BACKGROUND & AIMS: :Time-resolved fluorescence technique can reduce the short-lived background luminescence and auto-fluorescence interference from cells and tissues by exerting the delay time between pulsed excitation light and signal acquisition. Here, we prepared persistent luminescence nanoparticles (PLNPs) to design a universal time-resolved fluorescence resonance energy transfer (TR-FRET) platform for biosensing, lifetime imaging of cell apoptosis and in situ lifetime quantification of intracellular caspase-3. Three kinds of PLNPs-based nanoprobes are assembled by covalently binding dye-labeled peptides or DNA to carboxyl-functionalized PLNPs for the efficient detection of caspase-3, microRNA and protein. The peptides-functionalized nanoprobe is also employed for fluorescence lifetime imaging to monitor cell apoptosis, which shows a dependence of cellular fluorescence lifetime on caspase-3 activity and thus leads to an in situ quantification method. This work provides a proof-of-concept for PLNPs-based TR-FRET analysis and demonstrates its potential in exploring dynamical information of life process.

背景与目标： : 时间分辨荧光技术可以通过在脉冲激发光和信号采集之间施加延迟时间来减少来自细胞和组织的短寿命背景发光和自荧光干扰。在这里，我们制备了持久性发光纳米颗粒 (PLNPs)，以设计通用的时间分辨荧光共振能量转移 (tr-fret) 平台，用于生物传感，细胞凋亡的寿命成像和细胞内caspase-3的原位寿命定量。通过将染料标记的肽或DNA与羧基官能化的plnp共价结合来组装三种基于plnp的纳米探针，以有效检测caspase-3，microRNA和蛋白质。肽官能化的纳米探针也用于荧光寿命成像以监测细胞凋亡，这显示了细胞荧光寿命对caspase-3活性的依赖性，因此导致了原位定量方法。这项工作为基于PLNPs的TR-FRET分析提供了概念验证，并证明了其在探索生命过程的动态信息方面的潜力。

BACKGROUND & AIMS: :This study was designed to obtain covalently coupled conjugates as means for achieving higher stability and better coverage of the AuNPs by antibodies on the particle surface suitable for sensor performance enhancement. Starting by using a modified protocol, colloid gold solution, with mean AuNP core size of ~6 nm was synthesized. The protocol used for conjugation of AuNPs to osteocalcin antibody in this study relies on covalent and electrostatic attractions between constituents. Varieties of conjugates with varying combinations of crosslinkers and different concentrations were successfully synthesized. The obtained products were characterized and their properties were studied to determine the best candidate in sense of antibody - antigen reactivity. Using AuNP-GSH-NHS-Ab combination (1:1:1), the tertiary structure of the protein was maintained and thus the antibody remained functional in the future steps. This one-pot method provided a simple method for covalently coupling antibodies on the particle surface while keeping their functionality intact. The AuNP content of the solution also accelerated electron transfer rate and thus amplifies the detection signal. With the developed and discussed technique herein, a simple solution is modeled to be used for measuring serum levels of biomarkers in single and/or multiplexed sensor systems.

背景与目标： : 本研究旨在获得共价偶联的缀合物，以通过适于增强传感器性能的颗粒表面上的抗体实现更高的稳定性和更好的AuNPs覆盖。从使用改进的方案开始，合成了平均AuNP核尺寸约为6 nm的胶体金溶液。在这项研究中，用于将AuNPs与骨钙素抗体结合的方案依赖于成分之间的共价和静电吸引力。成功合成了具有不同交联剂组合和不同浓度的共轭物。对获得的产物进行了表征，并研究了它们的性质，以确定抗体-抗原反应性方面的最佳候选物。使用AuNP-GSH-NHS-Ab组合 (1:1:1)，蛋白质的三级结构得以维持，因此抗体在未来的步骤中保持功能。这种一锅法提供了一种简单的方法，用于在颗粒表面共价偶联抗体，同时保持其功能完整。溶液的AuNP含量也加快了电子转移速率，从而放大了检测信号。利用本文所开发和讨论的技术，对简单的解决方案进行建模以用于测量单个和/或多路传感器系统中生物标志物的血清水平。

BACKGROUND & AIMS: :Recently, semiconductor nanoparticles such as quantum dots (QDs) have attracted significant attention for bioimaging. Complex chemical functionalization, surface modification, and bioconjugation chemistry are generally required to tag biomolecules to QDs for imaging of different biomarkers. In this study, we report a simple method for production of QDs stabilized by the small protein, Affibody (AF-QDs) for fluorescent imaging of the human epidermal growth factor receptor type 2 (HER2) in human A549 lung cancer cells. This one-pot synthesis of AF-QDs avoids complex chemical conjugation procedures and demonstrates a promising approach for the preparation of fluorescent nanoprobes for imaging of cancer targets.

