Zhu Hui, Guo Dagang, Qi Wenli, Xu Kewei
State Key Laboratory for Mechanical Behavior of Materials, School of Material Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
Biomed Mater. 2017 Jan 17;12(1):015016. doi: 10.1088/1748-605X/12/1/015016.
To follow the design strategy of traditional biphasic calcium phosphate (BCP) ceramic, in the present study, strontium-doped biphasic calcium phosphate bone cement (Sr-BCPC) composites comprising Sr-β-tricalcium phosphate (TCP)/Sr-hydroxyapatite (HAP) had been prepared for the first time using Sr -β-TCP/tetracalcium phosphate (TTCP) as a cement powder and diluted phosphoric acid as a cement liquid. The phase composition, setting time, compressive strength, washout resistance, in vitro degradation rate, microstructure evolutions, hydration dynamics and cytotoxicity of Sr-BCPC at various Sr contents were intensively investigated. It was found that the final cement product was composed of entangled Sr-HAP nano-needles and cobblestone-like Sr-β-TCP sub-micron particles, and the weight percentages in the final cement product after hydration in simulated body fluid for 24 h were in the ranges of 60 wt%-70 wt% Sr-HAP and 30 wt%-40 wt% Sr-β-TCP, respectively. Sr and the concentration of Sr exhibit significant effects on the phase compositions, compressive strength, setting time, in vitro degradation rate and cytotoxicity of the biphasic bone cement. In particular, the degradation rate increased considerably with the increase of the Sr-β-TCP phase. It is anticipated that the introduction of the 'biphasic' design into calcium phosphate bone cements is an effective strategy to improve their degradation properties.
为遵循传统双相磷酸钙（BCP）陶瓷的设计策略，在本研究中，首次以Sr-β-磷酸三钙（TCP）/Sr-羟基磷灰石（HAP）组成的掺锶双相磷酸钙骨水泥（Sr-BCPC）复合材料为研究对象，以Sr-β-TCP/磷酸四钙（TTCP）为水泥粉末，以稀释的磷酸为水泥液体进行制备。对不同Sr含量的Sr-BCPC的相组成、凝固时间、抗压强度、耐冲刷性、体外降解率、微观结构演变、水化动力学和细胞毒性进行了深入研究。结果发现，最终的水泥产物由缠结的Sr-HAP纳米针和鹅卵石状的Sr-β-TCP亚微米颗粒组成，在模拟体液中水化24小时后，最终水泥产物中的重量百分比分别在60 wt%-70 wt% Sr-HAP和30 wt%-40 wt% Sr-β-TCP范围内。Sr及其浓度对双相骨水泥的相组成、抗压强度、凝固时间、体外降解率和细胞毒性有显著影响。特别是，降解率随着Sr-β-TCP相的增加而显著增加。预计将“双相”设计引入磷酸钙骨水泥是改善其降解性能的有效策略。
