Gelatin methacryloyl (GelMA) hydrogel scaffolds and GelMA-based bioinks are widely used in tissue engineering and bioprinting due to their ability to support cellular functions and new tissue development. Unfortunately, while terminal sterilization of the GelMA is a critical step for translational tissue engineering applications, it can potentially cause thermal or chemical modifications of GelMA. Thus, understanding the effect of terminal sterilization on GelMA properties is an important, though often overlooked, aspect of material design for translational tissue engineering applications. To this end, we characterized the effects of FDA-approved terminal sterilization methods (autoclaving, ethylene oxide treatment, and gamma (γ)-irradiation) on GelMA prepolymer (bioink) and GelMA hydrogels in terms of the relevant properties for biomedical applications, including mechanical strength, biodegradation rate, cell culture in 2D and 3D, and printability. Autoclaving and ethylene oxide treatment of the GelMA decreased the stiffness of the hydrogel, but the treatments did not modify the biodegradation rate of the hydrogel; meanwhile, γ-irradiation increased the stiffness, reduced the pore size and significantly slowed the biodegradation rate. None of the terminal sterilization methods changed the 2D fibroblast or endothelial cell adhesion and spreading. However, ethylene oxide treatment significantly lowered the fibroblast viability in 3D cell culture. Strikingly, γ-irradiation led to significantly reduced ability of the GelMA prepolymer to undergo sol–gel transition. Furthermore, printability studies showed that the bioinks prepared from γ-irradiated GelMA had significantly reduced printability as compared to the GelMA bioinks prepared from autoclaved or ethylene oxide treated GelMA. These results reveal that the choice of the terminal sterilization method can strongly influence important properties of GelMA bioink and hydrogel. Overall, this study provides further insight into GelMA-based material design with consideration of the effect of terminal sterilization.

明胶甲基丙烯酰 (GelMA) 水凝胶支架和基于 GelMA 的生物墨水因其支持细胞功能和新组织发育的能力而广泛用于组织工程和生物打印。不幸的是，虽然 GelMA 的最终灭菌是转化组织工程应用的关键步骤，但它可能会导致 GelMA 的热或化学修饰。因此，了解最终灭菌对 GelMA 特性的影响是转化组织工程应用材料设计的一个重要方面，但经常被忽视。为此，我们描述了 FDA 批准的终端灭菌方法（高压灭菌、环氧乙烷处理、GelMA 预聚物（生物墨水）和 GelMA 水凝胶上的 γ（γ）辐照）在生物医学应用的相关性能方面，包括机械强度、生物降解率、2D 和 3D 细胞培养以及可印刷性。GelMA 的高压灭菌和环氧乙烷处理降低了水凝胶的刚度，但这些处理并未改变水凝胶的生物降解速率；同时，γ-辐照增加了刚度，减小了孔径并显着减慢了生物降解速率。没有一种终端灭菌方法改变了 2D 成纤维细胞或内皮细胞的粘附和扩散。然而，环氧乙烷处理显着降低了 3D 细胞培养中的成纤维细胞活力。引人注目的是，γ-辐照导致 GelMA 预聚物经历溶胶-凝胶转变的能力显着降低。此外，适印性研究表明，与由高压灭菌或环氧乙烷处理的 GelMA 制备的 GelMA 生物油墨相比，由 γ 辐照的 GelMA 制备的生物油墨的印刷适性显着降低。这些结果表明，终端灭菌方法的选择可以强烈影响 GelMA 生物墨水和水凝胶的重要特性。总体而言，本研究进一步深入了解基于 GelMA 的材料设计，并考虑了终端灭菌的影响。这些结果表明，终端灭菌方法的选择可以强烈影响 GelMA 生物墨水和水凝胶的重要特性。总体而言，本研究进一步深入了解基于 GelMA 的材料设计，并考虑了终端灭菌的影响。这些结果表明，终端灭菌方法的选择可以强烈影响 GelMA 生物墨水和水凝胶的重要特性。总体而言，本研究进一步深入了解基于 GelMA 的材料设计，并考虑了终端灭菌的影响。