Guan-shu Liu

Learn More
Biocompatible nanomaterials and hydrogels have become an important tool for improving cell-based therapies by promoting cell survival and protecting cell transplants from immune rejection. Although their potential benefit has been widely evaluated, at present it is not possible to determine, in vivo, if and how long cells remain viable following their(More)
PURPOSE Modern imaging technologies such as CT, PET, SPECT, and MRI employ contrast agents to visualize the tumor microenvironment, providing information on malignancy and response to treatment. Currently, all clinical imaging agents require chemical labeling, i.e. with iodine (CT), radioisotopes (PET/SPECT), or paramagnetic metals (MRI). The goal was to(More)
Chemical exchange saturation transfer (CEST) has emerged as a novel MRI contrast mechanism that is well suited for molecular imaging studies. This new mechanism can be used to detect small amounts of contrast agent through the saturation of rapidly exchanging protons on these agents, allowing a wide range of applications. CEST technology has a number of(More)
PARAmagnetic Chemical Exchange Saturation Transfer (PARACEST) is a novel contrast mechanism for MRI. A PARACEST MRI methodology with high temporal resolution is highly desired for in vivo MRI applications of molecular imaging. To address this need, a strategy has been developed that includes a long selective saturation period before each repetition of a(More)
11 Abstract 12 We have investigated the antitumor functions and mechanisms of 1,2-naphthoquinone-2-thiosemicarbazone (NQTS) and its metal 13 complexes (Cu 2+ , Pd 2+ , and Ni 2+) against MCF-7 human breast cancer cells. The cells were dosed with these complexes at varying 14 concentrations, and cell viability was measured by a sulforhodamine B (SRB) method.(More)
PURPOSE Protein kinases including protein kinase A (PKA) underlie myriad important signaling pathways. The ability to monitor kinase activity in vivo and in real-time with high spatial resolution in genetically specified cellular populations is a yet unmet need, crucial for understanding complex biological systems as well as for preclinical development and(More)
A variety of (super)paramagnetic contrast agents are available for enhanced MR visualization of specific tissues, cells, or molecules. To develop alternative contrast agents without the presence of metal ions, liposomes were developed containing simple bioorganic and biodegradable compounds that produce diamagnetic chemical exchange saturation transfer MR(More)
PURPOSE To develop a noninvasive MRI method for determining the germination and infection of tumor-homing bacteria in bacteriolytic cancer therapy using endogenous CEST contrast. METHODS The CEST parameters of the anaerobic gram-positive bacterium Clostridium novyi-NT (C. novyi-NT) were first characterized in vitro, then used to detect C. novyi-NT(More)
Alterations in mucin expression and glycosylation are associated with cancer development. Underglycosylated mucin-1 (uMUC1) is overexpressed in most malignant adenocarcinomas of epithelial origin (for example, colon, breast and ovarian cancer). Its counterpart MUC1 is a large polymer rich in glycans containing multiple exchangeable OH protons, which is(More)
Chemical exchange saturation transfer MRI is a promising new technique for cellular and molecular imaging. This contrast allows the detection of tumors and ischemia without the use of gadolinium as well as the design of microenvironment-sensitive probes that can be discriminated based on their exchange contrast properties and saturation frequency. Current(More)