DSM Ahead b.v., P.O. Box 18, 6160 MD Geleen, The Netherlands.
Biomaterials. 2010 Sep;31(26):6685-91. doi: 10.1016/j.biomaterials.2010.05.053. Epub 2010 Jun 17.
To reduce wear UHMwPE implants are commonly cross-linked by use of gamma or e-beam irradiation. After irradiation however, radicals are still present that may cause oxidative degradation of the polymer. A way to reduce oxidative degradation could be to add a stabilizer to the polymer. Currently Vitamin E is the state of the art in stabilizing irradiation cross-linked UHMwPE implants. However, this stabilizer has some drawbacks. It interferes with the cross-link chemistry, leading to a lower cross-link density, it will be consumed and it results in the discolouration of the UHMwPE compound due to Vitamin E conversion products. It has been shown that all these drawbacks can be overcome by using HALS stabilizers. Due to their different mechanism of action, HALS stabilizers do not interfere with the cross-link chemistry. As part of the stabilization mechanism the radical scavenging molecules are actually regenerated, which allows for using a lower total concentration. The HALS conversion products do not result in discoloration of the polymer compound. Although their biocompatibilities still have to be evaluated, HALS stabilizers are potential alternative stabilizers for UHMwPE implants.
为了减少磨损，超高分子量聚乙烯植入物通常通过伽马或电子束辐照进行交联。然而，辐照后仍存在自由基，可能导致聚合物发生氧化降解。减少氧化降解的一种方法是向聚合物中添加稳定剂。目前，维生素 E 是稳定辐照交联超高分子量聚乙烯植入物的最新技术。然而，这种稳定剂有一些缺点。它会干扰交联化学，导致交联密度降低，而且会被消耗掉，并且由于维生素 E 转化产物的原因导致 UHMwPE 化合物变色。已经表明，所有这些缺点都可以通过使用 HALS 稳定剂来克服。由于它们的作用机制不同，HALS 稳定剂不会干扰交联化学。作为稳定机制的一部分，自由基清除分子实际上会被再生，这允许使用较低的总浓度。HALS 转化产物不会导致聚合物化合物变色。尽管它们的生物相容性仍有待评估，但 HALS 稳定剂是 UHMwPE 植入物的潜在替代稳定剂。
