Enzymatic Janus Liposome Micromotors

Langmuir. 2023 Mar 21;39(11):4198-4206. doi: 10.1021/acs.langmuir.3c00335. Epub 2023 Mar 9.

Abstract

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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Avidin / chemistry
  • Biotin* / chemistry
  • Lipids / chemistry
  • Liposomes* / chemistry
  • Motion

Substances

  • Liposomes
  • Biotin
  • Avidin
  • Lipids