Centre for Therapeutic Innovation, Department of Mechanical Engineering, University of Bath, Bath, UK.
J Biomater Appl. 2021 Apr;35(9):1168-1179. doi: 10.1177/0885328220977353. Epub 2020 Dec 26.
Ultra-high molecular weight polyethylene (UHMWPE) can be made radiopaque for medical imaging applications through the diffusion of an iodised oil-based contrast agent (Lipiodol Ultra Fluid). A similar process is used for Vitamin E incorporated polyethylene which provides antioxidant properties. This study aimed to investigate the critical long-term properties of oil-infused medical polyethylene after 4 weeks of accelerated thermal ageing. Samples treated with an oil (Vitamin E or Lipiodol) had a higher oxidation stability than currently used medical grade polyethylene, indicated by a smaller increase in oxidation index after ageing (Vitamin E + 36%, Lipiodol +40%, Untreated +136%, Thermally treated +164%). The tensile properties of oil treated polyethylene after ageing were significantly higher than the Untreated and Thermally treated controls (p<0.05) indicating less mechanical degradation. There was also no alteration in the percentage crystallinity of oil treated samples after ageing, though the radiopacity of the Lipiodol treated samples reduced by 54% after ageing. The leaching of oil with time was also investigated; the leaching of Lipiodol and Vitamin E followed the same trend and reached a steady state by two weeks. Overall, it can be concluded that the diffusion of an oil-based fluid into polyethylene not only increases the oxidative and chemical stability of polyethylene but also adds additional functionality (e.g. radiopacity) providing a more suitable material for long-term medical applications.
超高分子量聚乙烯（UHMWPE）可通过扩散碘油基造影剂（Lipiodol Ultra Fluid）使其具有医学成像应用的放射可检测性。类似的过程也用于维生素 E 结合的聚乙烯，它提供抗氧化性能。本研究旨在研究经过 4 周加速热老化后注入油的医用聚乙烯的关键长期性能。用油（维生素 E 或 Lipiodol）处理的样品的氧化稳定性高于目前使用的医用级聚乙烯，这表现为老化后氧化指数的增加较小（维生素 E + 36%，Lipiodol +40%，未处理 +136%，热处理 +164%）。老化后油处理聚乙烯的拉伸性能明显高于未处理和热处理对照物（p<0.05），表明机械降解较少。油处理样品的结晶度百分比在老化后也没有变化，尽管经过老化后 Lipiodol 处理的样品的放射可检测性降低了 54%。还研究了油随时间的浸出；Lipiodol 和维生素 E 的浸出遵循相同的趋势，并在两周内达到稳定状态。总的来说，可以得出结论，将油基流体扩散到聚乙烯中不仅可以提高聚乙烯的氧化和化学稳定性，还可以增加额外的功能（例如放射可检测性），为长期医疗应用提供更合适的材料。
