A Novel Injectable Magnesium/Calcium Sulfate Hemihydrate Composite Cement for Bone Regeneration.

Shanchuan Zhang,Yi Jiang,Fuzhai Cui,Lingling E,Hongchen Liu,Baohua Xu,Ke Yang

doi:10.1155/2015/297437

Abstract

Objective. A novel injectable magnesium/calcium sulfate hemihydrate (Mg/CSH) composite with improved properties was reported here. Methods. Composition, setting time, injectability, compressive strength, and bioactivity in simulated body fluid (SBF) of the Mg/CSH composite were evaluated. Furthermore, the cellular responses of canine bone marrow stromal cells (cBMSCs) and bone formation capacity after the implantation of Mg/CSH in tibia defects of canine were investigated. Results. Mg/CSH possessed a prolonged setting time and markedly improved injectability and mechanical property (p < 0.05). Mg/CSH samples showed better degradability than CSH in SBF after 21 days of soaking (p < 0.05). Moreover, the degrees of cell attachment, proliferation, and capability of osteogenic differentiation on the Mg/CSH specimens were higher than those on CSH, without significant cytotoxicity and with the increased proliferation index, ALP activity, and expression levels of integrin β1 and Coll I in cBMSCs (p < 0.05). Mg/CSH enhanced the efficiency of new bone formation at the tibia defect area, including the significantly elevated bone mineral density, bone area fraction, and Coll I expression level (p < 0.05). Conclusions. The results implied that this new injectable bone scaffold exhibited promising prospects for bone repair and had a great potential in bone tissue engineering.

Highlights

Bone defects are usually caused by trauma and nonunion, and autologous bone graft is commonly known as a gold standard in reconstruction of bone defects [1]
After setting for 24 h, the phase composition of the hardened magnesium/calcium sulfate hemihydrate (Mg/CSH) composite was characterized by using X-ray diffraction (XRD)
The CSH construct contained diffraction peaks of CaSO4⋅2H2O (Figure 1(b)), and a mixture of CaSO4⋅2H2O and Mg could be seen in the XRD patterns of the Mg/CSH composites with 10% and 20% Mg (Figures 1(c) and 1(d))

Summary

Introduction

Bone defects are usually caused by trauma and nonunion, and autologous bone graft is commonly known as a gold standard in reconstruction of bone defects [1]. The clinical use of autologous bone graft is accompanied by size limitations and a considerable donor site morbidity, like bleeding, hematoma, infection, and chronic pain. A variety of biomaterials, like acrylate-, calcium phosphate-, or apatite-based bone cements, and porous composites, are being used for reconstruction of bone defects [3]. Calcium sulfate hemihydrate (CaSO4⋅1/2H2O; CSH) has long been used in clinic as a bone regeneration material, because it is characterized by low curing temperature (about 30∘C), rapid setting, excellent biocompatibility without inducing an inflammatory response, and promotion of bone healing [4,5,6,7,8]. The solidified CSH paste has poor mechanical properties, which fails to provide constant longterm mechanical support for the defect site [9, 10]. The fast resorption of CSH cement may negatively affect the bone regeneration [12, 13]

Methods

Results

Discussion

Conclusion