A method to deoxygenate blood's oxygen-carrier, haemoglobin, could lead to treatments for sickle cell anaemia. London-based chemists have prepared a microcell that can be used to study the causes of the debilitating genetic condition.

In sickle cell disease, the patient's red blood cells are curved into a sickle shape and can become stuck in blood vessels, blocking blood flow and causing pain. Sickle cell haemoglobin (HbS) is different from normal haemoglobin (Hb) by just a single amino acid. This amino acid replacement means that HbS tends to polymerise into long insoluble fibres and it is this that changes the shape of the cell. 

'The key to HbS polymerisation is the deoxygenated molecule, as fibre formation occurs only in this state,' said Daren Caruana, an electrochemist at University College London, UK. Caruana and colleagues have developed a novel technique for removing oxygen from HbS by electrochemical reduction allowing them to control and study HbS polymerisation in detail. 

The group used the new technique to reduce a small volume of HbS within a custom-built transparent cell and were able to follow the resulting polymerisation as a change in turbidity. 

The electrochemical method offers an advantage over previous deoxygenation methods, since these use oxygen scavengers which can have a negative effect on HbS structure, said Caruana.

'Sickle cell disease is an international health problem affecting millions of people around the world,' said Caruana. 'This method could not only be used to gain an understanding of the pathophysiology of sickle cell disease, but also as a screening method for drugs that could lead to novel therapeutic strategies for disrupting HbS polymerisation in patients.'

Michael Spencelayh