Abstract
Neo Red Cells (NRCs) prepared by encapsulating Stroma Free Hemoglobin (SFH) together with the allosteric effector in liposomes, sufficiently function as artificial oxygen carriers under physiological condition. In animal models, rabbits were carried out twice bleeding and followed infusion of 6%-hydroxy ethyl starch. With this procedure, rabbits were made anemic (Hb conc. 1.6g/dl, Hct 5.0%), then this anemic model rabbits were infused with 40ml/kg of NRC suspention. The anemic rabbits, receiving NRCs showed recovery from anemic condition within 4-5h after exchange transfusion (ET) and were remained over 20h. Cardiac output was increased from 0.5 to 0.6-0.8l/min after ET, but remained this over 20h. Rabbits lived normally without any assist up to 6 months until sacrificed after ET. NRCs oxygen transporting rate (OTR) was 10.5ml/min after ET, the OTR of NRCs was reduced to 50% at 48h post-exchange due to clearance of NRCs by the reticuloendotherial system and methemoglobin formation, but after 24h, OTR of own blood begun to increase such that the animals could become independent of NRC, with full recovery within 2 weeks. The pathological diagnosis of rabbits indicated that phagocytosis of NRC by Kupffer's cells in liver and splenocytes, but there were no appearance of toxically damage. The present investigations clearly indicate that NRCs are efficacious oxygen carriers without causing serious adverse reaction.
