量子点荧光成像在肿瘤诊治应用研究进展

量子点(quantum dot,QD),又名“人造原子”,是一种用原子人工合成的纳米材料,其在紫外光激发下可发出不同波长的荧光.QD直径小、发出的荧光峰窄、荧光亮度持久,具有取代有机染料用于肿瘤诊治的潜能.总结近年QD在荧光成像及肿瘤诊治方面的研究进展.方法 应用PubMed及中国知网(CNKI)数据库检索系统,以“quantum dots,fluorescence imaging,oncotherapy,tumor therapy,量子点,肿瘤治疗,肿诊断,荧光成像”为关键词,检索2005-01-2016-03的相关文献391篇.纳入标准:(1)可用于生物荧光成像的低毒化QD;(2)靶向识别的功能化QD.根据纳入标准最终分析31篇文献.结果 低毒化QD在细胞成像、活体靶向成像、淋巴结成像、活体肿瘤成像、活体肿瘤细胞示踪等荧光成像方面的研究,使正确定位淋巴结、利用QD深成像能力发现极小的肿瘤、乃至彻底切除肿瘤组织成为可能.功能化QD在肿瘤早期诊断和治疗上发挥更大作用,QD的药物靶向和QD介导的光热治疗肿瘤也有很好的临床应用前景.结论 QD在生物荧光成像及肿瘤诊疗中的潜力巨大,具有进一步探索开发利用于临床的价值.     

量子点标记技术在肿瘤诊断和治疗中的应用

量子点(QD)是一种荧光标记物,其研究领域涉及生物医学成像、疾病诊断和细胞生物学.QD独特的光学和电子特性使其用于肿瘤标记的检测和前哨淋巴结(SLN)的定位.在肿瘤的光化学疗法中,将QD与光敏剂相连可使图像更加清晰精确,并能够检测深部组织的肿瘤.将QD与治疗剂连接用于药物释放系统能够更加准确地定位肿瘤组织.基于以上优点,QD将有希望应用于肿瘤的临床诊断和治疗.     

量子点探针技术在肿瘤侵袭转移研究中的应用

量子点(QD)因其独特的光学和电子特性,已经成为新一类纳米探针.越来越多的研究证实,QD探针在分子成像和肿瘤检测方面具有显著优势,可用于肿瘤侵袭转移的研究.通过生物功能化特异性标记肿瘤侵袭转移过程中的关键分子,实现侵袭转移过程的可视化,进一步阐明肿瘤侵袭转移的分子机制.     

活体动物体内成像技术及其在生物医学中的应用进展

活体动物体内成像是近年来新兴的检测活体动物体内基因表达及细胞活动的光学成像技术，具有操作简便，直观性强的特点。这项技术包括生物发光成像和荧光成像，采用报告基因产生的生物发光、荧光蛋白质或染料产生的荧光作为体内生物光源，与新型冷CCD成像相结合，实时探测活体动物体内生理或病理条件下的细胞和分子事件。本文简要综述了活体动物体内成像技术的原理、应用领域及发展前景。     

在量子点探针介导下共聚焦显微镜检测肾癌组织HSP70的表达意义

本研究探讨新型纳米荧光材料量子点在免疫荧光分析法中的应用价值。我们分别利用量子点QD605或异硫氰酸荧光素(FITC)作为免疫荧光分析中的标记探针,通过激光扫描共聚焦显微镜观察肾细胞癌组织中HSP70的表达,并比较所得图像之间的成像差异性和成像稳定性。在所有的肾细胞癌组织样本中,量子点QD605标记的图像信号都要比常用的荧光染料FITC标记信号发光强度更高,更有特异性,在激光连续照射1 h下QD605标记的图像未有明显的荧光漂白现象,表现出极佳的发光稳定性。因此以新型荧光材料量子点为标记探针,用免疫荧光分析法检测病理组织切片中的蛋白标记物更有特异性,有潜力代替传统的有机荧光染料应用于生物大分子的荧光标记和光学成像。     

