Biophysical features of plant-derived nanovesicles: Focus on almonds

Almond is a traditional food with established beneficial effects on health. Nothing is known about the presence of extracellular vesicles (EVs), recently isolated from other plant material, ingested with food, or as engineered bioactive nanovectors. Aiming to develop and optimize a method to isolate almonds derived nano vesicles (ADNVs), we tested different protocols on pure, blanched and roasted almonds, and investigated the resulting biophysical features. The most feasible and valid method was the sucrose-based ultracentrifugation (DGUC). Size distribution ranged on average 100–200 nm. A negative zeta-potential in the range of –27 to –21 mV has been measured. Microscopy showed a spheroid morphology and preserved structural integrity of isolated ADNVs. Pure almond ADNVs showed the greater amount of TET8; PEN1 was also found, although cooking treatments resulted in a decrease. Attention should be paid to sample managing during DGUC steps and to sample deposition and drying for microscopy procedures. Our findings contribute to enriching the hot issue on EVs research from edible sources, giving reason to their possible role in interspecies communication, and their exploitation for the delivery of bioactive compounds or therapeutics molecules. The potentiality of almonds' industrial residuals should be investigated in further research. •Almond contains extracellular vesicles following density-based ultracentrifugation.•ADNVs show spheroid morphology and zeta-potential suggests colloidal stability.•ADNVs from pure almonds express tetraspanin TET8 compared to treated ;almonds.•ADNVs are preserved after thermal treatments but putative microvesicles are limited.•Critical steps refer to the fat layers and procedures prior to microscopy.