CN115044051B - Platinum cluster radiotherapy sensitizer for relieving tumor hypoxia - Google Patents

Abstract

The invention discloses a platinum cluster radiotherapy sensitizer for relieving tumor hypoxia, belonging to the cross field of nano material chemistry and biochemistry. The invention takes levonorgestrel with good biocompatibility as a protective ligand, and synthesizes the alloy nanocluster with high yield and excellent fluorescence performance and accurate atom size by a room-temperature volatilization one-pot method. The chemical formula of the nano alloy cluster is as follows: pt ₂ Au ₄ C ₁₆₈ H ₂₁₆ O ₁₆ (abbreviated as: pt) ₂ Au ₄ L ₈ ) Belonging to trigonal system, the space group is chiral space groupP3221. The nano alloy cluster has a small size (-2 nm) and good dispersibility; the fluorescent material has strong red fluorescence at room temperature, the fluorescence quantum yield is 37.9%, and the fluorescent material can be used for high-quality cell imaging. The nano alloy cluster material can relieve tumor hypoxia, has a radiotherapy sensitization effect when being used as a radiotherapy sensitizer, and has high efficiency of killing tumor cells.

Description

A Platinum Cluster Radiosensitizer for Alleviating Tumor Hypoxia

technical field

The invention belongs to the cross field of nanometer material chemistry and biochemistry, in particular relates to an atomically precise nano-alloy cluster material radiotherapy sensitizer, in particular to a nano-alloy cluster material radiotherapy sensitizer that can relieve tumor hypoxia.

Background technique

With the rapid development of cluster science, researchers in the field of radiotherapy have proposed the idea of studying high atomic number nanoclusters as next-generation radiosensitizers due to the strong interaction between high atomic number nanoclusters and incident radiation. Up to now, Au clusters such as bovine serum albumin (BSA)-protected Au ₂₅ clusters and levonorgestrel-protected Au ₈ clusters have been deeply explored in radiosensitization. Studies have shown that metal clusters with a size of 1-3nm can be effectively cleared by the kidney, showing low toxicity. Furthermore, nanoclusters with atomically precise structures offer good opportunities to analyze the structure-activity relationships of radiosensitizers.

Most of the previously reported nanocluster radiosensitizers have a single function and cannot overcome the radiation resistance of hypoxic tumors. In situ _O2 generation by decomposing overexpressed _H2O2 in the tumor microenvironment is _a viable approach. In addition, many platinum-related nanomaterials have good catalase-like activity. Therefore, the preparation of platinum-based alloy clusters holds great promise for achieving radiosensitization to block the negative impact of hypoxia on cancer therapy.

Contents of the invention

The purpose of the present invention is to provide an atom-level precise nano-alloy cluster radiotherapy sensitizer that can relieve tumor hypoxia. Another object is to provide its preparation method.

α＝90°,β＝90°,γ＝120°,

L代表左炔诺孕酮配体。In order to achieve the purpose of the present invention, the chemical formula of the nano-alloy cluster material is Pt ₂ Au ₄ C ₁₆₈ H ₂₁₆ O ₁₆ , abbreviated as: Pt ₂ Au ₄ L ₈ , which belongs to the trigonal crystal system; the space group is the chiral space group P3221 ,

α=90°, β=90°, γ=120°,

L represents the levonorgestrel ligand.

In order to achieve the purpose of the present invention, the nano-alloy cluster material of the present invention is prepared through the following steps:

Dissolve the ligand levonorgestrel in dichloromethane (DCM), stir at room temperature to dissolve and clarify; add methanol solution of chloroplatinic acid, stir at room temperature for reaction; then add triethylamine, continue stirring at room temperature; finally add tetrahydrothiophene Gold chloride, stirred at room temperature, and after the reaction, place the clear solution at room temperature to avoid light and volatilize to obtain crystals, filter, wash, and dry at room temperature.

The nano-alloy cluster material is composed of two platinum atoms, four gold atoms and eight organic ligands (shown in Figure 1), and six metal atoms form an octahedral core through the interaction of metal bonds, each The platinum atom is coordinated to the carbon atoms on the terminal alkynes of the four ligands through σ bonds, and each gold atom is coordinated to the carbon atoms on the terminal alkynes of the two ligands through π bonds (shown in Figure 2).

The nano-alloy cluster material has an ultra-small size (~2nm) and good dispersion (shown in Figures 3 and 4). It has strong red fluorescence at room temperature, and its optimum emission wavelength position is 663nm (excitation wavelength 390nm) (shown in Figure 5); the fluorescence quantum yield is 37.9% at room temperature. Tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) dichloride ([Ru(dpp) ₃ ]Cl ₂ , an O ₂ -based Time-varying O ₂ concentration to indicate whether O ₂ is produced. In the presence of H ₂ O ₂ , the fluorescence intensity of [Ru(dpp) ₃ ]Cl ₂ in the Pt ₂ Au ₄ L ₈ group decreased significantly with the increase of the reaction time (shown in Figure 6), indicating that the Pt ₂ Au ₄ L ₈ It can catalyze the decomposition of hydrogen peroxide into O ₂ , that is, it has catalase-like properties, doped with other metals (such as Ag and Cu), and has no catalase-like activity. The material was used in the cell cloning experiment, and it was treated under different conditions during the experiment, and the cell necrosis in the Pt ₂ Au ₄ L ₈ ray experiment group was the most significant (as shown in Figure 7 ).

