As blood banks nationally struggle to keep their shelves stocked, scientists are working at full speed to develop a blood product that can act as a substitute during severe traumatic blood loss. Blood provides fluid volume, is a transit for cells and nutrients, but most importantly, it carries oxygen to all parts of the body through its hemoglobin.
A team at Washington University in St Louis has developed synthetic nanocells that can carry oxygen and release it to tissues. This can be stored in powder form and freeze dried, a huge advantage as most blood products have a shelf life of 42 days. The powder could last for a year and paramedics, trauma staff and soldiers would only need to add water. This “Tang” type of technology could provide a fast, ready to use blood product without need for extensive storage, a necessity on a battlefield or trauma scene. Its called ErythroMer.
The nanocells are about 1/50 the size of red blood cells. They are made up of human hemaglobin proteins and enveloped in a synthetic polymer aiding storage, transit and oxygen release. Prior attempts at making artificial blood failed because the artificial blood would react with nitric oxide, stimulating vasoconstriction which would enhance tissue blood loss. This polymer acts as a coating to prevent the direct hemaglobin-nitric oxide contact. The polymer knows when to capture and release the oxygen as it senses levels in pH. As tissues become hypoxic, the lack of oxygen and increase in carbon dioxide makes the area more acidic. This will trigger the polymer to release the oxygen. As it circulates near the lungs and notes a higher pH, it will pick up the oxygen, working similarly to a natural red blood cell. However, as opposed to the life of a red blood cell, which is close to 120 days, ErythroMer may only last hours to a few days. But this could be enough time until the victim is transported to a hospital.
Senior researcher, Dr. Allan Doctor, states, “It’s a dried powder that looks like paprika, basically,” …….“It can be stored in an IV plastic bag that a medic would carry, either in their ambulance or in a backpack, for a year or more. When they need to use it, they spike the bag with sterile water, mix it, and it’s ready to inject right then and there.”
Moreover he states, “Blood pH is high in the lungs, is low in tissue, and is even lower in tissue that doesn’t have enough oxygen,” …….. “By linking oxygen affinity to blood pH, we imitate the behavior of a normal red cell.”
When they tested the product in lab mice, Doctor said, “We replaced 70 percent of the mouse’s blood volume with the blood substitute,”……… “Those mice were indistinguishable from those who received a transfusion from another mouse.”
Clinical trials need to begin to test its efficacy and safety in humans, but it looks promising. Dr. Allan Doctor will present his preliminary findings this weekend in San Diego at at the American Society of Hematology’s annual meeting.
However, despite this advancement, blood is urgently needed by blood banks nationally. Please visit www.redcrossblood.org, or www.unitedbloodservices.org to find out where you can donate blood. With the Holidays, giving a pint of blood is the best present ever! #pintsaspresents can save lives as one donation of blood can help saves the lives of up to three people.
Daliah Wachs, MD, FAAFP is a nationally syndicated radio personality on GCN Network and Board Certified Family Physician
Medical Spanish made easy!!!