Naphthalimide-based light diagnosis and treatment molecule with controllable self-assembly behavior as well as preparation method and application of naphthalimide-based light diagnosis and treatment molecule

Abstract

The invention discloses a naphthalimide-based light diagnosis and treatment molecule with a controllable self-assembly behavior as well as a preparation method and application thereof, and relates to the technical field of near-infrared two-region light diagnosis and treatment. According to the functionalized light diagnosis and treatment molecular library based on the naphthalimide skeleton, the problems that the aggregation-induced performance of a traditional light diagnosis and treatment agent is reduced, the assembly controllability is insufficient, the structural characteristics, the accumulation mode and the performance adjustment are not clear and the like are solved by adjusting the molecular structure, the accumulation mode and the light physical performance of the traditional light diagnosis and treatment agent; the method is suitable for the field of near-infrared two-zone light diagnosis and treatment in biomedicine, and aims to improve the deep tissue imaging and treatment effect.

Description

Technical Field

[0001] The present invention relates to the field of near-infrared second-region optical diagnosis and treatment technology, and in particular to a naphthaleneimide-based optical diagnosis and treatment molecule with controllable self-assembly behavior, and a preparation method and application thereof. Background Art

[0002] Near-infrared II (NIR-II) optical diagnostic and therapeutic technology is reshaping the landscape of biomedical research at an unprecedented rate. Compared to traditional near-infrared I (NIR-I) imaging, photons in the NIR-II band have longer wavelengths, which means that their absorption and scattering in biological tissues are significantly reduced. This unique physical property gives NIR-II technology unparalleled advantages: it can penetrate deeper tissue layers, easily breaking through the depth bottleneck of traditional optical imaging, and achieving clear visualization of deep organs and even submillimeter vascular networks. At the same time, due to the extremely low background fluorescence interference in this band, the signal-to-noise ratio is greatly improved, which significantly improves the imaging resolution and can capture more delicate physiological structures and pathological changes. Not only that, NIR-II photons have moderate energy, which can be effectively absorbed by diagnostic and therapeutic agents and converted into heat, realizing efficient and precise photothermal therapy (PTT), while avoiding excessive photodamage to biological tissues. It is this potential that combines "deep perspective", "high-definition imaging" and "precision treatment" that has made NIR-II optical diagnosis and treatment technology rapidly become a research hotspot in the fields of biomedical imaging, disease diagnosis and photodynamic / photothermal therapy.

[0003] In this booming field, small molecule organic diagnostic and therapeutic agents have attracted widespread attention due to their relatively simple synthesis, adjustable biocompatibility, and diverse photophysical properties. Among them, naphthalimide (NI) compounds have stood out due to their outstanding advantages such as inherent strong fluorescence emission, excellent photochemical and chemical stability, good photothermal conversion efficiency, and ease of molecular structure modification, becoming one of the core molecular skeletons for constructing high-performance NIR-II photodiagnostic and therapeutic agents. Through strategies such as carefully designing side chains, changing conjugated systems, or introducing heteroatoms, researchers have successfully developed a series of diagnostic and therapeutic agents based on the NI skeleton and achieved a series of remarkable results in in vitro and in vivo imaging and photothermal therapy.

[0004] However, translating laboratory research findings into truly reliable and effective clinical applications remains a long and challenging journey. Currently, the design and synthesis of most naphthaleneimide-based phototherapeutic agents often focus on optimizing a single property. For example, some researchers strive to maximize photothermal conversion efficiency by expanding the π-conjugated system or introducing strong electron-withdrawing groups, hoping to achieve greater tumor killing potential; while others may be more concerned with enhancing the intensity and stability of fluorescence emission in the NIR-II window by adjusting the molecular structure to achieve clearer imaging. While this "single-point breakthrough" strategy has achieved progress in specific areas, it ignores the increasingly complex demands placed on materials by modern biomedical diagnosis and treatment, especially the integrated development of disease diagnosis and treatment. Real-world diagnostic and treatment scenarios often require phototherapeutic agents to both accurately indicate lesion location and provide rich physiological and pathological information (diagnosis) and effectively intervene based on this information (treatment). Currently, multifunctional naphthaleneimide-based phototherapeutic agents that can simultaneously and efficiently accomplish these two tasks, with their properties synergistic and non-interfering, are still very scarce.

