Targeted siRNA delivery using aptamer‐siRNA chimeras and aptamer‐conjugated nanoparticles

The sequence‐specific gene‐silencing ability of small interfering RNA (siRNA) has been exploited as a new therapeutic approach for the treatment of a variety of diseases. However, efficient and safe delivery of siRNA into target cells is still a challenge in the clinical development of siRNA‐based therapeutics. Recently, nucleic acid‐based aptamers that target cell surface proteins have emerged as a new class of targeting moieties due to their high specificity and avidity. To date, various aptamer‐mediated siRNA delivery systems have been developed to enhance the RNA interference (RNAi) efficacy of siRNA via targeted delivery. In this review, we summarize recent advances in developing aptamer‐mediated siRNA delivery systems for RNAi therapeutics, mainly aptamer–siRNA chimeras and aptamer‐functionalized nanocarriers incorporating siRNA, with a focus on their molecular designs and formulations. In addition, the challenges and engineering strategies of aptamer‐mediated siRNA delivery systems for clinical translation are discussed. This article is categorized under: Biology‐Inspired Nanomaterials > Nucleic Acid‐Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Cell receptor‐targeting aptamers can be directly conjugated to siRNA to form aptamer–siRNA chimeras or serve as an active targeting ligand to guide siRNA‐loaded nanocarriers to a target cell for targeted siRNA delivery.