Department of Radiology, Case Western Reserve University, Cleveland, Ohio 44106, United States.
Department of Chemistry and Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States.
ACS Appl Mater Interfaces. 2020 May 13;12(19):22308-22317. doi: 10.1021/acsami.0c02091. Epub 2020 May 1.
Microbubbles (MBs) stabilized by particle surfactants (., Pickering bubbles) have better thermodynamic stability compared to MBs stabilized by small molecules as a result of steric hindrance against coalescence, higher diffusion resistance, and higher particle desorption energy. In addition, the use of particles to stabilize MBs that are typically used as an ultrasound (US) contrast agent can also introduce photoacoustic (PA) properties, thus enabling a highly effective dual-modality US and PA contrast agent. Here, we report the use of partially reduced and functionalized graphene oxide as the sole surfactant to stabilize perfluorocarbon gas bubbles in the preparation of a dual-modality US and PA agent, with high contrast in both imaging modes and without the need for small-molecule or polymer additives. This approach offers an increase in loading of the PA agent without destabilization and increased thickness of the MB shell compared to traditional systems, in which the focus is on adding a PA agent to existing MB formulations.
微泡（MBs）由颗粒表面活性剂（例如 Pickering 气泡）稳定，与由小分子稳定的 MBs 相比，由于空间位阻防止聚结、更高的扩散阻力和更高的颗粒解吸能，具有更好的热力学稳定性。此外，使用颗粒稳定通常用作超声（US）造影剂的 MBs 也可以引入光声（PA）特性，从而实现高效的双模态 US 和 PA 造影剂。在这里，我们报告了使用部分还原和功能化的氧化石墨烯作为唯一的表面活性剂来稳定全氟碳气体气泡，以制备双模态 US 和 PA 造影剂，两种成像模式均具有高对比度，而无需小分子或聚合物添加剂。与传统系统相比，这种方法在不破坏稳定性的情况下增加了 PA 造影剂的负载量，并增加了 MB 壳的厚度，而传统系统的重点是将 PA 造影剂添加到现有的 MB 制剂中。
