ABSTRACT
Aptamers, also known as chemical antibodies, are short singlestranded DNA, RNA, or peptide molecules that can fold into complex three-dimensional structures and bind to target molecules with high afϐinity and speciϐicity.1 In this chapter, we discuss the applications of nucleic acid aptamers in medicine. The term “aptamers” was derived from the Latin aptus (to ϐit) and the Greek meros (part or region).2 In 1990, the laboratories of Gold and Ellington independently pioneered the selection procedures of nucleic acid aptamers from combinatorial libraries by an iterative in vitro selection procedure known as the systematic evolution of ligands through exponential enrichment (SELEX).2,3 It is now well established that aptamers bind to their ligands via adaptive recognition involving conformational alteration of either the target or the aptamer, precise stacking of ϐlat moieties, speciϐic hydrogen bonding, and molecular shape complementarity. The multiple, highly speciϐic, spatially distinct contacts across the target are formed without the involvement of covalent bonds.4
