A bio-inspired approach to creating universal red blood cells.
Chinese scientists are developing a new approach to create “universal” blood: red blood cells (RBCs) that can be transfused into any patient, regardless of the patient's or recipient's blood group.
Blood groups are characterised by the presence (or absence) of various proteins known as antigens on the surface of RBCs, the most well-known of which form the ABO system and the Rhesus D (RhD) system. One consequence of the existence of these groups is that blood mismatching can occur when an incompatible blood group is used for transfusion. The recipient’s antibodies recognise the antigens on the donor RBCs as being foreign and attack the cells – with potentially fatal results.
Several approaches have been investigated in the past to strip RBCs of their antigen identity, such as chemical cleavage of the antigens, disruption of antigen–antibody binding by grafted poly(ethylene glycol) molecules or ex vivo production of universal RBCs from genetically engineered hematopoitic stem cells, but each of these methods has its downfalls. Ruikang Tang and co-workers, from Zheijiang University, have used a simple method to mask the ABO group antigens by chemically modifying the RBC surface with polydopamine (PDA), a mimic of the bioadhesive produced by the mussel Mytilus edulis.
‘The concept is very clever because the coatings can be performed in situ using dopamine as a precursor molecule,’ says Christopher Bettinger, a biomaterials researcher from Carnegie Mellon University in the US. ‘The resulting polydopamine coating is therefore composed of materials that already exist in the human body.’