Mussel-inspired nanocellulose scaffold for antibacterial and anti-inflammatory coating for clear aligners

Aesthetic demands in contemporary dentistry have driven the widespread adoption of clear aligners (CAs), yet their polymeric substrates lack intrinsic antibacterial and anti-inflammatory functionality, predisposing the periodontium to inflammation during prolonged wear. Here, we present a multifunctional surface coating for PETG-based CAs, comprising dopamine-grafted TEMPO-oxidized bacterial cellulose nanofibers (TOBC-DA), curcumin (Cur), and polyvinyl alcohol (PVA), applied via a facile spin-coating process. TOBC-DA serves as a bioadhesive matrix that forms a robust, long-lasting bond with PETG while maintaining chemical stability in simulated oral conditions. Incorporation of Cur endows the coating with potent antibacterial and anti-inflammatory activity, and PVA enhances Cur solubility to ensure uniform film formation. The resulting composite layer-measuring under 5 μ m in thickness-preserves the optical transparency, dimensional fidelity, and mechanical integrity of PETG. Structurally, the cross-linked TOBC-DA network and PVA backbone confer enhanced wear resistance and fracture resistance without compromising flexibility. Functionally, the hydrophilic surface repels early colonizers such as P. gingivalis , while sustained Cur release disrupts bacterial cell membranes and downregulates pro-inflammatory mediators (IL-6, TNF-α, MMP-9) in periodontal tissues. This work demonstrates a clinically translatable coating strategy that integrates aesthetic preservation with active periodontal protection, offering a promising route to improve oral health outcomes during CAs therapy.