[Show abstract][Hide abstract] ABSTRACT: OxyVita-zero-link polymerized hemoglobin (OxyVita Hb) is a novel generation hemoglobin based oxygen carrier (HBOC). Our focus in this paper is to address the question of "Why is OxyVita Hemoglobin different than the previous generation of HBOCs?" Several critical related topics will be discussed: 1) OxyVita's unique chemistry; 2) the introduction of a viable powder form of OxyVita hemoglobin for dissolution in IV water or other IV fluids; 3) the physiochemical characteristics of OxyVita hemoglobin preparations; 4) the ability to formulate different products based upon specific applications; and 5) the important storage properties essential for use in a wide range of geographical locations.
No preview · Article · Feb 2011 · Artificial Cells Blood Substitutes and Biotechnology (formerly known as Artificial Cells Blood Substitutes and Immobilization Bi
[Show abstract][Hide abstract] ABSTRACT: A zero-linked polymeric hemoglobin (OxyVita Hb) has been developed for application as an acellular therapeutic hemoglobin-based-oxygen-carrier (HBOC). For effective and safe oxygen binding, transport and delivery, an HBOC must meet essential molecular requirements related to its structural integrity and redox stability. OxyVita is a super polymer possessing an average M.wt. of 17 x 10(6) Da. Structural integrity was determined by unfolding studies of OxyVita in the presence of increasing concentrations of urea. The unfolding midpoints (D(1/2)) of different preparations of OxyVita (solution and powder forms) were compared to Lumbricus Hb (LtHb) and Arenicola Hb (ArHb), natural acellular polymeric hemoglobins, which are serving as models for an effective and safe acellular HBOC. Reduction studies of OxyVita Hb using endogenous reducing agents were also investigated. Results from these studies indicate that: 1) OxyVita Hb exhibits greater resistance to conformational change than either LtHb or ArHb in the reduced (oxyHb) state; and 2) the reduction of met OxyVita Hb to oxyHb occurs slowly in the presence of either ascorbic acid (70% reduction in 560 min.) or beta-NADH (40% reduction in 90 min.). These studies provide consistent evidence that OxyVita Hb possesses physiochemical properties that exhibit structural integrity and redox behavior necessary for functioning as an effective and safe HBOC within clinical applications. These results are in agreement with observations made by other investigators as to the reduction in heme-loss of OxyVita Hb, essential for the reversible binding/release of molecular oxygen within the circulatory system.
No preview · Article · Mar 2010 · Artificial Cells Blood Substitutes and Biotechnology (formerly known as Artificial Cells Blood Substitutes and Immobilization Bi