CN104483296A - Breast cancer molecular probe and preparation method thereof - Google Patents

Abstract

The invention discloses a molecular probe for breast cancer, which is composed of a signal component and an affinity component, and is characterized in that the affinity component is a component specifically binding to a breast cancer stem cell target; the signal component is composed of a near-infrared fluorescent signal unit and an affinity component. Magnetic resonance signal unit composition. The preparation method is as follows: the signal function unit is coupled with the specific surface marker monoclonal antibody of breast cancer stem cells by chemical covalent coupling method, and then purified. The present invention is a molecular probe specifically binding to multiple targets of breast cancer stem cells, through which the molecular probe can solve the in vivo detection and quantitative analysis of breast cancer stem cells, and provide a new strategy for solid tumor stem cell imaging diagnosis and targeted therapy curative effect evaluation Provide evidence, provide a "new model" for early diagnosis and grading of tumors, provide accurate information and evaluation methods for tumor treatment, and lay a foundation for diagnostic information to further solve recurrence and metastasis problems.

Description

Breast cancer molecular probe and manufacturing method thereof

technical field

The invention belongs to the technical field of medical imaging, and specifically relates to a molecular probe, in particular to a breast cancer molecular probe, which is used for medical imaging of breast cancer diagnosis and treatment.

Background technique

Breast cancer is one of the most common malignant tumors in women. The incidence rate accounts for 7-10% of all kinds of malignant tumors in the whole body. It is second only to uterine cancer in women and has become the main cause of threat to women's health. It is one of the most common malignant tumors that usually occurs in the glandular epithelial tissue of the breast, seriously affecting women's physical and mental health and even threatening their lives. Breast cancer is rare in men, and only about 1-2% of breast cancer patients are men.

The principle of breast cancer treatment is clinically the first choice for early and mid-stage breast cancer, and radical resection is the main method. In the middle and late stages, comprehensive treatment is the main method. It is obvious to all that the side effects of radiotherapy and chemotherapy in cancer treatment have caused harm and pain to the normal body of patients.

For the treatment of cancer, the effect of early detection and early treatment is better than late treatment. However, breast cancer may be asymptomatic in the early stage, and may show local and systemic symptoms as the disease progresses. Examples include lumps, pain, breast skin changes, breast contour changes, nipple and areola changes, nipple discharge, regional lymph node enlargement, and distant metastases. Therefore, early and accurate diagnosis of breast cancer is the basis and guarantee for early detection and effective treatment. There are many diagnostic methods for breast cancer. The traditional methods mainly include: X-ray diagnosis, ultrasonography, cytology and histological diagnosis, etc. Although these methods play an important role in the routine detection of breast cancer, they are all The anatomical changes in the end stage of the disease make it difficult to achieve early diagnosis in the true sense.

Molecular imaging is the use of high-precision imaging technology to non-invasively visualize the qualitative and quantitative detection of changes in molecules, genes and cells involved in physiological or pathological processes in vivo. The main application field of molecular imaging is oncology, and its basic strategy is to introduce into the body molecular probes (composed of two parts: signal component and affinity component) that can specifically bind to the target, by directly detecting the signal component on the probe, or indirectly Detect the products of molecular probes in and out of cells, and obtain molecular information to achieve the purpose of tracing and diagnosis. Molecular imaging is to directly monitor cells and molecular pathways through images in a real and complete physiological environment, and to perform real-time imaging of the occurrence and development of biological activities. Compared with traditional methods, molecular imaging technology can better study the mechanism and characteristics of diseases at the molecular level, and can observe the treatment mechanism and curative effect early and continuously in vivo. The effect, the reduction of recurrence rate, and the reduction of mortality are of weight significance.