荧光蛋白活体成像系统在肿瘤研究中的应用

活体动物体内光学成像作为一项新兴的分子、基因表达的分析检测技术,已成功应用于生命科学、生物医学、分子生物学和药物研发等领域。荧光技术介导的活体动物光学成像在活体肿瘤研究中的应用已日趋深入,包括应用荧光蛋白对肿瘤内环境、肿瘤转移过程、休眠肿瘤细胞以及肿瘤治疗应答成像,本文对这些研究进展作一综述。     

量子点在肿瘤诊断中的研究进展

 新型纳米荧光量子点（QD）具有优良的光学特性，在临床肿瘤研究中的应用日益广泛。将其与各种靶向配体结合，已成功用于早期检测原发瘤、肿瘤血管发生和转移瘤，为肿瘤的早期诊断研究开辟了新领域。     

人肺癌裸小鼠模型活体成像的动态观察

目的:建立稳定表达绿色荧光蛋白的人肺癌细胞系,并探讨小动物活体荧光成像系统在肺癌皮下移植瘤模型中的应用.方法:用慢病毒转染的方法建立表达绿色荧光蛋白的人肺癌细胞系NCI-H460-GFP,接种至裸小鼠体内建立皮下移植瘤模型,通过小动物活体成像系统连续5周观察肿瘤在小鼠皮下的动态生长情况.结果:建立了转染率接近100%的人肺癌NCI-H460-GFP细胞系,在体外及裸小鼠体内均能够长期稳定表达绿色荧光蛋白.活体荧光成像观察发现,1～4周随着肿瘤体积逐渐增大,平均荧光光子数逐渐增加;5周时随着肿瘤出现明显坏死,平均荧光光子数呈现下降趋势.结论:稳定表达绿色荧光蛋白的NCI-H460-GFP细胞系及其动物模型可以为肺癌研究提供理想的实验材料,应用小动物活体成像系统能够客观定量评价肿瘤在动物体内的生长情况.     

近红外荧光探针和成像系统临床转化应用的初步探索

目的 围绕近红外荧光成像探针、成像系统和临床转化评价开展探索,为进一步研发和应用提供依据.方法 应用FDA批准的吲哚菁绿(ICG)评价近红外成像在复杂创面伤情评估中的价值,应用课题组前期发现的具有肿瘤靶向特性的近红外染料IR-780评价其在外科手术切除肿瘤组织及淋巴结成像中的意义.通过对IR-780的动物体内成像实验对...     

EGFP标记的人肺癌裸鼠原位移植模型的建立

背景与目的 小鼠活体分子成像模型可以连续实时监测活体肿瘤的变化.本研究拟通过外科原位移植法建立表达绿色荧光蛋白的肺癌裸鼠原位移植模型并探讨其肿瘤生物学特性,从而建立一个良好的肺癌动物实验研究平台.方法 利用逆转录病毒转染法将增强型绿色荧光蛋白基因导人人肺癌大细胞系NCI-H460,采用外科原位移植法建立肺癌原位移植模型.定期通过小动物活体荧光成像系统观察肿瘤生长,利用相关性检验分析荧光面积和肿瘤体积之间的相关关系,并观察原位移植术后裸鼠的生存期和肿瘤转移情况.结果 模型建立后1周通过皮瓣在荧光体视镜下可观察到肺部肿瘤的绿色荧光,成瘤率为100%.荷瘤裸小鼠平均生存期为34.2天.解剖裸鼠观察到肿瘤侵及对侧肺、纵隔及肺门淋巴结、胸膜和膈肌,转移率分别为87.596、75%、25%和12.5%.肿瘤体积和荧光面积具有相关性(r=0.873,P=0.001).结论 外科原位移植法建立的表达EGFP的裸鼠肺癌原位模型是肺癌临床前研究的理想的实验工具.应用小动物活体荧光成像系统能够定量客观评价肿瘤在动物体内的生长、侵袭和转移,该模型可应用于肺癌的基础研究和新药开发.     

