A gold nanocluster organic framework and its preparation method and application

Abstract

The present invention belongs to the field of nano new material technology and tumor treatment, and relates to a gold nanocluster organic framework and its preparation method and application; specifically, it relates to the construction of a gold nanocluster organic framework and its application in tumor treatment. Due to the stabilizing effect of TEPP ligands, the optical properties and structural stability of the AuNC organic framework AuNCOF prepared by the present invention are significantly improved; singlet oxygen ( 1 The photocatalytic activity of AuNC was significantly improved, and the PDT for tumors produced better therapeutic effects. The prepared AuNC organic framework AuNCOF expanded the construction method of AuNC assembly and was successfully applied to killing tumor cells, showing the development potential of AuNCOF and taking an important step towards the further development of AuNC-based functional nanomaterials.

Description

Technical Field

[0001] The present invention belongs to the field of nano new material technology and tumor treatment, and relates to a gold nanocluster organic framework and a preparation method and application thereof; specifically, relates to the construction of a gold nanocluster organic framework and its application in tumor treatment. Background Art

[0002] Cancer is the second leading cause of death in the world, causing about 10 million deaths each year, seriously endangering people's lives and health. Currently, the commonly used methods for treating malignant tumors in clinical practice mainly include chemotherapy, radiotherapy and surgery. However, due to the inherent defects of traditional treatment methods, namely, radiotherapy is highly damaging to normal tissues, and patients cannot withstand multiple radiotherapy treatments; chemotherapy drugs usually have poor targeting, large toxic side effects, and are prone to drug resistance, making it difficult to eradicate tumors; surgery is highly damaging to patients, and non-solid tumors cannot be treated surgically, so the mortality rate of cancer has remained high.

[0003] The rise and rapid development of nanotechnology has brought new hope for human cancer cure. Nanomaterials have many advantages such as high specific surface area, small size, high activity, ability to carry drugs directly into tumor tissues, and directly act on tumor cells. Various nanomaterials have been developed for cancer treatment. Gold nanoclusters (AuNCs) with novel topological structures not only have the excellent properties of the above-mentioned nanomaterials, but also have good biocompatibility, easy functionalization and fast synthesis. They have broad application potential in photoelectrochemistry, biomedicine, catalysis and other fields. However, despite the rapid development of AuNCs in recent years, there are few reports on its practical application in the above-mentioned fields, which may be mainly due to its structural instability. Therefore, the development of AuNCs or AuNCs-based nanomaterials with stable structures is of great significance to expand the practical application of AuNCs. Summary of the invention

[0004] In order to solve the instability of gold nanoclusters and expand their practical applications at the current stage, the present invention provides a covalently assembled novel metal organic framework (MOF) mimetic AuNC organic framework (AuNCOF) and a preparation method thereof, and applies it to tumor treatment.

[0005] The technical solution of the present invention is as follows:

[0006] A gold nanocluster organic framework, wherein the gold nanocluster organic framework is prepared by the following method: TEPP reacts with Au8 nanoclusters and then extracts, collects the organic phase, and obtains AuNCOF;

[0007] Preferably, the molar ratio of Au8 nanoclusters to TEPP is 2:1.

[0008] Preferably, the reaction conditions are room temperature for 10-24 h.

[0009] Preferably, the extraction phase is water and dichloromethane; washing is required after extraction, and the washing is three times with methanol and ether respectively.

[0010] Preferably, TEPP and Au8 nanoclusters are dissolved in a methanol solution and reacted under the catalysis of CH3ONa.

[0011] The application of the gold nanocluster organic framework in the preparation of drugs for treating tumors.

[0012] Furthermore, the tumor is a breast tumor.

[0013] Beneficial effects of the present invention

[0014] (1) Compared with Au8 nanoclusters alone, the AuNC organic framework AuNCOF prepared in the present invention has significantly improved optical properties and structural stability due to the stabilizing effect of TEPP ligands, which provides a basis and guarantee for the future practical application of Au8 nanoclusters.

[0015] (2) Compared with free TEPP, the AuNC organic framework AuNCOF prepared by the present invention produces singlet oxygen ( 1 The photocatalytic activity of AuNCs was significantly improved, and PDT for tumors produced better therapeutic effects, which is an important step for the further development of AuNC-based functional nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the process of the gold nanocluster organic framework of the present invention;

[0017] Figure 2 TEM and HRTEM images of AuNCOF prepared in Example 1; wherein (a) is a TEM image of AuNCOF, and (b) is a HRTEM image;

[0018] Figure 3 PXPD image of AuNCOF prepared in Example 1;

[0019] Figure 4 TCA diagram of AuNCOF prepared in Example 1;

[0020] Figure 5 FTIR images of Au8 nanoclusters, TEPP, and AuNCOF in Example 1;