Beneficial effects of the present invention: the nano-alloy cluster material has strong red fluorescence at room temperature, and has good dispersion and good biocompatibility, and can be used for high-quality cell imaging, regulating tumor hypoxia, and as a radiotherapy sensitizer The agent plays a radiosensitizing effect and has high efficiency in killing tumor cells. This provides a potential platform for further analysis of the structure-activity relationship of alloy cluster radiosensitizers, and opens up a new avenue for the construction of atomically precise nanomedicines to block the negative effects of hypoxia on tumor radiosensitivity.

Description of drawings

Fig. 1 is a single crystal structure diagram of the nano-alloy cluster material of the present invention.

Fig. 2 is a diagram of the core structure and ligand coordination mode of the nano-alloy cluster material of the present invention.

Fig. 3 is a transmission electron microscope image of the nano-alloy cluster material of the present invention.

Fig. 4 is a dynamic light scattering diagram of the nano-alloy cluster material of the present invention.

Fig. 5 is the excitation curve and emission curve diagram of the nano-alloy cluster material of the present invention and the fluorescence photo diagram of the material at 365 nm.

Fig. 6 is a time-dependent diagram of [Ru(dpp) ₃ ]Cl ₂ fluorescence intensity of the nano-alloy cluster material of the present invention in the presence of H ₂ O ₂ .

Fig. 7 is a graph showing the results of cell cloning experiment using the nano-alloy cluster material of the present invention as a radiosensitizer.

Detailed ways

Below by example the present invention will be further described:

Embodiment 1: the synthesis of nano-alloy cluster material of the present invention

Dissolve the ligand levonorgestrel in dichloromethane (DCM), stir at room temperature to dissolve and clarify; add methanol solution of chloroplatinic acid, stir at room temperature for reaction; then add triethylamine, continue stirring at room temperature; finally add tetrahydrothiophene Gold chloride, stirred at room temperature for 15 minutes, after the reaction, put the reaction solution at room temperature to avoid light and volatilize, after 2 to 3 days, yellow strip crystals were obtained, filtered, washed with acetonitrile, the yield was 69.87%, dried at room temperature for other Properties of test materials.

Embodiment 2: The nano-alloy cluster material of the present invention is used as a radiotherapy sensitizer

Take the nano-alloy cluster material sample of the present invention obtained in Example 1, dissolve it in a small amount of DMSO, add it into the culture medium and ultrasonically homogenize it, use the culture medium containing this material for cell cloning experiments, and conduct X-rays for different groups Ray processing. The results are shown in Figure 7. It can be seen that the cell necrosis in the Pt ₂ Au ₄ L ₈ +X-ray experimental group was the most significant.

The nano-alloy cluster material of the present invention obtained in Example 1 is further characterized, and the process is as follows:

(1) Determination of crystal structure

为衍射源通过ω扫描方式在200K温度下收集。结构解析是先通过SHELXS-97程序用直接法得到初结构，然后使用SHELXL-97程序用全矩阵最小二乘法精修。溶剂分子通过OLEX2里的mask程序进行处理。所有非氢原子均采用各向异性热参数法精修。所有的氢原子均包含在理想位置。详细的晶体测定数据见表1；重要的键长数据见表2。The X-ray single crystal diffraction data of the complexes were measured on a Rigaku XtaLAB Pro single crystal diffractometer with a single crystal sample of appropriate size. Data with Mo-Kα rays

The diffraction source was collected at 200K by ω-scanning. The structure analysis is obtained by the direct method through the SHELXS-97 program, and then refined by the full matrix least square method using the SHELXL-97 program. Solvent molecules are processed by the mask program in OLEX2. All non-hydrogen atoms were refined using the anisotropic thermal parameter method. All hydrogen atoms are contained in ideal positions. Detailed crystal determination data are shown in Table 1; important bond length data are shown in Table 2.

The main crystallographic data of table 1 nano-alloy cluster material of the present invention

Table 1 Main crystallographic data

R1＝∑||F _o |-|F _c |/∑||F _o |.wR ₂ ＝[∑w(F _o ² -F _c ² ) ² /∑w(F _o ² ) ² ] ^1/2

Table 2 Important bond lengths of Pt ₂ Au ₄ L ₈

Symmetric code: ¹ -Y+X,-Y,1/3-Z

The above embodiments are only used to illustrate the contents of the present invention, and besides this, the present invention also has other implementations. However, all technical solutions formed by equivalent replacement or equivalent deformation fall within the protection scope of the present invention.

Claims (5)

1. A nanoalloy cluster material, characterized by: the chemical formula is as follows: pt ₂ Au ₄ C ₁₆₈ H ₂₁₆ O ₁₆ The abbreviation is: pt ₂ Au ₄ L ₈ Belonging to the trigonal system; space group is chiral space groupP3221，a = 25.48940(10) Å, b = 25.48940(10) Å, c = 25.13260(10) Å, α =90°, β = 90°, γ = 120°, V = 14141.23(12) Å ³ (ii) a L represents levonorgestrel ligand.

2. The nanoalloy cluster material of claim 1, wherein: the catalyst consists of two platinum atoms, four gold atoms and eight organic ligands, wherein six metal atoms form an octahedral inner core through the interaction of metal bonds, each platinum atom is coordinated with a carbon atom on terminal alkyne in the four ligands through a sigma bond, and each gold atom is coordinated with a carbon atom on terminal alkyne in the two ligands through a pi bond; the organic ligand is levonorgestrel.

3. The nanoalloy cluster material of claim 1 or 2, wherein: the single crystal structure is shown in figure 1.

4. Use of a nanoalloy cluster material as claimed in any one of claims 1 to 3, characterized in that: it is used as radio sensitizer for non-disease diagnosis and treatment.

5. Use of a nanoalloy cluster material as claimed in any one of claims 1 to 3, characterized in that: it is used as a radiotherapy sensitizer for relieving tumor hypoxia in non-disease diagnosis and treatment.

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