背景与目标： : 最近，诸如量子点 (qd) 之类的半导体纳米颗粒在生物成像方面引起了极大的关注。通常需要复杂的化学功能化，表面修饰和生物缀合化学来将生物分子标记为量子点，以对不同的生物标志物进行成像。在这项研究中，我们报告了一种简单的方法，用于生产由小蛋白质固定体 (af-qds) 稳定的量子点，用于人A549肺癌细胞中人表皮生长因子受体   2型 (HER2) 的荧光成像。这种一锅法合成的AF-QDs避免了复杂的化学缀合程序，并证明了一种用于制备用于癌症靶标成像的荧光纳米探针的有前途的方法。

BACKGROUND & AIMS: :Human apurinic/apyrimidinic endonuclease/redox effector factor 1 (APE1) is an essential DNA repair protein. Herein, we demonstrate that avidin-oriented abasic site-containing DNA strands (AP-DNA) on the surface of silica coated magnetic nanoparticles (SiMNP) can selectively respond to APE1 while resist the digestion by other nucleases. Mechanism studies have revealed that avidin may serve as an organizer protein and recruit APE1 to the DNA substrates on the nanoparticles via strong and specific interactions. Taking advantage of this newly disclosed property, we for the first time successfully displayed the intracellular activities of APE1 in living cells by fluorescence imaging. The avidin organized AP-DNA-SiMNP assembly holds great potential for enzyme-mediated release of drugs inside tumor cells which often contain higher levels of APE1 than normal cells.

背景与目标： : 人嘌呤/嘧啶核酸内切酶/氧化还原效应因子1 (APE1) 是一种必需的DNA修复蛋白。在本文中，我们证明了二氧化硅涂覆的磁性纳米颗粒 (SiMNP) 表面上的面向抗生物素蛋白的含碱基位点的DNA链 (ap-dna) 可以选择性地响应APE1，同时抵抗其他核酸酶的消化。机理研究表明，抗生物素蛋白可以作为组织蛋白，并通过强而特异性的相互作用将APE1募集到纳米颗粒上的DNA底物中。利用这种新发现的特性，我们首次通过荧光成像成功地显示了活细胞中APE1的细胞内活性。抗生物素蛋白组织的AP-DNA-SiMNP组装具有酶介导的药物在肿瘤细胞内释放的巨大潜力，而肿瘤细胞通常含有比正常细胞更高水平的APE1。

BACKGROUND & AIMS: :The present study aimed to investigate the feasibility and effectiveness of detecting K-ras mutation by using magnetic nanoparticles in fecal samples of patients with pancreatic cancer at different stages. The novel methodology of K-ras mutation detection was compared to the existing methodology of cancer antigen (CA)19-9 examination. Patients with pancreatic cancer (n=88), pancreatic benign diseases who displayed chronic pancreatitis (n=35), pancreatic mucinous cyst neoplasms (n=10) and pancreatic serous cyst (n=9) admitted to the Department of Surgery, Jiaxing Second Hospital were enrolled in the present study. Fecal samples were collected from all patients, DNA was extracted and magnetic nanoprobe was then used to detect K-ras mutation. The results obtained using the novel magnetic nanoprobe detection technique showed a K-ras mutation rate of 81.8% (72/88) in the patients with pancreatic cancer and 18.5% (10/54) in patients with pancreatic benign diseases. In patients with pancreatic cancer, the K-ras mutation rate was comparable in stages I + IIA and IIB + III + IV (78.9 vs. 84.0%; P>0.05). The sensitivity and specificity of K-ras mutation for detection of pancreatic cancer was 81.8 and 81.5%, respectively. Sixty-eight pancreatic cancer patients had >37 U/ml CA99 with a sensitivity and specificity for pancreatic cancer detection of 77.3 and 77.8%, which was not significantly lower than detection by the fecal K-ras mutations (P>0.05). Combinational detection of fecal K-ras mutations and serum CA19-9 significantly increased the sensitivity regarding pancreatic cancer detection to 97.7% (P<0.05), while the specificity was not enhanced (80.9%; P>0.05) compared with fecal K-ras mutations or CA19-9 alone. The findings showed that the magnetic nanoprobe is able to detect fecal K-ras mutations in different stages of pancreatic cancer, with comparable sensitivity and specificity to CA19-9 examination for differentiating pancreatic cancer. Furthermore, combined detection of CA19-9 and K-ras mutations has enhanced sensitivity compared with CA19-9 alone.

