Dual miRNA-Triggered DNA Walker Assisted by APE1 for Specific Recognition of Tumor Cells.

The identification of a specific tumor cell is crucial for the early diagnosis and treatment of cancer. However, it remains a challenge due to the limited sensitivity and accuracy, long response time, and low contrast of the recent approaches. In this study, we develop a dual miRNA-triggered DNA walker (DMTDW) assisted by APE1 for the specific recognition of tumor cells. miR-10b and miR-155 were selected as the research models. Without miR-10b and miR-155 presence, the DNA walker remains inactive as its walking strand of W is locked by L1 and L2. After miR-10b and miR-155 are input, the DNA walker is triggered as miR-10b and miR-155 bind to L1 and L2 of W-L1-L2, respectively, unlocking W. The DNA walker is driven by endogenous APE1 that is highly catalytic and is highly expressed in the cytoplasm of tumor cells but barely expressed in normal cells, ensuring high contrast and reaction efficiency for specific recognition of tumor cells. Dual miRNA input is required to trigger the DNA walker, making this strategy with a high accuracy. The DMTDW strategy exhibited high sensitivity for miRNA analysis with a detection limit of 44.05 pM. Living cell-imaging experiments confirmed that the DMTDW could effectively respond to the fluctuation of miRNA and specifically identified MDA-MB-231 cells from different cell lines. The proposed DMTDW is sensitive, rapid, and accurate for specific tumor cell recognition. We believe that the DMTDW strategy can become a powerful diagnostic tool for the specific recognition of tumor cells.

Recent advances in MOF-based nanoplatforms generating reactive species for chemodynamic therapy.

Still today, cancer remains a threat to human health. Possible common treatments to cure this disease include chemotherapy (CT), radiotherapy (RT), photothermal therapy (PTT), and surgical resection, which give unreasonable results because of their limited efficiency and also lead to side-effects. Hence, different strategies are now being exploited to not only enhance the efficiency of these traditional therapeutic methods or treat the tumor cells but also curtail the side effects. A latest method with authentic proof of chemodynamic therapy (CDT) utilizing the Fenton reaction is now gaining importance. This approach, which is developed based on the high level of hydrogen peroxide (H2O2) in a tumor microenvironment (TME), can be used to catalyze the Fenton reaction to generate cancer cell-killing reactive oxygen species (ROS). The selection of materials is extremely important and nanomaterials offer the most likely method to facilitate CDT. Among various materials, metal-organic frameworks (MOFs) which have been extensively applied in medical areas are regarded as a promising material and possess potential for the next generation of nanotechnology. This review focuses on summarizing the use of MOFs in CDT and their synergetic therapeutics as well as the challenges, obstacles, and development.