The key technology in molecular imaging is the preparation and application of molecular probes. Molecular probes refer to labeled compound molecules that are specific to a specific biological molecule (such as protein, DNA, and RNA) and can be traced in vivo or in vitro. These labeled compound molecules can reflect their target in vivo or in vitro. The quantity or function of a biomolecule. Molecular probes usually consist of two parts: signal component and affinity component. The signal component refers to the contrast agent or marker part (such as radionuclide, fluorescein or paramagnetic molecule) that can generate imaging signals and can be detected by high-precision imaging technology. The affinity component is specifically bound to the imaging target Parts (such as ligands or antibodies, etc.).

Li Xubin et al. used chemical coupling method to couple superparamagnetic iron oxide particles (SPIO) with somatostatin analogue octreotide (OCT) to prepare specific binding to breast cancer cell epidermal growth hormone receptor (SSTR). The magnetic resonance molecular probe SPIO-OCT has a positive cell labeling rate of 96.15% (Peking University Journal of Medicine, Vol.41No.2Apr.2009).

Zhu Yuan et al. took breast cancer epidermal growth factor receptor 2 (HER2) as a target, prepared magnetic resonance (MR) molecular probes with paramagnetic gadolinium particles as carriers, and provided images for individualized treatment of breast cancer through MR targeted imaging academic basis. Materials and methods The HER2-targeted fluorescent probe FITC-LTVSPWY prepared by the research group was coupled with gadopentetic acid meglumine (Gd-DTPA) to obtain an MR-targeted probe (“breast cancer HER2-targeted molecular probe”) Preparation and preliminary study of in vitro MRI", "Chinese Journal of Medical Imaging", Volume 22, Issue 5, 2014).

Chinese patent document CN102399772A discloses fluorescently labeling plasmid DNA to obtain HER2, TOP2A, and AGTRE gene probes.

However, the currently published molecular probes for breast cancer generally have the following deficiencies: (1) The obtained molecular images cannot more comprehensively reflect the biological behavior of breast cancer. The rate is high, and the effect of radiotherapy and chemotherapy is not good. (2) The current molecular probes for breast cancer have their own shortcomings in imaging. Among them, although fluorescence imaging is non-invasive and highly sensitive, and can perform real-time multi-target imaging in vivo, it has the disadvantages of low spatial resolution and unclear anatomical background. In contrast, magnetic resonance imaging has extremely high spatial resolution and tissue resolution, is noninvasive, and has no radiation, but its sensitivity is relatively poor. (3) Most tumors such as breast cancer are polygenic diseases. On average, each tumor patient has 8-10 abnormal gene mutations related to the tumor. Currently, most of the single-target tumor or tumor stem cell targeted therapies are not effective.

With the successful isolation and identification of breast cancer stem cells (BCSC), and the study of their physiological functions and processes, it has been shown that there are some breast cancer cells with spontaneous renewal, multidirectional differentiation potential and high tumorigenic ability. Cell subsets of breast cancer stem cells. Breast cancer stem cells account for a small proportion (about 2-9% on average) in breast cancer tissues, and their absolute content in metastatic foci or metastatic lymph nodes is even less, so their detection is difficult. However, it is closely related to tumor invasion and metastasis, recurrence and treatment resistance ("Research progress of breast cancer stem cells", Liu Mingming et al., "Chinese Journal of Cancer", Vol. 23, No. 8, 2013). According to an article published in the February 13, 2012 issue of the journal Stem Cells, researchers at the University of California, San Francisco reported for the first time that radiation therapy kills tumor cells while also turning other cancer cells into resistant cells. Therapeutic breast cancer stem cells. And some researchers believe that breast cancer stem cells are the only source of breast cancer recurrence. However, although the isolation and identification of breast cancer stem cells, as well as the research on their role, have achieved many scientific research results, there have been no reports of molecular probes for targeted imaging of breast cancer stem cells, thus providing a method that can treat breast cancer Molecular probes for targeted imaging of stem cells can solve in vivo imaging and quantitative analysis of breast cancer stem cells, provide new methods for early diagnosis and efficacy evaluation of breast cancer, and provide new strategies for targeted therapy of breast cancer, which is of great significance.

