Liposome nanoparticles with photothermal effect for the treatment of bacterial infectious periodontitis

A novel strategy is imperative to address the limitations of conventional mechanical and pharmacological periodontal treatments, which are constrained by the inherent difficulty in completely eradicating plaque biofilm and the tendency for bacterial resistance to develop. Photothermal therapy (PTT) emerges as an innovative therapeutic approach for managing periodontitis, offering the distinct advantage of circumventing drug resistance. Furthermore, Near-Infrared-II (NIR-II) guided PTT enhances therapeutic efficacy and provides a viable method for eliminating bacteria in deep periodontal pockets. In this study, we encapsulated 2TT-oC6B, a fluorophore with aggregation-induced emission (AIE) properties, into liposomes to make AIE nanoparticles (2TT-oC6B@LIP), thereby improving their water dispersibility and enabling their use as photothermal agents for treating periodontitis. Upon exposure to 808 nm NIR irradiation, 2TT-oC6B@LIP effectively eradicated a broad spectrum of periodontal pathogens, including both Gram-positive Streptococcus gordonii (S. gordonii) and Gram-negative Porphyromonas gingivalis (P. gingivalis). Post-PTT treatment with 2TT-oC6B@LIP resulted in significant damage to bacterial cell membranes, cytoplasmic leakage, and potent anti-biofilm activity against periodontal pathogens. Additionally, an experimental periodontitis model was established in Sprague-Dawley (SD) rats, and the application of 2TT-oC6B@LIP significantly mitigated the progression of periodontitis under NIR light irradiation at an intensity of 1 W cm^-2. 2TT-oC6B@LIP nanoparticles exhibit remarkable photothermal bactericidal efficacy and good biocompatibility, offering promising potential for periodontitis therapy.