  Dynamic Light Scattering (DLS), Small Angle X-ray Scattering (SAXS) and
Transmission Electron Microscopy (TEM) are physical techniques widely employed
to characterize the morphology and the structure of vesicles such as liposomes
or human extracellular vesicles (exosomes). Bacterial extracellular vesicles
are similar in size to human exosomes, although their function and membrane
properties have not been elucidated in such detail as in the case of exosomes.
Here, we applied the above cited techniques, in synergy with the thermodynamic
characterization of the vesicles lipid membrane using a turbidimetric technique
to the study of vesicles produced by Gram-negative bacteria (Outer Membrane
Vesicles, OMVs) grown at different temperatures. This study demonstrated that
our combined approach is useful to discriminate vesicles of different origin or
coming from bacteria cultured under different experimental conditions. We
envisage that in a near future the techniques employed in our work will be
further implemented to discriminate complex mixtures of bacterial vesicles,
thus showing great promises for biomedical or diagnostic applications.
