Connessioni scientifiche n.10: Francesco Valle

AFM Nanomechanics and Analysis of Extracellular Vesicles and Lipoproteins: From Single-Particle Profiling to Deconvolution of Complex Samples

Nanomechanical analysis using atomic force microscopy (AFM) is emerging as a key tool for the high-resolution characterization of biogenic nanoparticles. Starting with the development of an AFM protocol capable of rapidly capturing the morphology and mechanical response of hundreds of individual objects, research has progressively expanded its ability to distinguish extracellular vesicles (EVs) from non-vesicular contaminants, overcoming the limitations of population-averaged techniques and enabling the recognition of particle-specific nanomechanical fingerprints. [1, 2] On this methodological basis, the extension of this nanomechanical analysis to the deconvolution of complex biological samples is based, in which EVs and different classes of lipoproteins (LPs) coexist and have overlapping dimensions. The integration of morphometric and nanomechanical parameters allows us to identify characteristic regions occupied by each class of nanoparticles and to quantify their relative abundance not only in numerical terms, but also in terms of surface area and volume. This recognition capability at the single particle level offers an immediate and label-free reading of the purity of the preparations and of the contributions of EVs and LPs in real mixtures such as plasma or ultracentrifuged sera. [3] In this framework, nanomechanical analysis via AFM represents a robust and scalable platform for analyzing the complexity of the secretome, with direct implications on the quality of EV preparations and on application prospects in diagnostics and translational biology.

[1] AFM-Based High-Throughput Nanomechanical Screening of Single Extracellular Vesicles, Anal. Chem. 2020, 92, 15, 10274–10282[2] Exploring poly-L-lysine-based particle capture for atomic force microscopy studies of extracellular vesicles, Journal of Microscopy, 2026; 1–11.[3] Particle profiling of EV-lipoprotein mixtures by AFM nanomechanical imaging, Journal of Extracellular Vesicles 2023 12, 10 12349