Intracellularly actuated biomimetic nanorobots for chemo-mechanical breast cancer therapy.

A major challenge for injectable therapeutic nanorobots is to achieve efficient and spatially precise intracellular actuation under biologically compatible field conditions. Here we introduce homotypic membrane-camouflaged magnetic nanorobots that couple selective tumor-cell internalization, low-field intracellular rotation and glutathione-responsive drug release for chemo-mechanical breast cancer therapy. The nanorobots comprise disulfide-bridged mesoporous organosilica nanohelices loaded with doxorubicin, decorated with Fe3O4 nanoparticles and cloaked with MCF-7 cancer cell membranes. The membrane cloak promotes homologous recognition and enriches magnetic actuators inside MCF-7 cells, where a rotating magnetic field drives rapid intracellular rotation and localized mechanical perturbation. Intracellular glutathione concurrently cleaves the disulfide-containing organosilica framework, triggering nanorobot degradation and doxorubicin release. This spatial coupling of mechanical injury and chemotherapy induces pronounced tumor-cell death in vitro and suppresses tumor growth by 87.03% in an MCF-7 xenograft model without obvious systemic toxicity. These findings establish homotypic intracellular localization as a strategy for programmable magneto-mechanical nanotherapy.