Exploring the viability of using liposomes and bacterial extracellular vesicles (bEVs) in interaction studies by calorimetric methods

Abstract

The increasing level of AMR require an increase in new antimicrobial drug candidates. By proving that bEVs are a suitable model for the bacterial membrane, it can be applied to the development of new drug candidates. Potentially making the development of new candidates more efficient and reducing cost. To further examine the potential of bEVs, we isolated bEVs from E. coli, a gram-negative bacteria. The bEVs were characterized using zeta-potential, size distribution, and protein concentration measurements, while DMPC and DMPC-LPS liposomes were characterized using zeta-potential and size distribution measurements. The differences of the thermodynamic properties were compared using a differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC) instrument. The consequences of the alterations within the cell membrane of the bEVs caused by the different resistance mechanisms were measured with the ITC instrument. The analysis showed promising results regarding the thermodynamic properties and differences caused by the resistance mechanisms. This study provides support to the claim that bEVs are well suited to simulate the bacterial cell membrane. More extensive studies are required to fully explore the potential of bEVs.