Department of Chemistry and.
Annu Rev Biophys. 2015;44:77-100. doi: 10.1146/annurev-biophys-060414-034216.
Nature supports multifaceted forms of life. Despite the variety and complexity of these forms, motility remains the epicenter of life. The applicable laws of physics change upon going from macroscales to microscales and nanoscales, which are characterized by low Reynolds number (Re). We discuss motion at low Re in natural and synthetic systems, along with various propulsion mechanisms, including electrophoresis, electrolyte diffusiophoresis, and nonelectrolyte diffusiophoresis. We also describe the newly uncovered phenomena of motility in non-ATP-driven self-powered enzymes and the directional movement of these enzymes in response to substrate gradients. These enzymes can also be immobilized to function as fluid pumps in response to the presence of their substrates. Finally, we review emergent collective behavior arising from interacting motile species, and we discuss the possible biomedical applications of the synthetic nanobots and microbots.
大自然支持多方面的生命形式。尽管这些形式具有多样性和复杂性，但运动仍然是生命的中心。从宏观到微观和纳米尺度，适用的物理定律会发生变化，这些尺度的特点是低雷诺数 (Re)。我们讨论了在自然和合成系统中低 Re 下的运动，以及各种推进机制，包括电泳、电解质扩散泳和非电解质扩散泳。我们还描述了在非 ATP 驱动的自供能酶中运动性的新发现现象，以及这些酶在底物梯度下的定向运动。这些酶也可以被固定化以作为流体泵来响应它们的底物的存在。最后，我们综述了来自相互作用的运动物种的新兴集体行为，并讨论了合成纳米机器人和微机器人可能的生物医学应用。
