Department of Industrial, Manufacturing, and Systems Engineering, Texas Tech University, Lubbock, Texas 79409, United States of America. These authors contributed equally to this study.
Biomed Mater. 2020 Aug 7;15(5):055021. doi: 10.1088/1748-605X/ab954e.
Photocrosslinkable polymers such as gelatin methacrylate (GelMA) have various 3D bioprinting applications. These polymers crosslink upon exposure to UV irradiation with the existence of an appropriate photoinitiator. Two photoinitiators, Irgacure 2959 and lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) are commonly used. This study systematically investigates the effects of photoinitiator types on the cell viability, physical properties, and microstructure in 3D bioprinting of GelMA-based cellular constructs. The main conclusions are: (1) during the 3D bioprinting, the cell viability generally decreases as the photoinitiator concentration and printing time increase using both Irgacure 2959 and LAP. At the low photoinitiator concentrations (such as 0.3% and 0.5% (w/v)), the overall cell viability is good within the printing time of 60 min using both Irgacure 2959 and LAP. However, at the high photoinitiator concentrations (such as 0.7% and 0.9% (w/v)), the overall cell viability using LAP is much higher than that using Irgacure 2959 within the printing time of 60 min; (2) after the 3D bioprinting, the photoinitiator types, either Irgacure 2959 or LAP, have negligible effects on the post-printing cell viability after crosslinking; (3) after the 3D bioprinting, GelMA samples cured with Irgacure 2959 have slightly larger pore size, faster degradation rate, and greater swelling ratio compared to those cured with LAP; (4) 3D GelMA-based vascular-like constructs have been fabricated using dynamic optical projection stereolithography, and the measured dimensions have been compared with the designed dimensions showing good shape fidelity.
光交联聚合物，如甲基丙烯酸明胶（GelMA），在各种 3D 生物打印应用中都有应用。这些聚合物在存在适当光引发剂的情况下，通过暴露于紫外光下交联。两种常用的光引发剂是 Irgacure 2959 和苯基-2,4,6-三甲基苯甲酰基膦酸锂（LAP）。本研究系统地研究了光引发剂类型对基于 GelMA 的细胞构建体的 3D 生物打印中的细胞活力、物理性能和微观结构的影响。主要结论如下：（1）在 3D 生物打印过程中，使用 Irgacure 2959 和 LAP 时，随着光引发剂浓度和打印时间的增加，细胞活力通常会降低。在低光引发剂浓度（如 0.3%和 0.5%（w/v））下，使用 Irgacure 2959 和 LAP 时，在 60 分钟的打印时间内，整体细胞活力良好。然而，在高光引发剂浓度（如 0.7%和 0.9%（w/v））下，在 60 分钟的打印时间内，使用 LAP 的整体细胞活力远高于使用 Irgacure 2959 的细胞活力；（2）3D 生物打印后，光引发剂类型（Irgacure 2959 或 LAP）对交联后的打印后细胞活力几乎没有影响；（3）3D 生物打印后，用 Irgacure 2959 固化的 GelMA 样品的孔径稍大、降解速度更快、溶胀率更高，而用 LAP 固化的 GelMA 样品则更小、降解速度更慢、溶胀率更低；（4）使用动态光学投影立体光刻技术制造了基于 3D GelMA 的血管样结构，并且已经测量了这些结构的尺寸，并与设计尺寸进行了比较，结果显示具有良好的形状保真度。
