A rhombic supramolecular metal macrocyclic compound, its preparation method and application

Abstract

This invention discloses a rhombic supramolecular metal macrocyclic compound, its preparation method, and its applications, belonging to the fields of functional materials and pharmaceutical preparations. The preparation method of the rhombic supramolecular metal macrocyclic compound is as follows: a specific structured organic small molecule ligand and a platinum acceptor are dissolved in an organic solvent, and under sealed conditions, the mixture is stirred at 55-60°C for 6-8 hours to undergo a self-assembly reaction to obtain the rhombic supramolecular metal macrocyclic compound. Furthermore, the rhombic supramolecular metal macrocyclic compound is used with a surfactant to prepare nanoparticles via a nanoprecipitation method. The obtained nanoparticles have excellent photostability, water solubility, AIE properties, NIR-II penetration depth, and good biocompatibility. After entering tumor cells, the nanoparticles can be well taken up by the tumor cells, thus better exerting the effects of tumor diagnosis and / or treatment.

Description

Technical Field

[0001] This invention belongs to the field of functional materials and pharmaceutical preparations, specifically relating to a rhombic supramolecular metal macrocyclic compound, its preparation method, and its application. Background Technology

[0002] Cancer is a disease affecting multiple organs and tissues, leading to a decline in patients' quality of life and seriously threatening their lives. Traditional cancer treatments such as surgical resection, chemotherapy, and radiotherapy all have side effects, often placing an unnecessary burden on the patient's body. Photothermal therapy (PTT) is an emerging cancer treatment method that uses photothermal agents to convert light energy into heat energy, thereby killing tumor cells. It has the advantages of significant therapeutic effects and minimal side effects on the human body. Compared to the near-infrared I region (NIR-I), the NIR-II window has deeper tissue penetration and less autofluorescence, making it more favorable for PTT. However, currently, most small organic molecules can only reach the NIR-I window, which prevents deep tumor PTT. On the other hand, most organic fluorophores are affected by the aggregation-induced quenching (ACQ) effect, resulting in reduced imaging quality. How to avoid the ACQ effect is also a problem that organic fluorescent molecules need to solve in the field of tumor diagnosis and treatment.

[0003] Chinese patent document CN114540011A discloses a near-infrared II fluorescent probe molecule and nanoparticles for multimodal integrated diagnosis and treatment. This invention designs the structure of the near-infrared II fluorescent probe molecule to enable it to emit near-infrared II fluorescence, generate reactive oxygen species, and have photothermal effects. The nanoparticles prepared further can achieve fluorescence imaging at the cellular level, and can kill or ablate tumor cells while ensuring the health of the organism, thus inhibiting the growth of tumors in vivo.

[0004] Chinese patent document CN114315701A discloses a bispyridine ligand containing AIE and ACQ groups, an amphiphilic rhombic supramolecular metal ring, and its applications. The invention involves dissolving a bispyridine ligand containing AIE and ACQ groups and a bisplatinum acceptor in an alcohol solvent and heating the mixture at 40-60°C for 10-15 hours. After the reaction, a post-processing step is performed to obtain an amphiphilic rhombic supramolecular metal ring. This amphiphilic rhombic supramolecular metal ring exhibits good biocompatibility and coordinated fluorescence emission, and its inherent properties support convenient cell imaging.

[0005] Supramolecular coordination complexes (SCCs) are widely used in tumor imaging and treatment due to their specific shapes and sizes, but they suffer from poor photostability and limited penetration depth. This study aims to improve the photostability and penetration depth of Pt-based SCCs by rationally designing the self-assembly of small organic molecule ligands with excellent optical properties with platinum (Pt) receptors. Simultaneously, it seeks to utilize the chemotherapeutic activity of Pt to avoid the limitations of single PTT therapy, thus achieving synergistic phototherapy / chemotherapy. Summary of the Invention

[0006] This invention provides an organic small molecule ligand that can be self-assembled with a platinum acceptor to prepare a rhombic supramolecular metal macrocyclic compound. The rhombic supramolecular metal macrocyclic compound has good application prospects in the field of tumor treatment and / or diagnosis.

[0007] The specific technical solution adopted is as follows:

[0008] An organic small molecule ligand, with the structural formula shown in formula (I):

[0009]

[0010] Wherein, R1 is a C6-C10 n-alkyl group, and R1 is preferably –C8H. 17 .

[0011] This invention also provides a method for preparing the aforementioned small organic molecule ligand, comprising the following steps:

[0012] (1) 4,7-dibromo-5,6-dinitrobenzo[c][1,2,5]thiadiazole and N,N-diphenyl-4-(tributylmtinalkyl)aniline were reacted in an organic solvent system under the action of a catalyst, and the reactants were post-treated to obtain compound 1;

[0013] (2) Compound 1 and the substituted N,N-diphenyl-4-(tributyltinyl)-aniline were reacted in an organic solvent system under the action of a catalyst, and the reactants were post-treated to obtain compound 2.

[0014] (3) Compound 2 was dissolved in an organic solvent, and N-bromosuccinimide was added to react. The reactants were then post-treated to obtain compound 3.

