Benzobisthiazole derivatives and their use in the preparation of multimodal phototherapeutic agents

Abstract

The application discloses a benzobisthiazole derivative, and a structure general formula is as shown in the following: The benzobisthiazole derivative prepared by the application has strong near-infrared two-region emission, near-infrared one-region absorption, light-heat conversion capacity and active oxygen generation capacity, so as to meet the application requirement of multi-modal light diagnosis and treatment.

Description

Technical Field

[0001] This invention belongs to the field of biomedical engineering technology, specifically, it relates to a benzobisthiadiazole derivative and its application in the preparation of multimodal phototherapy agents. Background Technology

[0002] Over the past few decades, cancer has become one of the most serious threats to human health. However, traditional treatments, including surgical resection, chemotherapy, and radiotherapy, cause immense suffering and severe side effects for patients. Therefore, the development of more efficient cancer treatments is urgently needed. As an emerging treatment method, phototherapy relies on the energy dissipation of phototherapeutic agents in different excited states upon photoexcitation. It is highly efficient, non-invasive, spatiotemporally controllable, and has good biocompatibility, and has been considered a powerful tool for treating a wide range of superficial and localized tumors. As a special category of phototherapy, multimodal phototherapy involves fluorescence imaging (FLI), photoacoustic imaging (PAI), photothermal imaging (PTI), photodynamic therapy (PDT), and photothermal therapy (PTT). The ingenious integration of various phototherapy modalities can overcome their individual limitations and possesses a collective advantage in improving treatment efficacy, thus standing out from other therapies and attracting widespread attention from researchers. In addition, the innovative "One-for-all" strategy of preparing single-molecule species with multiple phototherapy properties has gradually become a research hotspot due to its advantages such as well-defined composition and structure, convenient preparation, high reproducibility and excellent biocompatibility.

[0003] However, currently reported multimodal phototherapy agents typically exhibit fluorescence wavelengths within the near-infrared I window (700-900 nm), severely hindering their application in the diagnosis and treatment of deep tumors. In the near-infrared II window (1000-1700 nm), fluorescence demonstrates greater tissue penetration due to a significant decrease in photon absorption, photon scattering, and autofluorescence intensity within biological tissues. However, the narrow molecular band gap in the near-infrared II region leads to a substantial increase in nonradiative transition rates, resulting in extremely low fluorescence quantum yields (QY) (<0.1%). Furthermore, to improve the water solubility and biocompatibility of organic materials, the preparation of water-soluble nanoparticles with amphiphilic polymer matrices is a common method. However, in this case, molecules tend to aggregate within the nanoshell, often leading to aggregation-induced quenching, further disrupting the energy dissipation pathway. To achieve "one-for-all" phototherapy based on single molecules, the key is to balance the multiple energy dissipation pathways of excited-state organic molecules, including radiative decay involved in the FLI mode, intersystem crossing (ISC) pathways related to the PDT mode, and non-radiative thermal inactivation related to the PAI, PTI, and PTT modes. Aggregation-induced emission (AIE) active luminescent agents (AIEgens), due to their abundant kinetic groups, can act as "knobs" to balance different energy dissipation pathways, giving them an inherent advantage in developing multimodal phototherapy agents. Currently, a comprehensive molecular design strategy is lacking in the field of multimodal phototherapy for developing NIR-II phototherapy agents. Therefore, proposing a new molecular design strategy and developing novel NIR-II AIEgens with cleverly balanced energy dissipation pathways is of great significance to the research progress of multimodal phototherapy agents. Summary of the Invention

[0004] The purpose of this invention is to provide a benzobisthiadiazole derivative.

[0005] Another object of the present invention is to provide the application of the benzobisthiadiazole derivative in the preparation of multimodal phototherapy agents.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a benzobisthiadiazole derivative with the following general structural formula:

[0008]

[0009] The π-bridge is selected from one of the following structures:

[0010]

[0011] n is selected from 0 to 10 (preferably 0, 1, 2, 3, 4, 5);

[0012] The structure of the electron donor is shown below:

[0013]

[0014] R1 is selected from hydrogen, C1-C20 alkyl, and C1-C20 alkoxy.

[0015] Preferably, the structure of the electron donor is selected from one of the following structures.

[0016]

[0017] Most preferably, the structure of the benzobisthiadiazole derivative is selected from one of the following structures:

[0018]

[0019]

[0020] In a second aspect, the present invention provides water-soluble nanoparticles prepared from the benzobisthiadiazole derivative and an amphiphilic polymer, wherein the amphiphilic polymer is selected from methoxy polyethylene glycol 2000-distearate phosphatidylethanolamine (DSPE-mPEG). 2000 ), Disteaylphosphatidylethanolamine-polyethylene glycol 2000-integrin-targeting cyclic peptide (DSPE-PEG) 2000 At least one of (-cRGDfk).

[0021] The method for preparing the water-soluble nanoparticles includes the following steps:

[0022] A benzobisthiadiazole derivative and an amphiphilic polymer in a mass ratio of 1:2 to 50 (preferably 1:20) are ultrasonically dissolved in tetrahydrofuran. The mixture is then rapidly injected into water and subjected to vigorous ultrasonication in the water for at least 2 minutes. The mixture is then dialyzed in deionized water for 1 to 24 hours (preferably 24 hours) to obtain the water-soluble nanoparticles.

[0023] A third aspect of the present invention provides the use of the benzobisthiadiazole derivative in the preparation of multimodal phototherapy agents.

[0024] In a fourth aspect, the present invention provides the application of the water-soluble nanoparticles in the preparation of multimodal phototherapy agents.

[0025] The multimodal phototherapy agent is used in multimodal phototherapy integration, which refers to a single material simultaneously containing multiple imaging modes and phototherapy modes. The imaging modes include fluorescence imaging, photoacoustic imaging, and photothermal imaging; the phototherapy modes include photodynamic therapy and photothermal therapy.

[0026] The fluorescence emission wavelength of the multimodal phototherapy agent is in the near-infrared II region, ranging from 1000 nm to 1700 nm.

[0027] The multimodal phototherapy agent can be used in the integrated multimodal phototherapy treatment of in situ breast cancer in mammals.

[0028] In a fifth aspect, the present invention provides the use of the benzobisthiadiazole derivative in the preparation of a medicament for treating breast cancer in situ.

[0029] In a sixth aspect, the present invention provides the use of the water-soluble nanoparticles in the preparation of a medicament for treating breast cancer in situ.

[0030] By adopting the above technical solution, the present invention has the following advantages and beneficial effects:

[0031] The benzobisthiadiazole derivative prepared by this invention has strong near-infrared II emission, near-infrared I absorption, photothermal conversion ability, and reactive oxygen generation ability, so as to meet the application needs of multimodal phototherapy.

