Aptamers: from bench side research towards patented molecules with therapeutic applications

Background: RNA and DNA aptamers recognize their targets with high specificity and affinity. These aptamers can be developed against almost any target protein through iterative cycles of in vitro screening of a combinatorial oligonucleotide library for target binding. Aptamer sequences from the final pool of in vitro selection are screened for pharmacological activity and possible medical applications. Methods: Chemical modifications and improvements of the identification of aptamer selection procedures made aptamers rival antibodies in diagnostic and therapeutic applications. This article reviews recent literature and patents and discusses the properties of aptamers as high-affinity and specificity target binders as well as their stability in biological fluids that turns them into therapeutic agents. Conclusion: The development of I aptamers into compounds with therapeutic and diagnostic compounds has resulted in patents protecting the sequences and the use of these oligonucleotides. Several of these patented aptamers are currently being tested in Phase I or II clinical trials. Moreover, an anti-VEGF aptamer has already been approved by the FDA for treatment of age-related macular degeneration in humans.