Aptamer-Conjugated Nanorods for Targeted Photothermal Therapy of Prostate Cancer Stem Cells

Prostate cancer results in about 30 000 deaths annually in the United States, making it the second leading cause of cancer mortality in men in the Western world. Therefore, it is of great significance to capture and kill prostate cancer cells. It is well known that cancer stem cells are responsible for the maintenance and metastasis of tumors. This concept offers the possibility of developing a selective therapeutic approach in which cancer stem cells are directly targeted and killed. In this work, aptamers selected against DU145 prostate cancer cells (aptamer CSC1) and their subpopulation of cancer stem cells (aptamer CSC13) were linked to the surfaces of gold nanorods (AuNRs), and the resulting conjugates were successfully used to target and kill both cancer cells and cancer stem cells by near‐infrared (NIR) laser irradiation. Even though cancer stem cells represent only a small population among all cancer cells, the entire cell viability was very low after laser irradiation, suggesting that tumorigenesis could be successfully controlled by this aptamer‐based method, thus paving the way for early diagnosis and targeted therapy. A more apt method: Aptamers CSC1 and CSC‐13 previously selected against cancer cells and their subpopulation of cancer stem cells (CSCs), respectively, were attached to the surface of gold nanorods (NRs) to target and kill prostate cancer cells (DU145 cell line) by photothermal therapy. Although CSCs represent only a small population among all cancer cells, the whole cell viability was very low after laser irradiation, suggesting that tumorigenesis could be successfully controlled by this aptamer‐based method.