[0032] This invention provides a three-dimensional donor engineering design strategy, which involves adjusting the molecular band gap by changing the strength of the electron donor, adjusting the intermolecular distance by changing the steric hindrance of the electron donor, and reducing the influence of water molecules by introducing hydrophobic groups onto the electron donor. Based on this molecular design strategy, this invention has developed a phototherapeutic agent that simultaneously possesses high near-infrared II fluorescence brightness, high photothermal conversion capability, and strong reactive oxygen species conversion capability. This agent can achieve photodynamic and photothermal therapy for in situ breast cancer guided by near-infrared II fluorescence imaging, photoacoustic imaging, and photothermal imaging. This phototherapeutic agent provides a powerful platform for multimodal phototherapy integration and offers new inspiration for the development of novel near-infrared II phototherapeutic agents.

[0033] This invention employs a donor-engineered design strategy to balance molecular energy dissipation pathways in the near-infrared II region. The rich selection of electron donors provides a solid foundation for regulating molecular properties through donor engineering. By altering the strength of electron donors, steric hindrance, and hydrophobic interactions, molecular energy dissipation pathways can be effectively adjusted at three dimensions: molecular level, aggregation state level, and solvent interaction level. Based on this, the molecular design strategy addresses the imbalance in molecular energy dissipation pathways in the near-infrared II region, thereby enabling multimodal phototherapy in the near-infrared II region for mammals.

[0034] This invention optimizes molecular properties by adjusting electron donors and π-bridges through three-dimensional donor engineering, enabling the preparation of small organic molecule fluorophores that simultaneously possess near-infrared I absorption, near-infrared II emission, photothermal conversion capabilities, and reactive oxygen species generation capabilities. After being prepared into water-soluble nanoparticles using amphiphilic polymers, this phototherapy agent can achieve photodynamic and photothermal therapy guided by near-infrared II fluorescence imaging, photoacoustic imaging, and photothermal imaging for in situ breast cancer.

[0035] The benzobisthiadiazole derivative provided by this invention exhibits peak absorption in the near-infrared I region (754 nm) and peak fluorescence emission in the near-infrared II region (1114 nm). Among these, compound OPITBT displays excellent aggregation-induced emission properties, with its fluorescence intensity increasing 21-fold compared to the initial value in a mixed solvent of 90% water and 10% tetrahydrofuran. Compound OPITBT and DSEP-mPEG... 2000 After being encapsulated into water-soluble nanoparticles OPITBT NPs, their fluorescence quantum yield increased by 16 times compared to the molecular state level, the absorption peak red-shifted to 805 nm, the photothermal conversion coefficient reached as high as 28.8%, and they also exhibited a certain ability to generate reactive oxygen species. The compound OPITBT and DSEP-mPEG... 2000 Water-soluble nanoparticles, OPITBT-RNPs, were prepared by encapsulating DSPE-PEG-cRGDfk, exhibiting active tumor-targeting capabilities. These OPITBT-RNPs demonstrate excellent near-infrared II fluorescence under 808nm excitation, allowing them to penetrate 7mm of chicken breast tissue in vitro and achieve whole-body vascular imaging in near-infrared II (LP1500nm) in mice. Under 808nm laser irradiation, OPITBT-RNPs can also provide photodynamic-photothermal therapy guided by near-infrared II fluorescence-photoacoustic-photothermal imaging for in situ breast cancer. Furthermore, OPITBT-RNPs exhibit excellent biocompatibility and do not damage major organs (heart, liver, spleen, lungs, and kidneys) in mice. Attached Figure Description

[0036] Figure 1 This is a schematic diagram showing the basic photophysical properties of compounds MPITBT, DPITBT, and OPITBT in tetrahydrofuran solution.

[0037] Figure 2 This is a schematic diagram of the gas-phase ground-state structure of compounds MPITBT, DPITBT, and OPITBT, optimized through theoretical calculations.

[0038] Figure 3 This is a schematic diagram showing the electron distribution of the lowest vacant orbital (LUMO) and the highest occupied orbital (HOMO) of compounds MPITBT, DPITBT, and OPITBT, obtained through theoretical calculations.

[0039] Figure 4 This is a schematic diagram showing the changes in fluorescence intensity as the water content varies in a tetrahydrofuran / water mixed solution (10 μM) for the aggregation-induced emission properties of compounds MPITBT, DPITBT, and OPITBT.

[0040] Figure 5 This is a schematic diagram showing the average particle size distribution of MPITBT NPs, DPITBT NPs, and OPITBT NPs measured in aqueous solution.

[0041] Figure 6 This is a schematic diagram of the basic photophysical properties of MPITBT NPs, DPITBT NPs and OPITBT NPs in aqueous solution.

[0042] Figure 7 The near-infrared II fluorescence quantum yields of compounds MPITBT, DPITBT, and OPITBT in tetrahydrofuran solution. Figure 7 The near-infrared II fluorescence quantum yield of its nanoparticle aqueous solution (as shown in a) Figure 7 (See diagram b)

[0043] Figure 8 This is a schematic diagram of the photothermal conversion efficiency of nanoparticles MPITBT NPs, DPITBT NPs, and OPITBT NPs.

[0044] Figure 9 This is a schematic diagram of the photothermal stability cycle test results of OPITBT NPs nanoparticles and the commercial photothermal agent indocyanine green (ICG, used as a stability control).

[0045] Figure 10 This is a schematic diagram showing the reactive oxygen species generation capacity and types of nanoparticles MPITBT NPs, DPITBT NPs, and OPITBT NPs.

[0046] Figure 11 This is a snapshot diagram of molecular aggregates formed in water by compounds MPITBT, DPITBT, and OPITBT through kinetic simulation.

[0047] Figure 12 This is a schematic diagram showing the effect of different electron donors on the properties of molecular aggregate state.

[0048] Figure 13 This is a schematic diagram of the basic photophysical properties test of OPITBT-RNP nanoparticles in aqueous solution.

[0049] Figure 14This is a diagram showing the particle size comparison and stability test results of OPITBT-RNPs and OPITBT NPs.

[0050] Figure 15 This is a schematic diagram illustrating the effect of OPITBT-R NPs nanoparticles as phototherapy agents on in situ breast cancer tumors using fluorescence-photoacoustic-photothermal imaging.

[0051] Figure 16 The nanoparticles OPITBT-RNPs were used as phototherapy agents after a single laser irradiation (808nm, 0.8W / cm²). 2 ) Schematic diagram of the relative tumor volume changes in mice after treatment and in the control group.

[0052] Figure 17 This is a schematic diagram of tumor tissue images of the treatment group and the control group after 14 days of treatment with OPITBT-R NPs nanoparticles as phototherapy agents.

[0053] Figure 18 This is a schematic diagram showing the physiological changes in tumor tissue in the treatment group and the control group after 14 days of treatment with OPITBT-R NPs nanoparticles as phototherapy agents.

