The development of a new bioprocessing stream to use natural source-derived EVs as new generation nanomaterials is an inherently interdisciplinary activity that requires the combination of a variety of research fields and specialised skills, including the biology of the natural source under consideration, the bioengineering aspects of the process, the chemistry of the functionalisation reactions and the biomedical context of the applications. VES4US is highly interdisciplinary and involves team members coming from different geographical and cultural areas (Mediterranean and Balkan regions, northern and central Europe); this diversity is a very valuable feature that is positively influencing the development of the project. This interdisciplinary work is supported by an integrated research approach with partners from different disciplines and backgrounds jointly collaborating and learning from one another in the process of carrying out specific tasks. As such, the high interaction among work packages and participants has ensured the creation of a powerful and well-integrated new research team; this is one of the main results achieved.
During the project, the cultivation and subsequent screening of the selected microalgal strains in terms of bioactivity, content in high-value metabolites and capacity to release into their growth medium EVs have been performed and reported upon as deliverables, and the related results have established the foundations for the high-risk high-reward research activities planned in VES4US. Indeed, extracellular nanoparticles were successfully purified from the selected microalgal species and characterised using a range of biophysical and biochemical methods. The analyses permitted the selection of the strains best suited for subsequent isolation and purification of EV-like objects in later parts of the VES4US work programme. Further results allowed us to choose, optimise and scale-up the purification method for EVs (i.e. Tangential Flow Fractionation, TFF) to allow laboratory-scale production of the microalgal EVs, named (nano)algosomes. The VES4US consortium also invested in the development of an innovative technology for EV purification. Similarly, VES4US has described the most promising approaches to be applied in the engineering of natural source-derived EVs. The functionalisation and loading strategies can be directly applied to the nanoalgosomes, without the need for parent cell engineering (metabolic labelling).
In parallel with the explosive growth of available studies and data on EVs derived from different types of cells, biofluids and tissues, the scientific community faces the urgent need for a standard and transparent way to report data, to refer to reproducible methodologies, or to deposit and search for common knowledge. Indeed, EV characterisation is needed as a starting point for the bioengineered exploitation of the natural source-derived EVs. In this context, VES4US has provided a list of Minimal Information required for Studies of Extracellular Vesicles (MISEV), specifically in the context of VES4US (VES4US-MISEV), for the not-yet-described natural source-derived EVs. VES4US-MISEV is based on the guidelines provided by the International Society for Extracellular Vesicles (MISEV2018) list which was further adapted for natural source-derived EVs on the basis of our considerations and experiments during the first year of the VES4US project, it allowed us to define in detail this novel biological nanoparticles.
