Control of oxidative reactions of hemoglobin in the design of blood substitutes: role of the Vc, NAC, TEMPO and their reductant system.

Oxidative reactions of hemoglobin (Hb) are still a serious problem for Hb-based blood substitute development. Although varieties of antioxidant strategies have been suggested, this in vitro study examined the ability of the ascorbate, N-Acetyl-L-Cysteine (NAC), 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-1-oxygen free radicals (TEMPO) and their reductant system in preventing Hb oxidation. The content of ferric Hb is monitored in the process of vitamin C (Vc), NAC, TEMPO and their reductant system. The results suggest that ascorbate is effective in reducing ferryl Hb, and TEMPO with Vc/NAC could obviously shorten the reaction time, but it does not play the role of Met-Hb reductases. It demonstrates that TEMPO did little to recover Hb under oxidative stress.