# Developing genetically encodable probes for multimodal tracking of exosomal RNA cargo

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2024 · $388,750

## Abstract

Project Summary
Exosomes, also referred to as small extracellular vesicles, play important roles in cellular communication under
physiological and pathophysiological conditions. Exosomes contain a wide range of both short and long non-
coding RNAs that regulate many aspects of gene expression including epigenetic processes that modulate
cellular fate, phenotype, polarization, and morphogenesis. Despite the important functional roles played by
exosomal RNAs, there are currently no methods that allow live exosomal RNA tracking. This is because RNA is
by nature non-fluorescent and difficult to label while maintaining its intended biological function. Access to
exosomal RNA is further complicated by the fact that each RNA species is present at extremely low copy
numbers in exosomes. This emphasizes both the need for a novel marker capable of tracking the intercellular
movement of exosomal RNA, and the need to enhance loading of RNAs into exosomes.
Given the central importance of exosomal RNAs in dictating cellular behavior, there is a need and demand for
exosomal RNA imaging methods to determine how (a) cells use exosomes and their cargoes to communicate
with each other and (b) how exosomes modulate their microenvironment and travel to distant organs and tissues.
Existing methods focus on tracking exosomes by labeling the lipid membrane via a lipid-based fluorophore or
exosomal protein labeling. None of these methods allow the tracking of exosomal RNA via genetic encoding or
barcoding without exogenously modifying the exosomes after extensive collection and alteration steps.
The overall goal of this proposal is to develop genetically encodable RNA EXO-Code probes that allow
multimodal tracking and imaging of exosomal RNAs. The EXO-Code probe will allow multimodal tracking of
exosomal RNA via (1) genetic encoding, (2) non-destructive labeling with fluorescent dyes, and (3) unique
identification and quantification based on barcoding. This combination is powerful as it allows tracking of
exosomal RNA via multiple modes for high content biodistribution mapping. Because EXO-Code barcodes are
composed of unique nucleotide sequences, they can be accurately decoded using sequencing with sensitivity in
the attomolar range. The combination with a fluorogenic RNA aptamer allows for complementary tracking of
exosomal RNA via simple incubation with dyes. The fluorescent exosome toolkit will be developed for
investigators to detect disruptions in membrane stability, exosomal fusion events, and endocytic processes as a
result of exosome biogenesis, distribution, and uptake. This will enable researchers to track exosomal RNAs
through organisms, cells, and their ultimate destinations within subcellular compartments.

## Key facts

- **NIH application ID:** 10919782
- **Project number:** 5R01GM150252-02
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Juliane Nguyen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $388,750
- **Award type:** 5
- **Project period:** 2023-09-15 → 2027-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10919782

## Citation

> US National Institutes of Health, RePORTER application 10919782, Developing genetically encodable probes for multimodal tracking of exosomal RNA cargo (5R01GM150252-02). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10919782. Licensed CC0.

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