Quantum dot labeling and tracking of human leukemic, bone marrow and cord blood cells

Quantum dots (QDs) are nanometer scale fluorescent semiconductors that are increasingly used as labeling tools in biological research. These nanoparticles have physical properties, such as high quantum yield and resistance to photobleaching, that make them attractive molecular probes for tracking hematologic cells. Here, we show that QDs attached to a transporter protein effectively label all hematologic cells tested, including cell lines and malignant and non-malignant patient samples. We demonstrate that dividing cells can be tracked through at least four cell divisions. In leukemic cell lines, some cells remain labeled for 2 weeks. We show that QDs can be used to follow cells as they differentiate. QDs are seen in monocyte-like and neutrophil-like progeny of labeled HL-60 myeloblasts exposed to Vitamin D analogues and DMSO, respectively. QDs are also observed in monocytes generated from labeled CD34+ cells. In addition, QDs attached to streptavidin can target cells with differing cell surface markers, including CD33. In summary, QDs have the ability to bind to specific cells of interest, be taken up by a diverse range of hematologic cells, and followed through many divisions and through differentiation. These results establish QDs as extremely useful molecular imaging tools for the study of hematologic cells.     

Quantum dots hold promise for early cancer imaging and detection

Despite all major breakthroughs in recent years of research concerning the complex events that lead to cancer expression and metastasis, we are not yet able to effectively treat cancer that has spread to vital organs. The various clinical phases originating from cancer diagnosis through treatment and prognosis require a comprehensive understanding of these events, to utilise pre-symptomatic, minimally invasive and targeted cancer management techniques. Current imaging modalities such as ultrasound, computed tomography, magnetic resonance imaging and gamma scintigraphy facilitate the pre-operative study of tumours, but they have been rendered unable to visualise cancer in early stages, due to their intrinsic limitations. The semiconductor nanocrystal quantum dots (QDs) have excellent photo-physical properties, and the QDs-based probes have achieved encouraging developments in cellular (in vitro) and in vivo molecular imaging. However, the same unique physical and chemical properties which renowned QDs attractive may be associated with their potentially catastrophic effects on living cells and tissues. There are critical issues that need to be further examined to properly assess the risks associated with the manufacturing and use of QDs in cancer management. In this review, we aim to describe the current utilisation of QDs as well as their future prospective to decipher and confront cancer.     

In vivo single molecular fluorescence imaging for analysis of pharmacokinetics

Nano-materials are expected for research on molecular imaging of pharmacokinetics. We measured in vivo migration of CdSe nano-particles(Quantum Dots(QDs))conjugated with monoclonal anti-HER2 antibody(trastuzumab)in tumor vessel to breast cancer cells. We established a high resolution in vivo 3D microscopic system for a novel imaging method at single molecular level. The HER2 protein expressed in cancer cells and its dynamics were visualized by QDs in vivo at the spatial resolution of 30 nm. It suggests future utilization of the system in medical applications to improve the drug delivery system to target primary and metastatic tumors for made-to-order treatment. Future innovation in cancer imaging by nano-technology and novel measurement technology will provide great improvement, not only in the clinical field, but also in basic medical science. Advances in nano-biotechnology have great potential to improve prevention, diagnosis and treatment of human disease.     

基于适配子的分子探针在肿瘤分子影像学中的应用

理想的分子影像探针应具有一定的特异性、敏感性、安全性。适配子是可与靶分子高特异性和高亲和力结合的单链 DNA 或 RNA 分子,具有靶分子广泛、分子小、易生产和修饰、免疫原性低、渗透性强等特点,是一种新型的分子影像探针。目前基于适配子的肿瘤分子影像学研究越来越多,为肿瘤的诊断和治疗提供了新的技术和工具。     

Optical biopsy of cancer: nanotechnological aspects

Naturally occurring differences in the optical properties of normal and cancerous tissue have been exploited frequently in optical detection systems. However, optical biopsy of cancer can be improved by using targeted, optically active and bright contrast agents to enhance the optical signal from disease-specific molecular markers. Nanotechnology has advanced greatly in recent years and can be applied to variety of biomedical research areas, as well as optical biopsy in clinical settings. Quantum dots (QDs) are stable, bright fluorophores that, under ideal conditions, can have high quantum yields, narrow fluorescence emission bands, high absorbency, very large effective Stokes shifts, high resistance to photobleaching, and can provide excitation of several different emission colours using a single wavelength for excitation. Optically efficient, cancer specific QDs provide a new tool to enable non-invasive visualization of disease-specific molecular and tissue changes with subcellular spatial resolution. Nanotechnology is in a unique position to transform cancer diagnostics and to produce a new generation of fluorescent markers and medical imaging techniques with higher sensitivity and precision of recognition.     

