What if blood can be stored for years?

We know that donated blood now can't be preserved for   more than six weeks after donation. But what if we can prolong that storage period for years? Scientists are now looking for such solutions. 

 A promising solution to the problem attempts to dry blood by using a sugar-based preservative that organisms living in some of Earth's most extreme environments produce to weather long periods of dryness. New work in ultrasound technology looks to provide a path to inserting these sugars into human red blood cells, in an effort to help them last for years.

Researchers now have demonstrated (1) a new way to use ultrasound to create pores in red blood cells (RBCs), which allows the molecule trehalose to enter the cells and prevent their degradation when dried for preservation. Oscillating microscopic bubbles of inert gases with ultrasound provides the microfluidic system with the ability to increase the number of viable cells that can be rehydrated. 

The approach could lead to ways of increasing the shelf life of blood donations from weeks to the order of years. Such advances would provide a boon to those needing blood in areas where access to donations is difficult, like on the battlefield or in space.

Using acoustofluidics to place a molecule like this inside RBCs is interesting because it allows us to store blood without keeping it cool.

Trehalose is a relatively cheap sugar that is so safe that it is used as a preservative for some food items, like donut glaze.

The researchers constructed a spiral-shaped channel that exposed blood cells to trehalose while surrounded by microbubbles. They tuned ultrasonic vibrations using several parameters until the bubbles shook nanosized holes in the membranes of the blood cells, just large enough for trehalose or a closely related fluorescent molecule called fluorescein to enter and just briefly enough to maintain the integrity of the blood. After confirming that fluorescein could enter cells on test samples, they added trehalose to a new batch of samples, dried the blood, rehydrated it, and performed tests to count how many of the blood cells were still viable after the process. The ultrasound technique was able to preserve a significantly higher portion of cells by adding trehalose versus leaving the trehalose out.

The group looks to improve on the yield for their technique with the hopes of verifying the effectiveness of dry-preserved blood in patients.

Citations:

1. https://aip.scitation.org/doi/10.1063/1.5144617