Browsing by Author "Chen, Ting-Jung"

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Ligand and metal complex
(2011-03-17)
Wang, Yun-Ming
;
Chen, Ting-Jung
A ligand of Formula (I) is provided:wherein A4 represents a hydrogen atom, a nitro group, an amino group, a thiocyanato group, or —Z—Y, in which Z is a divalent linking group and Y is a group derived from a biocompatible molecule, with the proviso that when X is methylene, A4 cannot be a hydrogen atom or a nitro group. A metal complex having the ligand is also provided and is useful as a blood pool contrast agent or a targeting contrast agent.
NANOPARTICLE AND MAGNETIC RESONANCE IMAGING CONTRAST AGENT
(2011-04-21)
Wang, Yun-Ming
;
Chen, Ting-Jung
A nanoparticle contains a core including superparamagnetic nanoparticles and having an outer surface, and siloxanyl moieties covalently coupled to the outer surface of the core and having Formula (I):In formula (I): X1 and X2 independently represent methylene, ethylene or propylene; R represents an optionally substituted pyridyl group, or —S—R is a group derived from a targeting ligand containing —SH group and effective to bind specifically with a predetermined targeted cell in an object; n and m independently represent an integer ranging from 1 to 3; and p represents an integer ranging from 9 to 45. The nanoparticles are suitable for use as a magnetic resonance imaging contrast agent.
Targeted Herceptin-dextran iron oxide nanoparticles for noninvasive imaging of HER2/neu receptors using MRI
(2009-02-01)
Chen, Ting-Jung
;
Cheng, Tsan-Hwang
;
Chen, Chiao-Yun
;
Hsu, Sodio C. N.
;
Cheng, Tian-Lu
A novel magnetic resonance imaging (MRI) contrast agent containing Herceptin is reported. The surfaces of superparamagnetic iron oxide nanoparticles were modified with dextran and conjugated with Herceptin (Herceptin-nanoparticles) to improve their dispersion, magnetization, and targeting of the specific receptors on cells. From analytical results, we found that Herceptin nanoparticles were well dispersed in solutions of various pH range, and had no hysteresis, high saturation magnetization ( 80 emu/g), and low cytotoxicity to a variety of cells. Notably, the magnetic resonance enhancements for the different breast cancer cell lines (BT-474, SKBR-3, MDA-MB-231, and MCF-7) are proportional to the HER2/neu expression level in vitro. When Herceptin-nanoparticles were administered to mice bearing breast tumor allograft by intravenous injection, the tumor site was detected in T(2)-weighted magnetic resonance images as a 45% enhancement drop, indicating a high level of accumulation of the contrast agent within the tumor sites. Therefore, targeting of cancer cells was observed by in vitro and in vivo MRI studies using Herceptin-nanoparticles contrast agent. In addition, Herceptin-nanoparticles enhancing the magnetic resonance signal intensity were sufficient to detect the cell lines with a low level of HER2/neu expression.
Targeted RGD nanoparticles for highly sensitive in vivo integrin receptor imaging
(2012-01-01)
Lin, Ren-Yen
;
Dayananda, Kasala
;
Chen, Ting-Jung
;
Chen, Chiao-Yun
;
Liu, Gin-Chung
A new magnetic resonance imaging (MRI) contrast bearing RGD peptide is reported. In this study, ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles with various sizes were prepared. Particles sizes between 6 and 13?nm were tuned by varying the stirring rate. Remarkable negative contrast was observed because USPIO nanoparticles (13.1?+/-?2.1?nm) generated high transversal relaxivity r2 (188?+/-?3?m m-1?s-1) and saturation magnetization (94?emu?g-1 Fe). The USPIO nanoparticles were coated with PDA [2-(pyridyldithio)-ethylamine; PDA nanoparticles] containing functional polymer, which can be readily synthesized by Michael addition. The PDA nanoparticles were conjugated with RGD peptide (RGD nanoparticles) for targeting the specific site. The target specificity and high relaxivity allowed RGD nanoparticles to differentiate the expression level of integrin receptor on several cell lines and tumors (MCF-7, A-549, HT-29 and HT-1080) by in vitro and in vivo MR imaging. Importantly, a remarkable negative contrast (-51.3?+/-?6.7%) was observed for in vivo MR imaging of MCF-7 tumor. This result implies that the RGD nanoparticles that greatly enhance the MR imaging are highly sensitive for early stage tumor detection. Copyright (c) 2012 John Wiley & Sons, Ltd.