Biocatalytically And Photoelectrochemically Driven Active Motion of Liposomes

Abstract

Self-propelled artificial micro/nanomotors are currently attracting increased interest as not only mimics of biological motors but also potential components of nanomachinery, robotics, and sensing devices. In regards to studying such kinds of self-propelled micro/nanomotors, Janus particles have been an excellent candidate for researchers for a long time due to their special asymmetrical structure and decoration. As micro-/nanosized soft-matter bilayer vesicles with biocompatibility and broad utility, liposomes have been widely regarded as a potential platform for drug delivery, biosensor application, and mimic cell models. Sharing similar chemical properties and character, Janus liposomes have numerous advantages as an amphiphilic material on which different chemical entities, such as peptides, nucleotides and antibodies, can be attached. In this Dissertation, by taking full advantage of the phase separation of saturated lipids and unsaturated lipids on the liposome membrane surface, we generated high-quality Janus liposomes via PVA gel-assisted swelling hydration method reproducibly with the common ternary lipids system (DPPC/DOPC/cholesterol). With such reproducible and effective liposomes hydration and membrane extrusion for uniform size control methods in hand, we then explored the enzyme-based (horseradish peroxidase and catalase) biocatalytically-driven active motion behavior of well-prepared Janus liposomes. In addition, we further investigated the enzyme-free liposome active motion driven by asymmetrical lipid efflux in which the motion was induced by -CD extraction of cholesterol from the membrane. Finally, we examined laser light-based photoelectrochemically-driven active motion behavior of Ru(bpy)32+ labeled Janus liposomes under different mass transfer molecule fuel in bulk by replacing the inserted rhodamine- DOPE with Ru(bpy)32+-DOPE (light-sensitive material) on the membrane of Janus liposomes.