Poster Y8 - Exosome Journey from Cellular Uptake to Cargo Release: Tracking with Chiral Nanoparticles

Saturday, October 26, 2024

10:00 AM - 11:00 AM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Gaeun Kim (she/her/hers)

Ph.D. Student
University of Notre Dame
Notre Dame, Indiana, United States

Co-Author(s)

RZ

Runyao Zhu

Ph.D. Student
University of Notre Dame, United States
Youwen Zhang, PhD

Assistant Professor
Rutgers UniversityCamden, New Jersey, United States
Hyunsu Jeon, MS

Ph.D. Student
University of Notre Dame
Notre Dame, Indiana, United States
FS

Farbod Shirinichi

Ph.D. Student
University of Notre Dame, United States

Primary Investigator(s)

Yichun Wang

Assistant Professor
University of Notre Dame, United States

Introduction: Exosomes have come into the spotlight as promising nanocarriers for drug delivery. However, the clinical application of exosomes remains a challenge due to the limited understanding of their physiological properties. While exosomes typically undergo cellular uptake through two potential routes, 1) endocytosis and 2) membrane fusion, the intricate mechanisms involved in their origin-dependent uptake and subsequent cargo release are not fully explored. Herein, we unravel the mechanisms governing exosome entry into recipient cells and subsequent intracellular release of their cargo. In this study, we utilized chiral graphene quantum dots as representative exosomal cargo, taking advantage of their effective lipid membrane permeability, as well as their unique optical properties for tracking.

Materials and

Methods: In this study, we utilized chiral graphene quantum dots as representative exosomal cargo, taking advantage of their effective lipid membrane permeability, as well as their unique optical properties for tracking. To investigate the cell-of-origin specific cellular entry mechanism and the following intracellular cargo fate of exosomes, we used confocal laser scanning microscopy imaging analysis, mass spectrometry-based proteomics, western blot, and fluorometry.

Results, Conclusions, and Discussions: *Results
We observed that the preferential cellular uptake of exosomes derived from the same cell-of-origin (intraspecies exosomes) is 1.4 to 3.2 times higher than that of exosomes derived from different cell-of-origin (cross-species exosomes). This uptake enhancement was attributed to the receptor-ligand interaction-mediated endocytosis, as we confirmed a 1.6 to 2.1 times higher lysosomal uptake of intraspecies exosomes and identified the expression of specific ligands (TGF-β1, GalNAc, and NRG1) on exosomes that favorably interact with receptors (TβR, ASGPR, and ErbB4) on their parental cells. On the other hand, we found that the uptake of cross-species exosomes primarily occurred through membrane fusion (colocalization correlation value of PCC > 0.7), followed by direct cargo release, whereas intraspecies exosomes exhibited a lower correlation value (PCC = 0.3~0.5).
*Conclusions
We utilized the fluorescent chiral quantum dots as a tracking agent and cargo to explore the homing-effect of exosomes depending on their cell-of-origin. Overall, our discovery envisions valuable insight into strategizing drug delivery for efficient targeting of exosomes, as well as provides a comprehensive understanding of intercellular communication through exosomes.
*Discussions
Despite achieving high exosome uptake into their parent cells mainly through receptor−ligand-mediated endocytosis, it is necessary to take into account the entrapment of exosomes within lysosomes. However, it was reported that only 24 ± 1.2% of intake exosomes were released from endosome/lysosome. To ameliorate or circumvent undesired degradation and deactivation of therapeutic efficacy within the lysosome, it is necessary to ensure effective drug delivery to intracellular sites without degradation through the successful lysosome escape of exosomes. Therefore, a functionalization approach, such as surface modification on exosomes to facilitate lysosomal escape, enables us to fully utilize the inherent homing effect of exosomes for targeted drug delivery.

Acknowledgements (Optional):