Solution to the problems of acellular hemoglobins by encapsulation and the intrinsic issues of hemoglobin vesicles as a molecular assembly

Abstract

SUMMARY Hemoglobin vesicles (HbV), or liposome-encapsulated hemoglobins, are developed as artificial oxygen carriers for the use as a transfusion alternative. The safety and efficacy of HbV have been clarified in detail: HbV can overcome the side effects of hemoglobin (Hb) molecules (stroma-free, and intra- or intermolecularly crosslinked) such as vasoconstriction, hypertension and possible vascular damage induced by direct contact of the vascular surface with Hb. On the other hand, intrinsic issues related to the suspension of HbV as a molecular assembly have to be considered: blood compatibility, structural and dispersion stabilities of the vesicles, and the requirement of prompt degradation in the reticuloendothelial system. Having overcome these issues, the results make us confident in advancing further development of HbV. Easy manipulation of physicochemical parameters of HbV provides possibilities for various clinical applications in addition to their use as a transfusion alternative.