[0054] Figure 19 This is a schematic diagram showing the changes in body weight of mice in the treatment group and the control group over 14 days as phototherapy agents using OPITBT-R NPs nanoparticles.

[0055] Figure 20 This is a schematic diagram showing the physiological changes of major organs and tissues (heart, liver, spleen, lung, and kidney) in the treatment group and the control group after 14 days of treatment with OPITBT-R NPs nanoparticles as phototherapy agents.

[0056] Figure 21 This is a schematic diagram of the proton NMR spectrum of the compound MPITBT.

[0057] Figure 22 This is a schematic diagram of the carbon NMR spectrum of the compound MPITBT.

[0058] Figure 23 This is a schematic diagram of the time-of-flight mass spectrometry of the compound MPITBT.

[0059] Figure 24 This is a schematic diagram of the proton NMR spectrum of the compound DPITBT.

[0060] Figure 25 This is a schematic diagram of the carbon NMR spectrum of the compound DPITBT.

[0061] Figure 26 This is a schematic diagram of the time-of-flight mass spectrometry of the compound DPITBT.

[0062] Figure 27 This is a schematic diagram of the proton NMR spectrum of the compound OPITBT.

[0063] Figure 28 This is a schematic diagram of the carbon NMR spectrum of the compound OPITBT.

[0064] Figure 29 This is a schematic diagram of the time-of-flight mass spectrometry of the compound OPITBT.

[0065] Figure 30 This is a schematic diagram illustrating the design strategy of the fluorescent molecule OPITBT in this invention and its application in multimodal phototherapy of in situ breast cancer after being prepared into OPITBT-RNP nanoparticles. Detailed Implementation

[0066] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0067] Unless otherwise specified, the experimental methods used in this invention are all conventional methods, and unless otherwise specified, the experimental materials used in the following examples are all purchased from conventional reagent stores.

[0068] Example 1

[0069] Synthetic route of compound MPITBT

[0070]

[0071] Under a nitrogen atmosphere, compound 1 (717 mg, 1 mmol; synthetic route of compound 1 is referenced in Zhicheng Yang, et al. Chem. Eur. J. 2021, 27, 14240–14249), compound 2 (185 mg, 0.25 mmol; purchased from Shanghai Maclean Biochemical Technology Co., Ltd.), Pd(PPh3)2Cl2 (18 mg, 0.025 mmol), and 20 mL of toluene were added to a 100 mL pre-dried double-necked flask. The reaction was carried out at 120 °C for 12 hours, cooled to room temperature, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using dichloromethane / petroleum ether (1:2, v / v) as the eluent to give compound MPITBT as a dark green solid (yield 70%). NMR and mass spectrometry results are as follows. Figures 21-23 As shown, Figure 21 This is a schematic diagram of the proton NMR spectrum of the compound MPITBT. Figure 22 This is a schematic diagram of the carbon NMR spectrum of the compound MPITBT. Figure 23This is a schematic diagram of the time-of-flight mass spectrometry of the compound MPITBT. 1 HNMR(400MHz, CDCl3)δ7.28(s,2H),7.23(d,J=1.6Hz,4H),7.10(dd,J=9.6,2.6Hz,8H),7.05(d,J=1.9Hz,2H),6.90–6.84(m,10H),3.84(s,12H) ,2.61(d,J=6.9Hz,4H),1.44(s,12H),1.40–1.35(m,2H),1.02(dddq,J= 42.1,19.6,13.2,6.9Hz,16H),0.71–0.62(m,6H),0.51(t,J=7.3Hz,6H). 13 C NMR(151MHz,THF-d8)δ158.02,157.28,156.06,153.07,147.36,144.25,141.23,140.63,139.13,138.18,129.31,129.09,125.99,125.42,12 0.06,119.02,117.78,115.78,115.68,114.43,54.59,45.70,40.47,34 .41,32.43,28.48,25.56,25.30,24.21,24.08,22.71,13.41,10.04.MS for C 84 H 84 N6O4S6[M] + :calcd.1432.4878,found1432.4258.

[0072] Example 2

[0073] Synthetic route of compound DPITBT

[0074]

[0075] Under a nitrogen atmosphere, compound 3 (235 mg, 1 mmol; synthetic route of compound 3, see Zhicheng Yang, et al. Chem. Eur. J. 2021, 27, 14240–14249), diphenylamine (507 mg, 3 mmol), bis(diphenylacetone)palladium (57 mg, 0.1 mmol), tri-tert-butylphosphine (60 mg, 0.3 mmol), potassium tert-butoxide (112 mg, 1 mmol), and 20 mL of toluene were added to a 100 mL pre-dried double-necked flask. The reaction was carried out at 120 °C for 12 hours, cooled to room temperature, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using petroleum ether as the eluent to give compound 4 as a pale yellow solid (yield 90%).

[0076] Under a nitrogen atmosphere, compound 4 (367 mg, 1 mmol) and 20 mL of tetrahydrofuran were added to a 100 mL pre-dried Shrek tube and cooled at -78 °C for 1 hour. Then, n-butyllithium (0.5 mL, 2 M / n-hexane, 2 mmol) was added dropwise, and the reaction was carried out at -78 °C for 1 hour. Tributyltin chloride (325 mg, 1 mmol) was then added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the solvent was evaporated, and the mixture was washed with deionized water and dried to obtain compound 5, which was not further purified or characterized.

[0077] Under a nitrogen atmosphere, compound 5 (657 mg, 1 mmol), compound 2 (185 mg, 0.25 mmol), Pd(PPh3)2Cl2 (18 mg, 0.025 mmol), and 20 mL of toluene were added to a 100 mL pre-dried double-necked flask. The mixture was reacted at 120 °C for 12 hours, cooled to room temperature, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using dichloromethane / petroleum ether (1:3, v / v) as the eluent to give compound DPITTBT as a dark green solid (68% yield). NMR and mass spectrometry results are as follows. Figures 24-26 As shown, Figure 24 This is a schematic diagram of the proton NMR spectrum of the compound DPITBT. Figure 25 This is a schematic diagram of the carbon NMR spectrum of the compound DPITBT. Figure 26 This is a schematic diagram of the time-of-flight mass spectrometry of the compound DPITBT. 1H NMR (600MHz, CD2Cl2) δ7.31(d,J=8.4Hz,4H),7.29–7.24(m,10H),7.18(d,J=2.1Hz,2H),7.15–7.10(m,8H),7.03(dd,J=8.1,6.9Hz,4H),6.97(dd,J= 8.1,2.1Hz,2H),2.58(d,J=7.0Hz,4H),1.44(s,12H),1.36(q,J=6.6Hz,2H ),1.17–0.84(m,16H),0.66(td,J=7.1,2.1Hz,6H),0.51(t,J=7.4Hz,6H). 13 CNMR(151MHz,CDCl3)δ158.57,157.42,153.43,153.10,147.92,145.88, 144.68,143.34,141.00,139.13,131.42,129.22,125.98,123.99,123.3 8,122.61,119.44,118.84,118.08,116.05,45.97,40.54,34.41,32.44, 28.55,28.27,26.91,25.97,25.59,22.78,17.29,14.01,13.60,10.61.MS for C 80 H 76 N6S6[M] + :calcd.1312.4456, found 1312.3545.

