Engineering a Built-in Piezoelectric Electron Sponge in Swallow Nanozyme for Inflammatory Bowel Disease Therapy

Inflammatory bowel disease (IBD) is characterized by chronic inflammation and excessive reactive oxygen species (ROS) production, leading to mucosal damage and impaired immune homeostasis. Here, we report the development of a core-shell structured barium titanate @ cerium oxide nanozyme (BTO@CeO_x, x = 1.9, 1.8, and 1.85), functioning as an orally administered "barium meal" for targeted IBD imaging and treatment. Leveraging the inherent piezoelectric properties of BaTiO₃, we imbue this nanozyme with a built-in piezoelectric electron sponge effect, enhancing its catalytic efficiency. Upon ultrasound stimulation, the piezoelectric interface dynamically modulates charges that sustain redox reactions in CeO_x, enhancing its superoxide dismutase (SOD)- and catalase (CAT)- like catalytic activities for scavenging ROS and producing oxygen. Following oral administration, BTO@CeO_x demonstrates excellent gastrointestinal stability, selectively accumulating at IBD lesions, enabling real-time computed tomography (CT) imaging and lesion tracking. Concurrently, it efficiently catalyzes ROS elimination, alleviates inflammation, restores immune balance, and reconstructs the intestinal mucosal barrier. The synergy of ultrasound-triggered piezoelectric modulation and nanozyme catalysis offer a controllable, noninvasive, and lesion-specific approach to the treatment of inflammatory diseases.