Tan Yanni, Liu Yong, Zhao Zhongwei, Paxton Jennifer Z, Grover Liam M
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, People's Republic of China; School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, People's Republic of China.
J Biomed Mater Res A. 2015 Jan;103(1):194-202. doi: 10.1002/jbm.a.35166. Epub 2014 Mar 25.
Magnesium oxychloride cement (MOC) has been used in civil engineering as it exhibits a relatively high early strength and a low coefficient of thermal expansion. Its poor water resistance, although, has prevented its widespread use. Steady degradation when immersed in an aqueous environment, however, could be a beneficial property for a resorbable bone replacement. In this study, we have evaluated how different concentrations of phosphoric acid may be used to enhance water resistance providing some control over the rate of degradation. The phase compositions, microstructures, mechanical properties, and the degradation of MOC have been evaluated. As a preliminary assessment of biological suitability, the response of a population of bone marrow stromal cells to the surface was evaluated. X-ray diffraction data demonstrate that 5Mg(OH)₂ ·MgCl₂·8H₂O (phase 5) was formed in all MOC samples. The MOC modified with H₃PO₄ exhibits good water resistance and can sustain strength in aqueous medium and by adjusting H₃ PO₄ concentration; degradation speed may be controlled. Cells cultured on the surface of the MOC attached and retained viability over the duration of the study.
氯氧化镁水泥（MOC）因其具有较高的早期强度和较低的热膨胀系数而被应用于土木工程领域。然而，其耐水性较差，这限制了它的广泛应用。不过，当浸泡在水环境中时，其持续降解的特性对于可吸收骨替代物来说可能是一项有益的特性。在本研究中，我们评估了如何使用不同浓度的磷酸来增强耐水性，从而对降解速率进行一定程度的控制。我们对MOC的相组成、微观结构、力学性能以及降解情况进行了评估。作为对生物适用性的初步评估，我们还评估了一群骨髓基质细胞对该材料表面的反应。X射线衍射数据表明，所有MOC样品中都形成了5Mg(OH)₂·MgCl₂·8H₂O（相5）。用H₃PO₄改性的MOC具有良好的耐水性，在水性介质中能够保持强度，并且通过调整H₃PO₄浓度，可以控制降解速度。在MOC表面培养的细胞在研究期间能够附着并保持活力。
