Photoactivated rose bengal functionalized chitosan nanoparticles produce antibacterial/biofilm activity and stabilize dentin-collagen

Treatment of infected teeth presents two major challenges: persistence of the bacterial-biofilm within root canals after treatment and compromised structural integrity of the dentin hard-tissue. In this study bioactive polymeric chitosan nanoparticles functionalized with rose-bengal, CSRBnp were developed to produce antibiofilm effects as well as stabilize structural-integrity by photocrosslinking dentin-collagen. CSRBnp were less toxic to fibroblasts and had significant antibacterial activity even in the presence of bovine serum albumin. CSRBnp exerted antibacterial mechanism by adhering to bacterial cell surface, permeabilizing the membrane and lysing the cells subsequent to photodynamic treatment. Photoactivated CSRBnp resulted in reduced viability of Enterococcus faecalis biofilms and disruption of biofilm structure. Incorporation of CSRBnp and photocrosslinking significantly improved resistance to degradation and mechanical strength of dentin-collagen (P < 0.05). The functionalized chitosan nanoparticles provided a single-step treatment of infected root dentin by combining the properties of chitosan and that of photosensitizer to eliminate bacterial-biofilms and stabilize dentin-matrix.From the Clinical EditorIn this study, bioactive polymeric chitosan nanoparticles functionalized with rose-bengal (a photosensitizer), CSRBnp were developed to produce antibiofilm effects as well as stabilize structural-integrity of dental root dentin by photocrosslinking dentin-collagen, leading to efficient elimination of bacterial-biofilms and stabilization of dentin-matrix.

Graphical AbstractFunctionalized chitosan conjugated rose bengal nanoparticles (CSRBnp) possessed properties of chitosan, rose bengal and nanoparticles. This nano-sized photosensitizer conjugated chitosan offered greater interaction with the bacterial cells as well as collagen matrix. When photoactivated the CSRBnp displayed dual function of antibacterial/antibiofilm efficacy and improved mechanical and chemical stability of dentin collagen matrix by crosslinking process. The present study provides a novel nanoparticle based approach to enhance biofilm elimination and simultaneously restore the ultrastructural integrity of infected dentin tissue.Figure optionsDownload high-quality image (236 K)Download as PowerPoint slide