Plastic Blood (May 2007 article)

Summary of article + Review (by Marcus Heng, Year1)

Researchers in Sheffield University have created artificial blood by synthesizing plastic with an iron-containing porphyrin ring core, capable of transporting oxygen like how blood does. This structure is remarkably similar to haemoglobin itself. The advantage of this blood is that there is no antigen specificity, meaning anyone can use it in times of emergency. Being artificial, it does not have to be chilled, is light to carry, can be manufactured sterile and lasts a great deal longer than real blood.

Previous attempts at artificial blood include hemoglobin-based oxygen carriers (HBOCs) and perflourocarbons (PFCs).

Many people involved in accidents die because of massive loss of blood before a suitable blood supply is found. The problems associated with utilizing current blood supplies lie in identifying the victim’s blood type, finding a suitable match from blood reserves, making sure the blood has not expired, defrosting the blood and so on. This poses a huge delay for a patient on the verge of death, especially when special storage of donated blood makes it only possible to transfuse larger quantities at a hospital itself. Plastic blood does not have these limitations.

Being synthetically-made from polyethylene glycol (PEG-a water-soluble monomer already used in medical applications) and porphyrin, plastic blood’s shelf life may even allow it to be kept in powder form in your regular first aid kits, ready to be mixed with pure water to form blood when the need arises. Moreover, there is no risk of catching blood-borne diseases like HIV & Hepatitis from plastic blood.

This alternative blood source also poses as a life line to ailing blood supplies as fewer people heed the call to donate blood. However, this may yet pose another problem as people start to adopt the mentality of “With synthetic blood, we need not donate blood anymore”. This is not true.

HemAssist, the first Haemoglobin-Based Oxygen Carrier (HBOC) tested on humans, was discontinued after patients who received the transfusion died more often than those who received donated blood.

In reality, research has yet to discover what long-term side-effects plastic blood may inflict on a user when used in high quantities. If improperly metabolized, severe kidney and liver damage may result. Moreover, the idea of putting plastics in your blood probably would sounds alien to most laymen. I guess to most people, blood remains as a very complex part of the body. To perfectly create a man-made substance that duplicates the real thing is extremely difficult, not to mention risky. In addition, to those in the medical field, making a new drug or homologue is more than utilizing its therapeutic effect. It is thus necessary to investigate other pertinent factors like its elimination after use, its toxicity & its perfusion.

Concerns have also surfaced about misuse of artificial blood, especially in the area of sports. Sportsmen normally have a relatively higher blood oxygen capacity than average, which gives them an advantage in endurance events. This can be achieved by the legal way of long-term training or by a shortcut known as doping. While there are no cases of doping artificial blood, it still remains a possibility in the near future. A possibility which would threaten the very nature of sports itself.

For now, it will probably be best to stick with the real thing.

Acknowledgements
http://www.mondovista.com/plasticblood.html

http://health.howstuffworks.com/artificial-blood1.htm