Sonodynamic nanocatalytic therapy: ultrasound-activated PVA/nanocellulose-tannic acid hydrogels for mechano-antimicrobial plaque disruption and enamel-safe chromophore degradation

Periodontitis represents a chronic inflammatory disorder triggered by multi-species oral bacterial infection of periodontal tissues. If left untreated, this condition can culminate in severe consequences, including alveolar bone resorption and loss of tooth support architecture. Given these clinical challenges, the development of a safe and effective strategy for plaque elimination and dental whitening remains a critical unmet need in periodontal care. To address this, we report the design and fabrication of polyvinyl alcohol (PVA)-based hydrogel loaded with tannic acid @ nanocellulose nanoparticles (PTAN). This novel composite system demonstrates dual functionality: robust antibacterial activity and biocompatible teeth-whitening efficacy. Under ultrasonic irradiation, the cavitation-generated mechanical forces drive targeted attachment of tannic acid @ nanocellulose nanoparticles (TAN) to bacterial surfaces. This process induces bidirectional impact and frictional forces, rendering bacterial cell walls mechanically sensitive. Additionally, it promotes the production of hydroxyl radicals and singlet oxygen, while enhancing the transmission of tannic acid-mediated death signals to pathogens. Concurrently, the hydrogel's porous architecture synergizes with the polyphenolic binding capacity of tannic acid to pigmented substrates. This dual-mechanism enables efficient capture and adsorption of chromogenic molecules within the hydrogel matrix. Collectively, our findings establish PTAN hydrogel as a rapid, highly effective, and biocompatible strategy for simultaneous plaque removal and dental decolorization, offering promising translational potential for clinical periodontal therapy.