The role of oxygen termination of nanocrystalline diamond on immobilisation of BMP-2 and subsequent bone formation.
Medical implants are increasingly often inserted into bone of frail patients, who are advanced in years. Due to age, severe trauma or pathology-related bone changes, osseous healing at the implant site is frequently limited. We were able to demonstrate that coating of endosseous implants with nanocrystalline diamond (NCD) allows stable functionalization by means of physisorption with BMP-2. Strong physisorption was shown to be directly related to the unique properties of NCD, and BMP-2 in its active form interacted strongly when NCD was oxygen-terminated. The binding of the protein was monitored under physiological conditions by single molecule force spectroscopy, and the respective adsorption energies were further substantiated by force-field-calculations. Implant surfaces refined in such a manner yielded enhanced osseointegration in vivo, when inserted into sheep calvaria. Our results further suggest that this technical advancement can be readily applied in clinical therapies with regard to bone healing, since primary human mesenchymal stromal cells strongly activated the expression of osteogenic markers when being cultivated on NCD physisorbed with physiological amounts of BMP-2.
Kloss
Frank R
FR
Department of Cranio-Maxillofacial and Oral Surgery, Medical University of Innsbruck, Maximilianstrasse 10, Innsbruck, Austria. frank.kloss@i-med.ac.at
Gassner
Robert
R
Preiner
Johannes
J
Ebner
Andreas
A
Larsson
Karin
K
Hächl
Oliver
O
Tuli
Tarkan
T
Rasse
Michael
M
Moser
Doris
D
Laimer
Klaus
K
Nickel
Eike A
EA
Laschober
Gerhard
G
Brunauer
Regina
R
Klima
Günther
G
Hinterdorfer
Peter
P
Steinmüller-Nethl
Doris
D
Lepperdinger
Günter
G
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000737:chemistry*; D018786:Bone Substitutes; D002454:Cell Differentiation; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible; D018130:Diamond / Q000737:chemistry*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology; D018625:Microscopy, Atomic Force; D053758:Nanoparticles / Q000737:chemistry*; D016348:Osseointegration; D010012:Osteogenesis; D010100:Oxygen / Q000737:chemistry*; D011485:Protein Binding; D012756:Sheep; D012886:Skull; D016212:Transforming Growth Factor beta / Q000737:chemistry*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D016212:Transforming Growth Factor beta; D018130:Diamond; D010100:Oxygen