[0005] There are many reasons for this dilemma, among which the lack of understanding of the complex relationship between molecular structure and ultimate performance is a key bottleneck. Specifically, for molecules with planar rigid structures such as naphthalimide, their aggregation behavior—that is, how the molecules arrange and stack with each other in the solid state or solution—has a decisive influence on their macroscopic photophysical properties (such as fluorescence quantum yield, photothermal conversion efficiency, stability, etc.). However, current research is still largely at the level of "molecular structure determines performance", and there is still a lack of systematic and in-depth understanding of the deeper question of "how molecular structure regulates its self-assembly and stacking mode, and thus how it precisely affects its photophysical properties." In other words, it is often difficult to accurately "design" molecules with specific stacking patterns (such as forming ordered face-to-face stacking (H aggregation), ordered shoulder-to-shoulder stacking (J aggregation), and random aggregation), making it difficult to achieve "on-demand customization" and precise control of the performance of phototherapeutic agents. This lack of understanding of the structure-stacking-performance relationship chain greatly limits our development of high-performance materials that truly meet complex diagnostic and therapeutic needs.

[0006] Therefore, how to actively regulate the self-assembly behavior and stacking mode of naphthaleneimide molecules through reasonable and precise molecular structure design, and ultimately achieve targeted optimization of photophysical properties, is an urgent problem to be solved. Solving this problem will not only overcome the limitations of current naphthaleneimide-based photodiagnostic agents, which have a single function and are difficult to meet the needs of integrated diagnosis and treatment, but will also provide a powerful new approach for this field - "molecular design - assembly regulation - performance regulation". By in-depth research on the intrinsic connection between molecular structure, self-assembly process and final performance, a set of prediction and regulation theories from the molecular level to macroscopic functional materials can be established. This is not only an exploration of basic scientific issues, but also paves the way for the subsequent development of NIR-II photodiagnostic technologies with better performance, more integrated functions and wider applications, providing a solid theoretical foundation and guiding principles.

[0007] In summary, developing naphthaleneimide-based photodiagnostic molecules with clear and controllable self-assembly behavior and exploring their simple and efficient preparation methods is not only a breakthrough in the existing technological bottleneck, but also a key step in promoting NIR-II photodiagnostic technology from basic research to clinical application. Its far-reaching significance is self-evident. Summary of the Invention

[0008] The technical problem to be solved by the present invention is: to overcome the shortcomings of the existing technology, to provide a naphthaleneimide-based phototherapy molecule with controllable self-assembly behavior, and its preparation method and application, and a functionalized phototherapy molecule library based on a naphthaleneimide skeleton, by adjusting the molecular structure, stacking mode and its photophysical properties, to solve the problems of traditional phototherapy agents in aggregation-induced performance degradation, insufficient assembly controllability, and unclear relationship between structural characteristics and stacking mode and performance adjustment. It is suitable for the field of near-infrared second-zone phototherapy in biomedicine, and aims to improve the effect of deep tissue imaging and treatment.

[0009] The technical solution of the present invention is:

[0010] In a first aspect, the present invention provides a naphthaleneimide-based phototherapy molecule with controllable self-assembly behavior, the structural formula of which is as follows:

[0011]

[0012] Wherein, x is 0 or 1, R1 is p is an integer of 0-16 and when p is 0, R1 is -CH3, n is an integer of 1-10, m is an integer of n+2, q is an integer of 1-100; R2 is *Structural connection points.

