title: Photoactivated rose bengal functionalized chitosan nanoparticles produce antibacterial/biofilm activity and stabilize dentin-collagen.
abstract: 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.
  
  
  BACKGROUND
  In 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.
authors.affiliation: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Annie
authors.initials: A
authors.lastname: Shrestha
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Department of Dermatology, Harvard Medical School, Boston, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
authors.affiliation: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada. Electronic address: anil.kishen@utoronto.ca.
authors.forename: Anil
authors.initials: A
authors.lastname: Kishen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology; D003094:Collagen / Q000032:analysis*; D003804:Dentin / Q000737:chemistry / Q000187:drug effects* / Q000382:microbiology; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000502:physiology; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D012395:Rose Bengal / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D017319:Photosensitizing Agents; D012395:Rose Bengal; D003094:Collagen; D048271:Chitosan
keywords: Biofilms; Chitosan; Collagen; Dentin; Functionalized nanoparticles; Photodynamic therapy