Fig. 1: Schematic diagram of the mechanism by which micro-nano microbial fuel cell electrical stimulation promotes tumor cell pyroptosis.

We synthesize MnO₂ nanoparticles in situ on the surface of Dsv. A polydopamine (NE) coating is subsequently formed via self-oxidation on the Dsv@MnO₂ complex, conferring mucoadhesive properties and extending gastrointestinal retention time. This is followed by covalent crosslinking with m-PEG-NH₂ to enhance mucus penetration capability. Upon oral administration, the MFC selectively colonizes tumor tissues. There, it induces calcium overload in tumor cells through bioelectrochemical effects, shifting apoptotic cell death toward more immunogenic pyroptosis. Through extracellular electron transfer, Dsv promotes the reduction of Mn²⁺, which enhances the Fenton reaction and activates the cGAS–STING pathway, thereby stimulating dendritic cell maturation. Additionally, the MFC consumes lactate, inhibiting regulatory T cell (Treg) activity while enhancing CD8⁺ T cell infiltration, ultimately disrupting the immunosuppressive tumor microenvironment. Figure 1 was created in BioRender. Li, R. (2025) https://BioRender.com/bnf3sro.