[0013] In a second aspect, the present invention provides a method for preparing the aforementioned naphthaleneimide-based phototherapy molecules with controllable self-assembly behavior, wherein 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride is capped with an amino compound containing an R1 group to obtain an intermediate product; under alkaline conditions, a compound containing an R2 group and the intermediate product are coupled and ring-closed to obtain a naphthaleneimide-based phototherapy molecule with controllable self-assembly behavior. The synthetic route is as follows:

[0014]

[0015] Preferably, the specific preparation process of the intermediate product comprises the following steps:

[0016] S1: Add 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride and an amino compound containing an R1 group to a reaction flask, add a solvent, and reflux under a protective gas atmosphere for 20-120 minutes. When the color changes to reddish brown, stop the reaction and cool to room temperature;

[0017] S2: precipitating the reaction mixture in an aqueous solution, separating the oil by suction filtration, and drying to obtain an oil;

[0018] S3: The oily substance is dissolved in an organic solvent and pre-reacted with phosphorus tribromide under a nitrogen flow for 10-30 minutes. The mixture is then refluxed for 12-24 hours under a nitrogen atmosphere, cooled to room temperature, and precipitated in an aqueous solution. The solvent is removed by rotary evaporation, and the product is purified by column chromatography to obtain an intermediate product.

[0019] Preferably, in step S1, the molar ratio of 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride to the amino compound containing the R1 group is 1:(2-10); the solvent is acetic acid or propionic acid, and the added amount is 10-20 times the volume of the amino compound containing the R1 group.

[0020] Preferably, in step S2, the drying temperature is 40-60°C, and the drying time is 2-12 hours.

[0021] Preferably, in step S3, the organic solvent is anhydrous toluene, dichlorotoluene or tetrahydrofuran (THF), and the amount added is 1-3 times the volume of the solvent in step S1; the molar ratio of phosphorus tribromide to 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride is (1.5-3):1.

[0022] Preferably, the specific preparation process of preparing the naphthalimide-based photodiagnostic molecule from the intermediate product comprises the following steps:

[0023] (1) Dissolve the intermediate product and the compound containing the R2 group in an organic solvent, add an alkaline substance, refrigerate and pump out, and react at 70-100°C under nitrogen protection for 10-24 hours;

[0024] (2) After the reaction is completed, the temperature is lowered to room temperature, and one of toluene, dichloromethane, chloroform, and ethyl acetate and water are added for extraction. The organic phase is taken and dried by rotation, and the obtained crude product is purified to obtain a naphthaleneimide-based photodiagnostic molecule;

[0025] (2) After the reaction is completed, the temperature is lowered to room temperature, and one of toluene, dichloromethane, chloroform, and ethyl acetate and water are added for extraction. The organic phase is taken and dried by rotation, and the obtained crude product is further purified to obtain a naphthaleneimide-based photodiagnostic molecule.

[0026] Preferably, in step (1), the molar ratio of the intermediate product to the compound containing the R2 group is 2:(1-2).

[0027] In step (1), the organic solvent is anhydrous toluene, dichlorotoluene or tetrahydrofuran (THF), and the molar ratio of the organic solvent to the intermediate product is (30-50):1; the alkaline substance is one or more of potassium carbonate, sodium carbonate, palladium acetate and sodium tert-butoxide, and the molar ratio of the alkaline substance to the intermediate product is (3-6):1.

[0028] In a third aspect, the present invention provides an application of the above-mentioned naphthaleneimide-based phototherapy molecules with controllable self-assembly behavior. The naphthaleneimide-based phototherapy molecules are dissolved in an organic phase, the amphiphilic polymer is dissolved in an aqueous phase by a nanoprecipitation method, and the organic phase is added dropwise to the aqueous phase or the aqueous phase is added dropwise to the organic phase to obtain a nanoparticle therapeutic agent for near-infrared second-region phototherapy; wherein the molar ratio of the naphthaleneimide-based phototherapy molecules to the amphiphilic polymer is (0.5-10):1; the organic phase is THF, DMF, DMSO or dioxane; the amphiphilic polymer is polyoxyethylene polyoxypropylene F-127 (F127), phospholipid polyethylene glycol (DSPE-PEG) or polyoxyethylene-polyoxypropylene-polyoxyethylene (P123); an experimental microinjection pump was used to control the droplet speed to 30-100 μL / min.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. This invention provides a novel approach for developing deep-penetrating diagnostic and therapeutic agents with both NIR-II absorption and light energy modulation capabilities: Groups with significant steric hindrance are bonded around the backbone to provide space for the motor units. This branched polymer with steric hindrance replaces the physical encapsulation of surfactants, thus avoiding the assembly controllability that physical encapsulation lacks. By varying the branching degree and rigidity and flexibility of the hydrophobic segment, regulated self-assembly behavior is achieved. This method is more precise and effective, and the research is systematic and innovative.

