title: Quantum dot capped magnetite nanorings as high performance nanoprobe for multiphoton fluorescence and magnetic resonance imaging.
abstract: In the present study, quantum dot (QD) capped magnetite nanorings (NRs) with a high luminescence and magnetic vortex core have been successfully developed as a new class of magnetic-fluorescent nanoprobe. Through electrostatic interaction, cationic polyethylenimine (PEI) capped QD have been firmly graft into negatively charged magnetite NRs modified with citric acid on the surface. The obtained biocompatible multicolor QD capped magnetite NRs exhibit a much stronger magnetic resonance (MR) T2* effect where the r2* relaxivity and r2*/r1 ratio are 4 times and 110 times respectively larger than those of a commercial superparamagnetic iron oxide. The multiphoton fluorescence imaging and cell uptake of QD capped magnetite NRs are also demonstrated using MGH bladder cancer cells. In particular, these QD capped magnetite NRs can escape from endosomes and be released into the cytoplasm. The obtained results from these exploratory experiments suggest that the cell-penetrating QD capped magnetite NRs could be an excellent dual-modality nanoprobe for intracellular imaging and therapeutic applications. This work has shown great potential of the magnetic vortex core based multifunctional nanoparticle as a high performance nanoprobe for biomedical applications.
authors.affiliation: Department of Materials Science and Engineering, National University of Singapore, 119260, Singapore.
authors.forename: Hai-Ming
authors.initials: HM
authors.lastname: Fan
authors.forename: Malini
authors.initials: M
authors.lastname: Olivo
authors.forename: Borys
authors.initials: B
authors.lastname: Shuter
authors.forename: Jia-Bao
authors.initials: JB
authors.lastname: Yi
authors.forename: Ramaswamy
authors.initials: R
authors.lastname: Bhuvaneswari
authors.forename: Hui-Ru
authors.initials: HR
authors.lastname: Tan
authors.forename: Gui-Chuan
authors.initials: GC
authors.lastname: Xing
authors.forename: Cheng-Teng
authors.initials: CT
authors.lastname: Ng
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Sasidharan S
authors.initials: SS
authors.lastname: Lucky
authors.forename: Boon-Huat
authors.initials: BH
authors.lastname: Bay
authors.forename: Jun
authors.initials: J
authors.lastname: Ding
mesh_terms: D052203:Ferrosoferric Oxide; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000473:pathology
chemical_list: D052203:Ferrosoferric Oxide