基于微流控技术的循环肿瘤细胞分析研究进展

癌症的精准诊疗是提高癌症患者生存率和生存质量的重要手段.液体活检通过采用非侵入采样方式,获取肿瘤病人全面、准确、实时的基因组、转录组及蛋白组等生物学信息,是一种新兴的癌症诊断技术,对癌症精确诊断、个体化治疗、预后评估等方面具有重要意义.循环肿瘤细胞(CTC)是一种从实体瘤组织脱落进入外周血的肿瘤细胞,因能提供完整的细胞生物学信息,是最具应用前景的液体活检靶标.然而, CTC的数量极其稀少、异质性强、所处外周血环境复杂等特点,给CTC的富集和分析带来了巨大的技术挑战.本文将总结本课题组近年来发展的基于CTC液体活检策略,着重讨论在CTC识别、富集与单细胞分析等方面的研究进展.     

肿瘤外泌体的分析检测

肿瘤外泌体是由肿瘤细胞释放到细胞外环境的微小囊泡,其直径约为30~150 nm,主要存在于血液、尿液、唾液等多种体液中,是早期肿瘤诊断的标志物之一。肿瘤外泌体具有较好的稳定性且含量丰富,因此是液体活检标志物的研究热点。肿瘤外泌体携带母细胞相关的蛋白、脂质和核酸等生物活性物质,为生物检测提供了多种特征标志物。本文就肿瘤外泌体的生成、分离、表征及分析检测进行了论述,重点讨论了肿瘤外泌体检测的研究进展。     

新型循环肿瘤细胞富集及精准分析方法的研究进展

外周血中循环肿瘤细胞(Circulating tumor cell,CTC)是癌症转移的重要媒介,可提供完整的细胞生物学信息,被认为是目前最具有应用前景的液体活检靶标之一.然而,全血中CTC具有含量极低、基质环境复杂、自身异质性强等特点,因此,开发高效的富集分离及检测方法是实现CTC精准分析的关键.目前已报道的CTC分...     

核酸适配体功能化磁珠在转移性大肠癌细胞富集中的应用

基于核酸适配体对转移性肿瘤细胞高亲和力和高特异性的靶向识别功能,采用生物素-链霉亲和素的交联方法,将核酸适配体W3修饰在磁珠微球上,形成特异性识别转移性大肠癌细胞的功能化磁珠(W3-beads),实现对转移性大肠癌细胞的靶向捕获和富集.核酸适配体W3在室温条件和人血浆环境下可保持对靶细胞的特异性结合能力,制备的修饰磁珠...     

基于适体识别及杂交链式反应放大信号检测细胞外囊泡

利用在细胞外囊泡表面高度表达的特定蛋白作为靶标识别细胞外囊泡,可用于检测癌症相关的细胞外囊泡。基于此,提出了一种同时捕获和定量细胞外囊泡的检测方法。将核酸适配体修饰在单分散聚苯乙烯微球上,可特异性捕获细胞外囊泡;通过适配体触发的杂交链式反应放大荧光信号,可提高检测灵敏度。优化条件下,将本方法用于检测MCF-7细胞衍生的细胞外囊泡,体系的荧光强度变化值与细胞外囊泡浓度的对数在1.7×10³～1.7×10⁶ particle/μL范围内呈良好的线性关系,相关系数(R²)为0.9984,相对标准偏差(RSD)为1.6%。     

基于聚苯胺纳米纤维复合膜界面构建电化学细胞传感器及其对癌细胞的识别检测

合成了聚苯胺纳米纤维,直径在50～70 nm之间;基于静电作用构建聚苯胺纳米纤维-纳米金复合膜界面,并在此界面上层层组装修饰叶酸分子,构建叶酸功能化传感界面,基于叶酸分子与癌细胞表面过量表达的叶酸受体之间的特异性识别作用,将此传感界面应用于对癌细胞的识别和捕获。结果表明:叶酸功能化传感界面能够特异性识别和捕获叶酸受体过量表达的癌细胞。采用电化学阻抗技术,以HeLa细胞为模型,应用于对癌细胞的识别和检测,细胞在1.0×104～6.4×106cells/mL浓度范围内与阻抗变化值ΔRct呈良好的线性关系;检出限为2000 cells/mL。本方法简单、快速灵敏、重现性和稳定性良好;制备的传感器可以再生使用。     