[0015] (4) Under alkaline conditions, compound 3, pyridine-4-boronic acid and catalyst were reacted in an organic solvent system, and the reactants were post-treated to obtain compound 4;

[0016] (5) Compound 4 and iron powder react in an acetic acid solvent system. After the reaction is complete, an intermediate is obtained. The intermediate and selenium dioxide react in an organic solvent system. The reactants are post-treated to obtain the organic small molecule ligand.

[0017] Preferably, in step (1), the molar ratio of 4,7-dibromo-5,6-dinitrobenzo[c][1,2,5]thiadiazole to N,N-diphenyl-4-(tributyltinyl)aniline is 1:0.8-1; and the catalyst is Pd(PPh3)4.

[0018] And / or, in step (2), the molar ratio of compound 1 to the substituted N,N-diphenyl-4-(tributyltinyl)-aniline is 1:1.8-2.2; the catalyst is Pd(PPh3)4;

[0019] And / or, in step (3), the molar ratio of compound 2 to N-bromosuccinimide is 1:2.0-2.5;

[0020] And / or, in step (4), the molar ratio of compound 3 to pyridine-4-boronic acid is 1:6-12; the catalyst is Pd(PPh3)4; and the alkaline conditions are provided by potassium carbonate.

[0021] And / or, in step (5), the molar ratio of compound 4, iron powder and selenium dioxide is 1:15-20:10-15.

[0022] The present invention also provides a rhombic supramolecular metal macrocyclic compound, the structural formula of which is shown in formula (II):

[0023]

[0024] Wherein, R1 is defined as above, and R2 is a C1-C3 alkyl group, preferably –CH3.

[0025] The present invention also provides a method for preparing the rhombic supramolecular metal macrocyclic compound, comprising: dissolving the organic small molecule ligand and platinum acceptor in an organic solvent, and under sealed conditions, stirring to induce a self-assembly reaction to obtain the rhombic supramolecular metal macrocyclic compound;

[0026] The structural formula of the platinum receptor is shown in formula (Ⅲ):

[0027]

[0028] The definition of R2 is the same as above.

[0029] Preferably, the molar ratio of the organic small molecule ligand to the platinum acceptor is 1:1-1.2.

[0030] Preferably, the organic solvent is dichloromethane and / or dimethyl sulfoxide, and the self-assembly reaction is carried out under the condition of stirring at 55-60°C for 6-8 hours.

[0031] The present invention also provides the use of the aforementioned rhombic supramolecular metal macrocyclic compound in the preparation of tumor therapeutic and / or diagnostic agents.

[0032] The present invention also provides a tumor treatment and / or diagnostic preparation comprising the aforementioned rhombic supramolecular metal macrocyclic compound.

[0033] Preferably, the tumor treatment and / or diagnostic formulation comprises nanoparticles formed from the rhombic supramolecular metal macrocyclic compound and the surfactant.

[0034] Preferably, the surfactant is DSPE-PEG. 2000 The mass ratio of the rhombic supramolecular metal macrocyclic compound to the surfactant is 1:10-15.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] The DA-structured organic small molecule ligands provided by the method of this invention can be self-assembled with platinum acceptors to prepare rhombic supramolecular metal macrocyclic compounds. The nanoparticles prepared by nanoprecipitation of the rhombic supramolecular metal macrocyclic compounds and surfactants have excellent photostability, water solubility, AIE properties, NIR-II penetration depth and good biocompatibility. After entering tumor cells, the nanoparticles can be well taken up by tumor cells, thus better exerting the effects of tumor diagnosis and / or treatment. Attached Figure Description

[0037] Figure 1 The 1H NMR spectrum of the organic small molecule ligand BDT-Se is shown.

[0038] Figure 2 The image shows the carbon NMR spectrum of the small organic molecule ligand BDT-Se.

[0039] Figure 3 This is a high-resolution mass spectrum of the organic small molecule ligand BDT-Se.

[0040] Figure 4 The image shows the proton NMR spectrum of platinum acceptor 6.

[0041] Figure 5 The phosphorus NMR spectrum of platinum acceptor 6.

[0042] Figure 6 This is the 1H NMR spectrum of the rhombic supramolecular metal macrocyclic compound MBDT-Se.

[0043] Figure 7 The phosphorus NMR spectrum of the rhombic supramolecular metal macrocyclic compound MBDT-Se.

[0044] Figure 8The images show the time-of-flight mass spectra of the rhombic supramolecular metal macrocyclic compound MBDT-Se, where (a) represents the theoretical calculation of the loss of four trifluoromethanesulfonic acid counterions (OTf–), (b) represents the actual test result of the loss of four trifluoromethanesulfonic acid counterions (OTf–), (c) represents the theoretical calculation of the loss of three trifluoromethanesulfonic acid counterions (OTf–), and (d) represents the actual test result of the loss of three trifluoromethanesulfonic acid counterions (OTf–).

[0045] Figure 9 The images show the optical characterization of four different materials, where (a) is the normalized ultraviolet absorption spectrum and (b) is the normalized fluorescence emission spectrum.

