Gold/Copper@Polydopamine Nanocomposite for Contrast-Enhanced Dual Modal Computed Tomography-Magnetic Resonance Imaging

Bimetallic nanostructures can be attractive contrast-enhancing materials for dual modal imaging, allowing improved diagnosis ability using two different physical phenomena, following administration of a single nanoagent. In this research, the potential of the biocompatible polydopamine (PDA) was explored as a binding matrix to produce CuO NPs embedded in a PDA matrix (CuO@PDA nanocomposite). PDA was then tested as a reducing agent for both CuO NPs and HAuCl₄ to yield a PDA composite embedded with gold nanoparticles and copper species, readily available for CT-MRI contrast enhancement. Moreover, in vitro cytotoxicity evaluation implied the low cytotoxicity of Au/Cu@PDA nanocomposite. The procedure, characterization, and imaging experiments focused on a representative Au:Cu atomic ratio of 86:14. The resulting longitudinal magnetic relaxation (T1) and X-ray attenuation properties of the nanocomposite are characterized by using phantom experiments and an ex vivo poultry heart model, demonstrating a consistent contrast improvement with both MRI and CT.