近红外荧光染料在肿瘤特异性成像中的研究

近年来,光学成像以其非侵袭性、实时、分辨率高等优势广泛应用于肿瘤研究领域,可对肿瘤进行早期诊断,反映肿瘤解剖学结构及代谢情况。近红外(near-infrared,NIR)荧光成像是目前光学分子成像领域研究的热点,以合适的荧光探针标记细胞、蛋白质分子或核酸,用特定波长的红光激发     

宽视场荧光内镜的构建及其初步应用

 目的 为探索胃癌分子成像技术的新方法,构建一套新型灵活的宽视场荧光内镜系统,并用于裸鼠胃癌移植瘤模型荧光成像研究。方法 通过合理的光路设计及光学组件机加工,装配宽视场荧光内镜系统,通过对不同浓度的2-DG-750荧光探针进行成像,分析系统性能;对尾静脉注射100 μl 2-DG-750荧光探针的裸鼠胃癌移植瘤模型进行在体荧光成像,对ROI的像素值和成像图进行分析。结果 体外成像ROI的像素值与荧光探针浓度存在较好的线性回归关系,在2-DG-750剂量为31.3 pmol时,该系统即可检测到荧光信号,提示该系统灵敏性好;在体成像显示用该系统联合2-DG-750荧光探针观察到了肿瘤组织的较高荧光信号强度。结论 宽视场荧光内镜系统具有很好的灵敏性,可以同时实现白光及荧光的双模式成像,具有实现光学分子成像诊断胃癌的潜在应用价值。     

裸鼠胃癌移植瘤的近红外荧光成像

目的：通过对非特异性探针Cy5.5在裸鼠体内分布及显像研究,探讨近红外荧光成像对胃癌的早期诊断及动态监测价值。方法：用MGC-803细胞株建立胃癌动物模型,进行早期、实时活体及离体显像实验。结果：近红外荧光成像可检测早期胃癌移植瘤的平均大小为2.807mm×3.045mm,与游标卡尺测得的肿瘤大小呈直线相关,r=0.924,P〈0.05。Cy5.5主要分布在肿瘤组织,主要代谢器官为肾脏;注入探针30min后,裸鼠肿瘤部位成像清晰,荧光寿命、荧光强度均高于对照部位（P〈0.05）。60min后,肿瘤区的荧光强度始高于血液（P〈0.05）。90min时达峰值。肿瘤部位的平均荧光寿命为（3.1376±0.9894）ns,明显高于对侧部位（P〈0.05）。结论：近红外荧光成像可用于胃癌的早期诊断及瘤体的动态监测。     

内生型转铁蛋白-金纳米簇探针的合成及其对前列腺癌的靶向成像研究

目的 以转铁蛋白(transferrin,Tf)为模板,氯金酸为原料,原位合成靶向荧光探针-内生型转铁蛋白-金纳米簇(gold nanoclusters,AuNCs),并以前列腺癌(prostate cancer,PCa)为模型,探讨该荧光探针的靶向成像效果.方法 利用场发射透射电子显微镜及粒度分析仪分析所合成的荧光探针的形貌、水合粒径及分布;利用紫外-可见分光光度计及荧光分光光度计对其光学性能进行表征;MTT法检测细胞毒性;并通过细胞荧光成像及竞争抑制实验表征其肿瘤的特异性靶向效果;静脉注射Tf-AuNCs至PC-3种植瘤鼠体内,进行连续荧光成像,评价其肿瘤靶向成像效果;通过组织病理学明确其活体毒性.结果 本研究制备的Tf-AuNCs粒径约为3 nm,荧光发射峰为700 nm,保留了Tf及金纳米簇的性能;细胞成像结果显示Tf-AuNCs对前列腺肿瘤细胞(PC-3)特异性靶向效果好;小动物活体成像结果显示Tf-AuNCs探针仅需15 min即可准确显示肿瘤部位,至2h时肿瘤区荧光强度达峰值,表明其具有良好的活体肿瘤成像能力;病理学结果表明Tf-AuNCs具有良好的生物相容性.结论 Tf-AuNCs荧光探针具有良好的光学性能、特异靶向能力,并具有优异的荧光成像能力及良好的生物相容性,将有望应用于PCa的早期影像学分析.     

