FedExosomes (Pt 1)

Ever wondered what exosomes are?

They are nano-sized extracellular vesicles that are secreted by all living cells, playing an important role in cellular communication and delivery.

Or more simply put, they are comparable to our modern FedEx delivery packages. Sent to a specific address, or target cell, they are packed with cargo consisting of proteins, lipids and genetic instructions (mRNA, miRNA).

Exosomes are equipped with specific surface proteins, or ‘shipping labels’, that ensure each package is delivered to the correct address. These surface proteins, including integrins and tetraspanins, are part of the tracking mechanism that we so often see with package deliveries. For example, exosomes derived from cancer cells contain a specific surface marker, or ‘label’, called EpCAM that can be used as a diagnostic but also to ensure cargo is delivered specifically to cancer cells.

Can you imagine just how important their targeting abilities are? It ensures that the package is not delivered to the wrong cell but rather ‘signed in’ at the correct recipient cell, or ‘address’.

But what happens once the package is delivered to the right destination? How is it received on a cellular level? There are three ways in which the package is received by the recipient.

One, direct drop-off. The exosome, or ‘package’, fuses with the cell membrane to dump its cargo inside.

Two, front desk. The exosome, or ‘package’, binds to the surface receptors of the cell (front desk) to trigger a signal. The exosome never enters the building.

Three, mailroom. The exosome, or ‘package’, undergoes endocytosis for internal processing.

The delivery capabilities of exosomes make them a valuable tool for drug delivery and patient treatment across many diseases.

It is a mechanism that has been utilized in the skincare industry for the treatment of topical diseases.

It is a mechanism that has been utilized in clinical trials spanning neurodegenerative diseases to immune-related diseases.

But it is a mechanism that has its faults…