Ex Vivo Assessment of Blue Laser-Activated Berberine-Loaded Nanoniosomes in Enhancing Photodynamic Therapy Against Streptococcus Mutans Biofilm on Tooth Enamel Publisher Pubmed



Pourhajibagher M ; Kazemimoghaddam E ; Moeininejad M ; Rahimi B ; Bahador A
Source: Photodiagnosis and Photodynamic Therapy Published:2025

Abstract

Background: Dental caries is a biofilm-mediated disease primarily caused by Streptococcus mutans, which produces extracellular polysaccharides via glucosyltransferases such as GtfB, promoting biofilm formation and cariogenicity. Photodynamic therapy (PDT) has gained attention as a promising alternative to conventional antimicrobials. This study investigates the efficacy of blue laser-activated berberine-loaded nanoniosomes (nNios@Ber) in enhancing PDT against S. mutans biofilms formed on tooth enamel.Materials and Methods: An ex vivo model using human tooth enamel slabs was employed to cultivate S. mutans biofilms. Berberine was encapsulated in nanoniosomes (nNios@Ber) to improve stability and delivery. Following determination of minimum inhibitory concentration (MIC) of nNios@Ber, biofilms were treated with various concentrations of nNios@Ber combined with blue laser irradiation (405 ± 10 nm) to activate PDT. Additionally, quantitative real-time PCR was used to quantify gtfB gene expression.Results: The MIC of nNios@Ber against S. mutans was found to be 15.6 μg/mL. All PDT-treated groups showed significant reductions in biofilm viability and a dose-dependent downregulation of gtfB expression. Specifically, gtfB expression decreased by 4.8-, 5.7-, and 7.4-fold in the 2 × MIC, 4 × MIC, and 8 × MIC nNios@Ber plus blue laser groups, respectively (P < 0.05). Neither nNios@Ber nor laser alone produced statistically significant effects (P > 0.05). These findings confirm that nNios@Ber’s anti-biofilm efficacy is enhanced when photoactivated by blue laser.Conclusion: Blue laser-activated nNios@Ber significantly inhibit S. mutans biofilm formation and virulence gene expression, offering an effective and targeted approach for caries management. This photoactivated nNios@Ber enhances the photodynamic activity, providing a promising adjunct or alternative to conventional antimicrobial agents such as CHX in oral healthcare. © 2025 Elsevier B.V., All rights reserved.