Contents of the invention

In view of this, the purpose of the present invention is to provide a novel molecular probe for breast cancer, which provides a new method for early diagnosis and curative effect evaluation of breast cancer by targeting molecular imaging of breast cancer stem cells, and provides breast cancer stem cells and/or Targeted tumor therapy for breast cancer provides new strategies.

The technology adopted in the present invention is as follows: a molecular probe for breast cancer, which is composed of a signal component and an affinity component, which is characterized in that the affinity component is a component that specifically binds to the breast cancer stem cell target, and the signal component is composed of a close It consists of an infrared fluorescence signal unit and a magnetic resonance signal unit. Although the signal components of breast cancer molecular probes can be existing signal components in existing molecular imaging, the present invention takes into account the impact of radiation on the living body, and solves the problem of single fluorescence imaging and single magnetic resonance imaging in terms of resolution and Insufficient in sensitivity, the present invention prefers fluorescence-magnetic resonance dual-modal imaging, that is, the signal component is a signal component that couples fluorescent substances suitable for molecular probes and magnetic resonance imaging substances to form a dual-mode molecule probe.

Further, the affinity component is a ligand in specific surface markers CD44+, ESA+ or CD24- of breast cancer stem cells. Since there is no or very little CD44+ and ESA+ on other cell membranes, the selection of these two targets can make the targeting specificity of this probe high. CD44+ and/or ESA+ ligands are preferred, especially the CD44 monoclonal antibody CD44 _mAb and/or ESA monoclonal antibody ESA _mAb with better specificity, and the molecular imaging strategy of antigen-antibody specific binding is used.

Due to the relatively weak ability of ordinary fluorescence to penetrate living tissues, the present invention preferably uses near-infrared fluorescent materials with a wavelength of 700nm-1200nm as signal components. The autofluorescence itself is weak, thereby avoiding background interference and improving detection sensitivity. Near-infrared fluorescent components can be organic fluorescent dyes, preferably quantum dots (quantum dots, QDs) with excellent optical properties as fluorescent materials, QDs are composed of II-VI or III-V or I-III-VI Composed of elements, semiconductor nanocrystals with a diameter of about 1nm-10nm and capable of receiving excitation light to generate fluorescence, QDs overcome the larger defects of organic dye molecules (narrow excitation spectrum, emission spectrum) commonly used in fluorescent labeling imaging of cells and biomolecules. Very wide and asymmetrical; the large overlap between the fluorescence spectrum peaks limits the number of fluorescent probes that can be applied at the same time; poor photostability, prone to photobleaching and photolysis, and photolysis products often have a killing effect on biomolecules, etc.), with The excitation spectrum is wide and continuously distributed, and various wavelengths of light can be used for excitation; the emission spectrum is narrow, symmetrical and non-overlapping; good photostability, rich and adjustable colors and other advantages. Among them, near-infrared QDs with a wavelength of 650nm-900nm are relatively easy to synthesize, can withstand multiple excitations and light emissions, have long-lasting photochemical stability, and can be used for long-term continuous imaging observations in vivo and in vitro. At the same time, since the fluorescence wavelength of near-infrared QDs can be precisely adjusted according to the particle size of quantum dots, they are the best probes for visually distinguishing different targets.

Furthermore, in a preferred embodiment of the present invention, QDs with different particle sizes are labeled with different targets, which can display different colors of fluorescence under the same excitation light, thereby realizing multi-target molecular imaging.

Among the existing QDs, studies have found that cadmium-containing QDs (such as CdTe) have mild toxicity. In order to improve the safety of molecular probes, non-cadmium near-infrared QDs, such as InP and CuInS, are preferred in the present invention. The QDs of the present invention preferably adopt Zn-Cu-In-S nuclear quantum dots, and most preferably, the nuclear quantum dots can also be coated with a surface inorganic layer (such as ZnS) to form core-shell near-infrared QDs, which can improve the core-shell Fluorescence efficiency and photochemical stability of quantum dots.