[0031] 2. The present invention prepares phototherapy molecules with different photophysical properties and stacking modes by “pushing-absorbing” electronic structures and extending the π conjugated system: specifically, by adjusting the molar ratio of the two components of the donor and acceptor, and replacing the donor structure (π conjugated structure with two or four amino groups), a series of structures with different degrees of conjugation, different types and numbers of amino groups are prepared. Due to the different molecular conjugation lengths, different π-π stacking forces, different types and numbers of amino groups contained, and different halogen bond forces between molecules, different stacking modes are exhibited after the nanoparticles are constructed, showing three types of stacking modes: typical H aggregation, J aggregation, and random aggregation. Subsequently, the aggregation mode affects the energy dissipation pathway. H aggregation and random aggregation are beneficial to the improvement of photothermal performance, and J aggregation is beneficial to the manifestation of fluorescence properties. The present invention takes “molecular design-assembly regulation-performance regulation” as the main idea, and modifies the photophysical properties of naphthaleneimide and explores the mechanism by changing the donor and acceptor groups and ratios; the molecular structure changes to regulate the stacking mode, thereby regulating its photophysical properties, and providing corresponding molecules for subsequent different diagnosis and treatment needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the Maldi-TOF mass spectrum of 4Br-NDI prepared in Example 1 of the present invention.

[0033] Figure 2 This is the Maldi-TOF mass spectrum of W1 prepared in Example 2 of the present invention.

[0034] Figure 3 This is the Maldi-TOF mass spectrum of W3 prepared in Example 2 of the present invention.

[0035] Figure 4 This is the Maldi-TOF mass spectrum of L2 prepared in Example 3 of the present invention.

[0036] Figure 5 It is the normalized absorption spectrum of W1, W3 and L2 prepared in Example 2-3 of the present invention in DCM solution.

[0037] Figure 6 This is the absorption spectrum of NP1, NP2, and NP3 assembled in the present invention in DCM solution.

[0038] Figure 7 It is the fluorescence signal of NP1, NP2 and NP3 assembled by the present invention in aqueous solution.

[0039] Figure 8 This is a graph showing the change in the enrichment signal of the NP1 diagnostic and therapeutic agent assembled by the present invention at the tumor site in vivo over time.

[0040] Figure 9 This is a graph showing the changes in the enrichment signal of the NP3 diagnostic and therapeutic agent assembled by the present invention at the tumor site in vivo over time.

[0041] Figure 10 This is a graph showing the changes in the enrichment signal of the NP2 diagnostic and therapeutic agent assembled by the present invention at the tumor site in vivo over time.

[0042] Figure 11 This is a graph showing the weight gain trends of mice in the groups treated with the NP1, NP2, and NP3 diagnostic and therapeutic agents assembled by the present invention and mice in the control group of PBS.

[0043] Figure 12 It is a graph showing the tumor growth trends of mice in the groups treated with the NP1, NP2, and NP3 diagnostic and therapeutic agents assembled by the present invention and mice in the control group of PBS. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0045] Example 1 Preparation of intermediate product 4Br-NDI

[0046] The following steps are involved:

[0047] S1: 2,3,6,7-Tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride (3 g, 5.1 mmol) and 2-n-octyl-1-dodecylamine (4.26 mL, 20.4 mmol) were added to a 250 mL eggplant-shaped reaction flask, followed by 50 mL of acetic acid. The mixture was refluxed under nitrogen for 30 min. When the color changed to reddish brown, the reaction was stopped and the mixture was cooled to room temperature.

