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Aging Does Not Lessen the Effectiveness of TGFβ 2 ‐Enhanced Bone Regeneration
Author(s) -
Sumner DR,
Turner TM,
Cohen M,
Losavio P,
Urban RM,
Nichols EH,
McPHERSON JM
Publication year - 2003
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.2003.18.4.730
Subject(s) - regeneration (biology) , medicine , microbiology and biotechnology , biology
Controversy exists over the potency of bone healing in the aged skeleton, and there is concern that enhancement of bone regeneration after use of bone‐stimulating growth factors may not be effective in the aged. In this study, 30 skeletally mature beagles (1–2 or 10–12 years old) had titanium implants placed bilaterally in the proximal humerus for a period of 4 weeks in a model of intramembranous bone regeneration. A bony defect made at the time of surgery created a 3‐mm gap between the implant surface and the host bone. Some of the implants were treated with recombinant human TGFβ2 (rhTGFβ2) at various does (0.32–35 μg per implant), and some served as paired controls. The dose response was similar in young and old animals. The most effective dose, 35 μg, led to a 3‐fold increase in the volume fraction of new bone within the gap in both the young ( p = 0.001) and old ( p = 0.002) animals. At this dose, there was a 5‐fold increase in osteoblast surface. While age did not significantly affect the quantity of new bone formed as assessed by backscatter scanning electron microscopy, the older animals had thinner regenerated trabeculae that tended to be spaced more closely than the younger animals. Coupled with the finding that the increase in osteoid was greater in the old animals compared with the young animals, these qualitative differences suggest that there may have been a slight delay in the rate or a defect of mineralization in the old animals.