Framework nucleic acid-programmed aptamer-paclitaxel conjugates as targeted therapeutics for triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is highly invasive with a poor prognosis, and chemotherapy remains the clinical treatment of choice. Paclitaxel is a commonly used first-line chemotherapy drug, but its untargeted distribution poses clinical challenges. Inspired by antibody-drug conjugates, we develop a precisely structured framework nucleic acid-programmed aptamer-paclitaxel conjugate (FAPC) with chemically well-defined paclitaxel loading dosing, enabling the regulation of receptor-aptamer affinity to facilitate tumor-targeted chemotherapy. Utilizing framework nucleic acids as a precise addressing scaffold, we organize the AS1411 aptamer with accurate intermolecular spacing and find that an inter-aptamer spacing of 19.04 nm could enhance the affinity of the FAPC for tumor cells. Then, the multifunctional FAPC can disrupt actin reorganization to achieve cytotoxicity in tumor cells. Furthermore, the AS1411-specifically modified FAPC further enhances the structure-dependent selective accumulation of drugs at tumor sites in a human xenograft model of triple-negative breast cancer, subsequently leading to significantly improved antitumor efficacy and reduced toxicity. The FAPC provides a precisely programmable platform for efficient targeted delivery of chemotherapeutic agents to malignancies.