Abstract
The Hb-vesicles which encapsulate the purified and concentrated Hb more than 40 g/dl with a uni-or bi-lamellar membrane are prepared by extruding the dispersion of mixed lipids through membrane filters (final pore size: 0.2 μmϕ). They transport large amount of oxygen with satisfying rheological properties such as oncotic pressure and solution viscosity. Oxygen affinity of the Hb-vesicles is adjusted so as to exceed the ability of oxygen transport of human blood by coencapsulating allosteric effectors in the Hb-vesicles. The solution is sterilizable because of the diameter of Hb vesicles less than 0.2 μmϕ. The Hb-vesicles are stabilized by using polyphospholipid or glycolipid as membrane components. No change in oxygen affinity and particle size was confirmed during long time storage at 4 °C. The stabilized Hb-vesicles can also be stored as frozen or dried state. The dried Hb-vesicles are regenerated by simply adding pure water. Simple in vitro test indicates that Hb-vesicles have the reduced inhibitory action of Hb to the EDRF-mediated vasorelaxation.