激光诱发肿瘤荧光图像定位方法的研究进展

激光诱发肿瘤荧光图像定位方法是利用光敏剂在癌组织中的选择聚集性和受激发射荧光特性，通过实时检测荧光图像，可较为准确地识别恶变肿瘤组织的范围，能在肿瘤手术过程中对肿瘤图像进行实时显示，有效减小手术或其它治疗对患者重要器官的损伤；此外，在早期诊断癌症的过程中，这种方法可以引导组织活检，并为X射线检查提供辅助信息，对早期癌变组织进行诊断和定位。     

乳腺癌分子分型用荧光分子影像探针

目前,乳腺癌的临床诊断就是结合病理类型和分子分型 (免疫组化)。该方法是有创的,而且不能原位、实时地展现关键生物分子与临床关键信息之间的关系。本文介绍了利用分子影像技术对乳腺癌进行分子分型检测的最新研究进展。荧光成像灵敏度高,且不过分依赖图像分析,只需相应的荧光分子探针,即可实时、定量或半定量、多通道地得到肿瘤组织分子分型信息。因此,研制安全高效、组织穿透力强的近红外荧光分子探针是未来荧光成像技术和乳腺癌分子分型研究的重点。     

光敏剂浓度和给药时间对荧光诊断效果的影响

目的 为探索光敏剂浓度和给药时间对蓝光诱导的荧光诊断的影响,以提高荧光诊断的准确度.方法 常规方法制备荷瘤小鼠,分别给荷瘤小鼠静脉注射不同浓度（0～70 mg/kg体质量）的光敏剂-血卟啉衍生物（HpD）,并在给药后不同时间（0～48 h）,以前置395～415 nm滤光片的碘镓灯为激发光源,蓝光诱导载体荧光,通过图像采集系统采集荧光图像,取活组织做病理切片检查.结果 HpD浓度为40mg/kg体质量,给药后18 h,可以较为精确地反映肿瘤组织的浸润范围,荧光诊断准确度高于其他实验组;同时假阳性率低于其它实验组,差异有统计学意义.结论 荧光诊断的效果与光敏剂的浓度和观察时间密切相关;优化2者参数,可提高荧光诊断的准确度并降低假阳性率,对临床肿瘤手术方案的制定有重要参考价值.     

激光诱发荧光在结肠肿瘤早期诊断中的应用

激光诱导荧光法 (L IF)利用生物组织的自体荧光特性来判断组织性质 ,能实时、无损地提供组织信息 ,从而区分正常与病变组织。本文详述了生物组织自体荧光谱技术应用于结肠肿瘤诊断的研究方法、最新成果和现状 ,并对其发展和应用提出了几点建议。     

近红外荧光散射断层成像的研究进展

近红外荧光光学断层成像(FODT)是以合适的荧光探针作为标记物或对比剂,用特定波长的红光激发荧光染料,使其发出波长长于激发光的近红外荧光,通过测量媒质边界处有限点的荧光强度,考虑光子在组织中传播的散射特性,来重建出组织内部的荧光光学特性的分布图像以及组织光学参数。这种成像方式具有无电离辐射、染料稳定、可长期监测和设备简单、成本低等优点,在肿瘤检测、基因表达、蛋白质分子检测和药物受体定位等方面有着很大的应用潜力。在给出近红外荧光散射断层成像典型系统的基础上,详述了近红外荧光在组织中的频域传播模型和重建算法;介绍了两家研究机构在此领域的研究进展;讨论了将该成像方法应用于临床的进一步的发展方向。     

激光诱发荧光在结肠肿瘤早期诊断中的应用

激光诱导荧光法（ＬＩＦ）利用生物组织的自体荧光特性来判断组织性质，能实时，无损地提供组织信息，从而区分正常与病变组织。本文详述了生物组织自体荧光谱技术应用于结肠肿瘤诊断的研究方法，最新成果和现状，并对其发展和应用提供了几点建议。     

近红外荧光散射断层成像的研究进展

近红外荧光光学断层成像(FODT)是以合适的荧光探针作为标记物或对比剂，用特定波长的红光激发荧光染料，使其发出波长长于激发光的近红外荧光，通过测量媒质边界处有限点的荧光强度，考虑光子在组织中传播的散射特性，来重建出组织内部的荧光光学特性的分布图像以及组织光学参数。这种成像方式具有无电离辐射、染料稳定、可长期监测和设备简单、成本低等优点，在肿瘤检测、基因表达、蛋白质分子检测和药物受体定位等方面有着很大的应用潜力。在给出近红外荧光散射断层成像典型系统的基础上，详述了近红外荧光在组织中的频域传播模型和重建算法；介绍了两家研究机构在此领域的研究进展；讨论了将该成像方法应用于临床的进一步的发展方向。     