[0046] Figure 10 The images are in vitro characterization diagrams, where (a) shows the temperature change curves of BDT-Se NPs at different series concentrations, (b) shows the temperature change curves of BDT-Se NPs at different powers, (c) shows the temperature rise and fall curves of BDT-Se NPs over four cycles, (d) shows the temperature change curves of MBDT-Se NPs at different series concentrations, (e) shows the temperature change curves of MBDT-Se NPs at different powers, (f) shows the temperature rise and fall curves of MBDT-Se NPs over four cycles, (g) shows the temperature rise and fall curves of BDT-Se NPs and the linear relationship between time and -ln(θ) within the cooling range, (h) shows the temperature rise and fall curves of MBDT-Se NPs and the linear relationship between time and -ln(θ) within the cooling range, (i) shows the infrared imaging diagrams of BDT-Se NPs at different powers, and (j) shows the infrared imaging diagrams of MBDT-Se NPs at different powers.

[0047] Figure 11 The diagram shows cell experiments, where (a) shows U87 cells co-incubated with different concentrations of BDT-Se NPs at 808 nm (1 W / cm²). 2 (a) Statistical graph of cell survival rate under laser irradiation (5 mins), (b) shows the survival rate of U87 cells after co-incubation with different concentrations of MBDT-Se NPs at 808 nm (1 W / cm²). 2 (c) Cell viability statistics under laser irradiation (5 mins), (d) Live / dead staining images of BDT-Se NPs and MBDT-Se NPs in U87 cells (scale bar: 100 μm), (e) Laser confocal scanning microscope images of U87 cells after incubation with BDT-Se / NR NPs and MBDT-Se / NR NPs (scale bar: 50 μm), (f) Cell flow cytometry diagrams of U87 cells co-incubated with BDT-Se NPs for different times, and (c) Cell flow cytometry diagrams of U87 cells co-incubated with MBDT-Se NPs for different times. Detailed Implementation

[0048] The present invention will be further illustrated below with reference to the embodiments and accompanying drawings. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0049] Example 1

[0050] Step 1: Preparation of the organic small molecule ligand BDT-Se

[0051]

[0052] Preparation of Compound 1: 200 mg (0.52 mmol) of 4,7-dibromo-5,6-dinitrobenzo[c][1,2,5]thiadiazole and 6 mg (0.0052 mmol) of Pd(PPh3)4 were added to a 100 mL Schulenck flask. The reaction flask was evacuated and purged under nitrogen, and this process was repeated three times. Subsequently, a mixture of 224 mg (0.42 mmol) of N,N-diphenyl-4-(tributyltinyl)aniline and 20 mL of ultra-dry toluene was injected into the Schulenck flask using a syringe. The mixture was placed in an oil bath at 115 °C under nitrogen protection and reacted for 9 h. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction flask was removed using a rotary evaporator. Purification was then performed by extraction with dichloromethane (40 mL × 3) / water. The organic solution was dried over anhydrous magnesium sulfate and filtered to obtain the crude product. The crude product was further purified by silica gel column chromatography (petroleum ether / dichloromethane, v / v, 3:1) to finally obtain wine-red solid compound 1 (26.7 mg, yield 11.7%).

[0053] Compound 1: 1 H NMR (500MHz, CDCl3, 298K) δ (ppm): 7.37 (d, J = 8.8Hz, 2H), 7.34 (t, 4H), 7.21 (d, J = 7.6Hz, 4H), 7.14 (t, J = 7.4Hz, 2H), 7.10 (d, J = 8.8Hz, 2H).

[0054] 13 C NMR (126MHz, CDCl3, 298K) δ (ppm): 152.5, 152.0, 150.1, 146.4, 145.1, 141.9, 130.1, 129.6, 126.01, 125.9, 124.6, 121.4, 120.4, 107.7.

[0055] ESI-HRMS[1+H] + :calcd.for[C 24 H 15BrN5O4S] + 548.0023, found 547.9948.

[0056] Preparation of Compound 2: Compound 1 (131 mg, 0.2388 mmol) and Pd(PPh3)4 (13.8 mg, 0.0119 mmol) were added to a 100 mL Schlenk flask. The reaction flask was evacuated and purged under nitrogen, and the process was repeated three times. Subsequently, a mixture of N,N-bis[4-(octoxy)phenyl]-4-(tributyltinyl)aniline (377.828, 0.4777 mmol) and 20 mL of ultra-dry toluene was injected into the Schlenk flask using a syringe. The mixture was placed in an oil bath at 115 °C under nitrogen protection and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the mixture was extracted with dichloromethane (40 mL × 3) / water. The organic phase solution was dried over anhydrous magnesium sulfate and filtered to obtain the crude product. The crude product was further purified by column chromatography (petroleum ether / dichloromethane, v / v, 4:1) to give a dark red solid compound 2 (159 mg, yield 69.2%).

[0057] Compound 2: 1 H NMR (400MHz, CDCl3, 298K) δ (ppm): 7.40 (d, J = 8.8Hz, 2H), 7.36 (t, 2H), 7.33 (t, 4H), 7.21 (d, J = 7.5Hz, 4H), 7.15 (d, J = 8.9Hz, 4H), 7.12 (d, J = 8.7Hz, 4H) ,6.95(d,J=8.8Hz,2H),6.87(d,J=8.9Hz,4H),3.94(t,J=6.5Hz,4H),1.82– 1.74(m,4H),1.49–1.41(m,4H),1.36–1.24(m,16H),0.89(t,J=6.8Hz,6H).

