Assessment of bovine milk exosome preparation and lyophilized powder stability

Abstract Exosomes are cell‐derived nanovesicles that play a crucial role in intercellular communication, presenting promising potential as biomarkers and therapeutic agents. Bovine milk exosomes (MK‐Exo) show production scalability and cost‐effectiveness, offering distinct advantages over cell‐derived exosomes. However, exosome storage and transportation are challenging owing to their unstable nature, necessitating preservation at ultralow temperatures. Research findings suggest that freeze‐drying could provide a viable solution; however, different sources of exosomes may require specific protocols. In this study, we aimed to successfully isolate high‐purity MK‐Exo and develop a specialized freeze‐drying and lyophilization method for improved long‐term preservation of MK‐Exo. Specifically, the stability of the lyophilized MK‐Exo was evaluated using storage stability tests. Notably, lyophilized MK‐Exo remained stable for at least 3 months under high temperature of 50°C and for at least 24 months under low temperatures of 2°C–8°C, preserving their physicochemical properties and biological activity. Conclusively, these findings provide a potential solution for ambient‐temperature transportation of MK‐Exo, facilitating their industrial‐scale production.