可见光和近红外荧光分光融合成像外科手术导航系统的研制

本文提出研制一种在开放手术过程中无创、实时、定位的外科手术光学导航系统。系统设计依据近红外荧光分子成像原理,采用活体荧光激发技术以及多通道分光摄像技术和图像融合软件技术。研制过程中将可见光和近红外光环形LED激发光源、多通道带通滤光片、分光摄像2CCD光电传感器和计算机系统技术集成,成功研制出一种新型外科手术光学导航系统。该系统在活体注射近红外荧光显影剂时,能够显示同一部位、同一时刻手术野组织表面的解剖学图像和近红外荧光功能图像。解决了医生在术中肉眼难以识别淋巴管、淋巴结、肿瘤边缘的技术问题,实现实时、无创的外科手术导航,有效引导外科医生切除肿瘤组织,显著提高手术成功率。该项技术已获得国家专利,专利号为ZI.2011 1 0292374.1。     

量子点探针辅助的近红外荧光成像技术在肿瘤显影中的应用

肿瘤早期检测是精准并高效诊疗癌症的关键因素。荧光成像技术凭借其高灵敏度、高时空分辨率、无电离辐射和无创实时成像等优点,在生物医学领域,尤其在肿瘤检测方面展现出了广泛的应用前景。近红外光穿过生物组织时,受到的吸收和散射较少,因此在生物成像方面体现了高信噪比和强组织穿透能力。在众多荧光探针中,近红外发光的量子点探针因其量子产率高、抗光漂白性强、发射光可调和稳定性良好等特点在荧光成像方面显示出突出的优势。本文基于量子点探针的近红外荧光成像技术在肿瘤显影中的应用,介绍了量子点优异的光学性能,并重点讨论了硫化铅（PbS）和硫化银（Ag2S）近红外发光量子点探针在肿瘤成像方面的研究进展,并对近红外发光量子点探针的应用前景进行了展望。     

一种荧光比例成像方法的研究

常规的技术,如免疫荧光共定位,允许在光学分辨率极限上显示细胞不同蛋白的共同定位,但是通过一般的图像分析处理方法,不能方便准确地比较各种蛋白的相对分布,也不能追踪这些分布模式随时间的变化情况.新近发展应用的荧光比例成像则可对多重荧光图像进行半定量分析,对细胞的粘附结构提供准确的时空信息,加深人们对细胞粘附结构和功能关系的理解.本文通过对双重荧光染色图像进行噪声滤除、图像分割、比例计算以及伪彩色显示,对荧光比例成像方法进行了研究.实际应用工作显示该方法行之有效.     

Optical imaging of metastatic tumors using a folate-targeted fluorescent probe

We describe the use of a tumor targeting ligand, the vitamin folic acid, to deliver an attached fluorescent probe to both primary and metastatic tumors overexpressing the folate receptor. Upon laser excitation, derived images of normal tissues generally show little or no fluorescence, whereas images of folate receptor-expressing tumors display bright fluorescence that can be easily distinguished from adjacent normal tissue. Furthermore, metastatic tumor loci of submillimeter size can also be visualized without the aid of image processing or enhancement. The sharp distinction between tumor and normal tissues provided by this technique could find application in the localization and resection of tumor tissue during surgery or in the enhanced endoscopic detection and staging of cancers.     

荧光谱客观分析在膀胱癌光动力学诊断中的应用

目的 探讨紫外激光激发膀胱癌组织细胞荧光谱分析对改进膀胱癌光动力学诊断的意义.方法 以不含细胞培养液和血卟啉单甲醚混合液为对照,分别取浓度为0、10、100、200 mg/L的血卟啉单甲醚作为光敏剂,孵育膀胱癌组织细胞株T24 1～3 h,再以全固态紫外激光作为激发光源(波长355 nm)激发,检测膀胱癌组织细胞特征荧光光谱并分析药物峰位置.结果 在可见光区域390～780 nm,不含细胞的培养液和血卟啉单甲醚混合液未出现特征峰;无血卟啉单甲醚光敏剂的膀胱癌组织细胞的自体峰在445～490 nm处;不同时间不同浓度血卟啉单甲醚光敏剂孵育的膀胱癌组织细胞除在445～490 nm处有自体峰外,在628.65 nm处均出现药物峰,200 mg/L血卟啉单甲醚孵育2 h时膀胱癌组织细胞药物峰及自体峰荧光强度达到最高,且药物峰的荧光强度超过了自体峰.结论 紫外激光激发的膀胱癌组织细胞荧光谱性质稳定、强度佳,对改进膀胱癌光动力学诊断具有确切价值.     