For MRI probe signaling components, superparamagnetic iron oxide (SPIO) and paramagnetic gadolinium (Gd ³⁺ ) can be used. The inventors found in this study that SPIO nanoparticles have strong light absorption and have a strong quenching effect on the fluorescence of QDs coupled with it, which affects the in vivo fluorescence imaging effect of QDs. Therefore, the present invention preferably uses paramagnetic gadolinium (Gd ³⁺ ) as the functional unit of the MR imaging signal of the dual-mode molecular probe.

As a preferred embodiment of the present invention, the present invention assembles two functional units of Gd ³⁺ and near-infrared QDs into complementary near-infrared non-cadmium quantum dot nanoparticles (paramagnetic QDs, pQDs) with high fluorescence efficiency and good paramagnetism As a signal component of a bimodal probe. At the same time, near-infrared non-cadmium QDs with different particle sizes (corresponding to different emission wavelengths) were selected to be combined with Gd ³⁺ ) to construct dual-modal molecular probes to label different targets to achieve multi-target molecular dual-modal imaging.

In order to realize multi-targeted molecular imaging, the preferred affinity assembly of the present invention is based on the ligands of specific surface markers CD44+ and ESA+, and two monoclonal antibodies of CD44 _mAb and ESA _mAb are coupled with near-infrared pQDs of different wavelengths respectively , forming two kinds of bimodal molecular probes targeted by BCSC, the near-infrared pQDS of different wavelengths selects two wavelengths, such as 700nm and 800nm, which are respectively expressed as pQD700 and pQD800, correspondingly, the two bimodal molecular probes of the present invention The needles are pQD ₇₀₀ -CD44 _mAb and pQD ₈₀₀ -ESA _mAb , or pQD ₈₀₀ -CD44 _mAb and pQD ₇₀₀ -ESA _mAb .

For dual-mode probes, the magnetic resonance imaging material needs to be coupled to the surface of the fluorescent material before coupling. For example, Gd ^{3+ is chelated on the surface of nano-QDs by modifying the Gd 3+} chelating agent DOTA on the surface of QDs before coupling. In this method, the Gd3+ chelating agent DOTA is modified on the surface of QDs to provide high-density ^Gd3+ binding sites and reduce the Gd3 ⁺ rotation to increase its relaxation rate and improve sensitivity.

In a preferred embodiment of the present invention, in order to avoid capture by the reticuloendothelial system, increase the time for the probe to circulate in the body, eliminate non-specific adsorption at non-focus sites, reduce background signals and false positives, and use Polymer materials such as polyethylene glycol (PEG), acrylic resin (PAA) or polyhydric alcohols are used to modify the surface of pQDs.

The present invention also provides a preparation method of the breast cancer molecular probe: coupling the fluorescence/magnetic resonance dual signal functional unit with the specific surface marker of breast cancer stem cells by chemical covalent coupling method, and then purifying.

Technical effect and significance of the present invention are embodied in the following aspects:

(1) Different from the existing breast cancer molecular probes, the present invention is a molecular probe that specifically binds to multiple targets of breast cancer stem cells, through which the molecular probe can solve the in vivo detection and quantitative analysis of breast cancer stem cells , providing the basis for new strategies for imaging diagnosis of solid tumor stem cells and evaluating the efficacy of targeted therapy, providing a "new model" for early diagnosis and grading of tumors, providing accurate information and evaluation methods for tumor treatment, and laying a solid foundation for further solving the problems of recurrence and metastasis Basics of diagnostic information.

(2) The use of dual-mode molecular probes enables fluorescence and MR imaging to maximize their strengths and avoid weaknesses and complement each other's advantages, which can double the number and density of signal components on a single BCSC, improve the sensitivity and resolution of molecular probes, and be able to detect Lower levels or even trace amounts of BCSC.

(3) Using multi-targeting technology combined with dual modes, important information such as the location, content and distribution of BCSCs in the living body can be obtained, and important information of BCSCs in sentinel lymph nodes can be detected, which can provide information for the selection of surgical methods and radiotherapy planning, etc. Accurate information provides the basis for personalized treatment. In addition, early non-invasive evaluation of treatment efficacy based on BCSC inactivation and residual status, timely adjustment and strengthening of BCSC treatment can more effectively prevent breast cancer recurrence and metastasis.

