Currently under research and development by many scientists and pharmaceutical companies is a substitute for human blood, which can carry oxygen and carbon dioxide both efficiently and safely through a patient??™s body. There are two types of oxygen carriers that are currently under development: Perfluorocarbon (PFC) based carriers and isolated Hemoglobin Based Oxygen carriers (HBOCs).
PFC is a compound that is made up of carbon and fluorine atoms. PFCs have the ability to at least 5 times more oxygen than RBCs. This is why PFC based blood substitutes are currently under development as it could be used in hospitals to save the lives of patients who have lost extensive amounts of blood. One such example is Oxycyte. Oxycyte is PFC based product that is currently under Phase II dose escalation clinical trials in Switzerland and The Israeli Military for the treatment of Traumatic Brain Injuries in hospitals. Through these clinical trials it can be seen that Oxycyte is very effective at treating brain trauma and may be granted approval for general use in hospitals. However like most PFC based products there is an increase in the risk of death and heart attacks. This is due the body??™s inability to break down and remove the PFC that is present in the blood quickly enough so it can cause blockages that could lead to heart attacks and even death. PFCs could also have a long term effect on the kidneys and liver as the PFC would have to be removed from the bloodstream. Due to the increased risk of death and heart attacks, as well as the possible long term damage to the kidneys and liver many PFC based has not been approved for use in hospitals in many developed countries such as the US and Australia.
HBOCs are made from isolated hemoglobin that have been extracted from humans, animals and even made, so they can be placed in the blood stream. One example of a HBOC is PolyHeme. PolyHeme is the only blood substitute that has finished a Phase III Trauma trial in the US; it did this in June 2006. PolyHeme was intended for use in hospitals for different types of trauma, which often involve severe blood loss. Unfortunately PolyHeme has not been approved for use by the FDA in the US as 47 out of 350 patient treated with PolyHeme died when compared to the 35 deaths out of 363 patients in the control group. 3% of those treated with PolyHeme died from heart attacks when compared to 1% in the control group. Due to the increased risk of death it can easily be seen that Hemoglobin based Oxygen Carriers have a long way to go before being approved for use in many countries of the world.