Scalable Purification, Storage, and Release of Plant-Derived Nanovesicles for Local Therapy Using Nanostructured All-Cellulose Composite Membranes.

Plant-derived nanovesicles such as bilberries nanovesicles (BNVs) show immense promise as next-generation biotherapeutics and functional food ingredients; however, their isolation, purification, and storage on a large scale remain a challenge. In this study, biocompatible and nanostructured composite all-cellulose membranes are introduced as a scalable and straightforward approach to the isolation of BNV. The membranes consisting of a cellulose acetate matrix infused with anionic or cationic nanocelluloses promoted selective capture of BNVs through electrostatic and size-exclusion-mediated depth filtration. Furthermore, the surface of the composite membrane acted as a storage matrix for BNVs, ensuring their prolonged stability at 4 °C. The BNVs stored in the membrane could be promptly released through elution assisted by low-pressure vacuum filtration or diffusion in liquid media. The morphology, bioactivity, and stability of the extracted BNVs were preserved, and the release rate of BNVs in different cell cultures could be regulated, facilitating their use for local therapy. Consequently, this approach paves the way for the scalable production, purification, and storage of nanovesicles and advances their use in biotherapeutics and functional foods.

Enrichment of bovine milk-derived extracellular vesicles using surface-functionalized cellulose nanofibers.

The isolation of extracellular vesicles (EVs) from milk, a complex mixture of colloidal structures having a comparable size to EVs, is challenging. Although ultracentrifugation (UC) has been widely used for EV isolation, this has significant limitations, including a long processing time at high g-force conditions and large sample volume requirements. We introduced a new approach based on nature nanoentities cellulose nanofibers (CNFs) and short time and low g-force centrifugation to isolate EVs from various milk fractions. The flexible and entangled network of CNFs forms nanoporous, which entraps the EVs. Further, positively charged CNFs interact with anionic EVs through an electrostatic attraction, promoting their isolation with efficiency comparable with UC. The functionality and toxicity of isolated milk EVs were tested in Caco2 cells. Overall, the newly developed approach provides straightforward isolation and biocompatibility and preserves the natural properties of the isolated EVs, enabling further applications.