Peroxisome proliferator activated receptor gamma loaded dental implant improves osteogenesis of rat mandible

Peroxisome proliferator activated receptor gamma (PPAR) has been known for their anti-inflammatory effects. But the application of this molecule in implant-induced inflammation has not been clearly studied yet. Here, we determined in vivo anti-inflammatory and osteogenic effects of PPAR coated dental implant in the rat mandible. We used chitosan gold nanoparticles (Ch-GNPs) as a non viral vector to carry PPAR plasmid DNA. Ch-GNPs were conjugated with PPAR plasmid DNA through a coacervation process. Conjugation was cast over titanium (Ti) implants (4.5 x 0.8 mm) by dipping, and implants were installed in rat mandibles. One, 2, 3, and 6 weeks post-implantation, mandibles were examined by microcomputed tomography (mu CT), immunohistochemistry, hematoxylin & eosin, and tartrate resistance acid phosphatase (TRAP) staining. In vivo Ch-GNPs/PPARcoated implants were associated with inhibition of implant induced inflammatory molecules interleukin-1 and receptor activator of nuclear factor kappa-B ligand and enhanced expression of osteogenic molecules like bone morphogenetic protein 2 and 7 (BMP-2/-7) by up-regulating anti-oxidant molecules heme oxygenase-1. mu CT demonstrated that PPAR overexpression increased the density and volume of newly formed bone surrounding the implants compared to control (n=4; p<0.05). Also, PPAR reduced the number of TRAP positive cells. These results support the view that PPAR overexpression diminishes inflammation and enhances osteogenesis around the dental implants. Thus, implant coated with anti-inflammatory molecules could have a significant utilization for the preparation of new biomaterials and may serve as prosthetic materials in patients suffering from inflammatory bone disease. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 587-595, 2015.