Abstract
Modified hemoglobins (Hbs) as a red blood cell (RBC) substitute have a long history and artificial O2 carriers of various kinds have been developed so far. Although this type of preparation is essentially aqueous solution of protein, unlike the dispersion of RBCs, it possesses many attractive features such as easy production method, low cost, and simple composition. In fact, most of the artificial O2 carriers currently under investigation are modified Hb preparations. We synthesized a core–shell structured “(hemoglobin–albumin)cluster” (Hb–HSA3, formulation name : Hemo Act) in which the core Hb is covalently wrapped with three molecules of human serum albumin (HSA). Its structure, characteristics, safety, and efficacy have been clarified in detail. We have also developed entirely synthetic protein clusters using recombinant Hb and recombinant HSA. Replacing the peripheral HSA to recombinant canine serum albumin and recombinant feline serum albumin yielded artificial O2 carriers for dogs and cats.
