[Progress in the red cell substitutes (artificial red cells)].

Recent progress of red cell substitutes to apply clinical use are overviewed. In response to the requisites as oxygen transporters, characteristics and present status are summarized for hemoglobin-based substitutes (polymer-conjugated Hb, polymerized Hb, crosslinked Hb). Concentrated hemoglobin covered with thin phospholipid bimolecular layer membranes (hemoglobin-vesicle) transports the sufficient amount of oxygen with excellent solution properties and safety. Furthermore, performances of two types of totally synthetic oxygen carrier are introduced such as lipid-heme embedding in the bilayer of a phospholipid vesicle and lipid-heme in the fat-microsphere composed of the emulsion for the nutrimental infusions.