title: Dentin Conditioning with Bioactive Molecule Releasing Nanoparticle System Enhances Adherence, Viability, and Differentiation of Stem Cells from Apical Papilla.
abstract: BACKGROUND
  Temporal-controlled bioactive molecule (BM) releasing systems allow the delivery of appropriate concentration of BM to enhance the interaction of stem cells to dentin matrix and subsequent odontogenic differentiation in regenerative endodontics.
  
  
  OBJECTIVE
  The goal of this study was to evaluate the effect of dentin conditioning with 2 variants of dexamethasone (Dex) releasing chitosan nanoparticles (CSnp), (1) Dex-CSnpI (slow releasing) and (2) Dex-CSnpII (rapid releasing), on adherence, viability, and differentiation of stem cells from apical papilla (SCAP) on root dentin exposed to endodontic irrigants.
  
  
  METHODS
  Slab-shaped dentin specimens were prepared parallel to the root canal and treated with 5.25% sodium hypochlorite (NaOCl) for 10 minutes and/or 17% EDTA for 2 minutes. Dentin was then conditioned accordingly by (1) no nanoparticle treatment, (2) CSnp, (3) Dex-CSnpI, and (4) Dex-CSnpII. The effect of nanoparticle conditioning on SCAP viability was determined by cell count and a circularity index. SCAP adherence and viability on dentin were assessed by fluorescence and scanning electron microscopy and odontogenic differentiation by immunofluorescence.
  
  
  RESULTS
  SCAP on dentin treated with NaOCl alone or NaOCl as the last irrigant showed the least adherence, minimal cytoplasmic extensions, and higher circularity. SCAP adherence and viability on Dex-CSnpI and Dex-CSnpII conditioned dentin were increased and had a well-developed cytoplasmic matrix and significantly lower circularity (P < .05). SCAP cultured in Dex-CSnpII group expressed higher levels for DSPP and DMP-1 than in CSnp or Dex-CSnpI groups.
  
  
  CONCLUSIONS
  Dex-CSnpI and Dex-CSnpII conditioning of dentin enhanced SCAP adherence and viability. Temporal-controlled release of Dex from Dex-CSnpII enhanced odontogenic differentiation of SCAP. This study highlighted the ability of dentin conditioning with temporal-controlled BM releasing nanoparticles to improve the local environment in regenerative endodontics.
authors.affiliation: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Suja
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Calvin D
authors.initials: CD
authors.lastname: Torneck
authors.affiliation: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada. Electronic address: akishen@gmail.com.
authors.forename: Anil
authors.initials: A
authors.lastname: Kishen
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D048271:Chitosan / Q000494:pharmacology; D003771:Dental Papilla / Q000166:cytology*; D003804:Dentin / Q000166:cytology / Q000187:drug effects*; D003907:Dexamethasone / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D016326:Extracellular Matrix Proteins; D005455:Fluorescent Antibody Technique; D006801:Humans; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry*; D009805:Odontogenesis / Q000187:drug effects; D010750:Phosphoproteins; D012038:Regeneration; D012388:Root Canal Irrigants / Q000494:pharmacology; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013234:Stem Cells / Q000187:drug effects*
chemical_list: C513309:DMP1 protein, human; D016326:Extracellular Matrix Proteins; D010750:Phosphoproteins; D012388:Root Canal Irrigants; D003907:Dexamethasone; D048271:Chitosan; D004492:Edetic Acid; D012973:Sodium Hypochlorite
keywords: Cell adherence; chitosan nanoparticles; dentin; dexamethasone; odontogenic differentiation; regenerative endodontic procedures; stem cells from apical papilla