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Enhancement of bone formation in hydroxyapatite implants by rhBMP‐2 coating
Author(s) -
Schnettler Reinhard,
Knöß Peter D.,
Heiss Christian,
Stahl JensPeter,
Meyer Christof,
Kilian Olaf,
Wenisch Sabine,
Alt Volker
Publication year - 2009
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.31255
Subject(s) - trephine , implant , calcein , bone formation , tibia , dentistry , biomedical engineering , bone morphogenetic protein 2 , materials science , medicine , chemistry , anatomy , surgery , in vitro , biochemistry , membrane , endocrinology
The combination of hydroxyapatite (HA) implants serving as osteoconductive scaffold with growth factors is an interesting approach for the improvement of bone defect healing. The purpose of this study was to test whether recombinant human bone morphogenetic protein‐2 (rhBMP‐2) coating of solid HA‐implants improves bone formation in a cortical bone defect. Cylindrical trephine mill defects (diameter: 9.8 mm, depth: 10 mm) were created into the cortical tibia shaft of minipigs and subsequently filled either by plain HA cylinders (Endobon®) or by rhBMP‐2‐coated HA cylinders. Fluorochrome labeling for the evaluation of time‐dependent bone formation was done on days 8, 9, and 10 postsurgery with tetracyclin‐100, at days 25 and 30 with alizarin‐komplexon, and finally on days 32, 37, 73, and 79 with calcein green. Twelve weeks after implantation, the tibiae were harvested and were prepared for standard histological staining, fluorochrome analysis, and histomorphometry. Coating of HA implants with rhBMP‐2 led to significant enhanced new bone formation of 84.7% (±4.6%) of the implant area with almost complete bony incorporation compared with only 27.7% (±8.5%) in the uncoated HA implants ( p = 0.028). In both types of implants, osteoconduction of HA led to bone ingrowth of the surrounding host bone into the implants. However, only rhBMP‐2‐coated implants showed multitopic de novo bone formation reflecting the osteoinductive properties of rhBMP‐2 in all areas of the HA implant. This study showed that the coating of HA ceramic implants with rhBMP‐2 can significantly enhance new bone formation attributable to its osteoinductive effects. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009