title: Effect of proline-rich synthetic peptide-coated titanium implants on bone healing in a rabbit model.
abstract: OBJECTIVE
  Previous studies have demonstrated the capacity of a designed proline-rich synthetic peptide to stimulate osteoblast differentiation and biomineralization in vitro. Therefore, the aim of the present study was to evaluate the osseointegration capacity of titanium (Ti) implants coated with these peptides in a rabbit model.
  
  
  METHODS
  Four calibrated defects were prepared in the tibiae of three New Zealand rabbits, and the defects were randomized into a test group (peptide-modified machined Ti implant) and a control group (unmodified machined Ti implant). The performance in vivo was investigated after 4 weeks of implantation by real-time reverse transcriptase polymerase chain reaction of bone and inflammatory markers, microcomputed tomographic analysis of mineralized bone, and histologic examination.
  
  
  RESULTS
  The peptides adsorbed in agglomerates on Ti and underwent a change in secondary structure upon adsorption, which induced an increase in surface wettability. Gene expression markers indicated that peptide-coated Ti implants had significantly decreased mRNA levels of tartrate-resistant acid phosphatase. A trend toward increased osteocalcin in the peri-implant bone tissue was also seen. Bone morphometric and histologic parameters did not show significant differences, although the peptide group showed a higher percentage of new bone histologically.
  
  
  CONCLUSIONS
  Proline-rich peptides have potential as a biocompatible coating for promoting osseointegration of Ti implants by reducing bone resorption.
authors.forename: Christiane
authors.initials: C
authors.lastname: Petzold
authors.forename: Marta
authors.initials: M
authors.lastname: Monjo
authors.forename: Marina
authors.initials: M
authors.lastname: Rubert
authors.forename: Finn P
authors.initials: FP
authors.lastname: Reinholt
authors.forename: Manuel
authors.initials: M
authors.lastname: Gomez-Florit
authors.forename: Joana Maria
authors.initials: JM
authors.lastname: Ramis
authors.forename: Jan Eirik
authors.initials: JE
authors.lastname: Ellingsen
authors.forename: S Petter
authors.initials: SP
authors.lastname: Lyngstadaas
mesh_terms: D000327:Adsorption; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D002113:Calcification, Physiologic / Q000187:drug effects / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology*; D015921:Dental Implants; D005260:Female; D020007:Implants, Experimental; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D016348:Osseointegration / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects / Q000235:genetics; D010455:Peptides / Q000737:chemistry / Q000493:pharmacokinetics; D055232:Proline-Rich Protein Domains; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D013499:Surface Properties; D013977:Tibia / Q000737:chemistry / Q000648:ultrastructure; D014025:Titanium / Q000737:chemistry*; D017155:Wettability
chemical_list: D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D010455:Peptides; D012333:RNA, Messenger; D015675:Osteocalcin; D014025:Titanium; D007770:L-Lactate Dehydrogenase; D000469:Alkaline Phosphatase