3. The BODIPY-type compound according to claim 2, characterized in that, n is 2, 5, or 12.

4. The BODIPY-type compound according to claim 1, characterized in that, The BODIPY compounds are selected from any of the following compounds: .

5. A nanoparticle, characterized in that, It includes the BODIPY-type compound as described in any one of claims 1-4.

6. The use of the BODIPY-type compound according to any one of claims 1-4 or the nanoparticle according to claim 5 as a photosensitizer in the preparation of tumor photodynamic therapy.

Images