背景与目标： : 本研究旨在探讨磁性纳米颗粒在不同阶段的胰腺癌患者粪便中检测K-ras突变的可行性和有效性。将新的K-ras突变检测方法与现有的癌症抗原 (CA)19-9检查方法进行了比较。本研究纳入嘉兴市第二医院外科收治的胰腺癌 (n = 88)，表现为慢性胰腺炎 (n = 35) 的胰腺良性疾病，胰腺粘液性囊肿 (n = 10) 和胰腺浆液性囊肿 (n = 9)。收集所有患者的粪便样本，提取DNA，然后使用磁性纳米探针检测K-ras突变。使用新型磁性纳米探针检测技术获得的结果显示，胰腺癌患者的K-ras突变率为81.8% (72/88)，胰腺良性疾病患者的18.5% (10/54)。在胰腺癌患者中，K-ras突变率在I + IIA和IIB + III + IV期相当 (78.9对84.0%; P>0.05)。K-ras突变检测胰腺癌的敏感性和特异性分别为81.8和81.5%。68例胰腺癌患者的CA99> 37 U/ml，对胰腺癌检测的敏感性和特异性为77.3和77.8%，不明显低于粪便K-ras突变的检测 (P>0.05)。粪便K-ras突变和血清CA19-9的组合检测显著提高了胰腺癌检测的敏感性至97.7% (P<0.05)，而特异性与粪便K-ras突变或单独CA19-9相比没有增强 (80.9%; P>0.05)。研究结果表明，磁性纳米探针能够检测胰腺癌不同阶段的粪便K-ras突变，与CA19-9鉴别胰腺癌的检查具有相当的敏感性和特异性。此外，与单独CA19-9相比，CA19-9和K-ras突变的联合检测具有增强的敏感性。

BACKGROUND & AIMS: :Although, superparamagnetic iron oxide nanoparticles (SPIONs) have extensively been used as a contrasting agent for magnetic resonance imaging (MRI), the lack of intrinsic fluorescence restricted their application as a multimodal probe, especially in combination with light microscopy. In Addition, the bigger size of the particle renders them incompetent for bioimaging of small organelles. Herein, we report, not only the synthesis of ultrasmall carbon containing magneto-fluorescent SPIONs with size ∼5 nm, but also demonstrate its capability as a multicolor imaging probe. Using MCF-7 and HeLa cell lines, we show that the SPIONs can provide high contrast mulicolor images of the cytoplasm from blue to red region. Further, single particle level photon count data revealed that the SPIONs could efficaciously be utilized in localization based super resolution microscopy in future.

背景与目标： : 尽管超顺磁性氧化铁纳米颗粒 (SPIONs) 已广泛用作磁共振成像 (MRI) 的对比剂，但缺乏固有荧光限制了它们作为多峰探针的应用，尤其是与光学显微镜结合使用。此外，较大的颗粒使它们无法对小细胞器进行生物成像。在这里，我们报告了不仅合成了尺寸约为5 nm的含超小碳的磁荧光尖子，而且还证明了其作为多色成像探针的能力。使用MCF-7和HeLa细胞系，我们表明SPIONs可以提供从蓝色到红色区域的细胞质的高对比度多色图像。此外，单粒子级光子计数数据表明，SPIONs将来可以有效地用于基于定位的超分辨率显微镜中。

BACKGROUND & AIMS: :So far, the development of a unique strategy for specific biomolecules activity monitoring and precise drugs release in cancerous cells is still challenging. Here, we designed a conformation-switchable smart nanoprobe to monitor telomerase activity and to enable activity-triggered drug release in cancerous cells. The straightforward nanoprobe contained a gold nanoparticle (AuNP) core and a dense layer of 5-carboxyfluorescein (FAM)-labeled hairpin DNA shell. The 3' region of hairpin DNA sequence could function as the telomerase primer to be elongated in the presence of telomerase, resulting in the conformational switch of hairpin DNA. As a result, the FAM fluorescence was activated and the anticancer drug doxorubicin (Dox) molecules which intercalated into the stem region of the hairpin DNA sequence were released into cancerous cells simultaneously. The smart method could specifically distinguish cancerous cells from normal cells based on telomerase activity. It also showed a good performance for monitoring telomerase activity in the cytoplasm by molecular imaging and precise release of Dox triggered by telomerase activity in cancerous cells. These advantages may offer a great potential of this method for monitoring telomerase activity in cancer progression and estimating therapeutic effect.

