This study investigated the effects of terminal sterilization of polyvinyl alcohol (PVA) biomaterials using clinically translatable techniques, specifically ethylene oxide (EtO) and gamma (γ) irradiation. While a few studies have reported the possibility of sterilizing PVA with γ-radiation, the use of EtO sterilization of PVA requires additional study. PVA solutions were chemically crosslinked with trisodium trimetaphosphate and sodium hydroxide. The three experimental groups included untreated control, EtO, and γ-irradiation, which were tested for the degree of swelling and water content, and mechanical properties such as radial compliance, longitudinal tensile, minimum bend radius, burst pressure, and suture retention strength. In addition, samples were characterized with scanning electron microscopy, differential scanning calorimetry, X-ray photoelectron spectroscopy, and water contact angle measurements. Cell attachment was assessed using the endothelial cell line EA.hy926, and the sterilized PVA cytotoxicity was studied with a live/dead stain. Platelet and fibrin accumulation was measured using an ex vivo shunt baboon model. Finally, the immune responses of PVA implants were analyzed after a 21-day subcutaneous implantation in rats and a 30-day implantation in baboon. EtO sterilization reduced the PVA graft wall thickness, its degree of swelling, and water content compared with both γ-irradiated and untreated PVA. Moreover, EtO sterilization significantly reduced the radial compliance and increased Young's modulus. EtO did not change PVA hydrophilicity, while γ-irradiation increased the water contact angle of the PVA. Consequently, endothelial cell attachment on the EtO-sterilized PVA showed similar results to the untreated PVA, while cell attachment significantly improved on the γ-irradiated PVA. When exposing the PVA grafts to circulating whole blood, fibrin accumulation of EtO-sterilized PVA was found to be significantly lower than γ-irradiated PVA. The immune responses of γ-irradiated PVA, EtO-treated PVA, and untreated PVA were compared. Implanted EtO-treated PVA showed the least MAC387 reaction. The terminal sterilization methods in this study changed PVA hydrogel properties; nevertheless, based on the characterizations performed, both sterilization methods were suitable for sterilizing PVA. We concluded that EtO can be used as an alternative method to sterilize PVA hydrogel material.

中文翻译：

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与伽马辐射相比，环氧乙烷灭菌对聚乙烯醇水凝胶的影响。

本研究使用可临床转化的技术，特别是环氧乙烷 (EtO) 和伽马 (γ) 辐射，研究了聚乙烯醇 (PVA) 生物材料的最终灭菌效果。虽然一些研究报告了用 γ 辐射对 PVA 进行消毒的可能性，但使用 EtO 对 PVA 进行消毒需要额外的研究。PVA 溶液与三偏磷酸三钠和氢氧化钠进行化学交联。三个实验组包括未处理的对照组、EtO 和 γ 辐照，分别测试溶胀程度和含水量，以及径向柔量、纵向拉伸、最小弯曲半径、爆破压力和缝合线保留强度等机械性能。此外，样品还通过扫描电子显微镜、差示扫描量热法、X 射线光电子能谱和水接触角测量。使用内皮细胞系 EA.hy926 评估细胞附着，并用活/死染色研究灭菌的 PVA 细胞毒性。血小板和纤维蛋白的积累使用离体分流狒狒模型。最后，在大鼠皮下植入 21 天和狒狒植入 30 天后，分析了 PVA 植入物的免疫反应。与 γ 辐照和未处理的 PVA 相比，EtO 灭菌降低了 PVA 移植物的壁厚、膨胀程度和含水量。此外，EtO 灭菌显着降低了径向顺应性并增加了杨氏模量。EtO 没有改变 PVA 的亲水性，而 γ 辐射增加了 PVA 的水接触角。因此，EtO 灭菌的 PVA 上的内皮细胞附着显示出与未处理的 PVA 相似的结果，而细胞附着在 γ 辐照的 PVA 上显着改善。当将 PVA 移植物暴露于循环全血时，发现 EtO 灭菌的 PVA 的纤维蛋白积累显着低于 γ 辐照的 PVA。比较了 γ 辐照的 PVA、EtO 处理的 PVA 和未处理的 PVA 的免疫反应。植入的 EtO 处理的 PVA 表现出最少的 MAC387 反应。本研究中的终端灭菌方法改变了 PVA 水凝胶的特性；尽管如此，根据所进行的表征，两种灭菌方法都适用于对 PVA 进行灭菌。我们得出结论，EtO 可用作对 PVA 水凝胶材料进行消毒的替代方法。两种灭菌方法都适用于 PVA 的灭菌。我们得出结论，EtO 可用作对 PVA 水凝胶材料进行消毒的替代方法。两种灭菌方法都适用于 PVA 的灭菌。我们得出结论，EtO 可用作对 PVA 水凝胶材料进行消毒的替代方法。