ABSTRACT
The effect of platelet-rich plasma (PRP) on bone formation was investigated in a rabbit segmental radial defect model. The purpose of the study was to evaluate the bone inductive properties of PRP with titanium fiber mesh and autologous bone chips in a 15-mm rabbit radial defect model. Eighteen New Zealand white rabbits were divided into three groups: I, PRP with autologous bone (PRP-Ti-Bone); II, autologous bone (Ti-Bone); III, control group (Ti). The implants were placed in the radial defect for 12 weeks. After sacrifice, all specimens were harvested for histological, histomorphometrical and radiographic analysis. Histomorphometrical analysis showed that bone formation was higher in the implants with PRP (PRP-Ti-Bone: 37+/-8%) than in those without PRP (Ti-bone: 25+/-6% and Ti: 25+/-5%) after 12 weeks of implantation. It was concluded that PRP has a stimulatory effect on bone formation in titanium fiber mesh filled with autologous bone graft in segmental bone defects. Titanium fiber mesh was also shown to be an excellent scaffold material for the application of autologous bone grafts with or without PRP.
Subject(s)
Bone Diseases/surgery , Bone Transplantation/methods , Osteogenesis/physiology , Platelet-Rich Plasma/physiology , Radius/surgery , Surgical Mesh , Tissue Scaffolds , Titanium , Animals , Bone Diseases/pathology , Bone Remodeling/physiology , Bony Callus/pathology , Bony Callus/physiopathology , Female , Image Processing, Computer-Assisted , Periosteum/surgery , Rabbits , Radius/pathology , Random Allocation , Time Factors , Transplantation, AutologousABSTRACT
Calcium phosphate (Ca-P) cement is a well established material for bone repair. The bone biological properties of Ca-P cement can even be further improved by creating porosity in the material. The current study aimed on the evaluation of the osteoconductive behavior of porous Ca-P cement. Therefore, circular defects (6, 9, and 15 mm in diameter) were created in the cranium of 3 months old rabbits and filled with porous Ca-P cement implants. The total porosity of implants was calculated to be 71, 74 and 74% respectively and the average pore diameter was 150 microm. In addition, empty control defects were prepared. After 12 weeks implantation time the animals were sacrificed and radiographic, histological, and histomorphometrical evaluation was performed. The Critical Size Defect (CSD) of this species at this location for an implantation time of 12 weeks was confirmed to be 15 mm. Bone was observed to be present over and through almost all porous Ca-P cement implants. Only, in one out of eight animals with a 15 mm implant complete bone bridging of the defect did not occur. The size of the defect was found not to affect the total percentage of bone formation in the cement; (17 +/- 7)%, (18 +/- 6)% and (17 +/- 3)% for respectively 6, 9, and 15 mm diameter implants. We concluded that porous Ca-P cement is an excellent osteoconductive material in non weight bearing situations and complete bridging of a critical sized skull defect occurs in this rabbit model after 12 weeks of implantation.
Subject(s)
Absorbable Implants , Bone Cements/pharmacology , Calcium Phosphates/pharmacology , Models, Animal , Skull/drug effects , Skull/surgery , Animals , Bone Regeneration/drug effects , Female , Materials Testing , Porosity , Rabbits , Skull/pathologyABSTRACT
Little is known about the ability of peptide-coated surfaces to influence cell responses in vivo. Many studies have demonstrated that peptide-modified surfaces influence cell responses in vitro. Integrins, which bind specifically short peptide sequences, are responsible for these cell responses. In this way, information can be transmitted to the nucleus through several cytoplasmic signaling pathways. The peptide sequence Arg-Gly-Asp (RGD peptide) plays an important role in osteoblast adhesion. The present study was designed to investigate new bone formation in a porous titanium (Ti) fiber mesh implant, which was coated with cyclic RGD peptide. The RGD-Ti implants were inserted into the cranium of a rabbit and were compared with porous titanium fiber mesh disks without RGD sequence (Ti) and with an open control defect. Histologic and histomorphometric examinations were performed 2, 4, and 8 weeks postoperatively. A significant increase in bone formation, or bone ingrowth, was seen in the RGD-Ti group compared with the Ti group after 4 and 8 weeks. All control defects stayed open in all three periods. It was concluded that the use of cyclic RGD peptide in combination with titanium fiber mesh has a positive effect on bone formation in vivo in a rabbit animal model.
