Bone Formation in a Rat Tibial Defect Model Using Carboxymethyl Cellulose/BioC/Bone Morphogenic Protein-2 Hybrid Materials

Sang-Heon Song,Hak-Jun Kim,Young-Pil Yun,Kyeongsoon Park,Hae-Ryong Song,Sung Eun Kim

doi:10.1155/2014/230152

Abstract

The objective of this study was to assess whether carboxymethyl cellulose- (CMC-) based hydrogel containing BioC (biphasic calcium phosphate (BCP); tricalcium phosphate (TCP) : hydroxyapatite (Hap) = 70 : 30) and bone morphogenic protein-2 (BMP-2) led to greater bone formation than CMC-based hydrogel containing BioC without BMP-2. In order to demonstrate bone formation at 4 and 8 weeks, plain radiographs, microcomputed tomography (micro-CT) evaluation, and histological studies were performed after implantation of all hybrid materials on an 8 mm defect of the right tibia in rats. The plain radiographs and micro-CT analyses revealed that CMC/BioC/BMP-2 (0.5 mg) led to much greater mineralization at 4 and 8 weeks than did CMC/BioC or CMC/Bio/BMP-2 (0.1 mg). Likewise, bone formation and bone remodeling studies revealed that CMC/BioC/BMP-2 (0.5 mg) led to a significantly greater amount of bone formation and bone remodeling at 4 and 8 weeks than did CMC/BioC or CMC/BioC/BMP-2 (0.1 mg). Histological studies revealed that mineralized bone tissue was present around the whole circumference of the defect site with CMC/BioC/BMP-2 (0.5 mg) but not with CMC/BioC or CMC/BioC/BMP-2 (0.1 mg) at 4 and 8 weeks. These results suggest that CMC/BioC/BMP-2 hybrid materials induced greater bone formation than CMC/BioC hybrid materials. Thus, CMC/BioC/BMP-2 hybrid materials may be used as an injectable substrate to regenerate bone defects.

Highlights

More than a million people in the United States and other countries require bone graft to regenerate bone defects caused by fracture, trauma, or tumor resection [1, 2]
Osteoinductive materials, including growth factors such as bone morphogenic proteins (BMPs), basic fibroblast growth factor, platelet-derived growth factor (PDGF), and vascular endothelial growth factor (VEGF), induce new bone formation but they do not provide a framework for vascular invasion and cellular infiltration
The objective of this study was to assess whether a CMCbased hydrogel containing BioC and BMP-2 induced a greater amount of new bone formation than did a carboxymethyl cellulose- (CMC-)based hydrogel containing BioC without BMP-2

Summary

Introduction

More than a million people in the United States and other countries require bone graft to regenerate bone defects caused by fracture, trauma, or tumor resection [1, 2]. Allograft has been used as a bone substitute because it prevents donor site morbidity [2] Both autograft and allograft have disadvantages, such as limited availability, donor site morbidity, transmission of infectious diseases, and immunerejection reactions [2, 3]. To address these shortcomings, a new approach to bone graft has been developed. Hydroxyapatite (HAp) and calcium phosphate (CaP) have been successfully used as bone graft materials for the regeneration of bone defects due to their physical and chemical properties and their structural similarity to natural bone.

Objectives

Methods

Results

Conclusion