title: Effects of anodized titanium with Arg-Gly-Asp (RGD) peptide immobilized via chemical grafting or physical adsorption on bone cell adhesion and differentiation.
abstract: OBJECTIVE
  This study examined the effects of the immobilization of Arg-Gly-Asp (RGD) peptide (CAAALLLKERGDSK) on anodized titanium (Ti) via chemical grafting or physical adsorption methods on cell adhesion and osteoblast differentiation.
  
  
  METHODS
  The RGD peptide was immobilized on the anodized Ti surface by means of physical adsorption or chemical grafting. The chemical composition of each RGD-immobilized Ti substrate was examined by x-ray photoelectron spectroscopy. The level of cell proliferation was investigated via tetrazolium (XTT) assay. Alkaline phosphatase activity and calcium deposition were evaluated by alizarin red S staining, and mRNA expression of the differentiated osteoblast marker genes was analyzed by reverse-transcriptase polymerase chain reaction.
  
  
  RESULTS
  Cell adhesion was enhanced on the RGD-immobilized Ti substrates compared to the anodized Ti surfaces. In addition, significantly increased cell spreading and proliferation were observed with the cells grown on the RGD-immobilized Ti (P < .05). Furthermore, the osteoblasts on the RGD-immobilized Ti showed significant increases in the integrin ?1 and type I collagen levels and small increases in osteonectin and osteocalcin levels (P < .05). Interestingly, the chemical grafting method resulted in significantly greater effects on adhesion and differentiation than the physical adsorption method (P < .05).
  
  
  CONCLUSIONS
  RGD-immobilized Ti substrates might be effective in improving the osseointegration of dental implants. In particular, the chemical grafting method of RGD immobilization is more favorable and is expected to provide positive outcomes with future animal and clinical studies.
authors.affiliation: Institute for Clinical Dental Research, Korea University Hospital, Korea University, Seoul, Korea.
authors.forename: Jae-Jun
authors.initials: JJ
authors.lastname: Ryu
authors.forename: Kyeongsoon
authors.initials: K
authors.lastname: Park
authors.forename: Hyo-Sop
authors.initials: HS
authors.lastname: Kim
authors.forename: Chang-Mo
authors.initials: CM
authors.lastname: Jeong
authors.forename: Jung-Bo
authors.initials: JB
authors.lastname: Huh
mesh_terms: D000327:Adsorption; D000818:Animals; D001672:Biocompatible Materials; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D015921:Dental Implants; D009842:Oligopeptides / Q000737:chemistry* / Q000494:pharmacology; D016348:Osseointegration / Q000187:drug effects* / Q000235:genetics; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects; D056951:Photoelectron Spectroscopy; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D001672:Biocompatible Materials; D015921:Dental Implants; D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid; D014025:Titanium