Jin Hui, Cui Jinyan, Zhan Wei
Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States.
Langmuir. 2023 Mar 21;39(11):4198-4206. doi: 10.1021/acs.langmuir.3c00335. Epub 2023 Mar 9.
A liposome-based micromotor system that utilizes regional enzymatic conversion and gas generation to achieve directional motion in water is presented. Constituted mainly of a low-melting lipid and a high-melting lipid together with cholesterol, these liposomes maintain stable Janus configuration at room temperature as a result of lipid liquid-liquid phase separation. Local placement of enzymes such as horseradish peroxidase is realized via affinity binding between avidin and biotin, the latter as a lipid conjugate sorted specifically into one domain of these Janus liposomes as a minor component. In the presence of the substrate, hydrogen peroxide, these enzyme-decorated Janus liposomes undergo directional motion, yielding velocities exceeding thermal diffusion by three folds in some cases. Experimental details on liposome size control, motor assembly, and substrate distribution are presented; effects of key experimental factors on liposome motion, such as substrate concentration and liposome Janus ratio, are also examined. This work thus provides a viable approach to building asymmetrical lipid-assembled, enzyme-attached colloids and, in addition, stresses the importance of asymmetry in achieving particle directional motion.
本文介绍了一种基于脂质体的微马达系统，该系统利用区域酶促转化和气体生成在水中实现定向运动。这些脂质体主要由低熔点脂质、高熔点脂质和胆固醇组成，由于脂质的液-液相分离，它们在室温下保持稳定的Janus结构。通过抗生物素蛋白和生物素之间的亲和结合实现辣根过氧化物酶等酶的局部放置，生物素作为脂质共轭物作为次要成分特异性地分选到这些Janus脂质体的一个区域中。在底物过氧化氢存在的情况下，这些酶修饰的Janus脂质体进行定向运动，在某些情况下产生的速度超过热扩散三倍。文中给出了脂质体尺寸控制、马达组装和底物分布的实验细节；还研究了底物浓度和脂质体Janus比等关键实验因素对脂质体运动的影响。因此，这项工作为构建不对称脂质组装、酶附着的胶体提供了一种可行的方法，此外，还强调了不对称在实现颗粒定向运动中的重要性。
