NanoInnovationLAB Highlights

 

Atomic Force Microscopy analysis of Extracellular Vesicles 

Extracellular vesicles (EV) are small vesicles (<1μm) ensuring transport of molecules between cells throughout the body. They represent a potent intercellular communication system, and their biological and physical functions make them perfect candidates as therapeutic agents in several fields (immune therapy, cell-free regenerative medicine, etc). Despite their great potential for biomedicine, there is still a lack of standards for EV isolation, characterization and quantification. Here we present our methodological analysis of morphological and biomechanical properties of EVs by means of Atomic Force Microscopy. P. Parisse et al, Eur. Biophys. J. 2017


Extracellular vesicles (EVs) are small vesicles (< 1 μm) enclosed by a lipid bilayer that are secreted into the extracellular space from cells in normal or diseased states. Depending on the biological origin, are classified as microvesicles or exosomes. They convey a biomolecular signature (i.e. lipids, proteins, metabolites, nucleic acids) specific of origin cells to target cells at local or distant sites selected by specific biorecognition, representing an important mode of intercellular communication. Their involvement in intracellular and intercellular communication makes EVs excellent candidates to serve as biomarkers, nanosized drug delivery vehicles, and therapeutic mediators in regenerative medicine. Their small dimensions and molecular/functional heterogeneity though has hampered their characterization, hence the need of new protocols and novel techniques able to define distinct functional EVs subpopulations. In this respect, Atomic Force Microscopy (AFM) represents a viable strategy, since allows to simultaneously determine size, morphology and stiffness vesicle maps with nanometric precision, besides to perform functional analysis of external membrane proteins (via antibody-coated tips). AFM can provide substantial information about EVs’ size distribution, nanomechanical properties, morphology, biochemical characteristics, and stiffness. Our results allowed us to point out the influence of isolation and deposition methods on size distribution and morphology of EVs, setting the basis for the standardization of protocols for proper characterizationand analysis that could be exploited for the discrimination of biophysical properties of differently originated EVs. The combination and integration of AFM with complementary techniques (from small angle scattering to vibrational spectroscopies, as micro-Raman and nanoIR, from fluorescence microscopy to electron microscopies) is envisaged for a better understanding of the biophysical and biochemical properties of EVs and their interaction with recipient cells.

 

 


 

Last Updated on Monday, 20 July 2020 14:36