Xiaoyuan Chen

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.

Gadolinium-Rose Bengal Coordination Polymer Nanodots for MR-/Fluorescence-Image-Guided Radiation and Photodynamic Therapy.

Abstract: Combination therapy based on nanomedicine has gained momentum in oncology in recent years, offering superior safety and efficacy over monotherapies. It is critical to design theranostics that are composed of imaging and therapeutic agents already approved. Herein, gadolinium (Gd)-rose bengal coordination polymer nanodots (GRDs) are reported. The GRDs exhibit a unique absorption property and 7.7-fold luminescence enhancement, as well as a 1.9-fold increase in singlet oxygen generation efficiency over free rose bengal. Meanwhile, GRDs exhibit a twofold increase in r1 relaxivity over gadopentetic acid (Gd-DTPA) and have better X-ray absorption ability than rose bengal alone. These excellent properties of the GRDs are verified both in vitro and in vivo. The combination of photodynamic therapy (PDT) and radiation therapy (RT) more significantly inhibits tumor growth than monotherapies (i.e., PDT or RT). This work offers a new route to designing and synthesizing Gd-based nanotheranostics for image-guided cancer therapy.

Quantitative radioimmunoPET imaging of EphA2 in tumor-bearing mice

Abstract: EphA2 receptor tyrosine kinase is significantly overexpressed in a wide variety of cancer types. High EphA2 expression has been correlated with increased metastatic potential and poor patient survival. Although many recent reports have focused on blocking the EphA2 signaling pathway in cancer, the in vivo imaging of EphA2 has not yet been investigated. We labeled 1C1, a humanized monoclonal antibody against both human and murine EphA2, with 64Cu through the chelating agent 1,4,7,10-tetraazacyclododecane N,N′,N″,N″′-tetraacetic acid (DOTA) and carried out positron emission tomography (PET) imaging of eight tumor models with different EphA2 expression levels. Western blotting of tumor tissue lysate was performed to correlate the EphA2 expression level with 64Cu-DOTA-1C1 uptake in the tumors. Immunofluorescence staining and biodistribution studies were also carried out to validate the in vivo results. The radiolabeling yield was 88.9 ± 9.5% (n = 7) and the specific activity of 64Cu-DOTA-1C1 was 1.32 ± 0.14 GBq/mg of 1C1 mAb. The antibody retained antigen-binding affinity/specificity after DOTA conjugation as measured by FACS analysis. The uptake of 64Cu-DOTA-1C1 in CT-26 tumors was as high as 25.1 ± 2.5 %ID/g (n = 3) at 18 h post injection. 64Cu-DOTA-IgG, an isotype-matched control, exhibited minimal non-specific uptake in all eight tumor models. In vivo EphA2 specificity of 64Cu-DOTA-1C1 was confirmed by successful blocking of CT-26 tumor uptake by unlabeled 1C1. Most importantly, the tumor uptake value obtained from PET imaging had excellent linear correlation with the relative tumor tissue EphA2 expression level measured by Western blot, where r 2 equals 0.90 and 0.92 at 18 h and 42 h post injection, respectively. The tumor uptake of 64Cu-DOTA-1C1 measured by microPET imaging reflects tumor EphA2 expression level in vivo. This is, to our knowledge, the first report of quantitative radioimmunoPET imaging of EphA2 in living subjects. Future clinical investigation of 64Cu-DOTA-1C1 is warranted.

Ultrahigh 19F Loaded Cu1.75S Nanoprobes for Simultaneous 19F Magnetic Resonance Imaging and Photothermal Therapy

Abstract: 19F magnetic resonance imaging (MRI) is a powerful noninvasive, sensitive, and accurate molecular imaging technique for early diagnosis of diseases. The major challenge of 19F MRI is signal attenuation caused by the reduced solubility of probes with increased number of fluorine atoms and the restriction of molecular mobility. Herein, we present a versatile one-pot strategy for the fabrication of a multifunctional nanoprobe with high 19F loading (∼2.0 × 108 19F atoms per Cu1.75S nanoparticle). Due to the high 19F loading and good molecular mobility that results from the small particle size (20.8 ± 2.0 nm) and ultrathin polymer coating, this nanoprobe demonstrates ultrahigh 19F MRI signal. In vivo tests show that this multifunctional nanoprobe is suitable for 19F MRI and photothermal therapy. This versatile fabrication strategy has also been readily extended to other single-particle nanoprobes for ablation and sensitive multimodal imaging.

Cell Death Mediated by the Pyroptosis Pathway with the Aid of Nanotechnology: Prospects for Cancer Therapy

Abstract: Pyroptosis, a unique form of programmed cell death (PCD) that is characterized by DNA fragmentation, chromatin condensation, cellular swelling with big bubbles, and leakage of cell content, has been proven to have a close relationship with human diseases, such as inflammatory diseases and malignant tumors. Since a new gasdermin-D (GSDMD) protein was identified in 2015, various strategies have been developed to induce pyroptosis for cancer therapy, including ions, small-molecule drugs and nanomaterials. Although there are a number of reviews about the close relationship between the pyroptosis mechanism and the occurrence of various cancers, a summary covering recent progress in the field of nanomedicines in pyroptosis-based cancer therapy has not yet been presented. Therefore, it is urgent to fill this gap and light up future directions for the use of this powerful tool to combat cancer. In this Minireview, recent progress in cancer treatment based on pyroptosis induced by nanoparticles will be described in detail, the design highlights and the therapeutic advantages are emphasized, and future perspectives in this emerging area are proposed.

Carbon-dot-based two-photon visible nanocarriers for safe and highly efficient delivery of siRNA and DNA.

Abstract: A simple and versatile nanoparticulate siRNA and DNA delivery vehicle is reported, based on photonic Cdots by using Alkyl-PEI2k for surface passivation.

I and i

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 …

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

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。

Chemistry and properties of nanocrystals of different shapes.

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