title: Functionalization of titanium implants using a modular system for binding and release of VEGF enhances bone-implant contact in a rodent model.
abstract: OBJECTIVE
  To test the immobilization of vascular endothelial growth factor (VEGF165 ) on the surface of titanium implants using DNA oligonucleotide (ODN) anchor strands for the ability to enhance periimplant bone formation.
  
  
  METHODS
  DNA oligonucleotides were anchored to the surface of sandblasted acid-etched (SAE) titanium screw implants and were hybridized with complementary strands of ODN conjugated to rhVEGF165 . The implants were tested against blank SAE implants and SAE implants with nano-anchored ODN. The implants were inserted into the tibiae of 36 Sprague-Dawley rats. Primary outcome parameters were bone-implant contact (BIC), amount of new bone formation and periimplant bone density (BD). density after 1, 4 and 13 weeks. Unit of analysis has been the individual implant.
  
  
  RESULTS
  Implants with rhVEGF165 hybridized to ODN anchor strands exhibited significantly increased average BIC after 1 month compared to blank implants and implants with anchored ODN strands.
  
  
  CONCLUSIONS
  It is concluded that rhVEGF165 immobilized on the surface of titanium implants through nano-anchored oligonucleotide strands can accelerate BIC of sandblasted and etched titanium implants to a certain extent. The radius of effect of the growth factor appears to be limited to tissue immediately adjacent to the implant surface.
authors: Department of Oral and Maxillofacial Surgery, George-Augusta-University, Göttingen, Germany.
authors: Henning
authors: H
authors: Schliephake
authors: Jennifer
authors: J
authors: Rublack
authors: Anne
authors: A
authors: Förster
authors: Bernd
authors: B
authors: Schwenzer
authors: Judith
authors: J
authors: Reichert
authors: Dieter
authors: D
authors: Scharnweber
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry; D015519:Bone Density / Q000187:drug effects; D001861:Bone Regeneration / Q000187:drug effects; D000069343:Bone-Implant Interface / Q000473:pathology*; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000627:therapeutic use*; D045662:Dental Etching / Q000379:methods; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry*; D005260:Female; D055767:Immobilized Proteins / Q000737:chemistry; D023421:Models, Animal; D053758:Nanoparticles / Q000737:chemistry; D010012:Osteogenesis / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D013977:Tibia / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry / Q000627:therapeutic use*
chemical_list: D052157:Aptamers, Nucleotide; D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D003764:Dental Materials; D055767:Immobilized Proteins; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D014025:Titanium
keywords: biofunctionalization; bone regeneration; controlled release; oligonucleotides; recombinant proteins; titanium implants; vascular endothelial growth factor