title: Magneto-optical nanoparticles for cyclic magnetomotive photoacoustic imaging.
abstract: Photoacoustic imaging has emerged as a highly promising tool to visualize molecular events with deep tissue penetration. Like most other modalities, however, image contrast under in vivo conditions is far from optimal due to background signals from tissue. Using iron oxide-gold core-shell nanoparticles, we have previously demonstrated the concept of magnetomotive photoacoustic (mmPA) imaging, which is capable of dramatically reducing the influence of background signals and producing high-contrast molecular images. Here, we report two significant advances toward clinical translation of this technology. First, we introduce a new class of compact, uniform, magneto-optically coupled core-shell nanoparticles, prepared through localized copolymerization of polypyrrole (PPy) on an iron oxide nanoparticle surface. The resulting iron oxide-PPy nanoparticles feature high colloidal stability and solve the photoinstability and small-scale synthesis problems previously encountered by the gold coating approach. In parallel, we have developed a new generation of mmPA featuring cyclic magnetic motion and ultrasound speckle tracking (USST), whose imaging capture frame rate is several hundred times faster than the photoacoustic speckle tracking (PAST) method we demonstrated previously. These advances enable robust artifact elimination caused by physiologic motions and demonstrate the application of the mmPA technology for in vivo sensitive tumor imaging.
authors: Department of Bioengineering, University of Washington , Seattle, Washington 98195, United States.
authors: Junwei
authors: J
authors: Li
authors: Bastien
authors: B
authors: Arnal
authors: Chen-Wei
authors: CW
authors: Wei
authors: Jing
authors: J
authors: Shang
authors: Thu-Mai
authors: TM
authors: Nguyen
authors: Matthew
authors: M
authors: O'Donnell
authors: Xiaohu
authors: X
authors: Gao
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000737:chemistry* / Q000633:toxicity; D005260:Female; D005290:Ferric Compounds / Q000737:chemistry* / Q000633:toxicity; D006046:Gold / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D060328:Magnetic Phenomena; D051379:Mice; D055620:Optical Phenomena; D061088:Photoacoustic Techniques / Q000379:methods*; D058105:Polymerization; D011108:Polymers / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D011108:Polymers; D011758:Pyrroles; C000499:ferric oxide; C067635:polypyrrole; D006046:Gold
keywords: cancer; diagnosis; magnetic; multifunctional; nanoparticles; near-infrared; photoacoustic imaging; polypyrrole