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.

A facile synthetic approach for SiO2@Co3O4 core–shell nanorattles with enhanced peroxidase-like activity

“…These type of structures are referred to as "nanorattles". 24,29 In addition to the nanorattle morphology, the SiO2@Co3O4 samples show porous hairlike morphology for the Co3O4 shell. The measured shell thickness values are 37 ± 3 nm, 63 ± 8 nm, for S1 and S2, respectively.…”

“…They have a large number of applications in biosensing, energy storage, catalysis and biomedicine. [22][23][24][25] Nanorattles exhibit interesting characteristics which are useful in multifunctional areas. One of the most explored applications of these materials is their use as nanocatalysts.…”

Multifunctional nanocomposite based on halloysite nanotubes for efficient luminescent bioimaging and magnetic resonance imaging

“…36 Earlier studies have reported that Fe 3 O 4 can shorten T 2 relaxation time and that Fe 3 O 4 NPs have great potential as MRI contrast agents. [37][38][39] To investigate the MRI signal enhancement effects of the …”

Ultra‐Early Diagnosis of Acute Myocardial Infarction in Rats Using Ultrasound Imaging of Hollow Double‐Layer Silica Nanospheres

“…Ultrasound (US) imaging is a well‐established medical imaging modality with convenient, fast, and cost‐effective features . Compared to coronary angiography and computed tomography, US is better at providing noninvasive real‐time detection, which is ideally suited for determining motion changes of the heart and identifying cardiovascular disease (CVD) .…”