新型可降解α-TCP/多元氨基酸共聚物复合材料制备与表征

通过原位共聚制备了一种新型可降解α-磷酸钙/多元氨基酸共聚物复合材料,采用FTIR、XRD、SEM和模拟体液浸泡法对其性能进行表征。结果表明:该复合材料由具有聚酰胺结构的氨基酸共聚物和α-磷酸钙组成;该材料初期降解较快,浸泡1周后材料失重6.8%,12周后材料总失重为20.1%;降解产物无强酸性物质,pH在6.6～7.0范围内;材料吸水率在11%左右,浸泡过程中无明显变化。扫描电镜分析表明,浸泡2周后,材料表面变得光滑,并有少量沉积物生成;随着浸泡时间增加,表面沉积物逐渐增加,12周时大量的沉积物几乎覆盖了样品全部表面。XRD分析表明沉积物为羟基磷灰石,这说明材料具有良好的生物活性;浸泡12周后,去除样品表面沉积物,用XRD分析其直接接触液体的表面和未接触液体的内部表面,发现材料表面的两相结晶峰宽化,而材料内部无显著变化,表明该复合材料可能是一种表面腐蚀降解材料。该新型复合材料可望在骨修复和组织工程方面得到广泛应用。

Novel degradable α-TCP/multi-(amino acid) copolymer composite: Preparation and characterization

A novel degradable α-tricalcium phosphate/multi-(amino acid) copolymer composite (α---TCP/MAACP) was prepared by the in situ copolymerization method and characterized by FTIR, XRD, SEM and in vitro degradation experiments in simulated body fluid. The results exhibit that the composite is composed of an amide copolymer and α-TCP. The composite shows a fast degradation in the primary period and 6.8% of mass loss is observed in the first week. A total of 20.1% mass is lost after 12 weeks immersion. No strong acidic degradation products are produced and the pH of soaking medium is in a range of 6.6～7.0 during the immersion period. The water absorption rate of the composite is about 11% and no significant change occurs during the soaking time. SEM analysis shows that the surface becomes smooth after 2 weeks immersion and some precipitation is observed. The precipitation increases with soaking time and covers the most part of surface at the end of 12 weeks. XRD determination shows that the precipitation is poorly crystallized hydroxyapatite, indicating the composite is bioactive. After 12 weeks soaking, compared to that of before soaking, the crystallinity of surface decreases but no significant change for that of cross section is observed, indicating that the composite may be a surface erosion material. Collectively, this composite can be potential bone substitutes for bone repair and tissue engineering.