title: A chemical phosphorylation-inspired design for Type I collagen biomimetic remineralization.
abstract: OBJECTIVE
  Type I collagen alone cannot initiate tissue mineralization. Sodium trimetaphosphate (STMP) is frequently employed as a chemical phosphorylating reagent in the food industry. This study examined the feasibility of using STMP as a functional analog of matrix phosphoproteins for biomimetic remineralization of resin-bonded dentin.
  
  
  METHODS
  Equilibrium adsorption and desorption studies of STMP were performed using demineralized dentin powder (DDP). Interaction between STMP and DDP was examined using Fourier transform-infrared spectroscopy. Based on those results, a bio-inspired mineralization scheme was developed for chemical phosphorylation of acid-etched dentin with STMP, followed by infiltration of the STMP-treated collagen matrix with two etch-and-rinse adhesives. Resin-dentin interfaces were remineralized in a Portland cement-simulated body fluid system, with or without the use of polyacrylic acid (PAA) as a dual biomimetic analog. Remineralized resin-dentin interfaces were examined unstained using transmission electron microscopy.
  
  
  RESULTS
  Analysis of saturation binding curves revealed the presence of irreversible phosphate group binding sites on the surface of the DDP. FT-IR provided additional evidence of chemical interaction between STMP and DDP, with increased in the peak intensities of the PO and P-O-C stretching modes. Those peaks returned to their original intensities after alkaline phosphatase treatment. Evidence of intrafibrillar apatite formation could be seen in incompletely resin-infiltrated, STMP-phosphorylated collagen matrices only when PAA was present in the SBF.
  
  
  CONCLUSIONS
  These results reinforce the importance of PAA for sequestration of amorphous calcium phosphate nanoprecursors in the biomimetic remineralization scheme. They also highlight the role of STMP as a templating analog of dentin matrix phosphoproteins for inducing intrafibrillar remineralization of apatite nanocrystals within the collagen matrix of incompletely resin-infiltrated dentin.
authors.affiliation: Department of Operative Dentistry and Endodontics, Sun Yat-sen University, Guangzhou, China.
authors.forename: Li-sha
authors.initials: LS
authors.lastname: Gu
authors.forename: Jongryul
authors.initials: J
authors.lastname: Kim
authors.forename: Young Kyung
authors.initials: YK
authors.lastname: Kim
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Sabine H
authors.initials: SH
authors.lastname: Dickens
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
authors.forename: Jun-qi
authors.initials: JQ
authors.lastname: Ling
authors.forename: Franklin R
authors.initials: FR
authors.lastname: Tay
mesh_terms: D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000494:pharmacology; D000327:Adsorption; D000469:Alkaline Phosphatase / Q000494:pharmacology; D001031:Apatites / Q000737:chemistry; D040761:Biomimetic Materials / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D003094:Collagen / Q000187:drug effects; D024042:Collagen Type I / Q000187:drug effects* / Q000648:ultrastructure; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005240:Feasibility Studies; D006801:Humans; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010750:Phosphoproteins / Q000494:pharmacology; D010758:Phosphorus / Q000737:chemistry; D010766:Phosphorylation; D011122:Polyphosphates / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014089:Tooth Remineralization
chemical_list: D000180:Acrylic Resins; D001031:Apatites; D002130:Calcium Phosphates; D024042:Collagen Type I; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D010710:Phosphates; D010750:Phosphoproteins; D011122:Polyphosphates; D010758:Phosphorus; C006903:carbopol 940; D002244:Carbon; D003094:Collagen; C020243:calcium phosphate; D000469:Alkaline Phosphatase; C009293:trimetaphosphoric acid; D010100:Oxygen