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.

Self-assembled microbubbles as contrast agents for ultrasound/magnetic resonance dual-modality imaging

“…3b, after getting the IONPs to self-assemble into microcapsules, r 2 greatly increased from 15.7 s À1 mM À1 to 87.9-139.6 s À1 mM À1 . When agglomeration of elementary IONP cores occurs, the transverse relaxivity increases as already described in the literature [4,5,33]. Furthermore, after introducing C 6 F 14 into the interiors of the microcapsules, the r 2 relaxation decreased to 16.7-23.0 s À1 mM À1 for the SAMBs.…”

Development of Stabilized Magnetite Nanoparticles for Medical Applications

“…Mesoporous iron oxides such as Fe 3 O 4 and -Fe 2 O 3 and CoFe 2 O 4 are successfully used in the field of magnetic fluids, catalysis, biotechnology/biomedicine, magnetic resonance imaging, and magnetic recording devices because of their paramagnetism, biocompatibility, and safety [7][8][9][10][11]. Owing to their large surface area and well-defined pore structure and size, the lack of toxicity, and the possibility of targeted accumulation in the desired tissue, mesoporous Fe 3 O 4 nanospheres are extensively used as targeted drug delivery systems [12].…”

Self-organization of an optomagnetic CoFe2O4–ZnS nanocomposite: preparation and characterization

“…In particular, optomagnetic nanocomposites have attracted attention in recent years due to their multifunctional properties, thereby expanding their use in photocatalyis and biomedical application such as multimodal fluorescence imaging, magnetic resonance imaging (MRI), magnetic separation and drug targeting [7][8][9]. More specifically, magnetic nanoparticles (MNPs) combined with QDs have been developed into specific functionalized luminescent magnetic nanocomposites (LMNs), which have the advantages of both MNPs and QDs [10][11][12].…”