近红外二区荧光成像在肿瘤诊疗中的研究进展

近红外光(NIR)根据其波长可分为NIR-Ⅰ(650～900 nm)和NIR-Ⅱ(900～1 700 nm)。相较于传统的NIR-Ⅰ荧光成像, NIR-Ⅱ荧光成像的组织吸收和光子散射值更低, 组织穿透性和分辨率更高, 是目前临床应用中最有前景的1种光学成像技术。此外, 结合多模态或诊疗一体化分子探针, NIR-Ⅱ荧光成像可以实现对肿瘤的精准定位及引导治疗, 对肿瘤的早期诊疗具有重要意义。该文就NIR-Ⅱ荧光成像技术在肿瘤诊断、监测转移以及治疗方面应用的研究进展进行综述。     

结肠癌裸鼠模型活体近红外荧光成像

目的 探讨人结肠腺癌裸鼠皮下微小移植瘤的近红外荧光成像表现及应用近红外荧光成像测量移植瘤大小的可行性.方法 应用小动物分子成像仪和非特异性探针Cy5.5对20只裸鼠行近红外荧光成像,进而得到关于肿瘤大小和荧光强度的信息;活体成像后裸鼠处死取瘤,游标卡尺测量肿瘤大小.结果 20只裸鼠皮下微小移植瘤早期成像清晰,荧光测量瘤体的平均径线为3.093 mm×2.188 mm,荧光强度均值为85219.40 PC.近红外荧光成像与游标卡尺测算移植瘤体积所得2组数据呈线性相关, r=0.915,P<0.0001.结论 近红外线光学成像具有敏感性高的特点,可在早期发现微小移植瘤, 并且可较准确直观地反映晚期移植瘤的形态和大小.     

携载Ce6核壳纳米粒的双模态成像及光热治疗研究

【摘要】目的：构建介孔二氧化硅（MSN）-聚多巴胺（PDA）核壳纳米粒子（MSN-Ce6@PDA-Gd nanoparticles,MSN-Ce6@PDA-Gd NPs）,探讨其应用于体内外磁共振成像及荧光成像的潜能和光热治疗效用。方法：采用十六烷基三甲基氯化铵（CTAC）模板法、甲苯回流法制备氨基化介孔二氧化硅（MSN-NH2）纳米粒子,并通过静电作用包裹二氢卟吩e6（Ce6）,最后采用溶液氧化法进行PDA涂覆及钆离子（Gd3+）配位后,制备获得MSN-Ce6@PDA-Gd NPs。采用透射电子显微镜（TEM）、Zeta电位、紫外光谱等方法对MSN-Ce6@PDA-Gd NPs进行表征。采用红外热成像仪监测光热升温效果。采用细胞增殖及细胞毒性检测（MTT）法分析此纳米材料对小鼠胚胎成纤维细胞NIH-3T3和人乳腺癌细胞MDA-MB-231的细胞毒性及光热杀伤231细胞的效果。采用3.0T磁共振扫描仪观察此纳米诊疗剂的体内代谢途径及治疗前、后肿瘤大小,采用倒置荧光显微镜及荧光成像系统观察其体内外荧光成像效果。采用单因素方差分析进行数据的统计学分析。结果：MSN-Ce6@PDA-Gd NPs水合粒径为（142.10±0.29）nm,电位（-16.03±0.12）mV。Ce6的最高包封率为53.58%,负载量为17.65%。在不同浓度MSN-Ce6@PDA-Gd NPs溶液的作用下NIH-3T3和MDA-MB-231细胞存活率的差异均无统计学意义（F=2.317,P>0.05;F=2.344,P>0.05）。体外成像结果显示MDA-MB-231细胞内磁共振T1信号及荧光成像信号的增强具有浓度依赖性。体外光热治疗结果显示,随着MSN-Ce6@PDA-Gd NPs浓度的递增（0.0、12.5、25.0、50.0、100.0、150.0和200.0mg/L）,激光辐照组的MDA-MB-231细胞的存活率递减;无激光辐照组在纳米粒子浓度为0.0~200.0mg/L以及激光辐照组在纳米粒子浓度为0~50.0mg/L时均表现出较高的细胞存活率,当纳米粒子的浓度为100.0~200.0mg/L时,激光辐照组的细胞存活率显著降低。在体实验结果表明MSN-Ce6@PDA-Gd NPs可以实现对乳腺癌荷瘤裸鼠的的双模态成像以及对乳腺癌肿瘤有效的治疗作用。结论：制备了一种新型诊疗材料MSN-Ce6@PDA-Gd NPs,可成功实现对乳腺癌的体内外磁共振/荧光双模态显像和光热治疗。     

鲜红斑痣光学测评技术的研究进展

鲜红斑痣（PWS）在病理学上主要表现为先天性的真皮浅层毛细血管网的扩张畸形。血管靶向光动力疗法（V-PDT）是治疗PWS的一种有效方法,在临床应用中,为了不断提高疗效,需要准确判定PWS患者病变靶组织特性（如病变血管深度、管径和血流等）,以便为不同患者制定个体化V-PDT治疗方案。近年来,大量研究组致力于开发用于评估PWS病变靶组织结构和功能特性的无创光学测评技术,笔者将在文中综述目前仍处于基础研究阶段以及已经应用于临床评估PWS的光学测评技术,主要包括：光学相干层析成像技术、光声成像技术、反射式共聚焦显微镜、激光多普勒血流成像技术、激光散斑成像技术和空间频域成像技术。     