[0021] Figure 6(a) of Example 1 is the particle size distribution of Au8 nanoclusters, TEPP, and AuNCOF, and (b) is the zeta potential distribution of Au8 nanoclusters, TEPP, and AuNCOF;

[0022] Figure 7 The photographs of the Au8 nanoclusters and AuNCOF solids of Example 1 under xenon lamp irradiation (λ = 320-780 nm) for 2 h;

[0023] Figure 8 The UV-visible absorption changes (within 10 minutes) of Au8 nanoclusters (a) and AuNCOF prepared in Example 1 (b) under xenon lamp irradiation (λ = 320-780 nm);

[0024] Fig. 9 The AuNCOF prepared in Example 1 was prepared in DMF 1 ESR spectrum of O2;

[0025] Fig.10 (a) AuNCOF or TEPP prepared in Example 1 was incubated with 4T1 cells for 2 h and illuminated with a 660 nm laser (0.8 W / cm 2 ) The survival rate of 4T1 cells after irradiation for 5 min; (b) The AuNCOF or Au8 nanoclusters prepared in Example 1 were incubated with 4T1 cells for 2 h and irradiated with a 660 nm laser (0.8 W / cm 2 ) Survival rate of 4T1 cells after 5 min of irradiation;

[0026] Fig.11 This is a SEM image of the gold nanocluster organic framework prepared in Example 2;

[0027] Fig.12 This is the SEM image of the gold nanocluster organic framework prepared in Example 3. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Example 1

[0030] A method for preparing a gold nanocluster organic framework (such as Figure 1 ), comprising the following steps:

[0031] (1) AuNCOF was prepared by covalent reaction of 5,10,15,20-tetrakis(4-ethynylphenyl)porphyrin with divalent Au8 nanoclusters. 6.4 mgTEPP (9 μmol) and 290 mgCH3ONa (5.4 mmol) were added to 100 mL of methanol solution containing 60.0 mgAu8 nanoclusters (18 μmol) and stirred at room temperature for 12 h. The reaction solution was extracted with H2O and CH2Cl2, and the organic phase was collected and dried. The AuNCOF was obtained by washing with methanol and ether three times.

[0032] Analysis of relevant characterization results:

[0033] 1. The morphology, structure and thermal stability of the AuNCOF prepared in Example 1 were characterized by transmission electron microscopy (TEM), high resolution transmission microscopy (HRTEM), powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). The results were: Figure 2-4 shown.

[0034] 2. The synthesis of AuNCOF was characterized by Fourier transform infrared (FTIR) spectroscopy, DLS and zeta potential. Figure 5-6 shown.

[0035] 3. Determination of photostability and photosensitivity of AuNCOF

[0036] AuNCOF was irradiated under a xenon lamp (λ = 320-780 nm) for 2 h. The morphology and UV-vis changes of AuNCOF before and after irradiation were observed to evaluate the photostability of AuNCOF. Electron spin resonance (ESR) was used to study its photosensitivity. The results are as follows: Figure 7-9 shown.

[0037] Example 2

[0038] A method for preparing a gold nanocluster organic framework (such as Figure 1 ), comprising the following steps:

[0039] (1) AuNCOF was prepared by covalent reaction of 5,10,15,20-tetrakis(4-ethynylphenyl)porphyrin with divalent Au8 nanoclusters. 3.2 mg TEPP (4.5 μmol) and 145 mg CH3ONa (2.7 mmol) were added to 50 mL DMF solution containing 30 mg Au8 nanoclusters (9 μmol) and stirred at room temperature for 10 h. The reaction solution was extracted with H2O and CH2Cl2, and the organic phase was collected and dried. After washing with methanol and ether three times, AuNCOF was obtained. The specific morphology is shown in Fig.11 .

[0040] Example 3

[0041] A method for preparing a gold nanocluster organic framework comprises the following steps:

[0042] (1) AuNCOF was prepared by covalent reaction of 5,10,15,20-tetrakis(4-ethynylphenyl)porphyrin with divalent Au8 nanoclusters. 3.2 mg TEPP (4.5 μmol) and 145 mg CH3ONa (2.7 mmol) were added to 50 mL DMSO solution containing 30 mg Au8 nanoclusters (9 μmol) and stirred at room temperature for 24 h. The reaction solution was extracted with H2O and CH2Cl2, and the organic phase was collected and dried. After washing with methanol and ether three times, AuNCOF was obtained. The specific morphology is shown in Fig.12 .

[0043] Implementation effect example

[0044] 1. Evaluation of the cell killing ability of AuNCOF

[0045] 4T1 cells were seeded in 96-well plates at a density of 1×10 4 Then, the cells were cultured with different concentrations of Au8 nanoclusters, TEPP or AuNCOF for 2 h, washed with DPBS to remove free substances, and illuminated with a 660 nm laser (0.8 W / cm 2 ) for 5 min. After 24 h, fresh cell culture medium containing CCK-8 (10 μL / well) was added and culture was continued. The absorbance at 450 nm was measured using an ELISA reader.

