Haemoglobin based oxygen carriers (HBOCs) have applications in wound healing, perfusion of donated transplant organs and ultimately in trauma. A patent filed by Spheritech in 2017 has now been granted in the US (patent number US 10,471,130 B2). The company has, in effect, created microparticles which mimic artificial red blood cells comprised entirely of fatty acids and haemoglobin. These microparticles have the advantage that they are the same order of magnitude as red blood cells and as such do not pass through capillary walls in the same way as other HBOCs in development. This new HBOC, termed SpheriSome Hb has already been shown to maintain porcine kidneys in ex-vivo perfusion models and is currently under development for transplant organ perfusion.