Scalable Entropy-Engineered Amorphous-Crystalline Heterojunction Piezo-Nanozymes for Ultrasound-Amplified Tumour Therapy
Effective treatment of solid tumours remains a major clinical challenge. Piezocatalytic and enzyme-mimetic therapies provide complementary strategies for exploiting ultrasound and endogenous tumour substrates to amplify reactive oxygen species (ROS) generation and immunogenic tumour cell death. However, integrating high piezoelectricity and efficient enzyme-like catalysis within a single material remains challenging because the crystallographic order required for piezocatalysis is difficult to reconcile with the structural disorder that favours catalytic activity; conventional multistep syntheses further hinder scalable production. Here, we develop oxygen-vacancy-rich entropy-engineered BiFeO3 (EE-BFO-OV) through one-step flame spray pyrolysis. In vitro, EE-BFO-OV generated abundant ROS through combined ultrasound-triggered piezocatalysis and enzyme-like catalysis, inducing PANoptosis-associated cell-death signatures. In vivo, ultrasound-activated EE-BFO-OV markedly suppressed tumour growth in both B16 melanoma and 4T1 breast-tumour models. These findings establish an entropy-engineered heterojunction piezo-nanozyme as a scalable material for tumour therapy.