Albumin-Binding Evans Blue Derivatives for Diagnostic Imaging and Production of Long-Acting Therapeutics

One of the major design considerations for a drug is its pharmacokinetics: a drug with short blood half-life is less available at a target organ which in turn dictates treatment with either high or more frequent doses, and increases the likelihood of undesirable side effects. One method to improve drug pharmacokinetics is adding functional chemical groups to the drug molecule that can increase the half-life in the blood, hopefully, without significantly affecting its desired biological activity. Evans Blue (EB) dye reversibly binds to serum albumin with moderate affinity and has a long blood half-life. The binding of EB to albumin has been exploited to quantify protein leakage as an indicator of increased vascular permeability. Design of new chemical entities based on EB structure and coupling them to drugs, enables the usage of albumin as a reversible carrier in the blood and improves drug's half-life. This Topical Review summarizes the recent developments of various EB derivatives for molecular imaging and therapy applications.