[0078] Example 3

[0079] Synthetic route of compound OPITBT

[0080]

[0081] Under a nitrogen atmosphere, compound 3 (235 mg, 1 mmol), bis(4-(2,4,4-trimethyl-2-pentyl)phenyl)amine (1181 mg, 3 mmol), bis(dibenzylacetone)palladium (57 mg, 0.1 mmol), tri-tert-butylphosphine (60 mg, 0.3 mmol), potassium tert-butoxide (112 mg, 1 mmol), and 30 mL of toluene were added to a 100 mL pre-dried double-necked flask. The mixture was reacted at 120 °C for 12 hours, cooled to room temperature, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using petroleum ether as the eluent to give compound 6 as a pale yellow solid (90% yield).

[0082] Under a nitrogen atmosphere, compound 6 (592 mg, 1 mmol) and 20 mL of tetrahydrofuran were added to a 100 mL pre-dried Shrek tube and cooled at -78 °C for 1 hour. Then, n-butyllithium (0.5 mL, 2 M / n-hexane, 2 mmol) was added dropwise, and the reaction was carried out at -78 °C for 1 hour. Tributyltin chloride (325 mg, 1 mmol) was then added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, the solvent was evaporated, and the mixture was washed with deionized water and dried to obtain compound 7, which was not further purified or characterized.

[0083] Under a nitrogen atmosphere, compound 7 (881 mg, 1 mmol), compound 2 (185 mg, 0.25 mmol), Pd(PPh3)2Cl2 (18 mg, 0.025 mmol), and 20 mL of toluene were added to a 100 mL pre-dried double-necked flask. The mixture was reacted at 120 °C for 12 hours, cooled to room temperature, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using dichloromethane / petroleum ether (2:5, v / v) as the eluent to give compound OPITBT as a dark green solid (yield 40%). NMR and mass spectrometry results are as follows: Figures 27-29 As shown, Figure 27 This is a schematic diagram of the proton NMR spectrum of the compound OPITBT. Figure 28 This is a schematic diagram of the carbon NMR spectrum of the compound OPITBT. Figure 29 This is a schematic diagram of the time-of-flight mass spectrometry of the compound OPITBT. 1 H NMR (600MHz, CD2Cl2) δ7.23–7.14(m,14H),6.97–6.92(m,10H),6.87(dd,J=8.1,2.1Hz,2H),2.48(d,J=7.1Hz,4H),1.6 5(s,8H),1.30(d,J=8.8Hz,38H),1.04–0.79(m,16H),0.68(s,36H),0.57(td,J=7.0,2.0Hz,6H),0.41(t,J=7.4Hz,6H). 13C NMR(151MHz,THF-d8)δ158.41,157.28,153.07,146.52,145.36,144.29,143.99 ,140.54,138.95,130.55,129.19,126.91,125.55,123.42,123.39,122.26,119 .08,117.97,117.80,115.79,56.95,45.72,40.48,37.91,34.42,32.43,32.11, 31.21,31.00,28.80,28.48,25.56,25.24,24.22,24.08,22.71,13.42,10.04.MS for C 112 H 141 N6S6[M+H] + :calcd.1762.9571,found 1762.8650.

[0084] Example 4

[0085] Determination of UV absorption-fluorescence emission spectra and molar extinction coefficients of benzobisthiadiazole derivatives in tetrahydrofuran solution.

[0086] The UV absorption spectra and molar extinction coefficients of compounds MPITBT, DPITBT, and OPITBT in tetrahydrofuran solution were measured using a Shimadzu UV-3600Plus UV-Vis-NIR absorption spectrometer, and the fluorescence emission spectra were measured using an Edinburgh Instruments FLS1000 fluorescence spectrometer.

[0087] Figure 1 This diagram illustrates the basic photophysical properties of compounds MPITBT, DPITBT, and OPITBT in tetrahydrofuran solution. In diagram a, we show the normalized UV absorption-fluorescence emission spectra of compounds MPITBT, DPITBT, and OPITBT, with the horizontal axis representing wavelength (in nanometers), the left vertical axis representing normalized absorbance, and the right vertical axis representing normalized fluorescence intensity. Diagram b shows the molar extinction coefficients of compounds MPITBT, DPITBT, and OPITBT in tetrahydrofuran solution; the horizontal axis represents concentration (in μM), the vertical axis represents absorbance, and the calculated slope represents the molar extinction coefficient of the compound. Figure 1 From equation a, we can deduce that the maximum absorption wavelengths of compounds MPITBT, DPITBT, and OPITBT are 763, 736, and 754 nm, respectively, and the maximum emission wavelengths are 1122, 1101, and 1114 nm, respectively. This indicates that the absorption and emission wavelengths of the three compounds gradually redshift with increasing electron donor strength, and all exhibit near-infrared I absorption and near-infrared II emission. Figure 1 From b, we can deduce that the molar extinction coefficients of compounds MPITBT, DPITBT, and OPITBT at the absorption peak are 1.80 × 10⁻⁶. 4 1.83×10 4 1.93×10 4 M -1 cm -1 All of them showed strong light absorption in the near-infrared region I.

[0088] Example 5

[0089] Theoretical calculations of the molecular structure of benzobisthiadiazole derivatives

[0090] Using the Gaussian 16 software package with B3LYP density functional theory and 6-31g(d) basis sets, the ground-state geometry of compounds MPITBT, DPITBT, and OPITBT was optimized using density functional theory. The optimized gas-phase ground-state structures, HOMO, and LUMO electron distributions of the three compounds were obtained. The calculation results are shown below. Figure 2 , 3 As shown. Figure 2 This is a schematic diagram of the gas-phase ground-state structure of compounds MPITBT, DPITBT, and OPITBT, optimized through theoretical calculations. Figure 3 This is a schematic diagram showing the electron distribution of the lowest vacant orbital (LUMO) and the highest occupied orbital (HOMO) of compounds MPITBT, DPITBT, and OPITBT, obtained through theoretical calculations. Figure 2 As can be seen from the data, in the three molecular structures, the benzobisthiadiazole core and the thiophene groups on both sides exhibit a large dihedral angle (>45°). The twisted molecular structure is beneficial to reducing intermolecular π interactions. In addition, the dihedral angle at the thiophene and indothiophene is reduced, which is beneficial to enhancing the degree of molecular conjugation and improving light absorption. Figure 3 As can be seen, the band gap of the three compounds gradually decreases with the increase of electron donor strength. OPITBT has a moderate band gap width of 1.21 eV, which achieves a good balance between nonradiative dissipation rate and absorption emission wavelength.

