NIR光で活性化されるポリドーパミンナノ粒子による根管消毒における腸球菌のバイオフィルム根絶

Persistent bacterial infection remains the primary cause of root canal treatment failure, posing a significant challenge in endodontics. Enterococcus faecalis, with its ability to form biofilms and resist conventional disinfectants, is one of the most commonly isolated species in failed cases. Herein, we developed a novel polydopamine (PDA) nanoparticle-based phototherapy system activated by 808 nm near-infrared (NIR) light for enhanced root canal disinfection. The PDA + NIR group exhibited a significantly superior antibacterial effect compared to 2.5% NaOCl, achieving a bactericidal rate of 97.87%. SEM and TEM observations revealed that PDA + NIR treatment caused complete bacterial cell disintegration and ultrastructural destruction, whereas 2.5% NaOCl only induced partial surface damage. Furthermore, PDA + NIR effectively eradicated mature E. faecalis biofilms in simulated root canal models. These findings demonstrate that PDA-mediated NIR phototherapy possesses powerful bactericidal and antibiofilm capabilities. This nanotechnology-based approach may offer a promising alternative strategy for clinical root canal disinfection.