贵金属纳米颗粒杂化囊泡的制备及拉曼增强效果研究

以超支化聚合物囊泡为模板制备了贵金属纳米颗粒表面功能化的杂化囊泡.模板囊泡通过多巴胺修饰的超支化聚醚HSP-DA在水中自组装形成.在碱性条件下,囊泡表面的多巴胺自聚合生成聚多巴胺,实现囊泡的交联.由于聚多巴胺具有强黏附特性,因此可以将HSP-PDA交联囊泡分别与Au纳米溶胶、Ag纳米溶胶直接混合,得到Au纳米颗粒或Ag纳米颗粒功能化的杂化囊泡.分别测定了2种杂化囊泡的拉曼光谱,发现杂化囊泡产生了明显的表面增强的拉曼光谱(SERS)信号,清晰显示了对应于囊泡模板分子的拉曼信号,表明可以通过SERS来原位检测囊泡的组成.Ag纳米颗粒杂化囊泡展示出更高的SERS灵敏度,可进一步作为探针检测水中浓度为10-7mol/L罗丹明6G分子,得到了显著增强的拉曼光谱,证明所制备的Ag纳米颗粒杂化囊泡可用于目标分子的痕量检测.     

微流控技术在循环肿瘤细胞异质性分析领域的应用

循环肿瘤细胞(circulating tumor cells,CTCs)的检测是液体活检的重要组成部分,可以通过低损伤甚至无创的方法达到检测体液中肿瘤细胞的目的 .肿瘤细胞在增殖、转移过程中极易产生多种类型的变异,如基因突变、蛋白质组学和表观遗传学改变等,这导致肿瘤细胞个体间发生差异,给临床诊疗带来巨大挑战.通过CTC...     

DNA四面体结构纳米材料及其应用

基于DNA纳米技术自组装的DNA四面体纳米材料,由于结构稳定、机械性能优越、分子修饰位点丰富等特点,逐渐成为DNA纳米材料领域的研究热点。此外,该DNA四面体纳米材料只需一步热变性即可自组装形成,具有合成方法简单、产率高的优点。可通过不同的设计,利用自组装方法将功能分子修饰在DNA四面体的顶点处,包裹在其笼状孔隙结构内,镶嵌或悬挂在双螺旋的边上,甚至通过引入发卡环结构等方式智能控制其结构变化。本文综述了DNA四面体结构纳米材料的设计和自组装原理、功能化修饰方法和结构的智能化,同时介绍了DNA四面体纳米材料在分子诊断、生物成像、分子输送和靶向给药等方面的应用研究,并探讨了此类纳米材料在今后应用研究中应关注的方面。     

基于生物功能化纳米DNA探针及其传感策略

随着人类基因组计划的完成和功能基因研究的深入,基因诊断已成为分子生物学和生物医学的重要研究领域。DNA生物传感器作为一种利用核酸碱基配对原则进行识别,能对基因片段实现持续、快速、灵敏和选择性检测的新方法,近年来发展非常迅速。纳米材料由于具有独特物理化学性质、良好的生物相容性、优越的机械性能及表面易于生物功能化等特点,被广泛应用到生物分析之中。各种各样组成、尺寸、维度及形状的纳米材料如量子点、贵金属纳米材料、碳纳米材料等被可控地修饰上不同的生物分子,用于发展特殊性质的纳米探针,构建DNA生物传感器,实现对DNA片段高灵敏及高特异性的检测。     

pH敏感铱、钌和铂配合物在肿瘤靶向荧光成像和治疗中的应用

肿瘤组织的微酸性环境为肿瘤准确诊断和有效治疗提供了新思路。pH敏感性金属配合物因具有较高的物理化学稳定性,突出的光谱特性和肿瘤靶向性等性质,引起高度关注。本文综述了这种肿瘤酸性微环境的产生机制以及近年来对这种酸性微环境敏感的铱、钌、铂配合物作为肿瘤成像和治疗试剂的研究进展。     

Magnolol‐induced inhibition of tumor growth in systemic malignancies

The commentary illustrates the significant tumor attenuating effects of magnolol and refers to the article on “Screening active anti‐breast cancer compounds from Cortex Magnolia officinalis by 2D LC–MS” (X. Hou, et al., J. Sep. Sci. 2013, 36 (4), 706–712). On the basis of the literature, there is definitively need for further studies to fully understand the magnolol reation pathways and to harness the antineoplastic effects.     