背景与目标： : 到目前为止，开发用于特定生物分子活性监测和癌细胞中精确药物释放的独特策略仍然具有挑战性。在这里，我们设计了一种构象可切换的智能纳米探针，以监测端粒酶活性并使活性触发的药物在癌细胞中释放。简单的纳米探针包含金纳米颗粒 (AuNP) 核心和5-羧基荧光素 (FAM) 标记的发夹DNA壳的致密层。发夹DNA序列的3' 区域可以用作端粒酶引物，在端粒酶存在下被拉长，从而导致发夹DNA的构象转换。结果，FAM荧光被激活，插入发夹DNA序列茎区的抗癌药物阿霉素 (Dox) 分子同时释放到癌细胞中。smart方法可以根据端粒酶活性特异性区分癌细胞和正常细胞。它还显示出通过分子成像监测细胞质中端粒酶活性以及癌细胞中端粒酶活性触发的Dox精确释放的良好性能。这些优点可能为该方法在癌症进展中监测端粒酶活性和评估治疗效果提供了巨大的潜力。

BACKGROUND & AIMS: :Development of rapid antiviral assays can expedite the process of screening potential agents against viral pathogens. In the present study, fluorescent quantum dots (QDs) incorporated with infectious pancreatic necrosis virus (IPNV) were used as imaging nanoprobes to detect the threshold amount of poly I:C (an interferon inducer) required to induce zebrafish cells into an antiviral state against IPNV. QD-IPNV hybrids were formed by colloidal clustering of negatively charged QDs and IPNV, using the cationic polymer polybrene (50 μg/mL). To test the screening potential of the QD-IPNV hybrids for anti-IPNV drug candidates, zebrafish ZF4 cells primed with the immunostimulant poly I:C at concentrations of 1, 5, and 10 μg/mL for 6h were used as a model system. After poly I:C treatment, cells were exposed to the QD-IPNV hybrids for 6h at a multiplicity of infection (MOI) of 5. The anti-IPNV effectiveness of poly I:C was assessed via fluorescence intensity of the QDs. Our results showed that ZF4 cells primed with poly I:C at 10 μg/mL were highly protected from IPNV challenge (i.e., no detection of QD fluorescence). In summary, a rapid and efficient cell-based imaging platform has been developed for assessing the anti-IPNV activity of poly I:C on ZF4 cells using QD-IPNV hybrids. This approach may be applied to a wider range of fish species and fish pathogenic viruses.

背景与目标： : 快速抗病毒检测的发展可以加快筛选针对病毒病原体的潜在药物的过程。在本研究中，结合了传染性胰腺坏死病毒 (IPNV) 的荧光量子点 (qd) 用作成像纳米探针，以检测将斑马鱼细胞诱导为抗IPNV的抗病毒状态所需的poly I:C (干扰素诱导剂) 的阈值量。使用阳离子聚合物聚乙烯 (50 μ g/mL)，通过带负电荷的量子点和IPNV的胶体聚集形成qd-ipnv杂种。为了测试QD-IPNV杂种对抗IPNV候选药物的筛选潜力，将用免疫刺激剂poly I:C以1、5和10 μ g/mL的浓度引发6小时的斑马鱼ZF4细胞用作模型系统。poly I:C处理后，将细胞以5的多重感染 (MOI) 暴露于QD-IPNV杂种6小时。通过量子点的荧光强度评估poly I:C的抗IPNV有效性。我们的结果表明，以10 μ g/mL的poly I:C引发的ZF4细胞受到IPNV攻击的高度保护 (即，未检测到QD荧光)。总之，已经开发了一种快速有效的基于细胞的成像平台，用于使用qd-ipnv杂种评估poly I:C对ZF4细胞的抗IPNV活性。这种方法可以应用于更广泛的鱼类物种和鱼类致病病毒。

