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BP: Fachverband Biologische Physik

BP 2: Membranes and Vesicles I

BP 2.4: Vortrag

Montag, 18. März 2024, 10:15–10:30, H 2032

Polysaccharide functionalization reduces lipid vesicle stiffness — •Kevin Jahnke and David A. Weitz — Harvard University, Cambridge, USA

The biophysical properties of lipid vesicles are important for their stability and integrity, key parameters that control the performance when these vesicles are used for drug delivery. The vesicle properties are determined by the composition of lipids used to form the vesicle. However, for a given lipid composition, they can also be tailored by tethering polymers to the membrane. Typically, synthetic polymers like polyethyleneglycol are used to increase vesicle stability but the use of polysaccharides in this context is much less explored. Here, we report a general method for functionalizing lipid vesicles with polysaccharides by binding them to cholesterol. We incorporate the polysaccharides on the outer membrane leaflet of giant unilamellar vesicles (GUVs) and investigate their effect on membrane mechanics using micropipette aspiration. We find that the presence of the glycolipid functionalization produces an unexpected softening of GUVs with fluid-like membranes. By contrast, the functionalization of GUVs with polyethylene glycol does not reduce their stretching modulus. Furthermore, we explore the effect of polysaccharide functionalization of lipid vesicles for drug delivery. We find that it increases the uptake of small unilamellar vesicles (SUVs) by cells and leads to an improved transfection. This work provides the potential means to study membrane-bound meshworks of polysaccharides similar to the cellular glycocalyx; moreover, it can be used for tuning the mechanical properties of drug delivery vehicles.

Keywords: Lipid vesicles; Polysaccharides; Membrane biophysics; Micropipette aspiration; Drug delivery