Present work on artificial blood tends to focus on narrow areas of functionality in which short-term augmentation of the capabilities of natural blood are useful, such as oxygen transport and clotting. From these diverse paths a wholly artificial blood substitute will no doubt eventually arise, but bear in mind that this line of development faces stiff competition from the use of cell technologies to produce biological blood as needed. One way or another blood donation will be a thing of the past not so many years from now:
An additive nanoparticle manufacturing process has been used to design and realize a synthetic platelet for the first time. The platelets are "super mimics", matching the natural shape, size, flexibility, and surface biochemistry of real platelets unlike prior incarnations that match only one or two qualities. The synthetic plates are made by a layer-wise build-up of synthetic polymers and biological proteins, some of which include polystyrene, polyallylamine hydrochloride, and bovine serum protein (a generic protein). The surfaces are conjugated to natural clotting factors such as von Willebrand Factor binding peptide, and fibrinogen-mimetic peptide. The new nanoparticle-derived synthetic platelets have a natural, flexible "discoid" shape rather than a rigid spherical shape that overcame the margination problem. Nanoparticles have been developed previously for solving the same challenges but thus far have been hampered by deficiencies such as poor circulation in the blood stream, poor margination (the migration from central bloodstream to extremities), and poor targeting.
The synthetic platelets also display preferential attachment to injury sites because they are decorated on the exterior with the right proteins including von Willebrand Factor and collagen. In animal experiments, the synthetic platelets were introduced into the blood stream after injury to the tail of the model animal - mice. The platelets circulated broadly and then settled on the site of physical insult. In the animals that received the synthetic platelets with the biological mimic of the surface, the accumulation of platelets was three times higher than without for synthetic platelets with unmodified surfaces, accompanied by the same accelerated stopping of bleeding.
The immediate application is imagined for control of bleeding in people who have suffered traumatic injury, and patients who are undergoing surgery or suffer from a clotting disorder due to problems with platelets. But in addition, the new medical material is generating excitement for its potential as a therapeutic delivery vehicle for treating diseases that involve platelets, such as atherosclerosis (thickening of arterial wall leading to constriction of blood vessels) and thrombosis.