Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana.
Department of Chemical & Biomolecular Engineering, University of California, Berkeley, California.
J Biomed Mater Res B Appl Biomater. 2020 Jul;108(5):2294-2307. doi: 10.1002/jbm.b.34565. Epub 2020 Jan 21.
There is significant interest in developing new approaches for culturing mammalian cells in a three-dimensional (3D) environment due to the fact that it better recapitulates the in vivo environment. The goal of this work was to develop thiol-acrylate, biodegradable hydrogels that possess highly tunable properties to support in vitro 3D culture. Six different hydrogel formulations were synthesized using two readily available monomers, a trithiol (ETTMP 1300 [ethoxylated trimethylolpropane tri(3-mercaptopropionate) 1300]) and a diacrylate (PEGDA 700 [polyethylene glycol diacrylate 700]), polymerized by a base-catalyzed Michael addition reaction. The resultant hydrogels were homogeneous, hydrophilic, and biodegradable. Different mechanical properties such as gelation time, storage modulus (or the elasticity G'), swelling ratio, and rate of degradation were tuned by varying the weight percentage of polymer, the molar ratio of thiol-to-acrylate groups, and the pH of the solution. Cytocompatibility was assessed using two model breast cancer cell lines by both 2D and 3D cell culturing approaches. The hydrogel formulations with a thiol-to-acrylate molar ratio of 1.05 were found to be optimal for both 2D and 3D cultures with MDA-MB-231 cellular aggregates found to be viable after 17 days of 3D continuous culture. Finally, MCF7 cells were observed to form 3D spheroids up to 600 μm in diameter as proof of principle for the thiol-acrylate hydrogel to function as a scaffold for in vitro 3D cell culture. A comparison of the different mechanical properties of the six hydrogel formulations coupled with in vitro cell culture results and findings from previously published hydrogels conclude that the thiol-acrylate hydrogels have significant potential as a scaffold for 3D cell culture.
由于能够更好地模拟体内环境，因此人们对开发用于在三维（3D）环境中培养哺乳动物细胞的新方法产生了浓厚的兴趣。本工作的目的是开发具有高度可调特性的巯基-丙烯酰胺，可生物降解水凝胶，以支持体外 3D 培养。使用两种易得的单体，即三巯基（ETTMP 1300[乙氧基化三羟甲基丙烷三（3-巰基丙酸）1300]）和二丙烯酸酯（PEGDA 700[聚乙二醇二丙烯酸酯 700]），通过碱催化的迈克尔加成反应合成了六种不同的水凝胶配方。所得水凝胶均为均匀的亲水性和可生物降解的。通过改变聚合物的重量百分比，巯基与丙烯酰基的摩尔比以及溶液的 pH 值，可以调节不同的机械性能，例如凝胶时间，储能模量（或弹性 G'），溶胀比和降解速率。通过 2D 和 3D 细胞培养方法，使用两种模型乳腺癌细胞系评估细胞相容性。发现巯基-丙烯酰基摩尔比为 1.05的水凝胶配方对 2D 和 3D 培养均为最佳，在 3D 连续培养 17 天后发现 MDA-MB-231 细胞聚集体仍具有活力。最后，观察到 MCF7 细胞形成直径达 600μm的 3D 球体，证明了巯基-丙烯酰胺水凝胶作为体外 3D 细胞培养支架的原理。六种水凝胶配方的不同机械性能的比较，结合体外细胞培养结果和先前发表的水凝胶的发现，得出结论，巯基-丙烯酰胺水凝胶具有作为 3D 细胞培养支架的巨大潜力。
