Functionalization of titanium implants using a modular system for binding and release of VEGF enhances bone-implant contact in a rodent model.
AIMS
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.


MATERIALS AND 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.
['Schliephake|Henning|H|', 'Rublack|Jennifer|J|', 'Förster|Anne|A|', 'Schwenzer|Bernd|B|', 'Reichert|Judith|J|', 'Scharnweber|Dieter|D|']
D000134:Acid Etching, Dental D000818:Animals D052157:Aptamers, Nucleotide D015519:Bone Density D001861:Bone Regeneration D000069343:Bone-Implant Interface D020099:Coated Materials, Biocompatible D045662:Dental Etching D015921:Dental Implants D003764:Dental Materials D005260:Female D055767:Immobilized Proteins D023421:Models, Animal D053758:Nanoparticles D010012:Osteogenesis D051381:Rats D017207:Rats, Sprague-Dawley D013499:Surface Properties D013977:Tibia D013997:Time Factors D014025:Titanium D042461:Vascular Endothelial Growth Factor A
titanium implants vascular endothelial growth factor oligonucleotides biofunctionalization bone regeneration controlled release recombinant proteins