VCOM Research Day Program Book 2023

Medical Student Research Biomedical

05 The Effects of Neuronal Cell Priming on the Uptake and Delivery Potential of Endothelial Exosomes

Taylor Wynne; Virginia (Grey) Fritz; Zachary Simmons; Kelly Roballo Corresponding author: twynne@vt.vcom.edu

Edward Via College of Osteopathic Medicine-Virginia Campus

Despite recent advancements in peripheral nerve transplant, many patients still experience suboptimal outcomes following peripheral nerve transplants due to the intricacies of axonal regeneration. Current practice involves the usage of peripheral nerve autografts or cadaveric allografts; however, the issue of Wallerian degeneration following transplant still remains. Previous research has shown promising results, using extracellular vesicles (exosomes) of peripheral nerve cell types (neurons, Schwann cells, and endothelial cells) to induce neuronal differentiation and regeneration. Our project investigates mechanisms to utilize exosome regenerative capability by exploring how different concentrations and conditions affect exosome uptake by other cells. Further, we have postulated that priming the exosomes through co-culture with neurons for 24 hours, will increase the exosome’s

tendency for uptake and long-term cell survival; thus minimizing the likelihood of axonal degeneration. Our data demonstrates that after 24 hours of cell priming, both endothelial and neuron exosome uptake into neurons occurred. All plates of endothelial and endothelial exosomes, at 15 uL and 25 uL concentrations, demonstrated increased exosome uptake after 7 days of neuron culture, as compared to 3 days of neuron culture. Both endothelial and neuron exosomes showed the greatest levels of uptake at a concentration of 25 uL and after 7 days of culture. Interestingly, the 15 uL concentration of endothelial exosomes showed a significant increase in neuron uptake between 3-day culture and 7-day culture, while the 15 uL concentration of neuron exosomes did not have a significant increase in uptake between the 3-day culture and 7-day culture. Overall, the findings suggest that peripheral nerve cell priming,

the length of neuronal and exosome culture, the cell origin of the exosome, and the dosage of exosomes affects the uptake potential of exosomes into neurons. Optimizing these conditions could serve a therapeutic benefit to peripheral nerve transplant and improve the success rate of peripheral nerve regeneration. Ultimately, we plan to next explore the drug delivery capabilities of peripheral nerve cell exosomes and thus improve the outcome of peripheral nerve damage.

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