[0091] Example 6

[0092] Aggregation-induced emission performance test of benzobisthiadiazole derivatives

[0093] By preparing tetrahydrofuran / water mixed solutions with the same compound concentration (10 μM) but different water contents (water contents are expressed as f... w (Indicates), test f w Fluorescence intensity was recorded every 10% change, ranging from 0% to 90%. Results are as follows: Figure 4 As shown, Figure 4This is a schematic diagram showing the changes in fluorescence intensity of compounds MPITBT, DPITBT, and OPITBT in a 10 μM tetrahydrofuran / water mixed solution as the water content changes, based on the aggregation-induced emission properties of these compounds. The horizontal axis represents water content, and the vertical axis represents fluorescence intensity. As can be seen from the graph, all three compounds show changes in fluorescence intensity with varying f... w With increasing concentration, solubility decreases, and the fluorescence intensity of the aggregated state increases significantly, exhibiting obvious aggregation-induced emission characteristics. However, it is worth noting that the fluorescence intensity of OPITBT at f... w At 90%, the fluorescence intensity was 21 times greater than the initial fluorescence intensity, significantly higher than the other two compounds.

[0094] Example 7

[0095] The preparation method of water-soluble nanoparticles of benzobisthiadiazole derivatives includes the following steps:

[0096] 1 mg of compound MPITBT and 20 mg of the amphiphilic polymer methoxy polyethylene glycol 2000-distearate phosphatidylethanolamine (DSPE-mPEG) were mixed. 2000 The sample (CAS No. 147867-65-0; purchased from Xi'an Kaixin Biotechnology Co., Ltd.) was ultrasonically dissolved in 1 mL of tetrahydrofuran. The mixture was then rapidly injected into 9 mL of water and subjected to vigorous sonication for 2 minutes. The mixture was then transferred to a dialysis bag and dialyzed in a large volume of deionized water for 24 hours to obtain stable water-soluble nanoparticles MPITBT NPs.

[0097] 1 mg of compound DPIBT and 20 mg of the amphiphilic polymer DSPE-mPEG were mixed. 2000 The mixture was dissolved in 1 mL of tetrahydrofuran and rapidly injected into 9 mL of water, followed by vigorous sonication for 2 minutes. The mixture was then transferred to a dialysis bag and dialyzed in a large volume of deionized water for 24 hours to obtain stable water-soluble nanoparticles DPITBT NPs.

[0098] 1 mg of compound OPITBT and 20 mg of the amphiphilic polymer DSPE-mPEG were mixed. 2000 The mixture was dissolved in 1 mL of tetrahydrofuran and rapidly injected into 9 mL of water, followed by vigorous sonication in the water for 2 minutes. The mixture was then transferred to a dialysis bag and dialyzed in a large volume of deionized water for 24 hours to obtain stable water-soluble OPITBT nanoparticles.

[0099] The average particle size distribution of the encapsulated nanoparticles was determined by dynamic optical dispersion, and the test results are as follows: Figure 5 As shown, Figure 5This is a schematic diagram showing the average particle size distribution of MPITBT NPs, DPITBT NPs, and OPITBT NPs in aqueous solution. The average particle sizes of MPITBT NPs, DPITBT NPs, and OPITBT NPs are 135.9, 130.7, and 139.8 nm, respectively, and their polymer dispersibility index (PDI) is less than 0.3. TEM images of MPITBT NPs, DPITBT NPs, and OPITBT NPs all show spherical nanoparticles. These results indicate the successful preparation of stable water-soluble nanoparticles.

[0100] Example 8

[0101] Determination of UV absorption-fluorescence emission spectra and molar extinction coefficient of water-soluble nanoparticles of benzobisthiadiazole derivatives in water.

[0102] The determination method is the same as that for benzobisthiadiazole derivatives, and the test results are as follows: Figure 6 As shown, Figure 6 This diagram illustrates the basic photophysical properties of MPITBT NPs, DPITBT NPs, and OPITBT NPs in aqueous solution. Figure a shows the normalized UV absorption-fluorescence emission spectra of MPITBT NPs, DPITBT NPs, and OPITBT NPs, with the horizontal axis representing wavelength (in nanometers), the left vertical axis representing normalized absorbance, and the right vertical axis representing normalized fluorescence intensity. Figure b shows the molar extinction coefficients of MPITBT NPs, DPITBT NPs, and OPITBT NPs at 808 nm. The horizontal axis represents concentration (in μM), the vertical axis represents absorbance, and the calculated slope represents the molar extinction coefficient of the compound. After the compounds MPITBT, DPITBT, and OPITBT were prepared into nanoparticles MPITBT NPs, DPITBT NPs, and OPITBT NPs, respectively, the fluorescence peak wavelengths did not change significantly, but the absorption wavelengths showed a marked redshift to around 800 nm. Since 808 nm is considered the optimal excitation wavelength in the near-infrared I region, the molar extinction coefficients of the nanoparticles MPITBT NPs, DPITBT NPs, and OPITBT NPs at 808 nm were calculated. The molar extinction coefficient of the nanoparticles OPITBT NPs was 1.72 × 10⁻⁶. 4 M -1 cm -1 It has a high molar extinction coefficient, and it is the highest of the three.

[0103] Example 9

[0104] Near-infrared II fluorescence quantum yield determination of benzobisthiadiazole derivatives and their water-soluble nanoparticles

[0105] 1-Benzothioperchloric acid (near-infrared fluorescent dye IR-26) was used as the reference fluorophore (QY = 0.5%). For reference calibration, IR-26 was dissolved in 1,2-dichloroethane and diluted to five samples with absorbance values ​​of 0.1–0.01 at 808 nm. Then, IR-26 solutions containing five linearly spaced DCE concentrations were sequentially transferred to 10 mm path length fluorescent cuvettes, and their emission spectra were recorded using an 808 nm infrared semiconductor laser as the excitation source. The emission spectra of all five samples were integrated in the 1000–1700 nm region. The corresponding absorbance values ​​(808 nm) were plotted against the integrated fluorescence intensity and fitted with linear functions. The same procedure was performed for compounds MPITBT, DPITBT, and OPITBT to obtain four linear functions. The fluorescence quantum yield of the samples was calculated using the slopes of these lines according to the following equation:

[0106]

[0107] Among them, QY sample It is the fluorescence quantum yield of the sample, QY ref It refers to the fluorescence quantum yield of the reference fluorophore, slope sample and slope ref These are the slopes of the straight lines representing the sample and reference fluorophores, respectively, n sample and n ref , respectively, are the refractive indices of tetrahydrofuran and 1,2-dichloroethane.

[0108] The fluorescence quantum yield of MPITBT NPs, DPITBT NPs and OPITBT NPs was measured using the same method as described above.

