| 摘要 |
Disclosed is a process for preparing hemoglobin- polysaccharide conjugates useful as hemoglobin-based oxygen carriers by (a) Subjecting a starting polysaccharide, such as hydroxyethyl starch or dextran, to oxidative ring-opening to produce an oxidatively ring-opened polysaccharide carrying aldehyde groups; (b) Reacting said oxidatively ring-opened polysaccharide with a hemoglobin under conditions suitable to form Schiff base linkages between the hemoglobin and the oxidatively ring-opened polysaccharide to from an initial hemoglobin- polysaccharide conjugate composition containing oxidized polysaccharides; (c) Degrading the oxidatively ring-opened polysaccharide by maintaining the conjugate composition under controlled conditions of aqueous solution with predetermined pH for a period of time until a desired lower average molecular weight hemoglobin-polysaccharide conjugate composition as compared to the initial hemoglobin-polysaccharide conjugate composition is reached, to form a detectable degraded further hemoglobin-polysaccharide conjugate composition with a lowered average molecular weight, a lowered amount of unreacted hemoglobin species as compared to the initial hemoglobin-polysaccharide conjugate composition (d) Reducing the further hemoglobin-polysaccharide conjugate composition once desired lower molecular weight is reached to form a reduced hemoglobin-polysaccharide conjugate composition; and (e) Recovering said reduced hemoglobin-polysaccharide conjugate composition. Reduced hemoglobin-polysaccharide conjugate compositions produced by this process are also claimed, and are useful as blood substitutes or supplements.
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