BACKGROUND & AIMS: :The application of intensity-based H2O2-responsive fluorescence nanoprobe for circulating tumor cell detection was limited by the complex background and the nanoprobe uptake in each CTC. In this context, we developed a ratiometric fluorescence nanoprobe, on which a H2O2-responsive subunit and a stable subunit grafted working as a H2O2 detector and a reference, respectively. When responding to intracellular H2O2, the reference fluorescence (580 nm) maintained as a correction background while the detector fluorescence (450 nm) was turned on to conduct CTC enumeration and intracellular H2O2 evaluation. Two normal cells and three colon cancer cells were examined to evaluate their endogenous H2O2 with the ratiometric nanoprobe by flow cytometry and confocal laser scanning microscopy. CTC sample from colorectal cancer patients was used to validate the performance of the nanoprobe for CTC enumeration and H2O2 evaluation. The results indicated that not only CTC could be effectively identified based on the "turn on" fluorescence, but also the viability of the identified CTCs could be assessed with the intensity of the reference fluorescence to avoid the false-positive number. Moreover, the clinical results demonstrated that the viability CTC count combined with intracellular H2O2 content (described as I450/580)were related to the tumor TNM stage, which might provide significant guidance for clinical treatments.

背景与目标： : 基于强度的H2O2-responsive荧光纳米探针在循环肿瘤细胞检测中的应用受到复杂背景和每个CTC中纳米探针摄取的限制。在这种情况下，我们开发了比率荧光纳米探针，在该探针上分别接枝了H2O2-responsive亚基和稳定亚基作为H2O2检测器和参考。当响应细胞内H2O2时，参考荧光 (580纳米) 保持为校正背景，同时开启检测器荧光 (450纳米) 以进行CTC计数和细胞内H2O2评估。通过流式细胞术和共聚焦激光扫描显微镜检查了两个正常细胞和三个结肠癌细胞，以使用比率纳米探针评估其内源性H2O2。使用来自结直肠癌患者的CTC样品来验证纳米探针用于CTC计数和H2O2评估的性能。结果表明，不仅可以根据 “开启” 荧光有效地鉴定CTC，而且可以根据参考荧光的强度评估鉴定的CTC的生存能力，以避免假阳性。此外，临床结果表明，活力CTC计数与细胞内H2O2含量 (描述为I450/580) 与肿瘤TNM分期有关，可为临床治疗提供重要指导。

BACKGROUND & AIMS: :Fabrication and synthesis of plasmonic structures is rapidly moving towards sub-nanometer accuracy in control over shape and inter-particle distance. This holds the promise for developing device components based on novel, non-classical electro-optical effects. Monochromated electron energy-loss spectroscopy (EELS) has in recent years demonstrated its value as a qualitative experimental technique in nano-optics and plasmonic due to its unprecedented spatial resolution. Here, we demonstrate that EELS can also be used quantitatively, to probe surface plasmon kinetics and damping in single nanostructures. Using this approach, we present from a large (>50) series of individual gold nanoparticles the plasmon Quality factors and the plasmon Dephasing times, as a function of energy/frequency. It is shown that the measured general trend applies to regular particle shapes (rods, spheres) as well as irregular shapes (dendritic, branched morphologies). The combination of direct sub-nanometer imaging with EELS-based plasmon damping analysis launches quantitative nanoplasmonics research into the sub-nanometer realm.

背景与目标： : 等离子体结构的制造和合成在控制形状和粒子间距离方面正迅速朝着亚纳米精度发展。这为基于新颖的非经典电光效应开发设备组件提供了希望。近年来，单色电子能量损失谱 (EELS) 由于其前所未有的空间分辨率，已证明其作为纳米光学和等离子体的定性实验技术的价值。在这里，我们证明了EELS也可以定量地用于探测单个纳米结构中的表面等离子体动力学和阻尼。使用这种方法，我们从大量 (>50) 的单个金纳米粒子系列中提出了等离子体激元质量因子和等离子体激元移相时间，作为能量/频率的函数。表明，测得的总体趋势适用于规则的颗粒形状 (杆，球) 以及不规则的形状 (树枝状，分支形态)。直接亚纳米成像与基于EELS的等离激元阻尼分析相结合，将定量纳米等离子体研究引入亚纳米领域。

