恭喜由罗明、李守丽等撰写的研究论文“Enhanced Propulsion of Urease-Powered Micromotors by Multilayered Assembly of Ureases on Janus Magnetic Microparticles”被ACS期刊Langmuir接收（https://doi.org/10.1021/acs.langmuir.9b03315）。本工作针对生物酶构建的微/纳米马达动力普遍较弱，难以应用于复杂生物环境，我们发展了一种可以显著提高酶动力微马达推进力的通用新方法。即利用生物素（Biotin）和链霉亲和素（SA）的特异性组装技术，在双面神磁珠上组装多层生物素化脲酶（BU），以提高酶驱动微米马达的驱动力。发现在组装过程中增加BU与SA的质量比或BU的量时，组装在双面神磁珠上的生物素化脲酶单调增加，微米马达的运动速度逐渐增大，直至达到最大值。在10 mM的尿素溶液中，多层酶驱动微米马达的平均速度达到21.5 ± 0.8 µm/s，是已报道运动速度最快的脲酶驱动微纳米马达的2倍。由于驱动力的提高，该马达可在与血液粘度相似的液体中保持自主运动。另外，利用外界磁场可以实现对该马达的快速分离和运动方向控制。本研究结果为设计、制备高效的酶驱动微/纳米马达提供了一种新方法，同时将促进酶驱动微/纳米马达在生物医学领域的实际应用。
原文摘要如下：Enzyme-powered micro-/nanomotors propelled by biocompatible fuels generally show a weak propulsive force, which greatly limits their applications in complex biological environments. Herein, we have developed a novel and versatile approach to significantly enhance the propulsion of enzyme-powered micromotors by multilayered assembly of enzymes. As an example, multilayers of biotinylated ureases (BU) were asymmetrically immobilized on biotinylated Janus Au/magnetic microparticles (MMPs) with the assistance of streptavidin (SA). When the mass ratio of BU into SA and the amount of BU used in the assembly process are increased, the amount of urease immobilized on the biotinylated Janus Au/MMPs increased monotonously while the migration speed of the micromotor augmented gradually until a saturated value. The as-optimized micromotors can be self-propelled with an average speed up to about 21.5 ± 0.8 µm/s at physiological urea concentrations (10 mM), which is five times faster than that of the monolayered counterparts and twice faster than that of the previously reported values. Owing to the enhanced thrust, the micromotors can move in liquids with a similar viscosity to that of blood. In addition, with the inherent magnetic property of MMPs, the micromotors can exhibit fast magnetic separation and controllable motion direction by external magnetic fields. Our results provide a new pathway for designing high-efficient enzyme-powered micro-/nanomotors, and thereby promote their biomedical applications.
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