Delivery and release of microRNA-34a into MCF-7 breast cancer cells using spherical nucleic acid nanocarriers

Herein, we designed and prepared two sets of spherical nucleic acid (SNA) nanocarriers to deliver and release microRNA-34a (miR-34a) in MCF-7 breast cancer cells. In this strategy, survivin mRNA was used as a trigger to start the running of the SNA-based delivery system, resulting in the release of miR-34a from the SNA nanocarriers. The quantitative RT-PCR shows a significant decrease in the mRNA level and ectopic expression of miR-34a. Moreover, the released miR-34a mimics largely reduced the cell viability and induced apoptosis, suggesting the high-efficiency and availability of this SNA-based delivery system.