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.

[1]  J. van den Dolder,et al.  Observations on the effect of BMP-2 on rat bone marrow cells cultured on titanium substrates of different roughness. , 2003, Biomaterials.

[2]  M. McKee,et al.  Chemical modification of titanium surfaces for covalent attachment of biological molecules. , 1998, Journal of biomedical materials research.

[3]  D. Puleo,et al.  A technique to immobilize bioactive proteins, including bone morphogenetic protein-4 (BMP-4), on titanium alloy. , 2002, Biomaterials.

[4]  S. Santavirta,et al.  Recombinant Human Bone Morphogenetic Protein-2 for Treatment of Open Tibial Fractures: A Prospective, Controlled, Randomized Study of Four Hundred and Fifty Patients , 2002, The Journal of bone and joint surgery. American volume.

[5]  B. Rezek,et al.  Geometric properties of covalently bonded DNA on single-crystalline diamond. , 2006, Journal of the American Chemical Society.

[6]  Adam J Starr,et al.  Recombinant human bone morphogenetic protein-2 for treatment of open tibial fractures. , 2003, The Journal of bone and joint surgery. American volume.

[7]  T. Sakou.  Bone morphogenetic proteins: from basic studies to clinical approaches. , 1998, Bone.

[8]  T. Webster,et al.  Mechanisms of enhanced osteoblast adhesion on nanophase alumina involve vitronectin. , 2001, Tissue engineering.

[9]  M. Dard,et al.  Histological and immunohistochemical analysis of initial and early osseous integration at chemically modified and conventional SLA titanium implants: preliminary results of a pilot study in dogs. , 2007, Clinical oral implants research.

[10]  Thomas J. Webster,et al.  Anodized Ti and Ti 6 Al 4 V Possessing Nanometer Surface Features Enhances Osteoblast Adhesion , 2005 .

[11]  Christian G Specht,et al.  Ordered growth of neurons on diamond. , 2004, Biomaterials.

[12]  S. Glassman,et al.  Clinical Outcomes and Fusion Success at 2 Years of Single-Level Instrumented Posterolateral Fusions With Recombinant Human Bone Morphogenetic Protein-2/Compression Resistant Matrix Versus Iliac Crest Bone Graft , 2006, Spine.

[13]  Regina Brunauer,et al.  Reduced oxygen tension attenuates differentiation capacity of human mesenchymal stem cells and prolongs their lifespan , 2007, Aging cell.

[14]  C. Huck,et al.  Strong binding of bioactive BMP-2 to nanocrystalline diamond by physisorption. , 2006, Biomaterials.

[15]  W. Sebald,et al.  Crystal structure of human bone morphogenetic protein-2 at 2.7 A resolution. , 1999, Journal of molecular biology.

[16]  Martin Stutzmann,et al.  Protein-modified nanocrystalline diamond thin films for biosensor applications , 2004, Nature materials.

[17]  Stuart K Williams,et al.  Covalent modification of porous implants using extracellular matrix proteins to accelerate neovascularization. , 2006, Journal of biomedical materials research. Part A.

[18]  M. Urist,et al.  Bone: Formation by Autoinduction , 1965, Science.

[19]  C. Huck,et al.  Nanocrystalline diamond--an excellent platform for life science applications. , 2007, Journal of nanoscience and nanotechnology.

[20]  Stefan Nowy,et al.  The ion sensitivity of surface conductive single crystalline diamond. , 2007, Journal of the American Chemical Society.

[21]  M. Textor,et al.  Immobilization of the cell-adhesive peptide Arg–Gly–Asp–Cys (RGDC) on titanium surfaces by covalent chemical attachment , 1997, Journal of materials science. Materials in medicine.

[22]  H. Eufinger,et al.  Growth and transplantation of a custom vascularised bone graft in a man , 2004, The Lancet.

[23]  F Rupp,et al.  High surface energy enhances cell response to titanium substrate microstructure. , 2005, Journal of biomedical materials research. Part A.

[24]  K E Healy,et al.  Ectopic bone formation via rhBMP-2 delivery from porous bioabsorbable polymer scaffolds. , 1998, Journal of biomedical materials research.

[25]  K. Larsson.  Surface properties of diamond under atmospheric conditions: A quantum mechanical approach. , 2005 .

[26]  N. Anand,et al.  Adverse swelling associated with use of rh-BMP-2 in anterior cervical discectomy and fusion: a case study. , 2007, The spine journal : official journal of the North American Spine Society.

[27]  S. Cannistraro,et al.  Single molecule recognition between cytochrome C 551 and gold-immobilized azurin by force spectroscopy. , 2005, Biophysical journal.

[28]  F. Kloss,et al.  Bone and aging: Effects on the maxillofacial skeleton , 2006, Experimental Gerontology.

[29]  H. Oppermann,et al.  Bovine osteogenic protein is composed of dimers of OP-1 and BMP-2A, two members of the transforming growth factor-beta superfamily. , 1990, The Journal of biological chemistry.

[30]  G. Zych,et al.  Osteogenic Protein-1 (Bone Morphogenetic Protein-7) in the Treatment of Tibial Nonunions: A Prospective, Randomized Clinical Trial Comparing rhOP-1 with Fresh Bone Autograft* , 2001, The Journal of bone and joint surgery. American volume.

[31]  F. Kienberger,et al.  A new, simple method for linking of antibodies to atomic force microscopy tips. , 2007, Bioconjugate chemistry.

[32]  F Layher,et al.  Osteointegration of hydroxyapatite-titanium implants coated with nonglycosylated recombinant human bone morphogenetic protein-2 (BMP-2) in aged sheep. , 2005, Bone.

[33]  Byung-Soo Kim,et al.  Enhancement of ectopic bone formation by bone morphogenetic protein-2 released from a heparin-conjugated poly(L-lactic-co-glycolic acid) scaffold. , 2007, Biomaterials.

[34]  K. Hruska,et al.  Bone Morphogenetic Proteins in Vascular Calcification , 2005, Circulation research.

[35]  E. Hunziker,et al.  Delivery Mode and Efficacy of BMP-2 in Association with Implants , 2007, Journal of dental research.