[0048] S2: The reaction mixture was poured into 300 mL of water for precipitation. A brown oil was separated by filtration. The formation of the oil was attributed to the presence of 2-n-octyl-1-dodecylamine. The oil was then dried in an oven at 50°C for 4 h.

[0049] S3: The above product was dissolved in 100 mL of anhydrous toluene, and phosphorus tribromide (0.97 mL, 10.2 mmol) was added. A pre-reaction was carried out under a nitrogen flow for 15 minutes, followed by reflux reaction under a nitrogen atmosphere for 12 hours. The reaction was stopped and cooled to room temperature. The product was precipitated in an aqueous solution, the solvent was removed by rotary evaporation, and then purified by column chromatography (dichloromethane:n-hexane = 1:2) to obtain a yellow crystalline solid product, 4Br-NDI, with a yield of 31.4%. The synthetic route is as follows:

[0050]

[0051] Example 2 Preparation of Naphthalimide-Based Phototherapeutic Molecules W1 and W3

[0052] The following steps are involved:

[0053] (1) The intermediate product 4Br-NDI (300 mg, 0.26 mmol) prepared in Example 1, 1,5-diaminonaphthalene (21 mg, 0.13 mmol), potassium carbonate (150 mg, 1.08 mmol) and palladium acetate (12 mg, 0.053 mmol) were dissolved in 1 mL of anhydrous toluene, refrigerated and pumped three times, and reacted at 100°C under nitrogen for 14 h;

[0054] (2) After the reaction, the mixture was cooled to room temperature and extracted three times with dichloromethane and water. The organic phase was dried by rotary evaporation. The crude product was purified by column chromatography (dichloromethane:n-hexane = 1:4) to obtain product W1 (dark green solid, yield 35.6%) and product W3 (brown solid, yield 28.9%). The synthetic route is as follows:

[0055]

[0056] Example 3 Preparation of Naphthalimide-Based Phototherapy Molecule L2

[0057] The following steps are involved:

[0058] (1) The intermediate product 4Br-NDI (300 mg, 0.26 mmol) prepared in Example 1 and 1,2,4,5-benzenetetramine tetrahydrochloride (36 mg, 0.26 mmol) were placed in a 10 mL reaction tube, potassium carbonate (150 mg, 1.08 mmol) and 1 mL of anhydrous toluene were added, the tube was sealed with a threaded stopper, and the tube was refrigerated and pumped three times. The reaction tube was placed in an oil bath at 100°C and reacted for 11 h.

[0059] (2) After the reaction, the mixture was cooled to room temperature and extracted three times with dichloromethane and water. The organic phase was taken and dried by rotary evaporation. The crude product was purified by column chromatography (dichloromethane:n-hexane = 1:5) to obtain product L2 (emerald green solid, yield 30.1%). The synthetic route is as follows:

[0060]

[0061] The chemical structures of 4Br-NDI and the products W1, W3, and L2 prepared above were characterized by nuclear magnetic resonance (1H NMR) spectra, demonstrating the successful synthesis of the above series of molecules. The specific 1H NMR structural data are as follows:

[0062] 4Br-NDI: 1H NMR (400MHz, CDCL2) δ4.18 (s, 4H), 1.96 (s, 2H), 1.23 (s, 64H), 0.87 (s, 12H).

[0063] W1:1H NMR (400MHz, CDCL2) δ13.48(s,1H),7.74(s,1H),7.22(s,1H),7.11(s,1H),6.89(s,1 H),6.58(s,1H),4.97(s,2H),4.17(s,4H),1.94(s,2H),1.22(s,64H),0.85(s,12H).

