影响掺锶聚磷酸钙降解速率的工艺条件

Technological conditions for the degradation velocity of strontium-doped calcium polyphosphate

目的:观察不同工艺条件下对掺锶聚磷酸钙降解速率的影响。方法:实验于2006-02/05在四川大学组织工程支架材料研究室完成。通过分别控制保温时间(3,5,7h)制备3种不同聚合度的掺锶聚磷酸钙烧料,将烧料分别在700,800,900℃下煅烧得到不同工艺条件的掺锶聚磷酸钙材料样品,并在三羟甲基氨基甲烷-氯化氢溶液中进行45d的降解实验。用31P核磁共振波谱仪检测其聚合度,扫描电镜观察其表面形貌变化,钼蓝比色法检测PO43-的质量浓度以表征其降解速率。结果:①31P核磁共振波谱表明,随着保温时间的延长,掺锶聚磷酸钙的聚合度逐渐增大,3种掺锶聚磷酸钙烧料的聚合度分别为9,13,19。②掺锶聚磷酸钙降解速率并不随聚合度增长而呈一单调变化的趋势。在相同的煅烧温度下,掺锶聚磷酸钙的降解速率由高到低分别为聚合度为13,9,19的掺锶聚磷酸钙。聚合度为13的掺锶聚磷酸钙降解液中PO43-的质量浓度达到0.44g/L;相同保温时间下,掺锶聚磷酸钙的降解速率随煅烧温度的升高而增大。③扫描电镜显示,降解速率快的掺锶聚磷酸钙表面有CaP沉积物。结论:不同工艺条件下掺锶聚磷酸钙的降解速率不同,通过调节保温时间和煅烧温度可以在一定程度上调控掺锶聚磷酸钙的降解速率。

AIM： To investigate the degradation velocities of strontium-doped calcium polyphosphate （SCPP） prepared by different technological conditions： METHODS： The experiment was performed at the Tissue Engineering Scaffold Materials Laboratory of Sichuan University from February to May 2006. Three types of SCPP frits with different polymerization degrees were prepared by controlling calcining time for 3, 5, 7 hours and then all these frits were sintered at 700 %, 800 %, 900 %, respectively. Degradation studies of SCPP were carried out during 45 days in Tris [hydroxymethyl] aminomethane-HCI （Tris-HCI） solution. The polymerization degree of SCPP frits was quantified using ^3p nuclear magnetic resonance （NMR）. Each type of SCPP was viewed by scanning electron microscopy （SEM） in order to study the surface topography change. The concentration of PO4^2- was measured by ultraviolet spectroscopy using the molybdenum blue method. RESULTS：① The result of NMR showed that with the increase of calcining time, polymerization degree of SCPP increased. The polymerization degrees of three types of SCPP were 9, 13, 19. ②The degradation velocity of SCPP didn ＇t increase with the increase of its polYmerization degree. At the same sintedng temperature, the degradation velocity sequence of SCPP was 13, 9, 19 in order. The PO4^2- of SCPP with 13 polymerization degree released into degradation solution was 0.44 g/L. At the same calcining time, degradation velocity of SCPP increased with the increase of sintering temperature, ③The result of SEM displayed a layer of precipitation was formed on SCPP whose degradation velocity were faster than others. CONCLUSION： The degradation velocities of SCPP differ by different technological conditions and can be controlled by calcining time and sintering temperature.