Mair Lamar O, Evans Emily E, Barnsley Lester, Nacev Aleksandar, Stepanov Pavel Y, Jafari Sahar, Shapiro Benjamin, Dennis Cindi L, Weinberg Irving N
Weinberg Medical Physics, Inc, Rockville, Maryland 20852, United States.
Image Guided Therapy Research Institute, Rockville, Maryland 20852, United States.
ACS Appl Bio Mater. 2025 Feb 17;8(2):1201-1209. doi: 10.1021/acsabm.4c01516. Epub 2025 Feb 3.
Magnetic drug targeting requires particles to move through the complex viscoelastic environments of tissues and biological fluids. However, these environments often inhibit particle motion, making it difficult for magnetically guided particles to reach their intended targets. Magnetic microrods are easy to grow and manipulate, but experience significant hindrance to transport in complex, tortuous, tissue-like environments. Simple magnetic force translation ("pulling" or "pushing") is often insufficient or inefficient for long-range transport of microrods through such environments. Designing microrods capable of rotating while being pulled with a magnetic force may enable rods to overcome hindrances to transport. We present microrods with orthogonally magnetized segments, actuated by simultaneous magnetic force and magnetic torque. By simultaneously pulling and rotating our rods we create smooth-surfaced magnetic drilling microrods (MDMRs) capable of enhanced motion through protein-dense biopolymers. We model magnetic force and torque on MDMRs, characterize MDMR dynamics during transport, and demonstrate enhanced MDMR transport through protein-dense matrices in vitro.
磁性药物靶向需要粒子在组织和生物流体的复杂粘弹性环境中移动。然而，这些环境常常会抑制粒子的运动，使得磁导向粒子难以到达其预定目标。磁性微棒易于生长和操控，但在复杂、曲折的类组织环境中传输时会遇到显著阻碍。简单的磁力平移（“拉”或“推”）对于微棒在此类环境中的远距离传输往往不足或效率低下。设计能够在磁力拉动时旋转的微棒或许能使微棒克服传输阻碍。我们展示了具有正交磁化段的微棒，通过同时施加磁力和磁转矩来驱动。通过同时拉动和旋转我们的微棒，我们制造出了表面光滑的磁性钻孔微棒（MDMR），它能够在蛋白质密集的生物聚合物中实现增强运动。我们对MDMR上的磁力和转矩进行建模，表征传输过程中MDMR的动力学，并在体外证明MDMR在蛋白质密集基质中的传输得到增强。