[0058] 13 C NMR (126MHz, CDCl3, 298K) δ (ppm): 156.4, 153.2, 153.1, 150.6, 149.6, 146.6, 142.4, 141.9, 139.1, 130.2, 130.1, 129.5 ,128.1,127.8,127.3,125.8,124.3,122.4,120.7,120.2,117.7,115.4,68.2,31.8,29.3,29.3,29.2,26.0,22.6,14.1.

[0059] ESI-HRMS[1+H] +:calcd.for[C 58 H 61 N6O6S] + 969.4368, found969.4345.

[0060] Preparation of Compound 3: Compound 2 (178 mg, 0.1838 mmol) was dissolved in 20 mL of ultra-dry tetrahydrofuran under N2 protection and transferred to a 100 mL two-necked flask. The flask was placed in the dark and in an ice bath. Then, under N2 protection, N-bromosuccinimide (81.8 mg, 0.4595 mmol) was slowly added. After stirring in an ice bath for 15 min, the ice bath was removed promptly, and the reaction was allowed to proceed at room temperature for 5 h. The solvent was then removed by vacuum distillation, and the product was extracted with dichloromethane and water, dried over anhydrous magnesium sulfate, and filtered to obtain the crude product. This crude product was then purified by column chromatography (petroleum ether / dichloromethane, v / v, 6:1) to give a red solid, compound 3 (124.0 mg, yield 60.0%).

[0061] Compound 3: 1 H NMR (400MHz, CDCl3, 298K) δ (ppm): 7.44 (d, J = 4.4Hz, 2H), 7.42 (d, J = 4.3Hz, 4H), 7.36(d,J=8.9Hz,2H),7.16(d,J=8.9Hz,4H),7.13(d,J=8.8Hz,2H),7.06(d,J=8 .8Hz,4H),6.95(d,J=8.9Hz,2H),6.88(d,J=9.0Hz,4H),3.95(t,J=6.5Hz,4H),1 .82–1.75(m,4H),1.49–1.42(m,4H),1.37–1.26(m,16H),0.89(t,J=6.9Hz,6H).

[0062] 13 C NMR (126MHz, CDCl3, 298K) δ (ppm): 156.5, 153.3, 153.1, 150.8, 150.1, 148.6, 147.5, 147.4, 142.7, 141.7, 139.1, 133.5 ,130.5,130.1,128.2,127.9,126.8,125.5,122.8,121.1,117.6,115.5,68.2,31.8,29.3,29.3,29.2,26.0,22.6,14.1.

[0063] ESI-HRMS[1+H] + :calcd.for[C 58 H59 Br2N6O6S] + 1125.2578, found 1125.2586.

[0064] Preparation of compound 4: Compound 3 (192 mg, 0.1707 mmol), pyridine-4-boronic acid (252 mg, 2.0493 mmol), potassium carbonate (47.2 mg, 0.3416 mmol), and Pd(PPh3)4 (39 mg, 0.0342 mmol) were added to a 200 mL Schlenk flask, followed by the addition of 20 mL of a mixed solvent (tetrahydrofuran / water, v / v, 4:1). After three freeze-thaw cycles, the Schlenk flask was placed in an oil bath at 75 °C under N2 protection, and the reaction was stirred for 12 h. After the reaction was complete, the solvent was removed by vacuum distillation, and the product was extracted with dichloromethane and water. The crude product was dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. Further purification was carried out using silica gel column chromatography (dichloromethane / methanol, v / v, 100:1) to obtain a wine-red solid, compound 4 (53.68 mg, yield 28.2%).

[0065] Compound 4: 1 H NMR (400MHz, CDCl3, 298K) δ (ppm): 8.66 (d, J=3.4Hz, 4H), 7.64 (d, J=8.3Hz, 4H), 7.52 (d, J= 4.6Hz,4H),7.49(d,J=8.7Hz,2H),7.37(d,J=8.6Hz,2H),7.34(d,J=8.3Hz,4H),7.28(d,J=8 .5Hz,2H),7.16(d,J=8.6Hz,4H),6.96(d,J=8.6Hz,2H),6.88(d,J=8.6Hz,4H),3.95(t,J=6 .4Hz,4H),1.82–1.75(m,4H),1.51–1.42(m,4H),1.36–1.25(m,16H),0.89(t,J=6.0Hz,6H).

[0066] 13C NMR (126MHz, CDCl3, 298K) δ (ppm): 156.5, 153.3, 153.1, 150.8, 150.2, 148.6, 147.5, 147.4, 142.7, 141.7, 139.1, 133.5, 130.5, 130.1, 128 .7,128.2,127.9,126.8,125.6,124.5,122.8,121.1,120.0,117.6,115.5,68.2,31.8,29.3,29.3,29.2,26.0,22.6,14.1.ESI-HRMS[1+H] + :calcd.for[C 68 H 67 N8O6S] + 1123.4899, found 1123.4880.

[0067] ESI-HRMS[1+H] + :calcd.for[C 68 H 67 N8O6S] + 1123.4899, found 1123.4880.

