Autonomous Soft Nanorobots for Active Targeting and Therapy of Triple‐Negative Breast Cancer

Abstract The extensive connective tissue proliferation and dense extracellular matrix (ECM) in triple‐negative breast cancer (TNBC) form abnormal physical barriers that impede the penetration of nanomedicines and hinder therapeutic efficacy. Herein, autonomous soft nanorobots with TNBC‐targeted ability are reported for enhanced photodynamic therapy. The nanorobots (denoted as CAT‐P@Ce6) are composed of catalase (CAT), targeting peptide P25343, and photosensitizer Ce6. The CAT‐P@Ce6 nanorobots possess an inwardly concave and wrinkled structure with a uniform diameter of 256 nm. Representative motion trajectories and transwell migration assay of the CAT‐P@Ce6 nanorobots demonstrate their excellent propulsion performance. Co‐incubation experiments with MDA/MB‐231 cells and 3D multicellular tumor spheroids show enhanced cellular internalization efficiency of the CAT‐P@Ce6 nanorobots, attributed to their targeting, migration, and soft properties. Furthermore, flow cytometry shows that the soft nanorobots functionalized with the targeting peptide P25343 exhibited a 1.82‐fold increase in fluorescence intensity compared to rigid and non‐targeted nanoparticles. Cellular and colony formation experiments reveal an efficient anti‐tumor cell proliferation effect of the CAT‐P@Ce6 nanorobots. In vivo experiments further demonstrate that the TNBC‐targeted nanorobots significantly inhibit tumor growth. The design of soft nanorobots with active targeting ability offers a promising strategy for overcoming dense tumor physical barriers and enhancing intratumoral penetration.