Swine hemoglobin as a potential source of artificial oxygen carriers, hemoglobin-vesicles

Abstract

Hemoglobin-based oxygen carriers (HBOCs) have been developed as a transfusion alternative and oxygen therapy. The Hb source is usually outdated donated human blood or cow blood obtained from cattle industries because of its abundance. This study examined the feasibility of using swine Hb ((S)Hb) for preparation of cellular-type HBOCs, hemoglobin-vesicles (HbV). Purification of (S)Hb from fresh swine whole blood was conducted with processes including carbonylation ((S)HbO(2) --> (S)HbCO), pasteurization (60 °C, 15 hours) and tangential flow ultrafiltration, with yield of 90%. Actually, differential scanning calorimetric analysis showed a denaturation temperature of (S)HbCO at 83 °C and assures its stability during pasteurization. Concentrated (S)HbCO together with pyridoxal 5'-phosphate (PLP) as an allosteric effector was encapsulated in phospholipid vesicles to prepare (S)HbV. After decarbonylation ((S)HbCO --> (S)HbO(2)), the oxygen affinity (P(50)) of (S)Hb changes mainly by PLP, and the influence of Cl(-) was small, in a manner similar to that of human Hb ((H)Hb). However, after encapsulation, vesicles of (S)HbV showed much lower oxygen affinity (higher P(50)) than (H)HbV did. Autoxidation of (S)HbV was slightly faster than (H)HbV. Although some differences are apparent in oxygen affinity and autoxidation rates, results clarified that (S)Hb is useful as a starting material for HbV production.

Increasing the stability of Lumbricus terrestris erythrocruorin via poly(acrylic acid) conjugation

“…The absence of hemichrome formation in the experiments by Mudhivarthi et al may be attributed to the fact that HbA has a much larger heme pocket than LtEc, thereby decreasing the likelihood of contact between the heme and distal histidine [11]. In conclusion, while it has been previously shown that human hemoglobin-based oxygen carriers can be sterilized via pasteurization in the presence of CO [22], our results suggest that it is not possible to sterilize native LtEc or LPE particles with pasteurization or autoclaving. Therefore, additional experiments will need to be conducted to develop a sterilization method that inactivates viruses while maintaining the O 2 transport properties of LtEc and/or LPE.…”

Synthesis and characterisation of aqueous haemoglobin-based microcapsules coated by genipin-cross-linked albumin

“…Within the last years artificial blood substitutes have gained more and more attention because of the above mentioned decrease of available RBCs (Ruchalla 2013, Njoku et al 2015, Chung et al 2016, Ellingson et al 2017, Taguchi et al 2017, Ferenz and Steinbicker 2019. Since the application of a pure solution of haemoglobin is impractical due to the enormous nephrotoxicity and short circulation time (Chang 2006), several different attempts have been made to create biocompatible artificial oxygen carriers, based on either perfluorocarbons or haemoglobin that needs to be encapsulated in protective shells in any case (Bauer et al 2010, von Storp et al 2012, Ferenz et al 2013, Sakai et al 2013, Stephan et al 2014, Wrobeln, Laudien, et al 2017, Wrobeln, Schlüter, et al 2017.…”