ABSTRACT
Bisphosphonates are well-known drugs as inhibitors of bone resorption acting on inducing programmed cell death of osteoclasts. However, many in vitro studies report that optimal concentration of the bisphosphonate affects not only osteoclasts but also osteoblasts, that is, it induces the anabolic effects of osteoblasts. Recently reported 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is an endogenous ligand of peroxisome proliferator-activated receptor-gamma, with an inhibitory activity on bone loss. Researchers have also suggested that 15d-PGJ2 has the ability to reduce bone destruction and as the possibility of regeneration of bone. The purpose of this study is to demonstrate the anabolic effect of two anti-resorptive materials, alendronate and 15d-PGJ2, in a critical sized segmental defect model of rat fibula. The regenerated bone on the operative site was assessed through gross, radiographic (plain X-ray, and micro-computed tomography), histomorphologic evaluation, and statistical analysis. Consequently, the locally applied alendronate prevented resorption of grafted materials, and had a positive effect on bone regeneration with positive micro-architectural modification of the surrounding bone, although this study did not verify a significant capacity of bone regeneration of 15d-PGJ2 and instead only shed a light on its possibility.