BACKGROUND & AIMS: :In this study we describe a new methodology to physically probe individual complexes formed between proteins and DNA. By combining nanoscale, high speed physical force measurement with sensitive fluorescence imaging we investigate the complex formed between the prokaryotic DNA repair protein UvrA2 and DNA. This approach uses a triangular, optically-trapped "nanoprobe" with a nanometer scale tip protruding from one vertex. By scanning this tip along a single DNA strand suspended between surface-bound micron-scale beads, quantum-dot tagged UvrA2 molecules bound to these '"DNA tightropes" can be mechanically interrogated. Encounters with UvrA2 led to deflections of the whole nanoprobe structure, which were converted to resistive force. A force histogram from all 144 detected interactions generated a bimodal distribution centered on 2.6 and 8.1 pN, possibly reflecting the asymmetry of UvrA2's binding to DNA. These observations successfully demonstrate the use of a highly controllable purpose-designed and built synthetic nanoprobe combined with fluorescence imaging to study protein-DNA interactions at the single molecule level.

背景与目标： : 在这项研究中，我们描述了一种物理探测蛋白质和DNA之间形成的单个复合物的新方法。通过将纳米级，高速物理力测量与灵敏的荧光成像相结合，我们研究了原核DNA修复蛋白UvrA2与DNA之间形成的复合物。这种方法使用三角形的，光学捕获的 “纳米探针”，其纳米级尖端从一个顶点伸出。通过沿着悬浮在表面结合的微米级珠子之间的单个DNA链扫描该尖端，可以机械地询问与这些 “DNA牵索” 结合的量子点标记的UvrA2分子。与UvrA2的相遇导致整个纳米探针结构的偏转，并将其转换为阻力。来自所有144检测到的相互作用的力直方图产生了以2.6和8.1 pN为中心的双峰分布，这可能反映了UvrA2与DNA结合的不对称性。这些观察结果成功地证明了使用高度可控的目的设计和构建的合成纳米探针结合荧光成像技术在单分子水平上研究蛋白质-DNA相互作用。

BACKGROUND & AIMS: PURPOSE:A complete surgical excision with negative tumor margins is the single most important factor in the prediction of long-term survival for most cancer patients with solid tumors. We hypothesized that image-guided surgery using nanoparticle-enhanced photoacoustic and fluorescence imaging could significantly reduce the rate of local recurrence. METHODS:A murine model of invasive mammary carcinoma was utilized. Three experimental groups were included: (1) control; (2) tumor-bearing mice injected with non-targeted nanoprobe; and (3) tumor-bearing mice injected with targeted nanoprobe. The surgeon removed the primary tumor following the guidance of photoacoustic imaging (PAI), then inspected the surgical wound and removed the suspicious tissue using intraoperative near-infrared (NIR) fluorescence imaging. The mice were followed with bioluminescence imaging weekly to quantify local recurrence. RESULTS:Nanoprobe-enhanced photoacoustic contrast enabled PAI to map the volumetric tumor margins up to a depth of 31 mm. The targeted nanoparticles provided significantly greater enhancement than non-targeted nanoparticles. Seven mice in the group injected with the targeted nanoprobes underwent additional resections based upon NIR fluorescence imaging. Pathological analysis confirmed residual cancer cells in the re-resected specimens in 5/7 mice. Image-guided resection resulted in a significant reduction in local recurrence; 8.7 and 33.3 % of the mice in the targeted and control groups suffered recurrence, respectively. CONCLUSIONS:These results suggest that photoacoustic and NIR intraoperative imaging can effectively assist a surgeon to locate primary tumors and to identify residual disease in real-time. This technology has promise to overcome current clinical challenges that result in the need for second surgical procedures.

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BACKGROUND & AIMS: PURPOSE:Early cancer diagnosis using MRI imaging is of high global interest as a non-invasive and powerful modality. In this study, methionine was conjugated on gadolinium-based mesoporous silica nanospheres to evaluate intra-cellular uptake and its accumulation in human breast cancer cells. PROCEDURES:The contrast agent was synthesized and characterized using different techniques including N2 physisorption, thermal gravimetric analysis, dynamic light scattering, and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The intra-cellular uptake of Gd(3+) was measured by ICP-AES, fluorescent microscopy, and flow cytometry. Finally, cellular and tumor MR imaging were performed to determine in vitro and in vivo relaxometry. RESULTS:According to the results, the contrast agents accumulated in tumor cells both in vitro and in vivo. There was no significant cellular toxicity on either normal or cancer cells along with strong intense signal on T 1 compared to the unlabeled cells. CONCLUSIONS:The results showed that the novel contrast agent could become a useful tool in early detection of cancer.