[0068] Preparation of Compound 5: Compound 4 (55 mg, 0.0490 mmol) and iron powder (54.73 mg, 0.9800 mmol) were weighed and added to a 100 mL Schlenk flask. The flask was evacuated three times under N2. Then, 45 mL of acetic acid was injected into the 100 mL Schlenk flask using a syringe. The mixture was stirred in an oil bath at 85 °C for 6-8 h. When the solution in the reaction flask changed from red to yellow, thin-layer chromatography was used to monitor the reaction progress. After the reaction was complete, the solvent was removed by vacuum distillation. After neutralization with 20 mg of sodium bicarbonate, the mixture was extracted with dichloromethane / water and dried over anhydrous magnesium sulfate to obtain an orange-yellow solid. No purification was required. The orange-yellow solid was transferred to a 100 mL Schlenk flask, and selenium dioxide (54.36 mg, 0.4899 mmol) was added. After evacuating three times, 20 mL of ultra-dry tetrahydrofuran and 20 mL of ultra-dry ethanol were added using a syringe. The reaction was then carried out at 70°C under N2 protection for 12 h. After removing the solvent using a rotary evaporator, the product was extracted with dichloromethane (50 mL × 3) / water, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. Further separation and purification were performed using column chromatography (dichloromethane / methanol, v / v, 60:1) to finally obtain the dark green solid organic small molecule ligand BDT-Se (17.85 mg, yield 32%).

[0069] The proton NMR spectrum, carbon NMR spectrum, and high-resolution mass spectrometry of the organic small molecule ligand BDT-Se are as follows: Figure 1-3 As shown.

[0070] Organic small molecule ligand BDT-Se: 1 H NMR (500MHz, CDCl3, 298K) δ (ppm): 8.66 (d, J=6.1Hz, 4H), 8.18 (d, J=8.7Hz, 2H), 8.07 (d, J= 8.8Hz,2H),7.63(d,J=8.6Hz,4H),7.52(d,J=6.2Hz,4H),7.40(d,J=4.0Hz,2H),7.38(d,J=3 .9Hz,4H),7.19(d,J=8.9Hz,4H),7.10(d,J=8.9Hz,2H),6.88(d,J=8.9Hz,4H),3.95(t,J=6 .5Hz,4H),1.83–1.75(m,4H),1.50–1.43(m,4H),1.38–1.27(m,16H),0.89(t,J=6.8Hz,6H).

[0071] 13 C NMR (126MHz, CDCl3, 298K) δ (ppm): 158.8, 158.7, 156.2, 152.9, 152.5, 150.1, 149.4, 147.9, 147.4, 146.7, 139.7, 133.2, 133.1, 13 2.6,131.3,128.0,127.5,127.1,124.9,123.5,121.4,121.1,118.6,118.2,115.3,68.2,31.8,29.6,29.3,29.2,26.0,22.6,14.1.

[0072] ESI-HRMS[1+H] + :calcd.for[C 68 H 67 N8O2SSe] + 1139.4195, found 1139.4255.

[0073] Step 2: Preparation of platinum acceptors

[0074]

[0075] Compound 5 was synthesized according to previously reported literature (Li Y., Yuan X., Yu J., et al. Amphiphilic Rhomboidal Organoplatinum(II) Metallacycles with Encapsulated Doxorubicin for Synergistic Cancer Therapy[J].ACS Applied Bio Materials, 2020, 3(11): 8061-8068.).

[0076] Preparation of the platinum acceptor: Compound 5 (12.76 mg, 0.0101 mmol) and AgOTf (16.25 mg, 0.0608 mmol) were dissolved in acetone (10 mL). After sealing the bottle, the solution was wrapped with aluminum foil to keep the reaction in the dark, and then stirred vigorously overnight. After the reaction was complete, the precipitate was filtered off, and the solvent was removed by a nitrogen stream under a fume hood. The solution was then concentrated to obtain a brownish-yellow solid platinum acceptor 6 (10.61 mg, 75% yield).

[0077] The proton and phosphorus NMR spectra of platinum acceptor 6 are as follows: Figure 4 and Figure 5 As shown.

[0078] Platinum receptor 6: 1 H NMR (500MHz, CDCl3, 298K) δ (ppm): 8.48 (s, 2H), 7.73 (d, J = 8.3Hz, 2H), 7.59 (d, J = 8.3Hz, 2H), 4.09 (s, 6H), 1.70–1.66 (m, 24H), 1.11–1.03 (m, 36H).

[0079] 31 P NMR (202MHz, CDCl3 298K) δ (ppm): 19.45 (s, 195 Pt satellites, 1 J Pt–P =2824.61Hz).

[0080] Step 3: Preparation of the rhombic supramolecular metal macrocyclic compound MBDT-Se

[0081]

[0082] Synthesis of the rhombic supramolecular metal macrocycle MBDT-Se: The organic small molecule ligand BDT-Se (2.17 mg, 0.0019 mmol) and platinum acceptor 6 (2.63 mg, 0.0019 mmol) prepared in the above steps were dissolved in 0.6 mL of a mixed solvent (dichloromethane / dimethyl sulfoxide, v / v, 1 / 1). The mixture was then stirred at 60 °C for 8 h to induce self-assembly. Subsequently, the mixture was transferred to a 10 mL sample vial, and after removing volatile solvents with a nitrogen stream, 10 mL of diethyl ether was added. The precipitate was collected by centrifugation three times. After drying, a dark green solid rhombic supramolecular metal macrocycle MBDT-Se (6.233 mg, yield 73.1%) was obtained.

