(641e) Molecular Tuned Extracellular Blebs for Improved Vaccination and Intracellular Delivery

Extracellular vesicles (EVs) have great potential as therapeutic carriers as they exhibit high levels of biocompatibility and allow for targeted delivery to specific tissues. Naturally-occurring EVs ranging in size have been widely studied for transport of biomacromolecules, small molecule drugs, nucleic acids, and viruses. However, limited yield and control of production associated with naturally-occurring EVs have been key challenges in the field. For translation of this technology, there is a critical need for methods that can meet clinical production criteria.

In this study, we address these challenges by employing novel production methods that induce rapid blebbing of the cell membrane. These techniques produce pure, and well-defined EV-like vesicles, termed extracellular blebs (EBs), in clinically relevant scales over the course of minutes to hours. Furthermore, blebbing agents act on the cell in a way which locks the current surface properties and contents of the producer cell, allowing for homogeneous EB production, and further preventing post-production changes. Here we demonstrate use of sulfhydryl-blocking for increasing cellular production of EBs by more than ten-fold. We show the utility of EBs derived from various cell types for the delivery of chemotherapeutic doxorubicin and for immunotherapy by stimulation of T cells in strong in vitro and in vivo studies. For the first time, we investigate the potential of a novel photo-induced method of extracellular bleb production for gene delivery. This technique presents a scalable and tunable option for producing safe cell-free vaccines and drug carriers that could meet commercial scalability requirements.