Clinical use and future perspective of aptamers

Aptamers are a unique class of nucleic acid molecules currently being investigated for clinical applications. Aptamers are functional single-stranded oligonucleotides able to form complex structures, which facilitates their therapeutic abilities. They have the advantage of being nonimmunogenic, easy to synthesize, stable, high affinity, and specificity for targets, thus emphasizing their role in clinical applications. Research on the therapeutic uses of aptamers has been growing rapidly for the past 30 years. Since aptamers were discovered, tremendous efforts have been devoted to making them clinically relevant in treating diseases such as cancer, hepatitis, and HIV among others. Up to date, one aptamer, Macugen, VEGF targeting aptamer, has made it into clinical use, while many other aptamers are currently in different stages in clinical trials. The development of Macugen is being studied to address the challenge of converting aptamers into therapeutic molecules. The current chapter highlights the most recent aptamer chemistry techniques that have been developed to improve the pharmacological characteristics of aptamers. Furthermore, this chapter will examine the benefits and drawbacks of such chemical alterations and how they affect the pharmacological capabilities of aptamers. In addition, this chapter will describe the present status of aptamers in clinical trials and preclinical research. Finally, the future perspectives and challenges of aptamers as therapeutics will be discussed.