Chapter 19 - Targeted drug delivery using aptamers as molecular probes

Abstract

Recently, several global ailments are tedious to cure attributing to lesser to virtually nonexistent effective drug delivery mechanisms. Aptamers have been identified to serve as a better molecular probe than antibodies in analytical scenarios due to their unique characteristics, such as specific binding ability, size, biocompatibility, low immunogenicity and toxicity, greater stability, and a straightforward, large-scale production rate. These aptamers are usually about 20–100 nucleotides in length, which when combined with their low immunogenicity, aids in reaching the targeted site facilitating drug delivery. Since the discovery of the aptamer’s excellent properties, the single-stranded oligonucleotides and peptide molecules have been highly beneficial toward the isolation, visualization, and in vivo tracking of cells. In recent times, most aptamers are formulated in vitro and are coded for a specific target. The current chapter explores the formulation of aptamers, the SELEX method for aptamer generation, their binding affinity, and applications in other biotechnological domains. In addition, it further examines the classes of certain existing, natural and artificially engineered aptamers, including their administration, as well as aptamer prospects in drug delivery systems.