Polymer microbubbles loaded with gold nanoparticles as hybrid contrast agent for computed tomography and ultrasound

Microbubbles (MBs) with size below 10 µm are commonly used as an ultrasound contrast agent (UCA). The aim of the novel UCA developed in our lab is to support imaging modalities other than ultrasound to form hybrid contrast agents. The hybrid contrast agents through the synergistic effect can potentially improve the diagnostic outcome of the combined multimodal imaging technique. In this study, we modified the polyvinyl alcohol (PVA) MB fabrication protocol to encapsulate the gold nanoparticles into the shell and also in the core of the MBs. Furthermore, we evaluated the morphology, nonlinear ultrasound response, and X-ray property of dual modal contrast agents. The results revealed that the loading of the gold nanoparticles into the PVA MB core is a promising step towards the development of the dual modal contrast agent.