[0109] The results are as follows Figure 7 As shown, Figure 7 The near-infrared II fluorescence quantum yields of compounds MPITBT, DPITBT, and OPITBT in tetrahydrofuran solution. Figure 7 The near-infrared II fluorescence quantum yield of its nanoparticle aqueous solution (as shown in a) Figure 7 (See diagram b) Where: the horizontal axis represents the absorbance at 808 nm, and the vertical axis represents the integral area of ​​fluorescence intensity. Since compounds MPITBT, DPITBT, and OPITBT all possess aggregation-induced emission properties, the fluorescence intensity is significantly enhanced after being prepared as water-soluble nanoparticles due to molecular aggregation. In particular, the near-infrared II fluorescence quantum yield of OPITBT nanoparticles reaches as high as 1.1%, which is 16 times higher than that of the molecular state, demonstrating enormous potential for near-infrared II fluorescence imaging.

[0110] Example 10

[0111] In vitro photothermal conversion performance testing of water-soluble nanoparticles MPITBT NPs, DPITBT NPs and OPITBT NPs

[0112] An aqueous solution (50 μM) of nanoparticles MPITBT NPs, DPITBT NPs, and OPITBT NPs was prepared at 0.8 W / cm². 2 The sample was irradiated with an 808 nm laser, and the temperature was recorded every 30 seconds until it reached its maximum value. Simultaneously, an infrared thermal image of the sample tube was recorded. The photothermal conversion efficiency was tested in a 50 μM aqueous solution, with the sample exposed to an 808 nm laser (0.8 W / cm²). 2 The sample was exposed to irradiation for 5 minutes, then cooled to room temperature. The photothermal conversion efficiency (η) can be calculated using the following formula:

[0113]

[0114] Where h is the heat transfer coefficient, s is the surface area of ​​the container, and ΔT max I is the temperature difference between the highest temperature and room temperature, I is the laser power, A is the absorbance of the nanoparticle solution at 808 nm, and Q is the light absorption of the nanoparticle solution at 808 nm. s This represents the heat change of the water in the system. λ is the absorbance of the nanoparticles at 808 nm. The unknown value of hs is calculated using the following formula: hs = ∑ i m i C p,i / K, where m represents the mass of the aqueous solution, and C represents the specific heat capacity of water. K is calculated from the linear data of the time versus -lnθ curve, with the formula t=-Klnθ (θ is defined as ΔT and ΔT). max The ratio). Qs was calculated using the same method based on the time variation of water on the cooling curve. Furthermore, at 808 nm (0.8 W / cm²), 2 The photothermal stability of OPITBTNPs was evaluated by five heating-cooling cycles under laser irradiation, with each heating / cooling cycle lasting 3 minutes.

[0115] Photothermal conversion efficiency results are as follows Figure 8 As shown, Figure 8 This diagram illustrates the photothermal conversion efficiency of MPITBT NPs, DPITBT NPs, and OPITBT NPs nanoparticles. As can be seen from the diagram, OPITBT NPs nanoparticles exhibit a photothermal conversion efficiency as high as 28.8% in aqueous solution. Photothermal stability cycling test results are shown below. Figure 9 As shown, Figure 9This is a schematic diagram illustrating the photothermal stability cycling test results of OPITBT NP nanoparticles and the commercial photothermal agent indocyanine green (ICG, used as a stability control). As can be seen from the figure, OPITBT NP nanoparticles exhibited good photothermal stability during five photothermal cycles. In contrast, the photothermal heating performance of the commercial photothermal agent ICG deteriorated with increasing cycle number. These results demonstrate that OPITBT NP nanoparticles possess excellent potential for photothermal therapy applications.

[0116] Example 11

[0117] In vitro reactive oxygen species generation performance testing of water-soluble nanoparticles MPITBT NPs, DPITBT NPs and OPITBT NPs

[0118] 2',7'-dichlorodifluorofluorescein diacetate (DCFH-DA) was used as a reactive oxygen species (ROS) indicator to detect reactive oxygen species under 808 nm laser irradiation (0.8 W / cm²). 2 The total amount of ROS generated under these conditions was determined. To activate DCFH-DA, 2 mL of NaOH solution (10 mM) was mixed with 0.5 mL of DCFH-DA solution (1 mM, dissolved in ethanol), stirred at room temperature in the dark for 30 minutes, and then 10 mL of pH 7.4 PBS solution was added. The activated solution was then mixed with solutions of MPITBT NPs, DPITBT NPs, and OPITBT NPs nanoparticles (DCFH: 5 μM; MPITBT NPs: 15 μM; DPITBT NPs: 15 μM; OPITBT NPs: 15 μM) and irradiated with an 808 nm laser for different times. The 525 nm fluorescence signal of ROS sensitized by MPITBT NPs, DPITBT NPs, and OPITBT NPs was measured using a photoluminescence (PL) instrument at an excitation wavelength of 488 nm.

[0119] To further differentiate the ROS types generated by MPITBT NPs, DPITBT NPs, and OPITBT NPs, 9,10-anthrayl-bis(methylene)dimalic acid (ABDA), hydroxyphenyl fluorescein (HPF), and dihydrorhodamine 123 (DHR123) were used as three additional indicators to evaluate the ROS generated by MPITBT NPs, DPITBT NPs, and OPITBT NPs under 808 nm laser irradiation. 1 O2, ·OH and O 2· -The specific procedure involved mixing ABDA solution with MPITBT NPs, DPITBT NPs, and OPITBT NPs (ABDA: 50 μM; MPITBT NPs: 5 μM; DPITBT NPs: 5 μM; OPITBT NPs: 5 μM) in an aqueous solution and subjecting the mixture to laser irradiation. The decrease in absorbance of ABDA at 378 nm was recorded at different irradiation times. HPF (15 μM) or DHR123 (50 μM) and MPITBT NPs (5 μM), DPITBT NPs (5 μM), and OPITBT NPs (5 μM) were added to PBS buffer solution and treated under the same laser irradiation conditions. The fluorescence signal of the indicator was monitored in the range of 500–600 nm, with an excitation wavelength of 488 nm. The results of the reactive oxygen species generation performance test are listed below. Figure 10 . Figure 10 This is a schematic diagram showing the reactive oxygen species (ROS) generation capacity and types of MPITBT NPs, DPITBT NPs, and OPITBT NPs nanoparticles. Figure 10 As shown in Figures a to d, the nanoparticles MPITBT NPs, DPITBT NPs, and OPITBT NPs all exhibit ROS generation capabilities. Moreover, ROS is a superoxide anion free radical. This Type-I ROS generation capability is less dependent on oxygen, which is beneficial for the nanoparticles MPITBT NPs, DPITBT NPs, and OPITBT NPs to generate ROS and kill cancer cells in the hypoxic environment of tumors.

