The Study Of Polymering Process On Polyhemoglobin

Poly-hemoglobin (Poly-Hb) is widely studied. The hemoglobin (Hb) is mainly supplied from outdated human blood and animal sources. But there are many disadvantages. As the alternative source, human placenta hemoglobin (PHb) has its own advantages. We take the lead in being occupied in the research of blood substitutes based on the placenta blood.Purified PHb readily undergoes dissociation to form two dimmers that are easily filtered by the kidneys and has high O 2 affinity, failing to transport O2 to tissues. To enhance PHb stability and decrease O2 affinity, bis (3,5-dibromosalicyl) fumarate (DBBF) is first adopted to modify deoxy-PHb. The factors affecting the process of DBBF modifying deoxyPHb are ascertained。It is proved that the PHb stability was improved, O2 affinity of the PHb solution was reduced, DBBF-αPHb had the appropriate capacity of oxygen carrying and DBBF-αPHb kept the biological activity well. On the whole, DBBF-αPHb is advantage to the synthesis of a potential blood substitute. At the same time, some primary researches on glutaraldehyde intermolecularly crossing the DBBF-αPHb solution are done。Despite glutaraldehyde is a crosslinker widely used, it seems that the glutaraldehyde molecule is unsuitable cross-linker for a number of reasons: it is a dialdehyde (too reactive), it is too long a molecule (facilitating intertetramer cross-links), and it lacks any intrinsic or functional specificity, leading to uncontrolled polymerization. A few influencing factors of homogeneous polymerization, such as pH and the process of GDA addition, are studied to solute those defects. In addition, an original heterogeneous polymerization method, based on displacement chromatography, has been tested. We named it"polymerization reaction in cation exchange chromatography". In this reaction, an asymmetric dynamic system is created. The poly-hemoglobin with lower degree of modification (polymerization) were found to be enriched on the cation exchange columns and can be further polymerized with glutaraldehyde. The results show that the poly-Hb with narrower molecular weight distribution is prepared in this way.