ABSTRACT
Aptamers are ssDNA or ssRNA molecules that are approximately 15–80 nucleotides long. Due to their excellent functional properties, they have gained extensive applications in cancer therapeutics as well as diagnosis. The isolation of these oligonucleotides can be done through systematic evolution of ligands by exponential enrichment (SELEX) technology and possess high specificity and affinity towards the target molecules. Numerous advantages, such as small size, low toxicity, ease in synthesis and versatility, make aptamer-based therapeutics superior to other technologies. Additionally, they can be functionalized with nanoparticles for precise, site-specific targeting and internalization of the aptamer-nanoparticle conjugates loaded with drugs. Recent years have also witnessed the application of aptamer-functionalized nanosensors for detection and targeting at multiple sites. Further, the ability of these small sized aptamers to cross the blood–brain barrier (BBB) also imparts significant diagnostic and drug-delivery properties, which can be used for the treatment of neurological disorders. Limitations associated with this unique technology, such as use of polymerase chain reaction (PCR) during SELEX that produces artifacts, however, can slow its progression. Nevertheless, an interdisciplinary approach can facilitate providing a roadmap for building a solid technological platform that could result in aptamer-based therapeutics.
