title: Fluorescence-tagged amphiphilic brush copolymer encapsulated Gd2O3 core-shell nanostructures for enhanced T 1 contrast effect and fluorescent imaging.
abstract: To obtain suitable T 1 contrast agents for magnetic resonance imaging (MRI) application, aqueous Gd2O3 nanoparticles (NPs) with high longitudinal relativity (r 1) are demanded. High quality Gd2O3 NPs are usually synthesized through a non-hydrolytic route which requires post-synthetic modification to render the NPs water soluble. The current challenge is to obtain aqueous Gd2O3 NPs with high colloidal stability and enhanced r 1 relaxivity. To overcome this challenge, fluorescence-tagged amphiphilic brush copolymer (AFCP) encapsulated Gd2O3 NPs were proposed as suitable T 1 contrast agents. Such a coating layer provided (i) superior aqueous stability, (ii) biocompatibility, as well as (iii) multi-modality (conjugation with fluorescence dye). The polymeric coating layer thickness was simply adjusted by varying the phase-transfer parameters. By reducing the coating thickness, i.e. the distance between the paramagnetic centre and surrounding water protons, the r 1 relaxivity could be enhanced. In contrast, a thicker polymeric layer coating prevents Gd(3+) ions leakage, thus improving its biocompatibility. Therefore, it is important to strike a balance between the biocompatibility and the r 1 relaxivity behaviour. Lastly, by conjugating fluorescence moiety, an additional imaging modality was enabled, as demonstrated from the cell-labelling experiment.
authors.affiliation: Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore (NUS), 7 Engineering Drive 1, Singapore 117574.
authors.forename: Fenghe
authors.initials: F
authors.lastname: Wang
authors.forename: Erwin
authors.initials: E
authors.lastname: Peng
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Pingjing
authors.initials: P
authors.lastname: Li
authors.forename: Sam Fong Yau
authors.initials: SF
authors.lastname: Li
authors.forename: Jun Min
authors.initials: JM
authors.lastname: Xue
mesh_terms: D003287:Contrast Media; D005453:Fluorescence; D005682:Gadolinium / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D053758:Nanoparticles; D011108:Polymers
chemical_list: D003287:Contrast Media; D011108:Polymers; C030581:gadolinium oxide; D005682:Gadolinium