Sugars comparable to glutathione as hemoglobin oxidation protectants during vacuum drying

One of the most significant challenges to stabilization of blood in the dry state is mitigation of hemoglobin oxidation. Here, oxidation of free hemoglobin vacuum desiccated in phosphate-buffered saline alone reached 65%±5%. Arabinose, glucose, sucrose, trehalose, and raffinose at 100 mM were shown to reduce oxidation to 24%±2%, 23%±2%, 3%±1%, 8%±3%, and 7%±2%, respectively. For comparison, 100 mM glutathione allowed 5%±2% hemoglobin oxidation. Oxidation protection provided by glucose, sucrose, and trehalose was shown to increase with concentration between 5 and 100 mM, plateauing thereafter. Oxidation of hemoglobin dried in the presence of 100 mM trehalose was shown to increase with decreasing initial pH.