用于骨组织工程的镁基泡沫生物材料的制备与体外降解行为

Development and degradation behavior in vitro of Mg-based foam biomaterials for bone tissue engineering

摘要:

采用熔体发泡法制备了一种镁基泡沫生物材料,其中以镁钙合金为基体材料,羟基磷灰石(HA)为增粘剂,以碳酸镁(MgCO3)为发泡剂。对结构均匀的镁基泡沫生物材料进行测试,研究其生物可降解行为。用腐蚀前后孔结构、浸泡试验和电化学测试对镁基泡沫材料的生物可降解性进行表征。结果表明,在固定时间内随着试样孔隙率的增加,失重率不断增加；相比于添加了羟基磷灰石(HA)的样品,不含HA颗粒地样品呈现出更高质量损失率。同时,Mg基泡沫生物材料的总孔隙率和羟基磷灰石(HA)含量均对Mg基泡沫材料的开孔率有重要的影响。在相同时间内,开孔率随试样总孔隙率的增加而增加。在模拟体液(SBF)介质中,含有羟基磷灰石(HA)的Mg基泡沫生物材料比不添加羟基磷灰石(HA)的试样具有更高的耐腐蚀性。

Abstract:

Mg-based foam biomaterials were prepared by a melt foaming process, wherein a Mg-Ca alloy was used as the matrix material, hydroxyapatite (HA) as the tackifier, MgCO3 as the foaming agent. The Mg-based foam biomaterials with uniform structure were tested to investigate their biodegradable behaviors. The biodegradable property of the Mg-based foam was mainly characterized by microstructure observation, immersion tests and electrochemical measurements. The results show that the weight loss rate increases with the increasing porosity of the specimen over a fixed period of time. The weight loss rate of the specimen without HA particles is much higher than that of the specimen with HA particles. Meanwhile, the open porosity of the Mg-based foam biomaterial increases with immersion time. Both the total porosity and added HA content have an important impact on the open porosity of the Mg-based foam biomaterial. Over a fixed period of time, the open porosity of the Mg-based foam biomaterial increases with the increase of the total porosity. Mg-based foam biomaterials with added HA exhibit higher corrosion resistance than Mg-based foam biomaterials without HA in simulated body fluid (SBF) media.