BMP‐2 immobilized on nanocrystalline diamond–coated titanium screws; demonstration of osteoinductive properties in irradiated bone. Issue 2 (11th March 2012) - Kloss, Frank 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, 2013