Abstract Bioresorbable polymers composed of Poly(lactide), Poly(glycolide) and their related copolymers have become increasingly popular for the preparation of bone substitute constructs. In vitro tests assessing the degradative changes in physicochemical, mechanical, and biological properties of bioresorbable polymers are generally carried out at 37 °C, in pH 7.4 phosphate-buffered saline (PBS). However, long degradation times, varying from months to years make it difficult to assess these polymers at their late stages of degradation. An increased temperature accelerated degradation methodology, that simulates the long-term degradation of Poly( d , l -lactide-co-glycolide) and Poly( l -lactide-co-glycolide), has been validated in this study. Samples were degraded in PBS, under sterile conditions. Degradation temperatures of 47 °C, 57 °C and 70 °C were selected and compared to physiological temperature, 37 °C. At predetermined time intervals, samples were retrieved and evaluated for changes in mass, swelling, molecular weight, crystallinity, and thermal properties. The results from this study suggest that the degradation mechanism at elevated temperatures is similar to that observed at 37 °C. It is recommended that 47 °C is adopted by the research community to accelerate the degradation of these polymers. It is hoped the application of this methodology could be used as a valuable tool, prior to the assessment of the long-term biocompatibility of these polymers.

中文翻译：

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聚（D,L-丙交酯-共-乙交酯）和聚（L-丙交酯-共-乙交酯）升温加速降解的比较

摘要 由聚丙交酯、聚乙交酯及其相关共聚物组成的生物可吸收聚合物在制备骨替代结构方面越来越受欢迎。评估生物可吸收聚合物的物理化学、机械和生物学特性的降解变化的体外测试通常在 37 °C、pH 7.4 磷酸盐缓冲盐水 (PBS) 中进行。然而，从几个月到几年不等的长降解时间使得在降解后期评估这些聚合物变得困难。本研究验证了一种模拟聚（d，l-丙交酯-共-乙交酯）和聚（l-丙交酯-共-乙交酯）长期降解的升温加速降解方法。在无菌条件下，样品在 PBS 中降解。降解温度为 47 °C，选择 57 °C 和 70 °C 并与生理温度 37 °C 进行比较。在预定的时间间隔，取回样品并评估质量、溶胀、分子量、结晶度和热性能的变化。这项研究的结果表明，高温下的降解机制与 37 °C 下观察到的类似。建议研究界采用 47 °C 来加速这些聚合物的降解。在评估这些聚合物的长期生物相容性之前，希望这种方法的应用可以作为一种有价值的工具。和热性能。这项研究的结果表明，高温下的降解机制与 37 °C 下观察到的类似。建议研究界采用 47 °C 来加速这些聚合物的降解。在评估这些聚合物的长期生物相容性之前，希望这种方法的应用可以作为一种有价值的工具。和热性能。这项研究的结果表明，高温下的降解机制与 37 °C 下观察到的类似。建议研究界采用 47 °C 来加速这些聚合物的降解。在评估这些聚合物的长期生物相容性之前，希望这种方法的应用可以作为一种有价值的工具。