Blood substitute based on hemoglobin
AssigneeHematech, LLC
InventorJeffrey Tze-Fei Wong
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Abstract
A blood substitute or blood extender is prepared by chemically coupling hemoglobin with a polysaccharide material selected from dextran and hydroxyethyl starch, and having a molecular weight of from about 5,000 to about 2,000,000, to form a covalently bonded chemical complex. The complex has similar oxygen transporting abilities to hemoglobin, and has a much lower rate of renal excretion.
Claims14
A composition useful as a blood substitute or blood extender for administration to human or animal patients, said composition comprising the water soluble high molecular weight product of covalently coupling hemoglobin and a modified polysaccharide having a molecular weight of from about 5,000 to about 2,000,000, the modified polysaccharide being selected from the group consisting of dextran and hydroxyethyl starch modified to contain chemical groups capable of reaction with the chemical side groupings on the hemoglobin, said chemical side groupings being selected from the group consisting of amino, phenolic, sulfhydryl, thiomethyl, imidazo and carboxyl groupings.
A process for preparing a composition useful as a blood substitute or blood extender, which comprises:
- a. chemically modifying a polysaccharide of approximate molecular weight 5,000 - 2,000,000 and selected from the group consisting of dextran and hydroxyethyl starch, to introduce into said polysaccharide chemical groups capable of reaction with hemoglobin and selected from acylating groups, alkylating groups, ester forming groups, amide forming groups and disulfide forming groups;
- b. reacting the high molecular weight product of step (a) with hemoglobin, to form a water soluble covalently coupled complex thereof;
- the polysaccharide being selected from the group consisting of dextran and hydroxyethyl starch.
A macromolecular water soluble compound having oxygen transporting capability and useful in blood substitute or blood extender composition, having an approximate molecular weight of from about 70,000 to about 2,000,000, and having the general formula
- (PS) -- X -- (HB),
- where
- (PS) represents a polysaccharide of molecular weight from about 5,000 to about 2,000,000 and selected from the group consisting of dextran and hydroxyethyl starch;
- X represents a covalently bonded chemical bridging group and
- Hb represents hemoglobin.
Dependencies are inferred from the claim text.