Kim Dong Wook, Wrede Paul, Estrada Hector, Yildiz Erdost, Lazovic Jelena, Bhargava Aarushi, Razansky Daniel, Sitti Metin
Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany.
Institute of Pharmacology and Toxicology and Institute for Biomedical Engineering, University of Zürich, Zürich, 8057, Switzerland.
Adv Mater. 2024 Dec;36(50):e2404514. doi: 10.1002/adma.202404514. Epub 2024 Oct 14.
Acoustic waves provide a biocompatible and deep-tissue-penetrating tool suitable for contactless manipulation in in vivo environments. Despite the prevalence of dynamic fluids within the body, previous studies have primarily focused on static fluids, and manipulatable agents in dynamic fluids are limited to gaseous core-shell particles. However, these gas-filled particles face challenges in fast-flow manipulation, complex setups, design versatility, and practical medical imaging, underscoring the need for effective alternatives. In this study, flower-like hierarchical nanostructures (HNS) into microparticles (MPs) are incorporated, and demonstrated that various materials fabricated as HNS-MPs exhibit effective and reproducible acoustic trapping within high-velocity fluid flows. Through simulations, it is validated that the HNS-MPs are drawn to the focal point by acoustic streaming and form a trap through secondary acoustic streaming at the tips of the nanosheets comprising the HNS-MPs. Furthermore, the wide range of materials and modification options for HNS, combined with their high surface area and biocompatibility, enable them to serve as acoustically manipulatable multimodal imaging contrast agents and microrobots. They can perform intravascular multi-trap maneuvering with real-time imaging, purification of wastewater flow, and highly-loaded drug delivery. Given the diverse HNS materials developed to date, this study extends their applications to acoustofluidic and biomedical fields.
声波提供了一种生物相容性好且能穿透深层组织的工具，适用于体内环境中的非接触式操作。尽管体内存在动态流体，但以往的研究主要集中在静态流体上，并且动态流体中可操控的介质仅限于气态核壳颗粒。然而，这些充气颗粒在快速流动操作、复杂设置、设计通用性和实际医学成像方面面临挑战，这凸显了寻找有效替代方案的必要性。在本研究中，将花状分级纳米结构（HNS）引入到微粒（MP）中，并证明了以HNS-MP形式制备的各种材料在高速流体流中表现出有效且可重复的声捕获。通过模拟验证，HNS-MP通过声流被吸引到焦点，并在构成HNS-MP的纳米片尖端通过二次声流形成陷阱。此外，HNS的材料种类繁多且可进行修饰，再加上其高表面积和生物相容性，使其能够用作可声操控的多模态成像造影剂和微型机器人。它们可以通过实时成像进行血管内多陷阱操作、净化废水流以及进行高负载药物递送。鉴于迄今为止已开发出多种HNS材料，本研究将它们的应用扩展到了声流体和生物医学领域。