Description of drawings

Figure 1 is a TEM image of quantum dots.

Fig. 2 is the fluorescence emission spectrum of Zn-Cu-In-S and its Zn-Cu-In-S/ZnS core-shell quantum dots. The inset is the fluorescence efficiency of Zn-Cu-In-S/ZnS core-shell quantum dots at different emission wavelengths.

Fig. 3 is the fluorescence decay diagram of Zn-Cu-In-S and Zn-Cu-In-S/ZnS core-shell quantum dots.

ZCIS in Figures 2 and 3 is the abbreviation of Zn-Cu-In-S quantum dots.

Figure 4 is the in vivo fluorescence imaging of hydrophilic non-cadmium Zn-Cu-In-S/ZnS core-shell quantum dots.

Figure 5a is the T1 measurement chart of the control group (QDs modified by PAA but without chelated Gd3+);

Figure 5b is the T1 measurement of the experimental group (pQDs, that is, QDs modified by PAA and chelated Gd3+);

Figure 5c shows T1-weighted imaging (TR=100ms, TE=3.1ms), where I is the deionized water signal, II is the QDs signal of the unchelated Gd3+ probe; III is the pQDs signal.

Detailed ways

In the following, the present invention will be further described by taking the dual-mode molecular probe as an example in conjunction with the best embodiments, so as to facilitate the understanding of the present invention.

1. Preparation of molecular probes

1.1 Preparation of paramagnetic quantum dots

1.1.1 Preparation of lipophilic quantum dots

In this example, Zn-Cu-In-S nuclear quantum dots with good monodispersity and high crystallinity were prepared by using group I-III-VI elements (such as copper, indium, sulfur, zinc, etc.) through a high-temperature oil phase method. In order to obtain more photostable quantum dots, the core quantum dots are then coated with a surface inorganic layer (such as ZnS) to improve the fluorescence efficiency and photochemical stability of the core-shell quantum dots. When designing the composition and structure of the shell, it is necessary to comprehensively consider the lattice matching parameters of the shell and the nuclear quantum dots, as well as the band gap width of the shell material, and the impact of the core-shell quantum dots with a reasonable structure and composition on the external physical and chemical environment. It has strong resistance and can well maintain the original fluorescence efficiency during the hydrophilic modification process. The specific synthesis process is as follows:

Preparation process of Zn-Cu-In-S nuclear quantum dots: Weigh copper acetate (0.1mmol), indium acetate (0.2mmol), zinc acetate (0.1mmol), measure 0.5mL oleic acid, mix and dissolve them in 10mL In octadecene. The entire mixed system was evacuated for 30 minutes, then argon was introduced, and then heated to 120 degrees Celsius until the mixed system became optically transparent, and then 1.0 mL of n-dodecyl mercaptan was added. The reaction was continued to heat up to 200°C, and then 0.3mmol of sulfur source (9.7mg dissolved in 0.5mL oleylamine and 1.0mL octadecene) was added, and the whole system was maintained at 200°C for 2 hours.

The preparation process of Zn-Cu-In-S/ZnS core-shell quantum dots: first configure the zinc precursor of the shell layer, that is, weigh 0.1 mmol of zinc acetate and dissolve it in the volume ratio (1/4) of oleylamine/ octadecene solution. Take the 4.0mL Zn-Cu-In-S nuclear quantum dots obtained above, add 5mL octadecene and 1mL n-dodecylmercaptan, heat up to 220 degrees Celsius after 30 minutes with argon gas, and then inject the pre-configured For a good zinc precursor, maintain the system temperature at 220 degrees Celsius, cool down to room temperature after 1 hour of reaction, add absolute ethanol, and centrifugally purify to obtain Zn-Cu-In-S/ZnS core-shell quantum dots.