[0120] Example 12

[0121] Structural analysis of benzobisthiadiazole derivative aggregates

[0122] The OPITBT nanoparticles exhibited optimal fluorescence brightness (fluorescence quantum yield × molar extinction coefficient), optimal photothermal conversion capability (photothermal conversion efficiency × molar extinction coefficient), and a certain Type-I ROS generation capability, achieving a good balance in energy dissipation. This can be attributed to the effective molecular design strategy of this three-dimensional donor engineering. To investigate the influence of different electron donors on the aggregation states of DPITBT, MPITBT, and OPITBT molecules, molecular dynamics simulations were performed using the GROMACS software package. In the simulations, the force field parameters of the dye molecules were calculated using the OPLS force field, and the water molecule model was calculated using the SPCE model. The time step was set to 2.0 fs, and the cutoff distance for all non-bonded interactions was 1.2 nm. Long-range electrostatic interactions were calculated using the particle mesh Ewald (PME) method, with LJ tail corrections added to the energy and pressure. The temperature was controlled by a Nosé-Hoover thermostat with a coupling time constant of 0.5 ps; the pressure was maintained at 1 bar by a Parrinello-Rahman pressure controller with a coupling time of 2.0 ps. Periodic boundary conditions were applied in all directions.

[0123] In this invention, 40 molecules were first placed in a cubic simulation chamber with a side length of 12 nm, and conjugate gradient energy minimization was performed. Subsequently, the aggregate configuration was obtained through a 10 ns NVT ensemble simulation under vacuum conditions. Next, the aggregates were solvated with water molecules and subjected to energy minimization. A 200 ns NPT simulation was then performed at 300 K and 1 bar, and the trajectory data for the last 100 ns were analyzed. The analysis results were visualized using the VMD software package.

[0124] Figure 11 These are snapshots of molecular aggregates formed in water by compounds MPITBT, DPITBT, and OPITBT, as simulated kineticly. Specifically, a) is a snapshot of molecular aggregates formed in water by compound MPITBT, b) is a snapshot of molecular aggregates formed in water by compound DPITBT, and c) is a snapshot of molecular aggregates formed in water by compound OPITBT.

[0125] Simulation analysis data such as Figure 12 As shown, Figure 12This diagram illustrates the influence of different electron donors on the properties of the aggregated state. In the diagram, a represents the distribution of intermolecular distance within the aggregate, b represents the distribution of water molecules around the molecule in the aggregated state, and c represents the dihedral distribution of the benzene ring on the electron donor in the aggregated state. Compound OPITBT exhibits the largest intermolecular packing distance in the aggregated state, which is beneficial for reducing intermolecular π interactions and improving fluorescence quantum yield. On the other hand, the large intermolecular packing distance also provides space for intramolecular motion, which is beneficial for enhancing photothermal conversion capabilities. Furthermore, compound OPITBT exhibits significant hydrophobicity, greatly reducing the interaction between water molecules and other molecules, and improving fluorescence quantum yield.

[0126] Example 13

[0127] Preparation of OPITBT-RNP nanoparticles and their multimodal phototherapy applications

[0128] OPITBT NPs possess strong near-infrared absorption at 808 nm, bright near-infrared II fluorescence, excellent photothermal conversion capabilities, and Type-I reactive oxygen species generation capacity, making them suitable for multimodal phototherapy and demonstrating significant potential for multimodal phototherapy applications. Therefore, OPITBT-R NPs with active tumor-targeting capabilities were prepared by doping with tumor-targeting materials and applied to multimodal phototherapy for in situ breast cancer in mice.

[0129] Preparation of OPITBT-R NPs nanoparticles: 1 mg of compound OPITBT and 16 mg of DSPE-mPEG were mixed. 2000 and 4 mg distearylphosphatidylethanolamine-polyethylene glycol 2000-integrin-targeting cyclic peptide (DSPE-PEG) 2000 -cRGDfk; purchased from Xi'an Ruixi Biotechnology Co., Ltd., product number R-9998-2k) was ultrasonically dissolved in 1 mL of tetrahydrofuran. The mixture was then rapidly injected into 9 mL of water and subjected to vigorous sonication for 2 minutes. The mixture was transferred to a dialysis bag and dialyzed in a large volume of deionized water for 24 hours to obtain stable water-soluble nanoparticles OPITBT-R NPs. Figure 30 This is a schematic diagram illustrating the design strategy of the fluorescent molecule OPITBT in this invention and its application in multimodal phototherapy of in situ breast cancer after being prepared into OPITBT-R NPs.

[0130] The basic photophysical properties of the prepared OPITBT-R NPs were tested, and the results are as follows: Figure 13 As shown. Figure 13This is a schematic diagram illustrating the basic photophysical properties of OPITBT-R NPs nanoparticles in aqueous solution. The maximum absorption wavelength of OPITBT-R NPs in aqueous solution is 805 nm, and the maximum emission wavelength is 1065 nm, consistent with the maximum absorption and emission wavelengths of OPITBT NPs in aqueous solution, indicating that DSPE-PEG... 2000 The doping of -cRGDfk did not affect the basic photophysical properties of OPITBT-R NPs. Furthermore, the particle size changes of OPITBT NPs and OPITBT-R NPs were compared after 7 days of storage in water, phosphate-buffered saline (PBS), Duchenne modified Eagle medium (DMEM), and 10% bovine serum albumin (FBS) at 8°C. The results are as follows: Figure 14 As shown, Figure 14 This is a comparison of the particle size of OPITBT-R NPs and OPITBT NPs, along with a schematic diagram of stability testing. The particle size of OPITBT NPs and OPITBT-R NPs did not change significantly after 7 days of storage in four different media, demonstrating their good micellar stability.

[0131] Multimodal imaging of tumor tissue: OPITBT-R NPs nanoparticles (1 mg / mL, 200 μL) in PBS solution were injected via tail vein into mice carrying 4T1 mammary tumors. NIR-II fluorescence images were captured using a 1300 nm long-pass filter on the NIR-II in vivo imaging system at predetermined time points post-injection (10 min, 6 h, 12 h, 24 h, 36 h, and 48 h). Subsequently, major organs (heart, liver, spleen, lung, and kidney) and tumors were removed, washed with saline, and subjected to NIR-II fluorescence imaging. In vivo photoacoustic imaging was performed using the Vevo LAZER system at specified time points (0, 1, 6, 12, 24, 36, and 48 h). Photothermal imaging was performed 24 h post-injection of the OPITBT-R NPs nanoparticle solution (1 mg / mL, 200 μL) by irradiation with an 808 nm laser (0.8 W / cm²). 2 Infrared thermal images were captured using an infrared camera. Mice injected with PBS under the same irradiation conditions served as a control group. Multimodal imaging results of tumor tissue are listed below. Figure 15 middle. Figure 15 This is a schematic diagram illustrating the effect of OPITBT-R NPs nanoparticles as a phototherapy agent on in situ breast cancer tumors using fluorescence-photoacoustic-photothermal imaging. In the diagram, a represents near-infrared II fluorescence imaging, b represents photoacoustic imaging, and c represents photothermal imaging. Figure 15 As shown, all three imaging modes can accurately locate tumor tissue, and the different imaging modes can compensate for each other's limitations in accuracy and tissue penetration depth, thus achieving precise localization.