[0083] The proton NMR spectrum, phosphorus NMR spectrum, and time-of-flight mass spectra of the rhombic supramolecular macrocyclic metallocycle MBDT-Se are as follows: Figure 6-8 As shown.

[0084] Rhombic supramolecular macrocyclic metallocycle MBDT-Se: 1 H NMR (500MHz, CDCl3, 298K) δ (ppm): 8.79 (s, 2H), 8.69 (d, J = 6.5Hz, 4H), 8.28 (d, J = 7.8Hz, 2H), 8.10 (d, J = 6.3Hz,4H),7.91(d,J=7.8Hz,4H),7.82(d,J=6.6Hz,4H),7.61(d,J=7.4Hz,2H),7.47(d,J=5.1Hz,6H),7 .20(d,J=6.1Hz,4H),7.12(d,J=6.8Hz,2H),6.89(d,J=6.5Hz,4H),4.12(s,6H),3.96(t,4H),1.86–1.76 (m,4H),1.50–1.45(m,4H),1.43–1.37(m,24H),1.34–1.28(m,16H),1.14(t,36H),0.89(d,J=6.9Hz,6H).

[0085] 31 P NMR (202MHz, CDCl3 298K) δ (ppm): 12.06 (s, 195 Pt satellites, 1 J Pt–P =2702.46Hz).

[0086] ESI-TOF-MS:m / z 1118.6489[M-4OTf] 4+ ,1541.7159[M-3OTf] 3+ Example 2

[0087] BDT-Se nanoparticles and MBDT-Se nanoparticles were prepared by nanoprecipitation method.

[0088] Preparation of BDT-Se nanoparticles: The organic small molecule ligand BDT-Se (1.0 mg) was dissolved in 0.3 mL of CHCl3, and DSPE-PEG was added... 2000 (30.0 mg) was dissolved in 2.5 mL of deionized water. Subsequently, the BDT-Se organic solution was added to the DSPE-PEG solution under ultrasonic oscillation. 2000 In an aqueous solution, after half an hour of ultrasonic agitation, the resulting solution was filtered through a 0.45 μm aqueous filter and concentrated under low temperature and high pressure. This yielded BDT-Se nanoparticles (BDT-Se NPs).

[0089] Preparation of MBDT-Se nanoparticles: 1.0 mg of the rhombic supramolecular metal macrocyclic compound MBDT-Se was dissolved in 2.5 mL of THF to prepare an MBDT-Se organic solution. Subsequently, DSPE-PEG was weighed... 2000 (10.0 mg) was dissolved in 10 mL of deionized water to prepare DSPE-PEG. 2000 Aqueous solution. Subsequently, the MBDT-Se organic solution was slowly added dropwise to DSPE-PEG. 2000 In an aqueous solution, the mixture was vigorously stirred at room temperature for 24 hours under a fume hood. After the reaction was complete, the resulting solution was filtered using a 0.45 μm aqueous filter and concentrated under low temperature and high pressure. MBDT-Se nanoparticles (MBDT-Se NPs) were finally obtained.

[0090] Sample Analysis

[0091] Performance characterization and analysis tests were performed on BDT-Se NPs and MBDT-Se NPs.

[0092] (1) Optical properties of BDT-Se NPs and MBDT-Se NPs

[0093] The BDT-Se NPs and MBDT-Se NPs obtained in the above steps were dissolved in deionized water, and the optical properties of the two nanoparticles were investigated using a UV-Vis spectrophotometer and a steady-state / transient fluorescence spectrometer. Figure 9As shown in (a) and (b), the UV absorption peaks of BDT-Se NPs encapsulated as nanoparticles and unencapsulated BDT-Se material are the same, both at 790 nm. However, the UV absorption peak of MBDT-Se NPs is redshifted by 10 nm compared to MBDT-Se, reaching 800 nm. Under 808 nm laser excitation, both nanoparticle materials also achieved NIR-II fluorescence emission. The maximum fluorescence emission peak of BDT-Se NPs is at 1071 nm, with a Stokes shift of 281 nm. The maximum fluorescence emission peak of MBDT-Se NPs is at 1053 nm, with a Stokes shift of 253 nm. Both nanoparticles exhibit large Stokes shifts, which effectively avoids the reduction in fluorescence efficiency caused by energy transfer.

[0094] (2) In vitro photothermal properties of BDT-Se NPs and MBDT-Se NPs

[0095] BDT-Se NPs and MBDT-Se NPs were dissolved separately in 1 mL of deionized water and transferred to 1.5 mL centrifuge tubes. Subsequently, an 808 nm laser (laser power density of 1.0 W / cm²) was used. 2 Different concentrations of BDT-Se NPs aqueous solutions and MBDT-Se NPs aqueous solutions were irradiated, and photothermal images were acquired minute by minute using an infrared thermal imager, with real-time temperature recorded. Subsequently, 40 μM MBDT-Se NPs aqueous solutions and 80 μM BDT-Se NPs aqueous solutions were used for laser irradiation under different power lasers, and photothermal images were acquired minute by minute using an infrared thermal imager, with real-time temperature recorded. Figure 10 As shown in (a)-(j), the temperature rise of the nanoparticle aqueous solution is positively correlated with the laser power and concentration. The photostability was detected by measuring the temperature change of 40 μM MBDT-Se NPs aqueous solution and 80 μM BDT-Se NPs aqueous solution during 5 radiation cooling cycles using laser irradiation. The photothermal conversion efficiency was found to be 36.7% for BDT-Se NPs aqueous solution and 38.9% for MBDT-Se NPs aqueous solution by substituting the temperature changes of 40 μM MBDT-Se NPs aqueous solution, 80 μM BDT-Se NPs aqueous solution and water during the photothermal cooling process into the photothermal conversion efficiency formula.