The morphology, structure, particle size, and spectrum of quantum dots were characterized by high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), photoelectron spectroscopy, particle size analyzer, fluorescence, and UV-visible spectrophotometer.

It can be seen from Figure 1 that the size of quantum dots is about 4 nanometers, and the size is uniform.

It can be seen from Figures 2 and 3 that the fluorescence efficiency of core-shell quantum dots wrapped with ZnS is several times higher than that of unwrapped nuclear quantum dots, and the decay speed is significantly reduced.

1.1.2 Hydrophilic modification of quantum dots

Preparation of amphiphilic polymer: poly(tert-butyl acrylate ethyl acrylate methacrylate) triblock copolymer and octylamine were mixed and dissolved in DMF at a molar ratio of 1:40, and the coupling agent EDC was added to react for 12 hours , the resulting mixture was purified by dialysis, freeze-dried and stored for future use.

Take an appropriate amount of lipophilic quantum dot powder and amphiphilic triblock polymer dissolved in chloroform/ethanol mixed solution, and stir for several hours to remove the chloroform organic solvent. Then add an appropriate amount of PBS buffer solution and ultrasonically disperse for 3 minutes. The resulting solution was passed through a 0.22um membrane to remove a large amount of unbound macromolecules, and the solution became optically transparent after passing through the membrane. The obtained solution is passed through a gel chromatographic column (G200) to further remove unbound macromolecules, and finally obtain purified hydrophilic quantum dots.

1.1.3 Preparation of paramagnetic quantum dots

The hydrophilic quantum dots were coupled with DOTA-NH ₂ molecules, and GdCl ₃ was added for Gd ³⁺ chelation to obtain paramagnetic quantum dots. The specific preparation process is as follows: according to the molar ratio of 1:100:4000, hydrophilic quantum dots, DOTA-NH ₂ and carbodiimide hydrochloride were mixed, reacted at room temperature for 2 hours, and purified by ultracentrifugation to obtain QDs-DOTA. On the basis of the obtained QDs-DOTA, Gd ³⁺ was added, chelated at room temperature for 4 hours, and then purified by ultracentrifugation to obtain paramagnetic quantum dots.

According to the different particle sizes of nanometer quantum dots, pQD700 and pQD800 were obtained respectively.

In order to investigate the MR imaging properties of the paramagnetic quantum dots of the present invention, MR imaging experiments were carried out. As shown in Figure 5, Figure 5a is the T1 measurement of the control group (QDs modified by PAA but without chelated Gd3+). Figure 5b is the T1 measurement of the experimental group (pQDs, ie QDs modified with PAA and chelating Gd3+). After comparing the two, it was found that the T1 time of pQDs was significantly shortened, and the relaxation rate was significantly increased. Figure 5c is T1-weighted imaging (TR=100ms, TE=3.1ms) showing that the signal intensity of pQDs (III) is significantly higher than that of deionized water (I) and QDs of unchelated Gd3+ probes (II).

1.2 Preparation of paramagnetic quantum dots targeting breast cancer stem cells

Paramagnetic quantum dots were coupled with monoclonal antibody molecules CD44 _mAb and ESA _mAb to obtain paramagnetic quantum dots that can specifically recognize breast cancer stem cells. The specific preparation process is as follows: the paramagnetic quantum dots, antibodies and carbodiimide hydrochloride are mixed according to the molar ratio of 1:10:4000, and reacted at room temperature for 2 hours. The paramagnetic quantum dots pQD700-CD44 _mAb and pQD800-ESA _mAb targeting breast cancer stem cells were purified by ultracentrifugation.

