Plasma carries nutrients to the tissues and delivers waste to the kidneys for excretion. It transports drugs, antibodies, hormones and proteins. Importantly, plasma is also the source of clotting factors that enable blood to coagulate. The primary function of red blood cells is to transport oxygen to the tissues. White blood cells fight infection and foreign invaders.
Platelets are the first line of defense against vascular injury.
Hextend is not a blood substitute or a synthetic substitute for any blood product. It cannot transport oxygen to the tissues to sustain life, fight infection, carry proteins and does not contain clotting factors. At the present time there are no synthetic products currently marketed that can transport oxygen in vivo. An enormous research effort, well beyond BioTime's technical and financial capacity, is being directed toward a synthetic red blood cell replacement. Hespan received its original FDA approval in 1972.