Self-assembly of tumor-targeting RNA nanoball for carrier-free delivery of therapeutic RNA

Rolling circle transcription (RCT) has been studied for enhancing the delivery efficiency of therapeutic RNA by densely packing RNA strands with particle formation. This facile fabrication method has been successfully employed to generate RNA nanoballs containing functional short interference RNA. In addition, the nanoballs produced by RCT showed high stability from the nuclease degradation. With these advantages, using biotin-labeled ribonucleoside triphosphate (rNTP), target specific and non-toxic bubble RNA nanoball (BNB) was synthesized. To achieve tumor-targeting, epidermal growth factor receptor antibody (EGFR Ab) was used to target the tumor cells by labeling the target ligands with biotin–avidin interaction. Target gene silencing by EGFR Ab-labeled RNA nanoball was confirmed in vitro. Therefore, RNA nanoball can be utilized for tumor cell-targeting delivery of therapeutic RNA.