MR扩散加权成像在鉴别乳腺非肿块样强化病变性质方面的价值

扩散加权成像（DWI）是磁共振功能成像技术的一种,它是目前唯一能用于活体观察水分子微观运动的成像方法。MRI因其对软组织分辨力高的优势使其在乳腺疾病诊断中得到广泛应用,其中DWI作为一种无创功能成像技术也逐步受到关注。本文将就DWI图像及表观扩散系数（ADC）、相对表观扩散系数（rADC）在鉴别非肿块样强化病变性质方面的价值进行综述。     

中国光子生物学研究与光诊断技术进展

激光技术由于具有非接触、凝血、消毒等优点而被广泛地应用到医学临床各科中，光子所特有高能量、高的空间、时间和光谱分辨的特性使得光学成像、光声成像、荧光光谱分析等光学诊断技术及相关基础研究工作得到越来越深入的发展，特别是结合现代信息检测与分析技术的高速发展，取得了诸多有益的成果。在此，简要叙述生物光子的组织内传输与相互作用分析、光学功能成像技术和光动力学疗法应用研究等方面的进展。     

光学分子影像技术在转基因动物模型中的应用研究

光学分子影像技术是一门快速发展的生物医学影像技术,能非侵袭性、定量及实时动态监测活体动物体内的生物学过程,操作简单、实时、灵敏度高、价格低等优点使其越来越多地应用到医学和生命科学等领域.通过建立携带光学分子影像报告基因的转基因动物模型加快了该领域的发展,也拓宽了光学分子影像技术的应用范围.光学分子影像技术联合转基因动物模型在监测肿瘤发生、发展及转移、监测细胞增殖、周期和凋亡、监测机体炎性反应和血管生成以及药物研发等领域均有良好的发展前景.     

Targeting of αVβ6 integrin in 3D head and neck cancer cells by functionalized Quantum Dots

Head and Neck cancers (HNSCC) management mainly relies on surgery, however the exact delineation of tumor during surgery is a real hurdle. Consequently, whole tumor resection and obtaining negative margins are challenging. However, surgical margin is a major prognostic factor for patients outcome¹. Currently, margin investigation relies on tissue frozen section analysis, but this process can be time-consuming and not always accurate². Development of intraoperative tools like fluorescence imaging could be of great help for real-time surgery³. In this context, use of fluorescent nanoparticles called Quantum Dots (QDs), with exceptional optical properties could be very attractive.In the present study we used Cd-based QDs (50 nM and 100 nM) emitting fluorescence in the visible spectrum (610 ± 20 nm) and functionalized with A20 peptide which contains the RGD sequence to specifically target αVβ6 integrin. The latter is overexpressed in HNSCC and not expressed in healthy tissue. Targeting properties of QDs were studied in 3D spheroid model of human tongue cancer cells HSC-3 in monoculture or co-cultured with human fibroblasts MRC-5. Considering that fibroblasts are the main stromal population within these cancers⁴, this cocultured 3D model better reflects tumor structure and complexity. The conducted study has confirmed the overexpression of αVβ6 integrin in HSC-3 by Western Blot and immunofluorescence. Further, a much better penetration of QDs functionalized with A20 peptide was observed in monoculture and coculture spheroids while no staining was registered for peptide-free QDs. Moreover the presence of fibroblasts has significantly enhanced QDs penetration into spheroids, highlighting the impact of tumor stroma on the uptake of nanoparticles. Toxicity of Cd-based QDs (25 nM-200 nM) was tested on MRC-5 fibroblasts using Crystal Violet assay and didn't demonstrate any loss of viability compared to control QDs-free samples.These positive results with visible functionalized QDs encourage us to conduct further studies with In-based QDs emitting light in the Near Infrared Region (NIR), functionalized with A20 peptide.     