[0096] (3) Cell experiments

[0097] Mouse glioma cells (U87 cells) were cultured in Dulbecco modified Eagle medium (DMEM) containing 10% newborn calf serum (NBS), 1% penicillin and streptomycin, and incubated in a humidified incubator at 37°C and 5% CO2.

[0098] Since confocal laser scanning microscopy has a limited excitation wavelength, BDT-Se and MBDT-Se must first be co-encapsulated with Nile Red (fluorescent dye, NR). Preparation of MBDT-Se / NR NPs: Dissolve 0.5 mg of Nile Red (NR) and 0.5 mg of MBDT-Se in THF (2 mL) to prepare an organic solution. Weigh 10 mg of DSPE-PEG... 2000 Dissolve in deionized water (10 mL). Add the organic solution containing MBDT-Se dropwise to the solution containing DSPE-PEG using a syringe. 2000 The resulting mixture was stirred overnight in a fume hood, then filtered through a 0.45 μm aqueous filter using a syringe-driven process, and concentrated using a freeze dryer at low temperature and high pressure. The final product was red MBDT-Se / NR NPs. Preparation of BDT-Se / NR NPs: 0.4 mg of Nile Red (NR) and 0.6 mg of BDT-Se were dissolved in CHCl3 to prepare an organic solution. Then, 30 mg of DSPE-PEG was weighed... 2000 Dissolve in deionized water (3 mL). Then, the organic solution containing BDT-Se is added to the solution containing DSPE-PEG. 2000 After being thoroughly shaken in an aqueous solution, the mixture was sonicated for 1 hour, then filtered using a 0.45 μm aqueous filter, and concentrated under low temperature and high pressure to obtain red BDT-Se / NR NPs.

[0099] Subsequently, a cell phagocytosis experiment was performed, in which U87 cells were placed in a 6×10 well. 4 Cells were seeded at a density of [number] cells / well in 8-well plates and incubated at 37°C with 5% CO2 for 22-24 hours. The original culture medium was then removed using a pipette and replaced with fresh serum-free DMEM medium containing BDT-Se / NR NPs (0.04 μM) and MBDT-Se / NR NPs (0.04 μM). After incubation for another 4 hours, the culture medium was removed by pipette, and 4% paraformaldehyde (for cell fixation) was added to each well. After 15 minutes, the fixative was removed by pipette, and the cells were washed and stained with 4',6-diamidinyl-2-phenylindole (DAPI) to stain the nuclei. After incubation for 20 minutes, the staining solution was removed by pipette, and the cells were washed three times with PBS. Cells were then observed under a confocal laser scanning microscope (LSM710, Zeiss). Results are shown below. Figure 11 As shown in (d), the nanoparticles (red fluorescence) are well-encapsulated near the cell nucleus (blue fluorescence). This figure demonstrates that the BDT-Se / NR nanoparticles and MBDT-Se / NR nanoparticles are uniformly distributed in the cytoplasm, are well phagocytosed by U87 tumor cells, and function within the cell.

[0100] Cellular uptake of BDT-Se NPs and MBDT-Se NPs was investigated. U87 cells were cultured in single wells at 8 × 10⁸ cells per well. 4 Cells were seeded at a density of [number] cells / well in 12-well plates and incubated in a cell culture incubator for 22-24 hours. The cells were then divided into three groups for experiments: the BDT-Se NPs DMEM solution group, the MBDT-Se NPs DMEM solution group, and the control group (serum-free DMEM solution). After cell adhesion, the culture medium was aspirated, and BDT-Se NPs DMEM solution or MBDT-Se NPs DMEM solution was added at different time points (1 h, 2 h, 4 h, 6 h, 8 h). For the control group, the culture medium was directly aspirated after 22-24 hours of incubation and replaced with serum-free DMEM solution. After 8 hours, the culture medium was removed, and the cells were washed three times with PBS. The cells were then scraped from the plate. Cells were transferred and filtered into flow cytometry tubes, and cell uptake at different time points was detected using flow cytometry.

[0101] The results are as follows Figure 11 As shown in (e) and (f), it is clearly evident that the amount of nanoparticles taken up by U87 cells gradually increases with the increase of incubation time. This uptake experiment further confirms the good uptake of nanoparticles, which can help to better evaluate the appropriate time for tumor phototherapy in the future.

