Exosomal nanoparticles (exosomes or nanovesicles) are biogenic membrane vesicles secreted by various cell types and represent a conservative mechanism of intercellular and interspecies communication in pro- and eukaryotic organisms. By transporting specific proteins, nucleic acids, and low molecular weight metabolites, the exosomes are involved in the regulation of developmental processes, activation of the immune system, and the development of a protective response to stress. Recently, the plant nanovesicles, due to an economical and affordable source of their production, have attracted a lot of attention in the biomedical field. Being a natural transport system, the plant exosomes represent a promising platform in biomedicine for the delivery of molecules of both endogenous and exogenous origin. This review presents current data on the biogenesis of plant exosomes and their composition, as well as mechanisms of their loading with various therapeutic compounds, which are determining factors for their possible practical use. We believe that further research in this area will significantly expand the potential of targeted therapy, particularly targeted gene regulation via the small RNAs, due to the use of plant exosomes in clinical practice.

Over recent years, extracellular vesicles (EVs), commonly termed exosomes, have gained prominence for their potential as natural nanocarriers. It has now been recognized that plants also secrete EVs. Despite this discovery, knowledge about EV biogenesis in plant cell cultures remains limited. In our study, we have isolated and meticulously characterized EVs from the callus culture of the model plant, Arabidopsis thaliana. Our findings indicate that the abundance of EVs in calli was less than that in the plant’s apoplastic fluid. This difference was associated with the transcriptional downregulation of the endosomal sorting complex required for transport (ESCRT) genes in the calli cells. While salicylic acid increased the expression of ESCRT components, it did not enhance EV production. Notably, EVs from calli contained proteins essential for cell wall biogenesis and defense mechanisms, as well as microRNAs consistent with those found in intact plants. This suggests that plant cell cultures could serve as a feasible source of EVs that reflect the characteristics of the parent plant species. However, further research is essential to determine the optimal conditions for efficient EV production in these cultured cells.

Background: Recent interest in plant-derived exosome-like nanoparticles (ENs) has surged due to their therapeutic potential, which includes antioxidant, anti-inflammatory, and anticancer activities. These properties are attributed to their cargo of bioactive metabolites and other endogenous molecules. However, the properties of ENs isolated from plant cell cultures remain less explored. Methods: In this investigation, grape callus-derived ENs (GCENs) were isolated using differential ultracentrifugation techniques. Structural analysis through electron microscopy, nanoparticle tracking analysis, and western blotting confirmed that GCENs qualify as exosome-like nanovesicles. Results: These GCENs contained significant amounts of microRNAs and proteins characteristic of plant-derived ENs, as well as trans-δ-viniferin, a notable stilbenoid known for its health-promoting properties. Functional assays revealed that the GCENs reduced the viability of the triple-negative breast cancer cell line MDA-MB-231 in a dose-dependent manner. Moreover, the GCENs exhibited negligible effects on the viability of normal human embryonic kidney (HEK) 293 cells, indicating selective cytotoxicity. Notably, treatment with these GCENs led to cell cycle arrest in the G1 phase and triggered apoptosis in the MDA-MB-231 cell line. Conclusions: Overall, this study underscores the potential of grape callus-derived nanovectors as natural carriers of stilbenoids and proposes their application as a novel and effective approach in the management of cancer.