基于光纤的荧光成像及荧光强度测量系统

基于光纤的荧光成像及荧光强度测量系统由作为激发光源的发光二极管、作为荧光探测器的电荷耦合器件、光纤探头以及用于系统控制和数据处理的计算机软件构成。当光纤探头使用传像光纤时,本系统实现显微荧光成像功能,可以对使用荧光标记的细胞进行离体或者在体观察;当光纤探头使用"1分4"传光光纤时,系统可实现多通道实时荧光强度测量功能,且能够以微创的方式对实验动物体内多个器官进行在体、实时及连续的荧光强度测量,为研究荧光染料在各器官内的代谢情况提供了一种新的工具。     

Taqman探针实时荧光定量PCR检测肝脏疾病患者血清中miR-122的表达水平及其临床意义

 目的:运用Taqman探针实时荧光定量聚合酶链式反应（PCR）检测肝脏疾病患者血清中miR-122的表达水平并探讨其临床意义。方法:设计miR-122及U6 snRNA的茎环引物和Taqman探针,运用Taqman探针实时荧光定量PCR检测27例肝癌术前(HCC)患者、15例乙型肝炎（hepatitis B）患者、15例丙型肝炎（hepatitis C）患者、15例正常对照者（HC）、11例肝癌术后（PHCC）患者及10例肝癌术后复发（recurrence）患者血清中miR-122的表达水平,并分析miR-122与肝脏疾病相关标志物的关系。结果:Taqman探针实时荧光定量PCR方法能检测血清中miR-122的表达。HCC、hepatitis B、hepatitis C及recurrence患者血清中miR-122的表达水平均高于HC和PHCC患者（P<0.05）, hepatitis C患者血清miR-122表达水平高于HCC、hepatitis B和recurrence患者（P<0.05）,但HCC、hepatitis B和recurrence患者血清miR-122的表达水平无明显差异（P>0.05）,PHCC患者血清miR-122的表达水平比HCC和recurrence患者低（P<0.05）。血清乙型肝炎病毒表面抗原（HBsAg）阳性和(或)乙型肝炎病毒e抗原（HBeAg）阳性患者血清miR-122的表达水平高于阴性者（P<0.05）。血清丙型肝炎病毒抗体（HCV-Ab）阳性患者血清miR-122的表达水平高于阴性者（P<0.05）。血清丙氨酸氨基转移酶（ALT）与miR-122的表达水平有正相关性（r=0.34,P<0.05）。血清甲胎蛋白（AFP）≥400 μg/L组血清miR-122的表达高于AFP＜400 μg/L组（P<0.05）。结论: Taqman探针实时荧光定量PCR适用于检测血清miR-122的表达水平。在HCC、hepatitis B、hepatitis C及recurrence患者血清中miR-22均有不同程度的增高,尤其是hepatitis C患者,且PHCC患者血清miR-122表达下降,复发后升高。血清miR-122的表达与肝脏疾病的某些指标有关,提示血清miR-122可作为肝脏疾病,特别是肝癌早期诊断、手术疗效及预后判断的新指标。     

An albumin-based theranostic nano-agent for dual-modal imaging guided photothermal therapy to inhibit lymphatic metastasis of cancer post surgery

A large variety of cancers are associated with a high incidence of lymph node metastasis, which leads to a high risk of cancer death. Herein, we demonstrate that multimodal imaging guided photothermal therapy can inhibit tumor metastasis after surgery by burning the sentinel lymph nodes (SLNs) with metastatic tumor cells. A near-infrared dye, IR825, is absorbed onto human serum albumin (HSA), which is covalently linked with diethylenetriamine pentaacetic acid (DTPA) molecules to chelate gadolinium. The formed HSA-Gd-IR825 nanocomplex exhibits strong fluorescence together with high near-infrared (NIR) absorbance, and in the mean time could serve as a T1 contrast agent in magnetic resonance (MR) imaging. In vivo bi-modal fluorescence and MR imaging uncovers that HSA-Gd-IR825 after being injected into the primary tumor would quickly migrate into tumor-associated SLNs through lymphatic circulation. Utilizing the strong NIR absorbance of HSA-Gd-IR825, SLNs with metastatic cancer cells can be effectively ablated under exposure to a NIR laser. Such treatment when combined with surgery to remove the primary tumor offers remarkable therapeutic outcomes in greatly inhibiting further metastatic spread of cancer cells and prolonging animal survival. Our work presents an albumin-based theranostic nano-probe with functions of multimodal imaging and photothermal therapy, together with a ‘photothermal ablation assisted surgery’ strategy, promising for future clinical cancer treatment.     

