Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11000 Belgrade, Serbia.
Ultrason Sonochem. 2010 Jun;17(5):902-8. doi: 10.1016/j.ultsonch.2010.01.007. Epub 2010 Jan 28.
In this work poly(D,L-lactide-co-glycolide) (PLGA) and a poly(d,l-lactide-co-glycolide)/hydroxyapatite (PLGA/HAp) composite processed in an ultrasonic field at higher (25 degrees C) and lower (8 degrees C) temperatures were studied with respect to the molecular properties of the obtained materials. The processing of the PLGA and the PLGA/HAp composite in an ultrasonic field resulted in a change of molar mass averages of the polymer/polymeric part of these materials, while an amorphous structure and a 50:50 lactide-to-glycolide co-monomer ratio were preserved without the formation of crystalline oligomers. However, mobility of polymeric chains obtained after ultrasonic processing was lower indicating ordering the structure of polymeric chains as a result of processing. Additionally, it was observed that the mobility of the PLGA macromolecules was lower within the composite in comparison with the mobility of the chains within the PLGA alone in the case when both were obtained after ultrasonic processing. This was a consequence of the structure formation through the interactions between the PLGA and the HAp. Based on these results different degradation rate of PLGA in composite can be expected, which is important in the application of this material for the controlled drug delivery of medicaments.
在这项工作中，聚（D，L-丙交酯-共-乙交酯）（PLGA）和聚（D，L-丙交酯-共-乙交酯）/羟基磷灰石（PLGA/HAp）复合材料在较高（25°C）和较低（8°C）温度下在超声场中进行了处理，以研究所得材料的分子性质。在超声场中处理 PLGA 和 PLGA/HAp 复合材料会导致这些材料的聚合物/聚合物部分的摩尔质量平均值发生变化，同时保持无定形结构和 50:50 的丙交酯-乙交酯共聚单体比，而不会形成结晶低聚物。然而，超声处理后获得的聚合物链的迁移率较低，表明处理导致聚合物链结构有序化。此外，还观察到在超声处理后获得的复合材料中，PLGA 大分子的迁移率低于单独的 PLGA 中链的迁移率，这是由于 PLGA 和 HAp 之间的相互作用导致结构形成的结果。基于这些结果，可以预期复合材料中 PLGA 的降解速率不同，这对于将该材料应用于药物的控释药物输送中非常重要。