2. In vivo test

In order to verify the effect and safety of the molecular probe of the present invention for BCSC multi-target dual-modal imaging, the following experiments were carried out:

2.1 In vivo fluorescence imaging based on hydrophilic non-cadmium Zn-Cu-In-S/ZnS core-shell quantum dots

The hydrophilic Zn-Cu-In-S/ZnS core-shell quantum dots were first tested for cytotoxicity, and the results showed that the prepared hydrophilic Zn-Cu-In-S/ZnS core-shell quantum dots had good biological phase Capacitance. The in vivo fluorescence imaging was then studied, and the results are shown in Figure 4. The results showed that the prepared near-infrared non-cadmium Zn-Cu-In-S/ZnS core-shell quantum dots could perform in vivo fluorescence imaging.

2.2 Safety experiment

Molecular probes with different concentrations are configured, and the cytotoxic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test shows that the molecular probe of the present invention has good biological safety. Calculated by the Cu content, the Cu ion content is 2 μM, after 96 hours of co-incubation, the cell survival rate is above 95%.

2.3 Imaging sensitivity experiment

For cells labeled with dual-mode molecular probes but with different numbers of BCSCs (the numbers of BCSCs were 1, 5, 1×10 ¹ , 50, 1×10 ² , 1×10 ³ , 1×10 ⁴ , 1× 10 ⁵ ) Ep tubes were subjected to fluorescence imaging and MR T1 imaging respectively, and the minimum number of cells that could be detected by fluorescence imaging and MR T1 imaging were observed and compared. Experimental data show that the minimum number of resolvable imaging cells in fluorescence imaging mode is 5; the minimum number of resolvable imaging cells in MR T1 imaging mode is 50.

2.4 Target-specific experiments

Using CD44-/ESA- breast cancer cells as a control, BCSCs were co-cultured with pQD700-CD44mAb dual-modal molecular probe and pQD700 respectively, after washing, BCSCs and CD44-/ESA- breast cancer cells were observed under a fluorescence microscope The fluorescent signals of the probes were then subjected to MR T1W imaging to evaluate whether the fluorescent signals were consistent with the magnetic resonance signals, and to judge the targeting performance of the probe. The above experiments were also performed on the pQD800-ESAmAb dual-modal molecular probe. Through cell-targeted imaging experiments, the dual-mode molecular probe of the present invention has excellent targeting detection effect.

Claims (10)

1. a breast cancer molecular probe, is made up of signal component and affine assembly, it is characterized in that its affine assembly is the assembly to breast carcinoma stem cell target spot specific binding; Signal component is made up of near-infrared fluorescent signal element and magnetic resonance signal unit.

2. breast cancer molecular probe as claimed in claim 1, is characterized in that: described affine assembly is the part of specific surfaces mark CD44+ and/or ESA+ of breast carcinoma stem cell.

3. breast cancer molecular probe as claimed in claim 1, is characterized in that: described affine assembly is CD44 monoclonal antibody CD44 _mAband/or ESA monoclonal antibody ESA _mAb.

4. breast cancer molecular probe as claimed in claim 3, is characterized in that: described fluorescence signal unit is near-infrared quantum dots.

5. breast cancer molecular probe as claimed in claim 4, is characterized in that: described near-infrared quantum dots is the non-cadmium quantum dot of Zn-Cu-In-S.

6. breast cancer molecular probe as claimed in claim 4, is characterized in that: described near-infrared quantum dots is the nuclear shell structure quantum point including ZnS outside Zn-Cu-In-S core quantum dot.

7. breast cancer molecular probe as claimed in claim 4, is characterized in that: described magnetic resonance signal material is paramagnetism gadolinium.

8. breast cancer molecular probe as claimed in claim 5, it is characterized in that: described probe is many targets bimodal molecular probe, is pQD ₁-CD44 _mAband pQD ₂-ESA _mAb, pQD ₁with pQD ₂at near-infrared band but wavelength is different.

9. the manufacture method of described breast cancer molecular probe one of in claim 1 to 8, is characterized in that: adopt chemical covalent coupling method by the specific surfaces mark monoclonal antibody coupling of semiotic function unit and breast carcinoma stem cell, then through purifying.

10. manufacture method as claimed in claim 9, is characterized in that: also carry out finishing with polyglycol, acryl resin or polyhydroxy-alcohol to pQDs.