ORCID Profile
0000-0003-4224-9333
Current Organisations
Consorzio Interuniversatario per lo Sviluppo dei Sistemi a Grande Interfase
,
Università degli Studi di Firenze
,
Vrije Universiteit Amsterdam
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Cold Spring Harbor Laboratory
Date: 16-04-2023
DOI: 10.1101/2023.04.14.536633
Abstract: Communication between cells located in different parts of an organism is often mediated by membrane-enveloped nanoparticles, such as extracellular vesicles (EVs). EV binding and cell uptake mechanisms depend on the heterogeneous composition of the EV membrane. From a colloidal perspective, the EV membrane interacts with other biological interfaces via both specific and non-specific interactions, where the latter include long-ranged electrostatic and van der Waals forces, and short-ranged repulsive “steric-hydration” forces. While electrostatic forces are generally exploited in most EV immobilization protocols, the roles played by various colloidal forces in controlling EV adsorption on surfaces have not yet been thoroughly addressed. In the present work, we study the interaction and adsorption of EVs with supported lipid bilayers (SLBs) carrying different surface charge densities. By probing the EV-SLB interaction using quartz crystal microbalance with dissipation monitoring (QCM-D) and confocal laser scanning microscopy (CLSM), we demonstrate that EV adsorption onto lipid membranes can be controlled by varying the strength of electrostatic forces. We then model the observed phenomena within the framework of nonlinear Poisson-Boltzmann theory. Modelling results confirm the experimental observations and highlight the crucial role played by attractive electrostatics in EV adsorption onto lipid membranes. Our results provide new fundamental insights into EV-membrane interactions and could be useful for developing novel EV separation and immobilization strategies.
Publisher: MDPI AG
Date: 04-03-2021
Abstract: Since the outbreak of the COVID-19 crisis, the handling of biological s les from confirmed or suspected SARS-CoV-2-positive in iduals demanded the use of inactivation protocols to ensure laboratory operators’ safety. While not standardized, these practices can be roughly ided into two categories, namely heat inactivation and solvent-detergent treatments. These routine procedures should also apply to s les intended for Extracellular Vesicles (EVs) analysis. Assessing the impact of virus-inactivating pre-treatments is therefore of pivotal importance, given the well-known variability introduced by different pre-analytical steps on downstream EVs isolation and analysis. Arguably, shared guidelines on inactivation protocols tailored to best address EVs-specific requirements will be needed among the analytical community, yet deep investigations in this direction have not yet been reported. We here provide insights into SARS-CoV-2 inactivation practices to be adopted prior to serum EVs analysis by comparing solvent/detergent treatment vs. heat inactivation. Our analysis entails the evaluation of EVs recovery and purity along with biochemical, biophysical and biomolecular profiling by means of a set of complementary analytical techniques: Nanoparticle Tracking Analysis, Western Blotting, Atomic Force Microscopy, miRNA content (digital droplet PCR) and tetraspanin assessment by microarrays. Our data suggest an increase in ultracentrifugation (UC) recovery following heat treatment however, it is accompanied by a marked enrichment in EVs-associated contaminants. On the other hand, solvent/detergent treatment is promising for small EVs ( nm range), yet a depletion of larger vesicular entities was detected. This work represents a first step towards the identification of optimal serum inactivation protocols targeted to EVs analysis.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1CP03201A
Abstract: Topological effects are key in driving nano-bio interface phenomena: the symmetry of the lipid membrane (cubic or lamellar) dictates the interaction mechanism, while nanoparticles shape (sphere or rod) modulates the interaction strength.
Publisher: Cold Spring Harbor Laboratory
Date: 11-12-2020
DOI: 10.1101/2020.12.10.417758
Abstract: Since the outbreak of COVID-19 crisis, the handling of biological s les from confirmed or suspected SARS-CoV-2 positive in iduals demanded the use of inactivation protocols to ensure laboratory operators safety. While not standardized, these practices can be roughly ided in two categories, namely heat inactivation and solvent-detergent treatments. As such, these routine procedures should also apply to s les intended for Extracellular Vesicles (EVs) analysis. Assessing the impact of virus inactivating pre-treatments is therefore of pivotal importance, given the well-known variability introduced by different pre-analytical steps on downstream EVs isolation and analysis. Arguably, shared guidelines on inactivation protocols tailored to best address EVs-specific requirements will be needed among the EVs community, yet deep investigations in this direction haven’t been reported so far. In the attempt of sparking interest on this highly relevant topic, we here provide preliminary insights on SARS-CoV-2 inactivation practices to be adopted prior serum EVs analysis by comparing solvent/detergent treatment vs. heat inactivation. Our analysis entailed the evaluation of EVs recovery and purity along with biochemical, biophysical and biomolecular profiling by means of Nanoparticle Tracking Analysis, Western Blotting, Atomic Force Microscopy, miRNA content (digital droplet PCR) and tetraspanin assessment by microarrays. Our data suggest an increase in ultracentrifugation (UC) recovery following heat-treatment, however accompanied by a marked enrichment in EVs-associated contaminants. On the contrary, solvent/detergent treatment is promising for small EVs ( 150 nm range), yet a depletion of larger vesicular entities was detected. This work represents a first step towards the identification of optimal serum inactivation protocols targeted to EVs analysis.
Publisher: Cold Spring Harbor Laboratory
Date: 29-03-2021
DOI: 10.1101/2021.03.29.437497
Abstract: Inverse bicontinuous cubic phase membranes are ubiquitous in nature but their properties and functions are still not fully understood. To shed light on this topic, we herein realize thin supported cubic phase lipid films, characterize their structure and provide the first study of the mechanical properties of these non-lamellar architectures.
Location: Italy
No related grants have been discovered for Andrea Ridolfi.