Stabilized Extracellular Vesicle Formulations for Inhalable Dry Powder Development

Abstract

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, with a significant impact on low- and middle-income countries, making it a critical challenge for global health equity and sustainable development goals. Extracellular vesicles (EVs) are emerging as a promising treatment for COPD, but conventional storage at −80 °C limits their global accessibility. This study explores alternative storage methods to enhance EV stability and accessibility, particularly in low-resource settings. EVs from lung fibroblasts are subjected to freezing, freeze drying, and spray drying with inulin or mannitol. The biophysical properties are evaluated by their capacity to support lung organoid formation. Inulin proves effective in stabilizing EVs, maintaining functionality after freezing at −20 °C for 12 weeks. Freeze drying with inulin preserves EV stability at 20 °C and 43% relative humidity. In contrast, EVs with mannitol exhibit aggregation and reduce bio-functionality. Additionally, spray drying EVs with inulin and leucine produces a dry powder suitable for inhalation, maintaining biophysical properties and functionality for 12 weeks. The powder demonstrates efficient lung deposition using the Cyclops inhaler. These findings suggest inulin as a stabilizer for EVs, eliminating the need for ultra-low temperature storage and improving the practicality of EV-based inhalable therapies.