One-size-fits-all synthetic blood

Donated blood has a short shelf-life – only 35 days for red cells – but now researchers in Essex hope to improve this by developing a synthetic blood substitute. The HaemO2 project hopes to develop a one-size-fits-all, third generation artificial blood substitute that can be stored easily at room temperature and available to all patients regardless of blood type. What’s more, the blood substitute can be stockpiled as it has a shelf life of up to two years. The substitute is a safe, long-lasting and virus-free alternative to current blood transfusions and could be used in all countries, particularly at the site of natural disasters. Led by Professor Chris Cooper from the University of Essex, the HaemO2 project aims to create an artificial haemoglobin-based oxygen carrier (HBOC) that could be used as a substitute for blood lost in trauma or surgery. It has so far been difficult to make a safe and effective HBOC outside the protective environment of the red cell since haemoglobin can be toxic. The product being developed by HaemO2 can be detoxified by the body’s own defences. “We take the human gene for haemoglobin and then modify it so that it can survive better outside the red cell by using patented synthetic biology techniques,” Cooper told Laboratory News. “We then clone the gene into bacteria so that they produce large quantities of the modified human protein. This is followed by adding PEG (Polyethylene glyco) to increase the size of the product so that it is not cleared via the kidneys.” “More technically we add tyrosine residues at crucial sites to enable electron transfer from plasma antioxidants such as Vitamin C and uric acid to detoxify the reactive ferryl state of the haemoglobin," he added. The implications of such a product could be huge said Cooper. “It means we could overcome some of the inherent problems with transfusions as there would be no need for blood group typing and a longer shelf life means you are able to stockpile the supplies necessary for major disasters,” he said. “It also offers the opportunity for routine transfusion support in ambulances or at remote inaccessible locations. The engineered haemoglobin has already been granted patents in the US and Australia, and has a patent pending in the EU.