Abstract: First and second compounds are provided, where the first compound is administered to a mammalian host into blood for covalent bonding to blood components, where the components have an extended lifetime in the blood stream. The first compound comprises an active functionality and an agent of interest or a first binding entity. A second compound may be subsequently administered to the patient, which comprises a second binding entity, complementary to the first binding entity and an agent of interest. By virtue of binding to long-lived blood components, the half-life of the agent of interest is greatly extended in vivo.

Abstract: First and second compounds are provided, where the first compound is administered to a mammalian host into blood for covalent bonding to blood components, where the components have an extended lifetime in the blood stream. The first compound comprises an active functionality and an agent of interest or a first binding entity. A second compound may be subsequently administered to the patient, which comprises a second binding entity, complementary to the first binding entity and an agent of interest. By virtue of binding to long-lived blood components, the half-life of the agent of interest is greatly extended in vivo.

Abstract: Novel bifunctional reagents useful in reducing the biological effect of an undesirable blood-borne agent are provided. The reagents comprise conjugates of a first binding member specific for a blood-borne agent having a detrimental biological activity in a mammalina host, such as a growth factor, coagulation factor, enzyme, toxin, drug of abuse, microbe, autoreactive immune cell, infected or tumorous cell, joined to an second binding member specific for an anchor, where the anchor is a long-lived blood component, including cells, such as a erythrocyte, platelet or endothelial cell and serum proteins, such as albumin, ferritin, or steroid binding proteins. These conjugates find therapeutic use by coupling the agent and the blood component and thereby reducing the biological activity or effective concentration of free agent, modulating the volume of distribution of the agent, targeting the agent to sites of enhanced immune response, or facilitating agent clearance from the bloodstream.

Abstract: First and second compounds are provided, where the first compound is administered to a mammalian host into blood for covalent bonding to blood components, where the components have an extended lifetime in the blood stream. The first compound comprises an active functionality and an agent of interest or a first binding entity. A second compound may be subsequently administered to the patient, which comprises a second binding entity, complementary to the first binding entity and an agent of interest. By virtue of binding to long-lived blood components, the half-life of the agent of interest is greatly extended in vivo.