Preparation and exchange transfusion effect of a double polymerization human umbilical cord hemoglobin of red blood cell substitute

Abstract: Objective: To study the red blood cell substitute preparation method of glutaraldehyde(GDA) and Bis(3,5-dibromosalicyl) fumarate(DBBF) polymerized (double polymerized)and evaluate its preliminary efficacy. Methods: The affecting factors of the crosslink of DBBF and human umbilical cord hemoglobin(CHb) were selected, including solution pH, inositol hexaphosphoric acid(IHP) concentration, and molar ratios of DBBF and CHb, and study the changes of P50, Hill coefficient, and methemoglobin(MetHb) content during the preparation process, determine the molar ratio of GDA and DBBF-CHb polymerization product, the final product was obtained through the steps of ultrafiltration, filtration, deoxygenation. And the final product was subjected to a study on the curative effect of rats 135% exchange transfusion model, the survival rate of rats within 12h and blood gas-related indexes after 0h, 2h exchange transfusion were evaluated. The rats were divided into 3 groups according to the reperfusion samples, the control group (5.0% albumin group), the experimental group 1 (3.0%GDA-DBBF-Hb product + 3.0% albumin+0.3% Vc) and the experimental group 2 (3.0% GDA-Hb product+3.0% albumin +0.3% Vc). Results: Under the condition of pH 8.0, the concentration of phytic acid was 10mm/l, the molar ratio of DBBF and CHb was 2:1, the content of dimer was (22.61±3.01)%, P50 was (25.25±2.31) mmHg. P50 and MetHb increased as the molar ratio of DBBF to CHb increased, and the Hill coefficient decreased as the molar ratio of DBBF to CHb increasing. The molar ratio of GDA and DBBF-CHb was 7:1, the content of dimer is (8.23±0.98)%, MetHb increased as the molar ratio of GDA and DBBF-CHb increasing, the P50 and Hill coefficient decreased as the molar ratio of GDA to DBBF-CHb increasing. The 12h survival rate of the control group was 1/6(16.67%), and the 12h survival rate of the two experimental groups were both 5/6(83.33%), and the difference was statistically significant (P=0.029, χ2=7.065). HCO3- of control group was lower than other two groups after 2h of exchange transfusion(P<0.05). The MAP of DBBF-GDA-CHb group at end of the exchange was higher than other two groups(P<0.01), after 2h of the exchange transfusion, the MAP of GDA-CHb group and DBBF-GDA-CHb group were higher than control group(P<0.01). After 2h exchange transfusion, the GDA-CHb group and DBBF-GDA-CHb group were significantly lower than control group(P<0.05), compared with control, the beecf in GDA-CHb group and DBBF-GDA-CHb group were significantly decrease at end of exchange transfusion(P<0.05). Compared with control and GDA-CHb group, the Lac in DBBF-GDA-CHb group were significantly decrease at end of exchange transfusion(P<0.05). Conclusion: The red blood cell substitutes with double polymerization can effectively reduce the dimer content, increase effective polymerization rate, which is more conducive to industrial production. Compared with GDA-CHb, DBBF-GDA-CHb can provide oxygen to hypoxic tissues and organs in a more timely manner, and can also increase the MAP in rats just right. However, the survival rate in rats did not show an advantage.