Intranasal Mesenchymal Stem Cell Delivery in a Mouse Model of Traumatic Brain Injury

Begin with an anesthetized mouse with a traumatic brain injury.

At the injury site, axonal demyelination and neuronal damage trigger the release of pro-inflammatory cytokines.

Secure the mouse and intranasally deliver a proteolytic enzyme.

Next, position the mouse face up for a short duration and repeat the enzyme delivery.

The proteolytic enzymes degrade the extracellular matrix in the nasal epithelia and enhance the cell permeability.

Then, intranasally administer the labeled mesenchymal stem cell, or MSC solution.

Hold the mouse’s head upright for a while to prevent premature drainage and allow MSC absorption into the nasal tissue.

Repeat the MSC delivery process.

Allow the mouse to recover.

The chemotactic signals of pro-inflammatory cytokines direct MSCs to migrate from the nasal cavity to the brain injury site.

At the injury site, MSCs secrete neurotrophic factors that promote remyelination. This highlights MSCs’ neurotherapeutic potential for neuronal repair.

For cell delivery, after confirming a lack of response to toe pinch, scruff the mouse while immobilizing the skull. Place the tip of a pipette containing 4 units of hyaluronidase per microliter of PBS near the nare of the mouse at a 45-degree angle and administer 3 microliters of hyaluronidase suspension into each nostril. Place the animal face up on a clean pad for five minutes before repeating the treatment four times for a total of 100 units of hyaluronidase treatment.

After the last treatment, place the mouse back onto the pad for 30 minutes before restraining the mouse, as just demonstrated. With the head immobilized, administer 3 microliters of the mesenchymal stem cell suspension into each nostril over a period of three seconds per solution delivery, holding the mouse in position for 30 seconds until the sample drops have completely disappeared. After two minutes, repeat the delivery up to three times until the entire volume of mesenchymal stem cell has been delivered. Then return the mouse to its cage with monitoring until full recumbency.