Living Microbe-Driven Bioorthogonal Catalysts Enables Cytotoxin Generation, Cuproptosis and Lactate Depletion for Synergistic Tumor Therapy.

Bioorthogonal chemistry provides a compelling strategy for in situ cytotoxin generation. However, the clinical translation of conventional bioorthogonal catalysts is impeded by poor tumor accumulation, insufficient targeting specificity, limited in vivo catalytic efficiency, and inadequate spatiotemporal control. Meanwhile, excessive lactate accumulation in the tumor microenvironment (TME) drives metabolic reprogramming, malignant progression, and therapeutic resistance. Here, we develop a living bacterial hybrid reactor by integratingShewanella oneidensis MR-1 (S.o) with Cu(II)-based zeolitic imidazolate frameworks to enable metabolism-guided and tumor-confined bioorthogonal catalysis. Exploiting the intrinsic hypoxia tropism of S.o, the hybrid reactor selectively accumulates within the TME. In the lactate-rich tumor, endogenous lactate drives bacterial reduction of inert Cu(II) to active Cu(I), enabling in situ catalyst activation and concurrent lactate depletion. The generated Cu(I) catalyzes a localized azide-alkyne cycloaddition between systemically administered prodrugs, producing a combretastatin A-4-like cytotoxin. Simultaneously, intracellular Cu(I) overload induces cuproptosis, while lactate depletion disrupts tumor metabolic homeostasis, together eliciting a synergistic triple antitumor effect. This work establishes a generalizable paradigm in which living bacterial vectors function as both tumor-targeting carriers and self-sustaining biochemical reactors, overcoming key limitations of conventional bioorthogonal catalysis and enabling precise, tumor-confined therapeutic activation.