Cell-specific aptamers and their conjugation with nanomaterials for targeted drug delivery

Abstract

Introduction: Aptamers are short, single-stranded DNA or RNA sequences that can fold into complex secondary and tertiary structures and bind to various target molecules with high affinity and specificity. These properties, as well as rapid tissue penetration and ease of chemical modification, make aptamers ideal recognition elements for in vivo targeted drug delivery and attractive molecules for use in disease diagnosis and therapy.

Areas covered: The general properties of aptamers as well as advantages over their counterpart antibodies are briefly discussed. Next, aptamer selection by cell- systematic evolution of ligands by exponential enrichment is described in detail. Finally, the review summarizes recent progress in the field of targeted drug delivery based on aptamers and their conjugation to liposomes, micelles and other nanomaterials.

Expert opinion: Advances in nanotechnology have led to new and improved nanomaterials for biomedical applications. Conjugation of nanoparticles (NPs) with aptamers exploits both technologies, making aptamer-NP conjugates ideal agents for drug delivery with proven therapeutic effects and the reduction of toxicity to normal tissue. The use of multivalent aptamer-conjugated nanomaterials represents one of the new directions for drug development in the future; as such, continuing studies of these multivalent aptamers and bioconjugates should result in important clinical applications in targeted drug delivery.

Keywords:

• aptamer
• cell-systematic evolution of ligands by exponential enrichment
• nanomaterials
• targeted drug delivery

Acknowledgements

The authors wish to thank Prof. Weihong Tan for his discussion and help with this paper.

Declaration of interest

This work was supported by the National Natural Science Foundation of China (NSFC 81370983), the National Key Scientific Instrument and Equipment Development Project (2011YQ03012414), the Hunan Provincial Science and Technology Program (S2014S2032) and the Science and research foundation of Hunan health department (132011-014). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Notes

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