High correlation of whole-body red fluorescent protein imaging and magnetic resonance imaging on an orthotopic model of pancreatic cancer

We have developed genetically fluorescent orthotopic models of human pancreatic cancer. In these models, noninvasive fluorescent protein imaging (FPI) of internal primary tumors and metastatic deposits has been carried out. Whole-body tumor images are easily and inexpensively obtained using FPI, permitting both detection and quantification of tumor load. In this study, we simultaneously compared single mice with a highly fluorescent, red fluorescent protein-expressing orthotopic pancreatic cancer xenografts with both FPI and high-resolution magnetic resonance imaging (MRI). Images were acquired at multiple time points after tumor implantation in the pancreas. Indwelling pancreatic primary tumors and metastatic foci were detected by both FPI and MRI. Moreover, a strong correlation existed between images taken with these two technologies. FPI permitted rapid, high-throughput imaging without the need for either anesthesia or contrast agents. Both FPI and MRI enabled accurate imaging of tumor growth and metastasis, although MRI enabled tissue structure to be visualized as well. FPI has high resolution and is exceedingly rapid with instant image capture. We suggest a complimentary role for these two imaging modalities.     

Management of SPN in France. Pathways for definitive diagnosis of solitary pulmonary nodule: a multicentre study in 18 French districts

Background

Breast cancer is the first cause of cancer death among women and its incidence doubled in the last two decades. Several approaches for the treatment of these cancers have been developed. The axillary lymph node dissection (ALND) leads to numerous morbidity complications and is now advantageously replaced by the dissection and the biopsy of the sentinel lymph node. Although this approach has strong advantages, it has its own limitations which are manipulation of radioactive products and possible anaphylactic reactions to the dye. As recently proposed, these limitations could in principle be by-passed if semiconductor nanoparticles (quantum dots or QDs) were used as fluorescent contrast agents for the in vivo imaging of SLN. QDs are fluorescent nanoparticles with unique optical properties like strong resistance to photobleaching, size dependent emission wavelength, large molar extinction coefficient, and good quantum yield.

Methods

CdSe/ZnS core/shell QDs emitting around 655 nm were used in our studies. 20 μL of 1 μM (20 pmol) QDs solution were injected subcutaneously in the anterior paw of healthy nude mice and the axillary lymph node (ALN) was identified visually after injection of a blue dye. In vivo fluorescence spectroscopy was performed on ALN before the mice were sacrificed at 5, 15, 30, 60 min and 24 h after QDs injection. ALN and all other organs were removed, cryosectioned and observed in fluorescence microscopy. The organs were then chemically made soluble to extract QDs. Plasmatic, urinary and fecal fluorescence levels were measured.

Results

QDs were detected in ALN as soon as 5 min and up to 24 h after the injection. The maximum amount of QDs in the ALN was detected 60 min after the injection and corresponds to 2.42% of the injected dose. Most of the injected QDs remained at the injection site. No QDs were detected in other tissues, plasma, urine and feces.

Conclusion

Effective and rapid (few minutes) detection of sentinel lymph node using fluorescent imaging of quantum dots was demonstrated. This work was done using very low doses of injected QDs and the detection was done using a minimally invasive method.     

Novel functional magnetic resonance imaging biomarkers for assessing response to therapy in hepatocellular carcinoma

The established and adapted image biomarkers based on size for tumor burden measurement continue to be applied to hepatocellular carcinoma (HCC) as size measurement can easily be used in clinical practice. However, in the setting of novel targeted therapies and liver directed treatments, simple tumor anatomical changes can be less informative and usually appear later than biological changes. Functional magnetic resonance imaging (MRI) has a potential to be a promising technique for assessment of HCC response to therapy. In this review, we discuss various functional MRI biomarkers that play an increasingly important role in evaluation of HCC response after treatment.