Enhanced load of biotin with diagnostic metals via biotin- conjugated polychelating agent

摘要

The avidin-biotin system is widely use for different biochemical and biomedical applications. Thus, the ability of avidin macromolecule to bind four biotin molecules with extremely high affinity (K_aapprox approx 10~(-15)M) is being used for targeted delivery of diagnostic or therapeutic agents. For this purpose, any ligand is modified either with avidin or with biotin and is then permitted to accumulate in a target area for a specific time interval. After that, the required pharmaceutical agent is administered as a conjugate with biotin (if avidin is accumulated in the target) or with avidin (if target is saturated with biotin). As a result, the agent concentrates locally in the target due to fast formation of avidin-biotin complex.