title: Potential induction of bone regeneration by nacre: an in vitro study.
abstract: OBJECTIVE
  Because of limitations of autogenous grafts, alternative bone substitute material was investigated for its capacity in promoting bone formation. This study compared the osteogenic effects of nacre (mother of pearl) and beta-tricalcium phosphate (β-TCP).
  
  
  METHODS
  Human bone cells (HBCs) were obtained from the culture of bone tissues after orthognathic surgery. The HBCs were cocultured with nacre chips of the giant oyster Pinctada maxima and with β-TCP particles for 1, 2, 3, and 4 weeks. Cells of each week specimens were used to study alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC) gene expression by noncompetitive reverse-transcriptase polymerase chain reaction and to study BSP synthesis by means of an immunocytochemical technique in conjunction with fluorescent microscopy.
  
  
  RESULTS
  Reverse-transcriptase polymerase chain reaction demonstrated stronger expression levels of ALP mRNA in HBCs cocultured with the nacre chips than those with β-TCP at weeks 2 and 4. BSP gene expression levels in HBCs with nacre were more intense compared with β-TCP at weeks 3 and 4. Although the OC gene expression level in HBCs with β-TCP was higher than those with nacre at week 2, the expression was not different at weeks 3 to 4. Immunocytochemical study revealed that BSP synthesis were presented in the nacre and β-TCP from week 2 and decreased toward week 4.
  
  
  CONCLUSIONS
  This study indicated that nacre promotes ALP, BSP, and OC gene expression.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Mahidol University, Bangkok, Thailand. dtpas@mahidol.ac.th
authors.forename: Pattapon
authors.initials: P
authors.lastname: Asvanund
authors.forename: Panjit
authors.initials: P
authors.lastname: Chunhabundit
authors.forename: Theeralaksna
authors.initials: T
authors.lastname: Suddhasthira
mesh_terms: D000293:Adolescent; D000328:Adult; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D001704:Biopolymers / Q000737:chemistry / Q000627:therapeutic use*; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000627:therapeutic use*; D002119:Calcium Carbonate / Q000737:chemistry / Q000627:therapeutic use; D002130:Calcium Phosphates / Q000627:therapeutic use; D002478:Cells, Cultured; D018920:Coculture Techniques; D003461:Crystallography; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006801:Humans; D007150:Immunohistochemistry; D058574:Integrin-Binding Sialoprotein / Q000032:analysis; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism; D015675:Osteocalcin / Q000032:analysis; D010012:Osteogenesis / Q000187:drug effects; D049911:Pinctada; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; D001704:Biopolymers; D018786:Bone Substitutes; D002130:Calcium Phosphates; D005456:Fluorescent Dyes; D058574:Integrin-Binding Sialoprotein; C485817:beta-tricalcium phosphate; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D002119:Calcium Carbonate; D016650:Fluorescein-5-isothiocyanate