Pyridoxylated polymerized hemoglobin solution processing. Interest of a membrane molecular fractionation step.
Glutaraldehyde hemoglobin polymerization gives too many high polymers, resulting in a too viscous solution. We describe here an alternate method leading to superior results, as compared to the classical one. This method includes a molecular fractionation step using a tangential flow ultrafiltration that secondarily lowers the unpolymerized tetramer's content of a mildly polymerized, pyridoxylated hemoglobin solution (Pyr-Poly Hb). This leads to an adequately polymerized product with a lesser high polymer content, implying a lower viscosity. We thus obtain a pyridoxylated, polymerized molecular fractionated solution presenting suitable features as a blood substitute: A 7.5 g% hemoglobin 2 g% albumin solution had a 16% unpolymerized tetramer's ratio, a 1.8 mPas viscosity, a P50 of 2.8 kPa, a Hill coefficient of 2.1, a binding coefficient of 1.3 mL/g, a colloid osmotic pressure of 2.4 kPa, and a methemoglobin concentration of 3% Male-Sprague-Dawley rats undergoing an isovolumic blood exchange with this Pyr-Poly Hb solution, down to a 2% hematocrit, present a mean survival time of 20 h.
D000818:Animals; D001802:Blood Substitutes; D006400:Hematocrit; D006454:Hemoglobins / Q000302:isolation & purification; D008297:Male; D010108:Oxyhemoglobins; D010951:Plasma Exchange; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000302:isolation & purification; D051381:Rats; D014783:Viscosity
D001802:Blood Substitutes; D006454:Hemoglobins; D010108:Oxyhemoglobins; C030939:polyhemoglobin-pyridoxal-5-phosphate; D011732:Pyridoxal Phosphate