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BACKGROUND & AIMS: :Abnormal H2O2 levels are closely related to many diseases, including inflammation and cancers. Herein, we simultaneously load HRP and its substrate, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), into liposomal nanoparticles, obtaining a Lipo@HRP&ABTS optical nanoprobe for in vivo H2O2-responsive chromogenic assay with great specificity and sensitivity. In the presence of H2O2, colorless ABTS would be converted by HRP into the oxidized form with strong near-infrared (NIR) absorbance, enabling photoacoustic detection of H2O2 down to submicromolar concentrations. Using Lipo@HRP&ABTS as an H2O2-responsive nanoprobe, we could accurately detect the inflammation processes induced by LPS or bacterial infection in which H2O2 is generated. Meanwhile, upon systemic administration of this nanoprobe we realize in vivo photoacoustic imaging of small s.c. tumors (∼2 mm in size) as well as orthotopic brain gliomas, by detecting H2O2 produced by tumor cells. Interestingly, local injection of Lipo@HRP&ABTS further enables differentiation of metastatic lymph nodes from those nonmetastatic ones, based on their difference in H2O2 contents. Moreover, using the H2O2-dependent strong NIR absorbance of Lipo@HRP&ABTS, tumor-specific photothermal therapy is also achieved. This work thus develops a sensitive H2O2-responsive optical nanoprobe useful not only for in vivo detection of inflammation but also for tumor-specific theranostic applications.

背景与目标： : H2O2水平异常与许多疾病密切相关，包括炎症和癌症。在本文中，我们同时将HRP及其底物2,2 '-叠氮基-双 (3-乙基苯并噻唑啉-6-磺酸) (ABTS) 加载到脂质体纳米颗粒中，获得Lipo @ HRP & ABTS光学纳米探针，用于具有高度特异性和灵敏度的体内H2O2-responsive显色测定。在存在H2O2的情况下，HRP会将无色ABTS转化为具有强近红外 (NIR) 吸光度的氧化形式，从而能够将H2O2的光声检测降至亚微摩尔浓度。使用Lipo @ HRP & ABTS作为H2O2-responsive纳米探针，我们可以准确地检测由LPS或细菌感染引起的H2O2引起的炎症过程。同时，在系统施用该纳米探针后，我们实现了小s.C.的体内光声成像。通过检测肿瘤细胞产生的H2O2，肿瘤 (约2毫米大小) 以及原位脑胶质瘤。有趣的是，根据H2O2含量的差异，局部注射Lipo @ HRP和ABTS进一步使转移淋巴结与非转移淋巴结区分。此外，使用Lipo @ HRP & ABTS H2O2-dependent强的NIR吸光度，还可以实现肿瘤特异性光热治疗。因此，这项工作开发了一种灵敏的H2O2-responsive光学纳米探针，不仅可用于体内检测炎症，而且可用于肿瘤特异性治疗应用。

BACKGROUND & AIMS: PURPOSE:The efficacy of pro-angiogenic therapy is difficult to evaluate with current diagnostic modalities. The objectives were to develop a non-invasive imaging strategy to define the temporal characteristics of angiogenesis and to evaluate the response to pro-angiogenic therapy in diabetic stroke mouse models. METHODS:A home-made ανβ3 integrin-targeted multi-modal nanoprobe was intravenously injected into mouse models at set time points after photothrombotic stroke. Magnetic resonance imaging (MRI) and near-infrared fluorescence (NIRF) imaging were carried out at 24 h post-injection. Bone marrow-derived endothelial progenitor cells (EPCs) were infused into the mouse models of ischemic stroke to stimulate angiogenesis. RESULTS:The peak signal intensity in the ischemic-angiogenic area of diabetic and wild-type mouse models was achieved on day 10, with significantly lower signal enhancement observed in the diabetic models. Although the signal intensity was significantly higher after EPC treatment in both models, the enhancement was less pronounced in the diabetic animals compared with the wild-type controls. Histological analysis revealed that the microvessel density and expression of β3 integrin were correlated with the signal intensity assessed with MRI and NIRF imaging. CONCLUSIONS:The non-invasive imaging method could be used for early and accurate evaluation of the response to pro-angiogenic therapy in diabetic stroke models.

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