title: Targeted biodegradable dendritic MRI contrast agent for enhanced tumor imaging.
abstract: Highly sensitive and safe contrast agents (CAs) are essential for magnetic resonance imaging (MRI) to achieve accurate tumor detection and imaging. Dendrimer-based macromolecular MRI contrast agents are advantageous owing to their tumor-targeting ability, enhanced imaging contrast and enlarged imaging window. However, most of them have drawbacks of non-degradability and thereby long-term retention in body and toxicity. Herein, a tumor-targeting biodegradable dendritic CA (DCA) (FA-PEG-G2-DTPA-Gd) was prepared from a polyester dendrimer conjugated with gadolinium (Gd) chelates and PEG chains with distal folic acid. The DCA had a high longitudinal relaxivity up to 17.1mM(-1)s(-1), 4 times higher than the clinically used CA Magnevist. The MRI contrasted by FA-PEG-G2-DTPA-Gd outlined the inoculated tumor more clearly, and had much higher contrast enhancement for a much longer time than Magnevist. More importantly, the biodegradable FA-PEG-G2-DTPA-Gd gave much less Gd retentions in all the organs or tissues than non-degradable DCAs. Thus, the high efficiency in MRI contrast enhancement and low Gd retention merit it a promising CA for contrast enhanced tumor MRI.
authors: Key Laboratory of Biomass Chemical Engineering of Ministry of Education and Center for Bionanoengineering, Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
authors: Mingzhou
authors: M
authors: Ye
authors: Yue
authors: Y
authors: Qian
authors: Jianbin
authors: J
authors: Tang
authors: Hongjie
authors: H
authors: Hu
authors: Meihua
authors: M
authors: Sui
authors: Youqing
authors: Y
authors: Shen
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D003287:Contrast Media / Q000737:chemistry / Q000378:metabolism; D050091:Dendrimers / Q000737:chemistry / Q000378:metabolism; D005260:Female; D019786:Gadolinium DTPA / Q000737:chemistry / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000175:diagnosis*; D011092:Polyethylene Glycols / Q000737:chemistry / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D003287:Contrast Media; D050091:Dendrimers; D011092:Polyethylene Glycols; D019786:Gadolinium DTPA