[0064] W3: 1H NMR (400MHz, CDCL2) δ13.82(s,2H),7.85(s,2H),6.89(s,2H),4.16(s,8H),1.93(s,4H),1.23(s,128H),0.85(s,24H).

[0065] L2: 1H NMR (400MHz, CDCL2) δ13.03 (s, 4H), 6.27 (s, 2H), 4.11 (s, 8H), 1.91 (s, 4H), 1.24 (s, 128H), 0.86 (s, 24H).

[0066] The chemical structures of 4Br-NDI and products W1, W3 and L2 were characterized by Maldi-TOF mass spectrometry, which proved that the series of molecules were successfully synthesized. Figure 1-4 The specific analysis data are as follows:

[0067] 4Br-NDI: The actual molecular weight is 1142.11, which is consistent with the theoretical value of 1142.88;

[0068] W1: The actual molecular weight is 1139.378, which is consistent with the theoretical value of 1139.26;

[0069] W3: The actual molecular weight is 2120.146, which is consistent with the theoretical value of 2120.31;

[0070] L2: The actual molecular weight is 2102.447, which is consistent with the theoretical value of 2102.29.

[0071] Example 4 Nanoparticle Assembly Regulation

[0072] Using the nanoprecipitation method, 0.88 μmol of each of W1, W3, and L2 were dissolved in 1 mL of tetrahydrofuran to form an organic solution. 0.44 μmol of F127 was dissolved in 1 mL of water to form an F127 aqueous solution. The molar ratio of W1, W3, or L2 to F127 was 2:1. The two phases were allowed to stand overnight to allow for complete dissolution. Using an experimental microsyringe pump, the organic phase was slowly dripped into the constantly stirring aqueous phase at a rate of 30 μL / min and a stirring rate of 600 rpm to form nanoparticles. After the injection, the mixture was stirred at a constant speed for 2 hours and then placed in a 3500 KD dialysis bag for 24 hours of dialysis in deionized water. After dialysis, the solution was concentrated to a volume of 0.5 mL using an ultrafiltration tube, sealed, and stored in a refrigerator at -4°C. The resulting three nanoparticles were designated NP1, NP3, and NP2.

[0073] Example 5 NP1, NP3, NP2 structure and property test

[0074] (1) NP1, NP2, and NP3 nanostructure testing

[0075] The prepared nanoparticles NP1, NP2, and NP3 were prepared into 1×10 -6 mg / mL aqueous solution, 2mL was taken and placed into a dynamic light scattering particle size analyzer to test the particle size. The measured particle sizes were 105nm, 104nm and 59nm respectively. The surface has a negative charge and can circulate well in the body environment.

[0076] (2) Optical property test of NP1, NP2 and NP3 in aqueous solution

[0077] Take 2mL of the three nanoparticle aqueous solutions prepared above and put them into a quartz dish for absorption and emission tests. The test results are as follows: Figure 5 As shown in the UV-visible-near infrared absorption spectrum, the absorption wavelength of W1 in DCM is between 600-850nm; the absorption wavelength of W3 is between 700-1100nm; and the absorption wavelength of L2 is between 600-830nm. Figure 6As shown, the absorption band of NP1 after assembly into nanoparticles is between 750-1100nm, which is comparable to the single-molecule absorption peak that spans the near-infrared region II; the absorption range of NP2 is 900-1050nm, also spanning the near-infrared region II; the absorption peak of NP3 is between 750-1050nm, also spanning the near-infrared region II. The red-shifted absorption band lays the foundation for subsequent diagnosis and treatment of deep tissues.

[0078] At the same time, fluorescence imaging equipment was used to detect the fluorescence signals of NP1, NP2 and NP3 in aqueous solution, such as Figure 7 As shown, NP2 exhibited the best fluorescence signal.