Research Progress of Natural Small-Molecule Compounds Related to Tumor Differentiation

Tumor differentiation is a therapeutic strategy aimed at reactivating the endogenous differentiation program of cancer cells and inducing cancer cells to mature and differentiate into other types of cells. It has been found that a variety of natural small-molecule drugs can induce tumor cell differentiation both in vitro and in vivo. Relevant molecules involved in the differentiation process may be potential therapeutic targets for tumor cells. Compared with synthetic drugs, natural small-molecule antitumor compounds have the characteristics of wide sources, structural diversity and low toxicity. In addition, natural drugs with structural modification and transformation have relatively concentrated targets and enhanced efficacy. Therefore, using natural small-molecule compounds to induce malignant cell differentiation represents a more targeted and potential low-toxicity means of tumor treatment. In this review, we focus on natural small-molecule compounds that induce differentiation of myeloid leukemia cells, osteoblasts and other malignant cells into functional cells by regulating signaling pathways and the expression of specific genes. We provide a reference for the subsequent development of natural small molecules for antitumor applications and promote the development of differentiation therapy.     

Metabolic shifts induced by human H460 cells in tumor‐bearing mice

Tumor markers are most popularly used in diagnosis of various cancers clinically. However, the confounding factors of individual background diversities, such as genetics, food preferences, living styles, physical exercises, etc., greatly challenge the identification of tumor markers. Study of the metabolic impact of inoculated tumors on model animals can facilitate the identification of metabolomic markers relevant to tumor insult. In this study, serum metabolites from nude mice (n = 14) inoculated with human H460 cells (human nonsmall cell lung carcinoma) were profiled using gas chromatography time‐of‐flight mass spectrometry. The mice with inoculated tumors showed an obviously different metabolic pattern from the control; identification of the discriminatory metabolites suggested the metabolic perturbation of free fatty acids, amino acids, glycolysis and tricarboxylic acid (TCA) cycle turnover. The significantly decreased TCA intermediates, free fatty acids, 3‐hydroxybutyric acid and fluctuating amino acids (t‐test, p < 0.05) in serum of tumor‐bearing mice characterized the metabolic impact of local inoculated H460 tumor cells on the whole system. This indicates that they are candidate metabolomic markers for translational study of lung cancer, clinically. Copyright © 2015 John Wiley & Sons, Ltd.     

发铜值对妇科肿瘤的诊断意义

为探讨发铜值对妇科肿瘤的诊断意义,取妇科肿瘤患者头发,经清洁并加酸处理后,加标准溶液,用微分电位溶出法,测定微量元素铜的含量。结果表明所有患者头发中,微量元素铜含量均低于正常值１０＊１０＾－６,恶性肿瘤患者低于８．５＊１０＾－６。提示妇科肿瘤患者发铜值过低,应警慢恶性肿瘤。     

Exploiting a New Approach to Destroy the Barrier of Tumor Microenvironment: Nano-Architecture Delivery Systems

Recent findings suggest that tumor microenvironment (TME) plays an important regulatory role in the occurrence, proliferation, and metastasis of tumors. Different from normal tissue, the condition around tumor significantly altered, including immune infiltration, compact extracellular matrix, new vasculatures, abundant enzyme, acidic pH value, and hypoxia. Increasingly, researchers focused on targeting TME to prevent tumor development and metastasis. With the development of nanotechnology and the deep research on the tumor environment, stimulation-responsive intelligent nanostructures designed based on TME have attracted much attention in the anti-tumor drug delivery system. TME-targeted nano therapeutics can regulate the distribution of drugs in the body, specifically increase the concentration of drugs in the tumor site, so as to enhance the efficacy and reduce adverse reactions, can utilize particular conditions of TME to improve the effect of tumor therapy. This paper summarizes the major components and characteristics of TME, discusses the principles and strategies of relevant nano-architectures targeting TME for the treatment and diagnosis systematically.     

