Increasing the shelf life of stored blood
Blood loses its quality upon storage and overall blood transfusion efficiency reduces. File
| Photo Credit: The Hindu
Our team at the Institute for Stem Cell Science and Regenerative Medicine (DBT-inStem), an autonomous institute of the Department of Biotechnology, has developed a novel blood bag technology to enhance the quality and shelf life of stored blood.
Despite inadequate blood donation, millions of blood units are discarded due to decline in quality during storage. Stored blood has a finite shelf life. Typically, stored cells produce various extracellular components known as damage-associated molecular patterns (DAMPs), which damage the blood cells during storage.
Previous attempts
Although multiple attempts have been made to increase the quality of stored blood, they have limited success. Thus far, studies have focused on improving storage conditions through additives, rejuvenation solutions, and cryopreservation protocols. However, none of those approaches addressed the cause of the problem — the presence of damage causing extracellular components in the blood.
To tackle this issue, contrary to the conventional approaches, we have developed a novel approach to scavenge/capture and remove the damage-causing extracellular components during blood storage. This prevented the damage of stored blood cells, and enhanced their quality, and increased the shelf life of stored blood by about 25%.
Typical extracellular components being generated are free-iron and free-hemoglobin, bioactive lipids such as poly unsaturated fatty acids, extracellular DNA, nucleosomes, and proteins. During the storage, these components interact and damage red blood cells (RBCs). Capturing these DAMPs components without causing damage to the stored blood cells is highly challenging. Therefore, we have custom-designed nanofibrous sheets that can capture such damage-causing components and protect RBCs.
Nanofibrous sheets
The key design factor is the following. Critical damage-causing agents are charged molecules. We hypothesised and demonstrated that charged nanofibrous sheets made with cationic and anionic polymers will help scavenge damage-causing agents through ionic interactions. These nanofibrous sheets can be made into blood bags.
DAMPs are produced when cells get destroyed and the DAMP components, in turn, damage the membrane of RBCs and reduce the membrane integrity, which makes the RBCs fragile. Upon transfusion, the fragile RBCs break down, leading to poor blood transfusion outcomes.
Intermittent capturing of DAMPs on day 21 or 28 after collection using the novel blood bags helped protect RBCs from losing their membrane integrity, and enhanced the transfusion efficiency. Scavenging of DAMPs can be completed in 15 minutes.
Typically, blood can be stored for 42 days before transfusion. Compared to fresh blood, blood loses its quality upon storage, and overall blood transfusion efficiency reduces. 42 days of stored old blood has the least transfusion efficiency than either fresh blood or 21 days of stored blood.
Increased shelf life
However, we have demonstrated that with our technology, the quality of 42 days of stored old blood is as good as freshly collected blood. Additionally, with our technology, the maximum shelf life of stored blood has increased by 25%. The results were published recently in Nature Communications.
Besides increasing the shelf life of stored blood, it may be a boon for preserving rare blood groups. Now, our team is setting up a start-up company in Bengaluru to develop this technology further and take it to the clinic.
( Praveen Kumar Vemula is Associate Professor at DBT-inStem, Bengaluru. Subhashini Pandey is a senior graduate student at DBT-inStem)
