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: The ability to quantitatively image HER-2 expression in a noninvasive manner can aid in lesion detection, patient stratification, new drug development/validation, dose optimization, and treatment monitoring, as well as enable maximum benefit in cancer patient management.
Abstract: The human epidermal growth factor receptor 2 (HER-2) is a key member of the HER family of receptor tyrosine kinases. Activation of HER-2 affects cell growth, proliferation, migration, adhesion, and survival. Due to its crucial role in carcinogenesis and tumor progression, HER-2 has been intensively investigated as a target for cancer therapy. The ability to quantitatively image HER-2 expression in a noninvasive manner can aid in lesion detection, patient stratification, new drug development/validation, dose optimization, and treatment monitoring. This review summarizes the current state of understanding in multimodality imaging of HER-2 using positron emission tomography (PET), single photon emission computed tomography (SPECT), optical, and magnetic resonance (MR) imaging with HER-2 specific antibodies, antibody derivatives and affibodies as targeting ligands. Successful development of new HER-2 targeted imaging agents with optimal in vivo stability, targeting efficacy, and desirable pharmacokinetics for clinical translation will enable maximum benefit in cancer patient management.
31 citations
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TL;DR: The results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.
Abstract: Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/ 64 Cu dual-labeled cyclic RGD peptide. Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA)-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD) method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data. Results: The dual-labeled probe 64 Cu-RGD-C(DOTA)-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp) derived from dynamic optical imaging (1.762 ± 0.020) is comparable to that from dynamic PET (1.752 ± 0.026). Conclusion: The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.
31 citations
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TL;DR: Dual-tracer imaging with the combination of lymphatic mapping agents and tumor targeting agents can identify tumor metastases within SLNs, thus may provide accurate and real-time intra-operative guidance to spare the time spent waiting for a biopsy result.
Abstract: Purpose: Sentinel lymph node biopsy (SLNB) has emerged as the preferred standard procedure in patients with breast cancer, melanoma and other types of cancer. Herein, we developed a method to intra-operatively map SLNs and differentiate tumor metastases within SLNs at the same time, with the aim to provide more accurate and real-time intraoperative guidance. Experimental Design: Hyaluronic acid (HA), a ligand of lymphatic vessel endothelial hyaluronan receptor (LYVE)-1, is employed as a SLN mapping agent after being conjugated with a near-infrared fluorophore (Cy5.5). Different sized HAs (5, 10 and 20K) were tested in normal mice and mice with localized inflammation to optimize LN retention time and signal to background ratio. Cetuximab, an antibody against epidermal growth factor receptor (EGFR), and trastuzumab, an antibody against human epidermal growth factor receptor 2 (HER2), were labeled with near-infrared fluorophore (IRDye800) for detecting metastatic tumors. LN metastasis model was developed by hock injection of firefly luciferase engineered human head neck squamous carcinoma cancer UM-SCC-22B cells or human ovarian cancer SKOV-3 cells. The metastases within LNs were confirmed by bioluminescence imaging (BLI). IRDye800-Antibodies were intravenously administered 24 h before local administration of Cy5.5-HA. Optical imaging was then performed to identify nodal metastases. Results: Binding of HA with LYVE-1 was confirmed by ELISA and fluorescence staining. HA with a size of 10K was chosen based on the favorable migration and retention profile. After sequential administration of IRDye800-antibodies intravenously and Cy5.5-HA locally to a mouse model with LN metastases and fluorescence optical imaging, partially metastasized LNs were successfully distinguished from un-metastasized LNs and fully tumor occupied LNs, based on the different signal patterns. Conclusions: Fluorophore conjugated HA is a potential lymphatic mapping agent for SLNB. Dual-tracer imaging with the combination of lymphatic mapping agents and tumor targeting agents can identify tumor metastases within SLNs, thus may provide accurate and real-time intra-operative guidance to spare the time spent waiting for a biopsy result.
31 citations
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TL;DR: PET and SPECT imaging are sensitive methods for the quantitation of AD biomarkers and there are only several radioligands with high selectivity and specificity to binding sites and appropriate pharmacokinetics that have been tested in AD patients.
Abstract: Alzheimer's disease (AD) is a neurodegenerative disease characterized by a progressive loss of neurotransmitters, as well as acetylcholinesterase and nicotinic acetylcholine receptors in the central nervous system that leads to learning and memory deficits, among other problems. The disease is associated with increased production and accumulation extracellular amyloid plaques and neurofibrillary tangles in aging human brain, shown in postmortem exams. New methods for reliable in vivo measurement of brain therefore would be much more ideal. PET and SPECT imaging are sensitive methods for the quantitation of AD biomarkers. The development of molecular imaging agents for AD is critically important in the early diagnosis, neuropathogenesis studies and treatment of AD. A number of potential diagnostic PET and SPECT imaging agents targeting AD have been synthesized and evaluated. Although many agents showed excellent results for in vitro monitoring of the disease, there are only several radioligands with high selectivity and specificity to binding sites and appropriate pharmacokinetics, such as [11C]MP4A, [11C]PMP, [11C]nicotine, 2- or 6-[18F]fluoro-A-85380, [11C]SB-13, [11C]PIB, and [18F]FDDNP, that have been tested in AD patients. Here we review some recent progress and development of AD imaging agents using PET and SPECT in human clinical studies.
30 citations
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TL;DR: Kinetic parameters were demonstrated to be valuable for separating specific and non-specific binding and may allow more sensitive and detailed quantification than simple standardized uptake value analysis.
Abstract: Purpose
Non-invasive PET imaging with radiolabeled RGD peptides for αvβ3 integrin targeting has become an important tool for tumor diagnosis and treatment monitoring in both pre-clinical and clinical studies. To better understand the molecular process and tracer pharmacokinetics, we introduced kinetic modeling in the investigation of 18F-labeled RGD peptide monomer 18F-FP-c(RGDyK) (denoted as 18F-FPRGD) and dimer 18F-FP-PEG3-E[c(RGDyK)]2 (denoted as 18F-FPPRGD2).
30 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