Biotin-Conjugated Poly(Acrylic Acid)-Grafted Ultrasmall Gadolinium Oxide Nanoparticles for Enhanced Tumor Imaging

Herein, biotin (Bio)-conjugated poly(acrylic acid) (PAA)-grafted ultrasmall gadolinium oxide nanoparticles (Bio-PAA-Gd₂O₃ NPs) were synthesized for enhanced tumor imaging using Bio as a tumor-targeting ligand. The average particle diameter of Gd₂O₃ NPs was 2.1 nm. The Bio-PAA-Gd₂O₃ NPs exhibited excellent colloidal stability (i. e., no precipitation) and a high longitudinal water proton spin relaxivity (r₁) of 23.8 s⁻¹ mM⁻¹ (r₂/r₁=1.6 and r₂=transverse water proton spin relaxivity), which was ∼6 times higher than those of commercial Gd-chelated magnetic resonance imaging (MRI) contrast agents. Cytotoxicity tests using two cell lines showed that the Bio-PAA-Gd₂O₃ NPs were almost non-toxic up to the measured concentration of 500 μM Gd. The enhanced tumor imaging of the Bio-PAA-Gd₂O₃ NPs was demonstrated through their higher positive contrasts and longer contrast retention at the tumor after intravenous injection in T₁ MR images, compared with those of the control PAA-Gd₂O₃ NPs.     

Tumor Microenvironment‐Activated NIR‐II Nanotheranostic System for Precise Diagnosis and Treatment of Peritoneal Metastasis

Activatable theranostic systems show potential for improved tumor diagnosis and therapy owing to high detection specificities, effective ablation, and minimal side‐effects. Herein, a tumor microenvironment (TME)‐activated NIR‐II nanotheranostic system (FEAD1) for precise diagnosis and treatment of peritoneal metastases is presented. FEAD1 was fabricated by self‐assembling the peptide Fmoc‐His, mercaptopropionic‐functionalized Ag₂S quantum dots (MPA‐Ag₂S QDs), the chemodrug doxorubicin (DOX), and NIR absorber A1094 into nanoparticles. We show that in healthy tissue, FEAD1 exists in an NIR‐II fluorescence “off” state, because of Ag₂S QDs‐A1094 interactions, while DOX remains in stealth mode. Upon delivery of FEAD1 to the tumor, the acidic TME triggers its disassembly through breakage of the Fmoc‐His metal coordination and DOX hydrophobic interactions. Release of A1094 switches on Ag₂S fluorescence, illuminating the tumor, accompanied by burst release of DOX within the tumor tissue, thereby achieving precise tumor theranostics. This TME‐activated theranostic strategy holds great promise for future clinical applications.     

对微量元素与恶性肿瘤关系的新认识

微量元素与恶性肿瘤关系是当前十分引人注目的研究课题．MEDLINE数据库显示．近5年中硒、锌、铜与肿瘤关系的文章最多．微量元素与恶性肿瘤相关性有三种可能,即微量元素的丰缺是恶性肿瘤的结果.是肿瘤发生的条件因素或病因．微量元素之间的关系相当复杂．既拮抗。又协同，微量元素的研究刚起步．取样和检测方法等均需标准化．其与恶性肿瘤的发生和发展的机理更需积极研究.     

Inhibition of Tumor Progression through the Coupling of Bacterial Respiration with Tumor Metabolism

By leveraging the ability of Shewanella oneidensis MR-1 (S. oneidensis MR-1) to anaerobically catabolize lactate through the transfer of electrons to metal minerals for respiration, a lactate-fueled biohybrid (Bac@MnO₂) was constructed by modifying manganese dioxide (MnO₂) nanoflowers on the S. oneidensis MR-1 surface. The biohybrid Bac@MnO₂ uses decorated MnO₂ nanoflowers as electron receptor and the tumor metabolite lactate as electron donor to make a complete bacterial respiration pathway at the tumor sites, which results in the continuous catabolism of intercellular lactate. Additionally, decorated MnO₂ nanoflowers can also catalyze the conversion of endogenous hydrogen peroxide (H₂O₂) into generate oxygen (O₂), which could prevent lactate production by downregulating hypoxia-inducible factor-1α (HIF-1α) expression. As lactate plays a critical role in tumor development, the biohybrid Bac@MnO₂ could significantly inhibit tumor progression by coupling bacteria respiration with tumor metabolism.