Vesicle Deformation

 

 

Figure: (a) An example of a vesicle imaged using a confocal microscope. A stack of XY slices renders a three dimensional image, as shown in the schematic. When vesicles (GUV, giant unilamellar vesicles, 5-50 m) are cooled without perturbations, they form round, spherical constructs. (b) A vesicle is enmeshed in a three dimensional flexible peptide matrix, similar to a collegen extracellular matrix. (a) The three dimensional reconstruction of the vesicles reveals a highly deformed vesicle with significant undulations to accommodate the surrounding matrix, indicating the conformation of the vesicle to the available space in the peptide scaffold. When the surface of the vesicle is examined, many small scale undulations are evident where it accommodates the individual tendrils of the matrix. When viewed in profile, there are several deviations form the normal spherical shape of the vesicle. In the YZ reconstruction, the vesicle has a curved, inverted bowl profile, instead of a full spherical shape, with a large protrusion to form an incomplete circle. In the XZ reconstruction, the surface undulations render the view blurry in contrast to the sharp edges of Fig. 1. (b) In the cut-away views, the edges are blurred due to the undulations on the surface of the vesicle, shown in (a). The XZ cut away reveals indentations along the profile not evident in the three dimensional reconstruction. In (c), the PuraMatrix is visible after a vesicle has ruptured and labeled the tendrils with the lipid dye. As evident in the image, the scaffold formed by PuraMatrix is complex with small rope-like tendrils, forcing the vesicles to conform to the rich topography with feature sizes larger and smaller than a micrometer.

 

We have explored Vesicles deforming on surface, three dimensional structure (above) and between interfaces (see RBC Model system).  It is fascinating how the bilayer deforms to fit the surfaces.

 

 

Dimpled Vesicles: The Interplay between Interfaces and Transient Pores. S. D. Gillmor, P. S. Weiss, J Phys Chem B 112, 13629 (2008).

Temperature-Dependent Vesicle Response to Surface Topography. S. D. Gillmor, J. J. Heetderks, P. S. Weiss, J Phys Chem B 112, 11490 (2009).