MicroRNA-Responsive Cancer Cell Imaging and Therapy with Functionalized Gold Nanoprobe.

Abstract

Integration of cancer cell imaging and therapy is critical to enhance the theranostic efficacy and prevent under- or overtreatment. Here, a multifunctional gold nanoprobe is designed for simultaneous miRNA-responsive fluorescence imaging and therapeutic monitoring of cancer. By assembling with folic acid as the targeted moiety and a dye-labeled molecular beacon (MB) as the recognition element and signal switch, the gold nanoprobe is folate receptor-targeted delivered into the cancer cells, and the fluorescence is lighted with the unfolding of MB by intracellular microRNA (miRNA), resulting in an efficient method for imaging and detecting nucleic acid. The average quantity of miRNA-21 is measured to be 1.68 pg in a single HeLa cell. Upon the near-infrared irradiation at 808 nm, the real-time monitoring and assessing of photothermal therapeutic efficacy is achieved from the further enhanced fluorescence of the dye-labeled MB, caused by the high photothermal transformation efficiency of the gold nanocarrier to unwind the remaining folded MB and depart the dye from the nanocarrier. The fluorescence monitoring is also feasible for applications in vivo. This work provides a simple but powerful protocol with great potential in cancer imaging, therapy, and therapeutic monitoring.