Storage Challenges

Red Blood Cells (RBCs) are an important blood component used for transfusions given in the course of surgical operations, bleeding complications resulting from trauma, etc. RBCs that have been separated from liquid plasma (packed RBCs) are given to persons who have anemia or have lost a significant amount of blood.

Currently, RBCs are stored in PVC bags plasticized with (Di(2-ethylhexyl) phthalate) DEHP at refrigeration temperature. A wide body of research undertaken over many years has shown that DEHP can leach out of PVC, resulting in exposure to body tissues and fluids. How much leakage occurs depends on a number of factors, including the lipid con­tent of the blood, the storage time, and the temperature.

DEHP is classified as a reproductive toxin, and its risks are severe in sensitive groups, such as neonates and chronically ill individuals. High-exposure patients include patients requiring extensive blood or blood product transfusions. Safety concerns over DEHP leaching from PVC blood bags have driven the search for substitute materials in medical devices.

A key benefit of DEHP is that it has a conservatory effect on RBCs.  Unique to the storage of RBCs, DEHP is a necessary component of these storage bags and is required to prevent excessive hemolysis over storage. This is one reason why DEHP/PVC has been so difficult to replace.


CPT Storage Technology

As CPT demonstrated for platelets and some other cells, xenon prevents the increase of extracellular membrane viscosity at refrigerated temperature.

At lower temperatures, cell metabolism is inhibited. However, RBCs reduce their deformability, which leads to hemolysis during storage.  This is likely due to the creation and solidification of ceramide-enriched membrane domains in the extracellular membrane. Incorporation of xenon atoms into the extracellular membrane helps prevent cell damage.

Storage of RBCs in a xenon-saturated medium can be considered desirable, and can extend RBCs storage time even beyond 42 days.

CPT is developing a packaging solution that enables the storage of RBCs at a refrigerated temperature in an atmosphere of xenon. Refrigeration provides a long storage period and inhibits bacterial growth; high xenon concentration prevents cold stored RBC hemolysis during storage.