Babaie Elham, Lin Boren, Goel Vijay K, Bhaduri Sarit B
Department of Bioengineering, University of Toledo, Toledo, OH 43606, USA.
Biomed Mater. 2016 Oct 7;11(5):055010. doi: 10.1088/1748-6041/11/5/055010.
This paper reports for the first time the development of a biodegradable, non-exothermic, self-setting orthopedic cement composition based on amorphous magnesium phosphate (AMP). The occurrence of undesirable exothermic reactions was avoided through using AMP as the solid precursor. The phenomenon of self-setting with optimum rheology is achieved by incorporating a water soluble biocompatible/biodegradable polymer, polyvinyl alcohol (PVA). Additionally, PVA enables a controlled growth of the final phase via a biomimetic process. The AMP powder was synthesized using a precipitation method. The powder, when in contact with the aqueous PVA solution, forms a putty resulting in a nanocrystalline magnesium phosphate phase of cattiite. The as-prepared cement compositions were evaluated for setting times, exothermicity, compressive strength, biodegradation, and microstructural features before and after soaking in SBF, and in vitro cytocompatibility. Since cattiite is relatively unexplored in the literature, a first time evaluation reveals that it is cytocompatible, just like the other phases in the MgO-PO (Mg-P) system. The cement composition prepared with 15% PVA in an aqueous medium achieved clinically relevant setting times, mechanical properties, and biodegradation. Simulated body fluid (SBF) soaking resulted in coating of bobierrite onto the cement particle surfaces.
本文首次报道了一种基于无定形磷酸镁（AMP）的可生物降解、无放热、自固化骨科水泥组合物的研发情况。通过使用AMP作为固体前驱体，避免了不良放热反应的发生。通过加入水溶性生物相容性/可生物降解聚合物聚乙烯醇（PVA），实现了具有最佳流变学性能的自固化现象。此外，PVA能够通过仿生过程使最终相可控生长。AMP粉末采用沉淀法合成。该粉末与PVA水溶液接触时会形成油灰状物质，从而产生一种名为水磷镁钙石的纳米晶磷酸镁相。对所制备的水泥组合物进行了凝固时间、放热性、抗压强度、生物降解以及浸泡在模拟体液（SBF）前后的微观结构特征和体外细胞相容性评估。由于水磷镁钙石在文献中相对未被充分研究，首次评估表明它与MgO-PO（Mg-P）体系中的其他相一样具有细胞相容性。在水性介质中用15%PVA制备的水泥组合物达到了临床相关的凝固时间、力学性能和生物降解性能。模拟体液（SBF）浸泡导致在水泥颗粒表面形成磷镁矿涂层。