[0079] (3) Determination of NP1, NP2, and NP3 stacking methods

[0080] Compared to single molecules, the absorption peaks of NP1 and NP2 nanoparticles in aqueous solution have red-shifted. Compared to W1 single molecules, the absorption range of NP1 has red-shifted from 600-850nm to 750-1100nm, and the peak shows a narrower absorption band, indicating a clear mixed state of J aggregation and random aggregation. Compared to L2 single molecules, the absorption range of NP2 has red-shifted from 600-830nm to 900-1000nm, and the peak shows a sharper and narrower absorption band, indicating regular J aggregation. Compared to W3 single molecules, the main absorption peak of NP3 has blue-shifted from 1001nm to 847nm, indicating typical face-to-face H aggregates.

[0081] (4) Photothermal performance test of NP1, NP2, and NP3 in aqueous solution

[0082] In a quartz cuvette, 1.0 mL of NP1, NP2, and NP3 aqueous solutions were added, and their concentrations were adjusted to ensure that the absorption peak at the main excitation wavelength was 1. An 808 nm laser was used at 1 W / cm -2 The solutions were irradiated with a power density of 100 nm for 15 minutes. Pure water served as a control group. Once the solution temperature reached a steady state, laser irradiation was stopped and the solution was allowed to cool naturally to room temperature. Temperature changes during the experiment were monitored and recorded by a thermal imaging camera.

[0083] The photothermal conversion efficiencies of the three aqueous solutions were measured to be 44.05%, 31.9%, and 46.79%, respectively. Compared to the single-molecule state, the photothermal performance of NP3 nanoparticles forming H aggregates was the most improved compared to the W3 single molecule. The photothermal performance of NP1 nanoparticles that underwent random aggregation and J aggregation was improved compared to the W1 single molecule. After the above two nanoparticles were assembled, the photothermal performance was improved, which is beneficial for thermal ablation treatment of tumors. The NP2 nanoparticles that underwent regular J aggregation showed a narrow absorption peak. NP2 with narrow-band absorption can minimize unnecessary light interference by selecting light of a specific wavelength for imaging, thereby significantly improving the clarity and contrast of the image. This technology can reduce background noise, making the image cleaner and the details clearer. Moreover, after NP2 is aggregated through J aggregation, it exhibits the characteristics of both fluorescence and photothermal, that is, it has the performance of fluorescence imaging and the ability of photothermal therapy, and can achieve multiple functions using a single molecule.

[0084] (5) In vivo near-infrared second-zone photoacoustic imaging and photothermal therapy for deep in situ brain gliomas

[0085] First, 5-week-old mice were selected as experimental mice to establish an orthotopic brain glioma model, and the in vivo imaging ability of the diagnostic and therapeutic agent was studied using a near-infrared second-zone in vivo photoacoustic imager; through in vivo photoacoustic imaging, such as Figure 8-10 As shown in the results, the optimal accumulation time of NP1, NP2, and NP3 therapeutic agents in the tumor site in vivo is 8 hours; and the development of the tumor is diagnosed. Illumination was implemented at the optimal accumulation time to further study the changes in body weight and tumor size after photothermal treatment. The mice treated with NP1, NP2, and NP3 showed the same weight gain trend as the mice in the control group PBS (as shown in the figure). Figure 11 As shown), it proves that NP1, NP2, and NP3 have good biocompatibility; the tumor growth of mice in the NP1, NP2, and NP3 treatment groups was significantly lower than that of mice in the control group (as shown Figure 12 shown).

[0086] The in vivo experiments in this section demonstrate that the photodiagnostic molecules prepared by the method of the present invention have good photoacoustic imaging and therapeutic effects on deep in situ brain gliomas.

[0087] This invention focuses on the needs faced by the diagnosis and treatment of cutting-edge major diseases, developing and designing a novel optical diagnostic and therapeutic molecular library with strong scientific and feasible results. This invention further enhances the application value of near-infrared second-zone optical diagnostic and therapeutic technology, laying the foundation for improving the diagnosis and treatment of major diseases.

Claims

1. Naphthalimide-based photodiagnostic molecules with controllable self-assembly behavior, characterized in that: Its structural formula is as follows: Wherein, x is 0 or 1, R1 is p is an integer of 0-16 and when p is 0, R1 is -CH3, n is an integer of 1-10, m is an integer of n+2, q is an integer of 1-100; R2 is *Structural connection points.

2. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 1, wherein: 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride is capped using an amino compound containing an R1 group to obtain an intermediate product; under alkaline conditions, a compound containing an R2 group and the intermediate product are coupled and ring-closed to obtain a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior.

3. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 2, wherein: The specific preparation process of the intermediate product includes the following steps: S1: Add 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride and an amino compound containing an R1 group to a reaction flask, add a solvent, and reflux under a protective gas atmosphere for 20-120 minutes. When the color changes to reddish brown, stop the reaction and cool to room temperature; S2: precipitating the reaction mixture in an aqueous solution, separating the oil by suction filtration, and drying to obtain an oil; S3: The oily substance is dissolved in an organic solvent and pre-reacted with phosphorus tribromide under a nitrogen flow for 10-30 minutes. The mixture is then refluxed for 12-24 hours under a nitrogen atmosphere, cooled to room temperature, and precipitated in an aqueous solution. The solvent is removed by rotary evaporation, and the product is purified by column chromatography to obtain an intermediate product.

4. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 3, characterized in that: In step S1, the molar ratio of 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride to the amino compound containing the R1 group is 1:(2-10); the solvent is acetic acid or propionic acid, and the added amount is 10-20 times the volume of the amino compound containing the R1 group.

5. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 3, wherein: In step S2, the drying temperature is 40-60°C and the drying time is 2-12 hours.

6. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 3, characterized in that: In step S3, the organic solvent is anhydrous toluene, dichlorotoluene or tetrahydrofuran, and the amount added is 1-3 times the volume of the solvent in step S1; the molar ratio of phosphorus tribromide to 2,3,6,7-tetrabromonaphthalene-1,4,5,8-tetracarboxylic dianhydride is (1.5-3):

1.

7. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 2, wherein: The specific preparation process of preparing naphthaleneimide-based photodiagnostic molecules from intermediate products includes the following steps: (1) Dissolve the intermediate product and the compound containing the R2 group in an organic solvent, add an alkaline substance, refrigerate and pump out, and react at 70-100°C under nitrogen protection for 10-24 hours; (2) After the reaction is completed, the temperature is lowered to room temperature, and one of toluene, dichloromethane, chloroform, and ethyl acetate and water are added for extraction. The organic phase is taken and dried by rotation, and the obtained crude product is further purified to obtain a naphthaleneimide-based photodiagnostic molecule.

8. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 7, characterized in that: In step (1), the molar ratio of the intermediate product to the compound containing the R2 group is 2:(1-2).

9. The method for preparing a naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior according to claim 7, wherein: In step (1), the organic solvent is anhydrous toluene, dichlorotoluene or tetrahydrofuran, and the molar ratio of the organic solvent to the intermediate product is (30-50):1; the alkaline substance is one or more of potassium carbonate, sodium carbonate, palladium acetate and sodium tert-butoxide, and the molar ratio of the alkaline substance to the intermediate product is (3-6):

1.

10. The use of the naphthaleneimide-based photodiagnostic molecule with controllable self-assembly behavior as claimed in claim 1, characterized in that: Using the nanoprecipitation method, the naphthaleneimide-based phototherapy molecule is dissolved in the organic phase, the amphiphilic polymer is dissolved in the aqueous phase, the organic phase is added dropwise to the aqueous phase or the aqueous phase is added dropwise to the organic phase to obtain a nanoparticle therapeutic agent for near-infrared second-region phototherapy; wherein the molar ratio of the naphthaleneimide-based phototherapy molecule to the amphiphilic polymer is (0.5-10):1; the organic phase is THF, DMF, DMSO or dioxane; the amphiphilic polymer is polyoxyethylene polyoxypropylene, phospholipid polyethylene glycol or polyoxyethylene-polyoxypropylene-polyoxyethylene; the dripping speed is controlled to 30-100 μL / min.

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