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。


本研究利用临床可转化技术，特别是环氧乙烷 (EtO) 和伽马 (γ) 辐照，研究了聚乙烯醇 (PVA) 生物材料最终灭菌的效果。虽然一些研究报道了用 γ 辐射对 PVA 进行灭菌的可能性，但使用 EtO 对 PVA 进行灭菌还需要进一步的研究。 PVA 溶液与三偏磷酸三钠和氢氧化钠进行化学交联。三个实验组包括未经处理的对照、EtO 和 γ 辐射，测试其膨胀程度和含水量，以及机械性能，如径向顺应性、纵向拉伸、最小弯曲半径、爆破压力和缝线保留强度。此外，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对样品进行了表征。使用内皮细胞系 EA.hy926 评估细胞附着，并使用活/死染色剂研究灭菌 PVA 的细胞毒性。使用离体分流狒狒模型测量血小板和纤维蛋白积累。最后，在大鼠皮下植入 21 天和狒狒植入 30 天后，对 PVA 植入物的免疫反应进行了分析。与 γ 辐照和未处理的 PVA 相比，EtO 灭菌降低了 PVA 接枝物的壁厚度、膨胀度和含水量。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-辐照增加了PVA的水接触角。 因此，内皮细胞在 EtO 灭菌的 PVA 上的附着显示出与未处理的 PVA 相似的结果，而细胞在 γ 照射的 PVA 上的附着显着改善。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 显示出最少的 MAC387 反应。本研究中的最终灭菌方法改变了PVA水凝胶的特性；然而，根据所进行的表征，两种灭菌方法都适合对 PVA 进行灭菌。我们得出结论，EtO 可以用作 PVA 水凝胶材料灭菌的替代方法。