Exosomes are small membrane vesicles that cells release to transfer proteins and RNA to other cells at a distance — a form of intercellular communication that doesn't require direct contact.
release_prob ~ cargoRate * proximity_to_recipient
cargo particle lifetime = 1/decay
- Orbit eccentricity — how far the exosome's path swings from a direct donor-to-recipient line as it navigates the extracellular matrix.
- Travel speed — how fast the vesicle moves through interstitial fluid or bloodstream.
- Cargo release rate — probability per unit time that the exosome fuses with a target membrane and dumps its miRNA/protein cargo.
- Cargo decay — how quickly released cargo particles are taken up or degraded once free.
Because tumor-derived exosomes carry a specific microRNA signature, liquid-biopsy tests now screen blood-borne exosomes as an early, minimally invasive cancer biomarker.