Author
Xiaoyuan Chen
Other affiliations: Brown University, University of Southern California, Uniformed Services University of the Health Sciences ...read more
Bio: Xiaoyuan Chen is an academic researcher from National University of Singapore. The author has contributed to research in topics: Physics & Photothermal therapy. The author has an hindex of 149, co-authored 994 publications receiving 89870 citations. Previous affiliations of Xiaoyuan Chen include Brown University & University of Southern California.
Topics: Physics, Photothermal therapy, Medicine, Molecular imaging, In vivo
Papers published on a yearly basis
Papers
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TL;DR: A novel intelligent tumor microenvironment-activated ratiometric PAI nanoprobe is developed with the intention of specific ultrasensitive detection of intratumoral GSH by overcoming the limitations of previously reported fluorescent or PA imaging sensors.
Abstract: Glutathione (GSH), one of the most significant reducing species in vivo, plays important roles in a variety of diseases and cellular functions. Precise quantification of GSH via advanced noninvasive photoacoustic imaging (PAI) is of vital significance for the early diagnosis and prompt treatment of GSH-related deep-seated diseases, which stresses the need for custom-design of GSH-sensitive PAI probes with changeable near-infrared spectroscopy (NIR) absorption. In this work, a novel intelligent tumor microenvironment-activated ratiometric PAI nanoprobe is first developed with the intention of specific ultrasensitive detection of intratumoral GSH by overcoming the limitations of previously reported fluorescent or PA imaging sensors. This special ratiometric PAI nanoprobe (CR-POM) is synthesized through the self-assembly of croconaine (CR) dye and molybdenum-based polyoxometalate (POM) clusters with opposite NIR absorbance change in response to GSH. The resulting amplified ratiometric absorbance (Ab866/Ab700), the relatively low limit of detection value (0.51 mM), and the unique acidity-activated self-aggregation contribute to the prolonged intratumoral retention and enhanced tumor accumulation of CR-POM for accurate quantification of intratumoral GSH (0.5-10 mM). Featuring the additional merit of 64Cu radiolabeling for whole-body positron-emission tomography imaging, the smartly designed CR-POM nanoprobe will open new horizons for real-time noninvasive monitoring of biodistribution and simultaneous accurate quantification of GSH levels, especially in tumor and other GSH-related pathophysiological processes.
35 citations
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TL;DR: Fluinated ion liquids (ILs) are reported as a new type of fluorine agents and a fluorinated ionic liquid-based activatable 19F MRI platform (FILAMP), which relies on the phase transition of ILs, which demonstrates the potential of FILAMP as a robust activatable 18F probe for diagnosis and monitoring of biological and pathological processes.
35 citations
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35 citations
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TL;DR: The data suggest that O SP-1 peptide is osteosarcoma specific, and the binding site of OSP-1 might be related to heparinase II/III family protein, which binds and reacts with heparan sulfate proteoglycans.
Abstract: Purpose: Osteosarcoma represents the most common malignant primary bone tumor in childhood; however, the survival rate has remained unchanged for the past 20 years. To improve existing diagnosis and treatment methods and broaden the spectrum of imaging agents that can be used for early detection and assessment of tumor response to therapy, we performed a phage display–based screening for peptide sequences that bind specifically to osteosarcoma cells. Experimental Design: From the Ph.D.-12 phage display peptide library composed of 2.7 × 10 9 different displayed peptides, one peptide was enriched after four rounds of in vitro selection in 143B osteosarcoma tumor cells with 293T human embryonic kidney cells as a control. Both the peptide and the phage clone displaying the peptide were conjugated with fluorescent dyes for in vitro cell and ex vivo tumor tissue stainings . The peptide was further labeled with 18 F for positron emission tomography imaging studies. Cell uptake and efflux and ex vivo biodistribution were also done with 18 F-labeled osteosarcoma specific peptide. Results: ASGALSPSRLDT was the dominant sequence isolated from biopanning and named as OSP-1. OSP-1 shares a significant homology with heparinase II/III family protein, which binds and reacts with heparan sulfate proteoglycans. The fluorescence staining showed that FITC-OSP-1-phage or Cy5.5-OSP-1 had high binding with a panel of osteosarcoma cell lines, much less binding with UM-SCC1 human head and neck squamous cell carcinoma cells, and almost no binding with 293T cells, whereas the scrambled peptide OSP-S had virtually no binding to all the cell lines. 18 F-OSP-1 had significantly higher accumulation in 143B tumor cells both in vitro and in vivo than 18 F-OSP-S. 18 F-OSP-1 also had higher uptake in 143B tumors than in UM-SCC-1 tumors. Conclusions: Our data suggest that OSP-1 peptide is osteosarcoma specific, and the binding site of OSP-1 might be related to heparan sulfate proteoglycans. Appropriately labeled OSP-1 peptide has the potential to serve as a novel probe for osteosarcoma imaging. Clin Cancer Res; 16(16); 4268–77. ©2010 AACR.
34 citations
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TL;DR: A novel FRET fluorescence “off–on” system based on the highly specific, sensitive and effective C–C bond cleavage of certain dihydropyridine derivatives was reported for real-time quantitative imaging of nitric oxide (NO).
Abstract: A novel Forster resonance energy transfer (FRET) fluorescence “off–on” system based on the highly specific, sensitive and effective C–C bond cleavage of certain dihydropyridine derivatives was reported for real-time quantitative imaging of nitric oxide (NO). 1,4-Dihydropyridine was synthesized as a novel linker which could connect customized fluorophores and their corresponding quenchers. The specific and quantitative response to NO is confirmed using fluorescence spectrometry with the classical example of fluorescein isothiocyanate (FITC) and [4′-(N,N′-dimethylamino)phenylazo] benzoyl (DABCYL). The fluorescence intensity increased linearly with the increase in the amount of NO. Cells incubated with an exogenous NO donor emitted fluorescence as expected. A high fluorescence intensity was detected in macrophages which generate NO when incubated with lipopolysaccharide (LPS). The in vivo imaging shows about an 8-fold contrast between Freund's adjuvant stimulated feet and normal feet in mice after intravenous injection, which was the first example of in vivo semiquantitative fluorescence imaging of NO in mammals.
34 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
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28,685 citations
28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
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TL;DR: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties are equally important.
Abstract: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties * To whom correspondence should be addressed. Phone, 404-8940292; fax, 404-894-0294; e-mail, mostafa.el-sayed@ chemistry.gatech.edu. † Case Western Reserve UniversitysMillis 2258. ‡ Phone, 216-368-5918; fax, 216-368-3006; e-mail, burda@case.edu. § Georgia Institute of Technology. 1025 Chem. Rev. 2005, 105, 1025−1102
6,852 citations