Radiopaque Nanorobots as Magnetically Navigable Contrast Agents for Localized In Vivo Imaging of the Gastrointestinal Tract Cagatay M. Oral, Martina Ussia, Mario Urso, Jiri Salat, Adam Novobilsky, Michal Stefanik, Daniel Ruzek, Martin Pumera* Advanced Healthcare Materials 2022, 12(8), 2202682