[0102] The cytotoxicity of MBDT-Se NPs and BDT-Se NPs was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. U87 cells were cultured at 1.2 × 10⁻⁶ cells / year. 4 Cells were seeded at a density of 4 wells in four 96-well plates. After 18 h of culture, the culture medium was removed and replaced with DMEM medium containing MBDT-Se NPs (0.6 μM) and BDT-Se NPs (0.6 μM), respectively. After 4 h, the cells were seeded using an 808 nm laser (1.0 W / cm²). 2 One plate was irradiated for 5 min, while the other plate was left untreated in the dark. After 24 h of incubation, the medium was replaced again with MTT solution (500 μg / mL). After 4 h of incubation, 100 μL of DMSO was added to each well. Subsequently, the absorbance at 570 nm was monitored using an enzyme labeling system (DNM-9602). The relative cell viability was calculated using the following formula:

[0103] Cell viability (%) = Experimental group / Control group × 100%

[0104] The results are as follows Figure 11 As shown in (a) and (b), the cell viability of MBDT-Se NPs (0.6 μM) was 52%, and that of BDT-Se NPs (0.6 μM) was 44%.

[0105] U87 cells were stored in single wells at a density of 1.5 × 10⁻⁶. 4 Cells were seeded at a density of [number] cells / well in 96-well plates and incubated for 20 hours. Subsequently, they were divided into six groups for live / dead cell staining experiments: (I) Control (serum-free medium), (II) Control (serum-free medium) + 808 nm (1.0 W / cm²). 2 (III) MBDT-Se NPs (0.6 μM), (IV) MBDT-Se NPs (0.6 μM) + 808 nm (1.0 W / cm²) 2 Laser irradiation for 5 min), (V) BDT-Se NPs (0.6 μM), (VI) BDT-Se NPs (0.6 μM) + 808 nm (1.0 W / cm²) 2 (Laser irradiation for 5 min). After 20 h, the culture medium containing MBDT-Se NPs and BDT-Se NPs was removed, and the cells were washed twice with PBS. Live and dead cells were stained with calcein acetoxymethyl ester (Calcine AM) and propidium iodide PI for 30 min each. The cells were then washed twice more with PBS, and images of live cells (green fluorescence) and dead cells (red fluorescence) were acquired using an inverted fluorescence microscope (Eclipse 200, Nikon). Figure 11 As shown in (c), the experimental results of MBDT-Se NPs and BDT-Se NPs are consistent with those of the MTT assay. This indicates that MBDT-Se NPs and BDT-Se NPs have low toxicity and good tumor-killing ability.

[0106] The embodiments described above provide a detailed explanation of the technical solutions of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An organic small molecule ligand, characterized in that, The structural formula is shown in equation (I): ； （I）； R1 is a C6-C10 n-alkyl group.

2. The method for preparing organic small molecule ligands according to claim 1, characterized in that, Includes the following steps: (1) Under the action of a catalyst, using 4,7-dibromo-5,6-dinitrobenzo[c][1,2,5]thiadiazole and N,N -Diphenyl-4-(tributyltinyl)-aniline was reacted in an organic solvent system, and the reactants were post-treated to give compound 1; (2) Under the action of a catalyst, using compound 1 and the substituted compound N,N -Diphenyl-4-(tributyltinyl)-aniline was reacted in an organic solvent system, and the reactants were post-treated to give compound 2; (3) Dissolve compound 2 in an organic solvent, and add N The reaction with bromosuccinimide yielded compound 3 after post-treatment of the reactants. (4) Under alkaline conditions, compound 3, pyridine-4-boronic acid and catalyst were reacted in an organic solvent system, and the reactants were post-treated to obtain compound 4; (5) Compound 4 and iron powder react in an acetic acid solvent system. After the reaction is complete, an intermediate is obtained. The intermediate and selenium dioxide react in an organic solvent system. The reactants are post-treated to obtain the organic small molecule ligand.

3. A rhombic supramolecular metal macrocyclic compound, characterized in that, The structural formula is shown in formula (II): ； （Ⅱ）； Wherein, R1 is a C6-C10 n-alkyl group, and R2 is a C1-C3 alkyl group.

4. The method for preparing the rhombic supramolecular metal macrocyclic compound according to claim 3, characterized in that, include: The organic small molecule ligand and platinum acceptor described in claim 1 were dissolved in an organic solvent, and under sealed conditions, a self-assembly reaction was carried out by stirring to obtain the rhombic supramolecular metal macrocyclic compound; the structural formula of the platinum acceptor is shown in formula (III): ； （Ⅲ）； R2 is a C1-C3 alkyl group.

5. The method for preparing the rhombic supramolecular metal macrocyclic compound according to claim 4, characterized in that, The molar ratio of the organic small molecule ligand to the platinum acceptor is 1:1-1.

2.

6. The method for preparing the rhombic supramolecular metal macrocyclic compound according to claim 4, characterized in that, The organic solvent is dichloromethane and / or dimethyl sulfoxide, and the self-assembly reaction is carried out under the condition of stirring at 55-60 °C for 6-8 h.

7. The use of the rhombic supramolecular metal macrocyclic compound according to claim 3 in the preparation of tumor therapeutic and / or diagnostic agents.

8. A tumor treatment and / or diagnostic agent, characterized in that, Including the rhombic supramolecular metal macrocyclic compound as described in claim 3.

9. The tumor treatment and / or diagnostic preparation according to claim 8, characterized in that, The tumor treatment and / or diagnostic formulations comprise nanoparticles formed from the rhombic supramolecular metal macrocyclic compound and surfactant.

10. The tumor treatment and / or diagnostic preparation according to claim 9, characterized in that, The surfactant is DSPE-PEG. 2000 The mass ratio of the rhombic supramolecular metal macrocyclic compound to the surfactant is 1:10-15.

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