[0046] like Figure 1 As shown, AuNCOF was constructed for cancer treatment.

[0047] like Figure 2-4 As shown, TEM and HRTEM images ( Figure 2 ) showed that the diameter of AuNCOF was 197±4 nm, in which single dispersed Au8 nanoclusters could be clearly seen; PXRD ( Figure 3 ) The results show that AuNCOF has a crystalline porous structure with a pore size of up to 3.95 nm; TGA data ( Figure 4 ) showed that AuNCOF hardly decomposed before the high temperature reached 220 °C, and the thermal stability was satisfactory.

[0048] like Figure 5-6 As shown, FTIR spectrum ( Figure 5 The results showed that the prepared AuNCOF contained the characteristic peaks of 1,3-bis(diphenylphosphino)propane ligands of Au8 nanoclusters (~728 cm -1), and also contains the characteristic peak of the acetylene (-C≡C-) group of TEPP (~2100 cm -1 ). In addition, after AuNC was covalently assembled with TEPP, the particle size became larger ( Figure 6 a), zeta potential ( Figure 6 b) The voltage changes from +17.2 mV to +39.6 mV, indicating that Au8 nanoclusters are successfully assembled with TEPP.

[0049] like Figure 7 As shown in Figure 2, Au8 nanoclusters, like most nanoclusters, are unstable under the action of light. Therefore, the photostability of Au8 nanoclusters and AuNCOF was investigated under Xe lamp irradiation (λ = 320-780 nm). Figure 7 It can be seen intuitively that the color of the solid powder of AuNCOF did not change significantly after irradiation, while the Au8 nanoclusters changed significantly under the naked eye, indicating that the Au8 nanoclusters were unstable and deteriorated under light. At the same time, the UV-vis absorbance of the Au8 nanoclusters also decreased with the extension of the light exposure time ( Figure 8 a), which fully reflects the photoinstability of Au8 nanoclusters, while the UV-vis absorbance of AuNCOF has no obvious change ( Figure 8 b). The above data prove that after forming AuNCOF with a rigid MOF-like structure, the structural stability of Au8 nanoclusters is significantly improved. The improvement of AuNCOF optical properties and structural stability provides a basis and guarantee for the practical application of Au8 nanoclusters in the future.

[0050] like Fig. 9 As shown, electron spin resonance (ESR) was used to study the generation of 1 The photosensitivity corresponding to the O2 capacity. The ESR spectrum showed a 1:1:1 triple peak, indicating that under laser irradiation (660 nm, 0.8 W / cm 2 ) is indeed generated 1 O2. In addition, at the same concentration of TEPP, AuNCOF produced 1 The amount of O2 is 2.18 times that of TEPP, indicating that the photosensitivity is significantly improved after the formation of AuNCOF, indicating that the covalent assembly strategy improves the photosensitivity.

[0051] like Fig.10 As shown, under 660 nm laser irradiation (0.8 W / cm 2, 5 min), the phototoxicity of AuNCOF and TEPP on 4T1 cells was measured. Specifically, when the concentration of AuNCOF was 200µg / mL (this concentration is equivalent to 19.2µg / mL of TEPP and 180.8µg / mL of Au8 nanoclusters), the cell survival rate was only 7.05%. When the concentrations of Au8 nanoclusters (180.8µg / mL) and TEPP (19.2µg / mL) were controlled to be the same as the concentration of AuNCOF (200µg / mL), the lethal effect of free TEPP (96.59% survival rate) and Au8 nanoclusters (82.29% survival rate) on cells was almost negligible, and the prepared AuNCOF organic framework can effectively kill breast tumor cells.

Claims

1. A gold nanocluster organic framework, characterized in that: The gold nanocluster organic framework is prepared by the following method: TEPP and Au8 nanoclusters are dissolved in a methanol solution, reacted at room temperature for 10-24 hours under the catalysis of CH3ONa, and then extracted and the organic phase is collected to obtain AuNCOF, wherein TEPP is 5,10,15,20-tetrakis(4-ethynylphenyl)porphyrin, and the Au8 nanoclusters are divalent Au8 nanoclusters [Au8(dppp)4] 2+ , the molar ratio of Au8 nanoclusters to TEPP is 2:

1.

2. The gold nanocluster organic framework according to claim 1, characterized in that: The extraction phases are water and dichloromethane; washing is required after extraction, and the washing is performed three times with methanol and ether respectively.

3. Use of the gold nanocluster organic framework according to claim 1 or 2 in the preparation of drugs for treating tumors.

4. The use according to claim 3, characterized in that: The tumor is a breast tumor.

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