Polyvalent aptamer DNA nanoassembly based near-infrared carbon dots and rolling circle amplification for synergistic therapy of breast cancer.

Integrating imaging and therapy is of great significance in the field of tumor treatment. Here, we report a polyvalent aptamer nanoplatform for breast cancer cell treatment based on rolling circle amplification (RCA). The platform consists of a long single-stranded DNA scaffold from RCA and short-stranded DNAs with various functions. One short strand is linked to near-infrared carbon dots (NIR-CDs), another carries a MUC1 aptamer targeting cancer cells, and the third loads small interfering RNA (siRNA) for gene therapy. Doxorubicin (Dox) attaches to the platform via CG base pairs, integrating fluorescence targeting, photothermal therapy (PTT), gene therapy, and chemotherapy. Aptamer enhances breast cancer cell uptake of the platform. NIR-CDs serve as fluorescence imaging agents and are used for PTT. When deoxyribonucleases degrade the nanoplatform, Dox is released and then exerts its chemotherapeutic effect. SiRNA can form the RNA-induced silencing complex to reduce drug tolerance and enhance the efficacy of loaded drugs. The experimental results show that the platform can accumulate in cancer cells, exert a killing effect on them, and meanwhile reduce side effects on normal cells. In summary, this study expands the application of DNA materials in biomedicine by constructing a diagnostic and therapeutic platform that integrates NIR-CDs and RCA.