title: Rational design of magnetic nanorattles as contrast agents for ultrasound/magnetic resonance dual-modality imaging.
abstract: Nanorattles, as promising functional hollow nanomaterials, show considerable advantages in a variety of applications for drug delivery, biosensors, and biomedical imaging because of their tailored ability in both the movable core and shell. In this study, we formulate a facile controllable route to synthesize a monodisperse magnetic nanorattle with an Fe3O4 superparticle as the core and poly(vinylsilane) (PVS) as the outer shell (Fe3O4@air@PVS) using the polymer-backbone-transition strategy. In the process of synthesis, besides acting as the precursor for the PVS shells of nanorattles, organosilica (o-SiO2) plays the role of template for the middle cavities. The structures of nanorattles can be easily formed via etching treatment of NaOH solution. Through encapsulating sensitive perfluorohexane (PFH) in the cavities of Fe3O4@air@PVS, the biocompatible magnetic nanosystem shows a relatively stable ultrasound signal intensity and a high r2 value of 62.19 mM(-1) s(-1) for magnetic resonance imaging (MRI). After intravenous administration of nanorattles to a healthy rat, dramatically positively enhanced ultrasound imaging and negatively enhanced T2-weighted MRI are detected in the liver. Furthermore, when the Fe3O4@PFH@PVS nanorattles are administered to tumor-bearing mice, a significant passive accumulation in the tumor via an electron paramagnetic resonance effect is detected by both ultrasound imaging and MRI. In vivo experiments indicate that the obtained Fe3O4@PFH@PVS nanorattles can be used as dual-modality contrast agents for simultaneous ultrasound and MRI detection.
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, and Laboratory of Advanced Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors.forename: Peng
authors.initials: P
authors.lastname: Yang
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Xianfu
authors.initials: X
authors.lastname: Luo
authors.forename: Yuting
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.forename: Weibin
authors.initials: W
authors.lastname: Shi
authors.forename: Changchun
authors.initials: C
authors.lastname: Wang
mesh_terms: D000818:Animals; D002470:Cell Survival; D003287:Contrast Media; D005290:Ferric Compounds / Q000737:chemistry; D005466:Fluorocarbons / Q000737:chemistry; D057809:HEK293 Cells; D006801:Humans; D060328:Magnetic Phenomena; D008279:Magnetic Resonance Imaging; D008819:Mice, Nude; D064847:Multimodal Imaging; D049329:Nanostructures / Q000648:ultrastructure; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology; D051381:Rats; D012821:Silanes / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014465:Ultrasonics
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D005466:Fluorocarbons; D012821:Silanes; C000499:ferric oxide; C078626:perflexane