Platelet substitutes

Many experimental approaches have been explored to produce hemostatically active novel human platelet products and substitutes capable of long-term storage. These include: platelet storage in the frozen state; storage in the cold (4 degrees C) in the liquid state; photochemical methods for the inactivation of viruses, bacteria and protozoa; infusible platelet membranes; and rehydrated lyophilized platelets. In addition to products using human platelets as their primary manufacturing source, other approaches have been used to make non-platelet-derived substitutes that might be capable of in vivo hemostasis. These include production of red blood cells, or liposomes, bearing hemostatically active agents on their surfaces; and fibrinogen-coated albumin microcapsules or microspheres. The development of platelet substitutes is an increasing scientific and technological endeavor and there are many reasons to believe that platelet substitutes will become more efficacious and safer to use over time. Ultimately, such work will result in safe and effective platelet substitutes being available for clinical use in thrombocytopenic or other patients with increased risk for bleeding.