Formation of giant unilamellar vesicles from spin-coated lipid films by localized IR heating

We report a novel method for the generation of GUVs (generate unilamellar vesicles) from spin-coated lipid films by means of localized heating. This technique enables GUV formation from both charged and neutral lipid species, as well as from a complex lipid mixture, in various ionic strength conditions. Encapsulation was possible during and after GUV formation

Heat-induced formation of single giant unilamellar vesicles

Giant unilamellar vesicles (GUVs) are an excellent model system for the investigation of lipid membranes, the study of membrane proteins and ion channels in a biomimetic environment, and in the creation of artificial cells. Here, we describe a novel method for the preparation of GUVs from single multilamellar liposomes by means of directed infrared laser heating. Our method generates individual unilamellar vesicles at selected locations, not only from natural and artificial lipid mixtures containing negatively charged lipids, but also from preparations of single lipids, such as neutral phosphatidylethanolamine. The presented method provides a new efficient resource for giant vesicle research and offers an alternative to the electroformation and de/rehydration techniques

Radial Sizing of Lipid Nanotubes Using Membrane Displacement Analysis

We report a novel method for the measurement of lipid nanotube radii. Membrane translocation is monitored between two nanotube-connected vesicles, during the expansion of a receiving vesicle, by observing a photobleached region of the nanotube. We elucidate nanotube radii, extracted from SPE vesicles, enabling quantification of membrane composition and lamellarity. Variances of nanotube radii were measured, showing a growth of 40-56 nm, upon increasing cholesterol content from 0 to 20%

Liposomes: Technologies and Analytical Applications

Liposomes are structurally and functionally some of the most versatile supramolecular assemblies in existence. Since the beginning of active research on lipid vesicles in 1965, the field has progressed enormously and applications are well established in several areas, such as drug and gene delivery. In the analytical sciences, liposomes serve a dual purpose: Either they are analytes, typically in quality-assessment procedures of liposome preparations, or they are functional components in a variety of new analytical systems. Liposome immunoassays, for example, benefit greatly from the amplification provided by encapsulated markers, and nanotube-interconnected liposome networks have emerged as ultrasmall-scale analytical devices. This review provides information about new developments in some of the most actively researched liposome-related topic

Injection and Transport of Bacteria in Nanotube-Vesicle Network

Microinjection of bacteria (the MG1655 strain of E. coli.) into unilamellar lipid vesicles contained in surface-immobilized nanotube-vesicle networks is demonstrated. Injected baceria can not escape from one vesicle to another as the size of interconnecting nanotubes is too small (~200 nm in diameter) to allow for entry. Bacteria can, however, be moved from one vesicle to another by using Marangoni flows. Thus, single or several species can be transferred to a neighboring vesicle at will. The technique offers new possibilities for live matter functionalization into synthetic host networks, and may provide a means of studying the effect of compartmentalization and chemical species on a single bacterium. Thus, it may serve as an experimental platform to study how vesicle-encapsulated bacteria evade destruction in macrophages or how bacteria surf along thin membrane nanotubes toward connected macrophage cell bodie