Artificial oxygen carriers, from nanometer- to micrometer-sized particles, made of hemoglobin composites substituting for red blood cells

Blood transfusions are regarded as the most well-known and frequently performed cell transplantations. Although current transfusion systems are sophisticated, they cannot be freed from the inherent difficulties that include infection, short shelf life, and blood type mismatching. Artificial oxygen carriers produced using hemoglobin (Hb) are designated as Hb-based oxygen carriers (HBOCs), which are anticipated for use as biomaterials that have potential to resolve issues of transfusion by a radical paradigm shift. Various HBOCs, nanometer-sized to micrometer-sized bioparticles having an oxygen-carrying function, are developed for use as substitutes for red blood cells (RBCs). This paper presents an overview of the classification of HBOCs with reference to their histories, preparations, structures, functions, and in vitro and in vivo properties. Additionally, we give a more detailed introduction of our academic studies of liposome encapsulated Hb, designated as Hb-vesicles (HbV), which mimic the physiologically important corpuscular structure of RBCs. This review outlines perennial efforts and approaches to mimic RBC functions through chemical, genetic, and encapsulation techniques. It will provide important insights into the eventual realization of an alternative for RBC transfusion. (c) 2021 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

Blood transfusions are essential but face inherent difficulties such as infection and blood type mismatching. HBOCs, artificial oxygen carriers produced using hemoglobin, show potential as biomaterials for resolving these issues. Encapsulated Hb, like Hb-vesicles (HbV), mimic the physiological structure of red blood cells and offer a promising alternative for RBC transfusion. Efforts to mimic RBC functions through various techniques are crucial in developing successful alternatives for transfusions.