[0132] Phototherapy of tumor tissue: Mice carrying 4T1 mammary tumors in situ were randomly divided into four groups (n=5 per group): "PBS solution injection only (PBS) group", "PBS solution injection and laser irradiation (PBS+Laser) group", "PBS solution injection of OPITBT-R NPs only (OPITBT-R NPs) group", and "PBS solution injection of OPITBT-R NPs and laser irradiation (OPITBT-RNPs+Laser) group".

[0133] Control group: In the "PBS" and "OPITBT-R NPs" groups, mice were intravenously injected with 200 μL of PBS solution or 1 mg / mL of OPITBT-R NPs in PBS solution, respectively, without laser irradiation. In the "PBS+L" group, 24 hours after intravenous injection of 200 μL of PBS solution (the optimal accumulation time for OPITBT-R NPs in vivo), the tumor site was irradiated with an 808 nm laser (0.8 W / cm²). 2 Irradiate for 5 minutes.

[0134] Experimental group: For the "OPITBT-R NPs+L" group, 24 hours after intravenous injection of 200 μL of OPITBT-R NPs nanoparticles in PBS solution (1 mg / mL), the tumor site was treated with an 808 nm laser (0.8 W / cm²). 2 Irradiation for 5 minutes. After completing the different treatments, during the two-week experiment, only subsequent culture and observation were conducted, and the weight and tumor volume of the mice were recorded every two days. The tumor size was measured using calipers, and the tumor volume (V) was calculated using the following formula: V = (length × width) 2 ) / 2. Relative tumor volume was calculated using the formula V / V0, where V0 is the initial tumor volume. After 14 days of different treatments, all tumors and major organs (heart, liver, spleen, lung, and kidney) from mice in each group were collected, fixed overnight with 4% (v / v) formaldehyde solution, embedded in paraffin, and sectioned to a thickness of 5 μm. Subsequently, the tumor sections from these four groups were stained with H&E, CD31, Ki67, and TUNEL, and histopathologically evaluated using an inverted optical microscope. The phototherapy results of the tumor tissues are listed below. Figures 16-18 As shown. Figure 16 The OPITBT-R NPs nanoparticles were used as phototherapy agents after a single laser irradiation (808nm, 0.8W / cm²). 2 ) Schematic diagram of the relative tumor volume changes in mice after treatment and in the control group. Figure 17 This is a schematic diagram of tumor tissue images of the treatment group and the control group after 14 days of treatment with OPITBT-R NPs nanoparticles as phototherapy agents. Figure 16 , 17 This indicates that when passing through 0.8W / cm 2 After a single 5-minute irradiation with an 808nm laser, the OPTBT-R NP nanoparticles can achieve highly efficient ablation of tumor tissue, and there is no recurrence within two weeks. Figure 18 This is a schematic diagram showing the physiological changes in tumor tissue in the treatment group and the control group after 14 days of treatment with OPITBT-R NPs nanoparticles as phototherapy agents. Figure 18 This indicates that when passing through 0.8W / cm 2 Five minutes after a single irradiation with an 808nm laser, the OPITBT-R NP nanoparticles effectively destroyed tumor tissue and inhibited angiogenesis. These results indicate that OPITBT-R NP nanoparticles, as a phototherapy agent, can achieve photothermal-photodynamic therapy guided by near-infrared II fluorescence-photoacoustic-photothermal imaging for in situ breast cancer.

[0135] Example 14

[0136] Biosafety testing of OPITBT-R NPs nanoparticles

[0137] Mouse body weight changes were recorded daily during the 14-day treatment period. Additionally, H&E staining was performed on sections of major organs to assess biosafety. The biosafety test results for the OPITBT-R NPs nanoparticles are as follows: Figure 19 , 20 As shown, Figure 19 This is a schematic diagram showing the changes in body weight of mice in the treatment group and the control group over 14 days as a phototherapy agent using OPITBT-R NPs nanoparticles. There was no significant difference in body weight between the treatment group and the control group, proving that OPITBT-R NPs nanoparticles have no significant effect on mouse growth. Figure 20 This diagram illustrates the physiological changes in major organs (heart, liver, spleen, lung, and kidney) in the treatment and control groups after 14 days of treatment with OPITBT-R NPs nanoparticles as a phototherapy agent. There were no significant differences in the morphology of the major organs between the treatment and control groups, demonstrating that OPITBT-R NPs nanoparticles had no significant effect on the major organs of mice. These results demonstrate that OPITBT-R NPs nanoparticles have good biocompatibility as a phototherapy agent.

[0138] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A benzobisthiadiazole derivative, characterized in that, The general structural formula is as follows: The π-bridge is selected from one of the following structures: n is selected from 0 to 10; The structure of the electron donor is shown below: R1 is selected from hydrogen, C1-C20 alkyl, and C1-C20 alkoxy.

2. The benzobisthiadiazole derivative according to claim 1, characterized in that, The structure of the electron donor is selected from one of the following structures.

3. The benzobisthiadiazole derivative according to claim 2, characterized in that, The structure of the benzobisthiadiazole derivative is selected from one of the following structures:

4. A water-soluble nanoparticle, characterized in that, It is prepared by the benzobisthiadiazole derivative according to any one of claims 1 to 3 and an amphiphilic polymer, wherein the amphiphilic polymer is selected from at least one of methoxy polyethylene glycol 2000-distearylphosphatidylethanolamine and distearylphosphatidylethanolamine-polyethylene glycol 2000-integrin-targeting cyclic peptide.

5. The water-soluble nanoparticles according to claim 4, characterized in that, The method for preparing the water-soluble nanoparticles includes the following steps: A benzobisthiadiazole derivative and an amphiphilic polymer in a mass ratio of 1:2 to 50 were ultrasonically dissolved in tetrahydrofuran. The mixture was then rapidly injected into water and subjected to vigorous ultrasonication in the water for at least 2 minutes. The mixture was then dialyzed in deionized water for 1 to 24 hours to obtain the water-soluble nanoparticles.

6. The use of a benzobisthiadiazole derivative according to any one of claims 1 to 3 in the preparation of a multimodal phototherapy agent.

7. The use of the water-soluble nanoparticles according to claim 4 or 5 in the preparation of multimodal phototherapy agents.

8. The use of a benzobisthiadiazole derivative according to any one of claims 1 to 3 in the preparation of a medicament for treating breast cancer in situ.

9. The use of the water-soluble nanoparticles according to claim 4 or 5 in the preparation of a medicament for treating in situ breast cancer.

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