动脉粥样硬化斑块MRI和近红外分子影像的实验研究

目的 探讨7.0 T MRI和近红外荧光成像(NIRF)检测动脉粥样硬化(AS)斑块的可行性.方法 对14周龄ApoE-/-小鼠按高脂饮食喂养20周,建立AS模型,以正常C57BL/6小鼠作为对照.MRI实验中,5只ApoE-/-小鼠及5只C57小鼠经尾静脉注入超微超顺磁性氧化铁颗粒(USPIO)前及36 h后分别行7.0 T MRI.NIRF实验中,10只ApoE-/-小鼠和4只C57小鼠经尾静脉注入抗氧化修饰的低密度脂蛋白(oxLDL)抗体-NIR 797(抗-oxLDL-抗体-NIR 797)近红外探针,4只ApoE-/-小鼠经尾静脉注入非特异性IgG-NIR 797,另4只ApoE-/-小鼠注入PBS,24h后分别行NIRF.用SPSS17.0软件对计量数据行独立样本t检验和单因素方差分析.结果 ApoE-/-小鼠注入USPIO 36 h后,在T2WI上腹主动脉斑块信号较注射前减低,相对信号强度分别为0.70±0.04和1.28±0.06,差异有统计学意义(t =3.376,P＜O.05),信号改变率达(-56.58±4.25)％;普鲁士蓝染色证实斑块内有铁沉积.注入抗-oxLDL-抗体-NIR 797 24 h后,ApoE-/-小鼠主动脉离体NIRF示强荧光信号(SNR为42.51 ±5.24)聚集于主动脉根、主动脉弓及降主动脉起始段,而非特异性IgG-NIR 797组(19.58±3.06)、PBS组(4.19±0.82)及对照C57小鼠(2.29±1.11)仅见较弱荧光信号,与靶向探针组比较差异有统计学意义(F =25.104,P＜0.05).斑块油红O染色与NIRF阳性面积分别为(41.69 ±5.29)％和(39.45±5.35)％,两者呈线性相关(r=0.738,P＜0.05,n=8),免疫荧光证实斑块内oxLDL的表达与巨噬细胞共区域.结论 应用新型分子影像探针在7.0 T MRI和NIRF上可有效检测AS斑块,有助于鉴别高危斑块,可为AS多模式成像提供依据.     

在体光学分子影像技术在乳腺癌基础及临床研究中的应用

在体光学分子影像作为一种快速发展的生物医学影像技术,以其实时、定量及非侵入性等特点,已被广泛应用于各学科的研究中.光学分子影像技术在监测乳腺癌的远处转移、检测肿瘤细胞的凋亡、细胞周期、细胞乏氧与肿瘤血管生成、观察ER介导的分子路径、观察乳腺癌干细胞等基础研究领域及在乳腺癌早期诊断、引导前哨淋巴结活组织检查、药物疗效评价、检测乳腺癌原癌基因人类表皮生长因子受体2 (HER-2)表达等基础研究及临床应用中有着良好的前景.     

Optical imaging: current applications and future directions.

Optical techniques, such as bioluminescence and fluorescence, are emerging as powerful new modalities for molecular imaging in disease and therapy. Combining innovative molecular biology and chemistry, researchers have developed optical methods for imaging a variety of cellular and molecular processes in vivo, including protein interactions, protein degradation, and protease activity. Whereas optical imaging has been used primarily for research in small-animal models, there are several areas in which optical molecular imaging will translate to clinical medicine. In this review, we summarize recent advances in optical techniques for molecular imaging and the potential impact for clinical medicine.     

Silica-coated graphene compared to Si-CdSe/ZnS quantum dots: Toxicity,emission stability,and role of silica in the uptake process for imaging purposes

Quantum dots (QDs) present a special type of nanocrystals (NCs) due to their unique optical and chemical properties. While cadmium-based QDs (Cd-QDs) have the most favorable physicochemical properties, their toxicity, instability in the aqueous phase, and loss of brightness at high temperature are some of the obstacles that prevent the wide use of Cd-QDs. Carbon-based QDs as graphene quantum dots (GQDs) represent a very promising biocompatible replacement. In the present work, we mainly focus on comparing the efficiency and uptake of GQDs and Cd-QDs for fluorescent imaging purposes and studying the effect of growing silica shell on the emission and the uptake of QDs inside living human and bacterial cells. Graphene and CdSe/ZnS QDs were prepared and encapsulated in silica to increase their emission and uptake by living cells. Moreover, we studied their photostability and cytotoxicity. The Prepared G-Si QDs showed good emission inside the cytoplasmic portion of the liver hepatocellular carcinoma cell line (HepG2) and Bacillus subtilis (B. subtilis), but they revealed lower photoluminescence (PL) intensity compared to Si-CdSe/ZnS NCs although G-Si QDs are advantageous in other aspects, i.e. possess lower toxicity and higher stability with temperature variations.     

Optische Bildgebung von Fluoreszenz im nahen Infrarot

The molecular imaging of specific targets using optical methods is currently possible in vivo, in part due to the advances in imaging modalities (epifluorescence, fluorescent endoscopy, fluorescence mediated tomography, intravital fluorescence microscopy), and in part due to the development of better contrast media. These are composed of a suitable fluorochrome, usually with emission in the near infrared due to tissue penetration, as well as by molecular specific contrast media from ligands. The latest generation of contrast media is not fluorescent in its unactivated state. Fluorescence first occurs after contact with certain (e.g. disease specific) enzymes by which a minimally unspecific fluorescent background as well as molecular specificity is made possible.