 Usual source of platelet fractions is adult human blood, but this source involves relevant drawbacks and problems. Peripheral blood from a human cannot be used without potential risks due to alloreactivity, resulting in several clinical complications. On the other hand, the availability of autologous blood is generally low, since it can be dangerous to withdraw a sufficient amount from a patient who cannot tolerate such a withdrawal. Moreover, allogeneic blood from adult donors can involve risks of infections. 