BMP-2 immobilized on nanocrystalline diamond-coated titanium screws; demonstration of osteoinductive properties in irradiated bone.

Head Neck. 2012 Mar 11. doi: 10.1002/hed.22958.


Kloss FR, Singh S, Hächl O, Rentenberger J, Auberger T, Kraft A, Klima G, Mitterlechner T, Steinmüller-Nethl D, Lethaus B, Rasse M, Lepperdinger G, Gassner R.


Abstract
BACKGROUND:Irradiation results in impaired bone healing. Thus, osteosynthesis procedures are afflicted with increased failure rates. To improve osseointegration bone morphogenetic protein-2 (BMP-2) immobilized on nanocrystalline diamond (NCD)-coated implant surfaces might be 1 solution.
METHODS:By 4 weeks after irradiation of pig's mandible with a dose of 60 Gy a fracture was accomplished. Osteosynthesis was performed either with titanium osteosynthesis screws or NCD-coated screws with immobilized BMP-2. Nonirradiated animals served as control. After 1, 2, 4, and 8 weeks screws were evaluated histologically. Bone biopsies were gained to extract mesenchymal stem or precursor cells (MSCs).
RESULTS:MSCs after irradiation demonstrated a behavior comparable to that of unirradiated cells. Consequently, immobilized BMP-2 resulted in an initial increased bone contact ratio (p = .014) but demonstrated no sustainable effect compared with osseointegration in nonirradiated bone (p = .08).
CONCLUSION:Immobilized BMP-2 demonstrates an osteoinductive effect in irradiated bone. MSCs as effector cells possess protective mechanisms to overcome the destructive effect of irradiation. © 2012 Wiley Periodicals, Inc. Head Neck, 2012.

Copyright © 2012 Wiley Periodicals, Inc.