Fluorescent Magnetic Nanoparticles with Specific Targeting Functions for Combinded Targeting,Optical Imaging and Magnetic Resonance Imaging

Abstract

Superparamagnetic iron oxides nanoparticles possess specific magnetic properties to be an efficient contrast agent for magnetic resonance imaging (MRI) to enhance the detection and characterization of tissue lesions within the body. To endow specific properties to nanoparticles that can target cancer cells and prevent recognition by the reticuloendothelial system (RES), the surface of the nanoparticles was modified with folic-acid-conjugated poly(ethylene glycol) (FA-PEG). In this study, we investigated the multifunctional fluorescent magnetic nanoparticles (IOPFC) that can specifically target cancer cells and be monitored by both MRI and optical imaging. IOPFC consists of an iron oxide superparamagnetic nanoparticle conjugated with a layer of PEG, which was terminal modified with either Cypher5E or folic acid molecules. The core sizes of IOPFC nanoparticles are around 10 nm, which were visualized by transmission electron microscope (TEM). The hysteresis curves, generated with superconducting quantum interference device (SQUID) magnetometer analysis, demonstrated that IOPFC nanoparticles are superparamagnetic with insignificant hysteresis. IOPFC displays higher intracellular uptake into KB and MDA-MB-231 cells due to the over-expressed folate receptor. This result is confirmed by laser confocal scanning microscopy (LCSM) and atomic flow cytometry. Both in vitro and in vivo MRI studies show better IOPFC uptake by the KB cells (folate positive) than the HT1080 cells (folate negative) and, hence, stronger T ₂-weighted signals enhancement. The in vivo fluorescent image recorded at 20 min post injection show strong fluorescence from IOPFC which can be observed around the tumor region. This multifunctional nanoparticle can assess the potential application of developing a magnetic nanoparticle system that combines tumor targeting, as well as MRI and optical imaging.     

Toward real-time virtual biopsy of oral lesions using confocal laser endomicroscopy interfaced with embedded computing

Oral lesions are conventionally diagnosed using white light endoscopy and histopathology. This can pose a challenge because the lesions may be difficult to visualise under white light illumination. Confocal laser endomicroscopy can be used for confocal fluorescence imaging of surface and subsurface cellular and tissue structures. To move toward real-time "virtual" biopsy of oral lesions, we interfaced an embedded computing system to a confocal laser endomicroscope to achieve a prototype three-dimensional (3-D) fluorescence imaging system. A field-programmable gated array computing platform was programmed to enable synchronization of cross-sectional image grabbing and Z-depth scanning, automate the acquisition of confocal image stacks and perform volume rendering. Fluorescence imaging of the human and murine oral cavities was carried out using the fluorescent dyes fluorescein sodium and hypericin. Volume rendering of cellular and tissue structures from the oral cavity demonstrate the potential of the system for 3-D fluorescence visualization of the oral cavity in real-time. We aim toward achieving a real-time virtual biopsy technique that can complement current diagnostic techniques and aid in targeted biopsy for better clinical outcomes.     

Liquid biopsy in breast cancer: A comprehensive review

Breast cancer is the most common cancer among women worldwide. Due to its complexity in nature, effective breast cancer treatment can encounter many challenges. Traditional methods of cancer detection such as tissue biopsy are not comprehensive enough to capture the entire genomic landscape of breast tumors. However, with the introduction of novel techniques, the application of liquid biopsy has been enhanced, enabling the improvement of various aspects of breast cancer management including early diagnosis and screening, prediction of prognosis, early detection of relapse, serial sampling and efficient longitudinal monitoring of disease progress and response to treatment. Various components of tumor cells released into the blood circulation can be analyzed in liquid biopsy sampling, some of which include circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), cell-free RNA, tumor-educated platelets and exosomes. These components can be utilized for different purposes. As an example, ctDNA can be sequenced for genetic profiling of the tumors to enhance individualized treatment and longitudinal screening. CTC plasma count analysis or ctDNA detection after curative tumor resection surgery could facilitate early detection of minimal residual disease, aiding in the initiation of adjuvant therapy to prevent recurrence. Furthermore, CTC plasma count can be assessed to determine the stage and prognosis of breast cancer. In this review, we discuss the advantages and limitations of the various components of liquid biopsy used in breast cancer diagnosis and will expand on aspects that require further focus in future research.