Key Laboratory of Functional Polymer Materials and State Key Laboratory of Medicinal Chemical Biology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
School of Material Science and Engineering, Tiangong University, Tianjin 300387, China.
Biomacromolecules. 2021 Aug 9;22(8):3474-3485. doi: 10.1021/acs.biomac.1c00570. Epub 2021 Jul 22.
Three-dimensional (3D) multicellular spheroids are a new generation cell model, however, their applications are severely limited by difficulties in their generation. Here patterned poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel films were synthesized for their generation. Instead of polymerization of HEMA monomers in the presence of a cross-linker, here the PHEMA films were synthesized by cross-linking furan-functionalized linear PHEMA, PHEMA-furan, and maleimide-functionalized linear PHEMA, PHEMA-mal, via Diels-Alder (DA) reaction between furan and maleimide groups. A thermal treatment temperature of 75 °C was chosen for the cross-linking reaction. The occurrence of DA reaction was confirmed by IR spectra. Using this method, cross-linked PHEMA films with smooth surface were successfully synthesized in the well of cell culture plates. The films were then patterned by simply adding water to swell them. Highly ordered, honeycomb-like wrinkling patterns were successfully obtained by adjusting the furan and maleimide contents in the precursor linear polymers. The patterned hydrogel films were used to generate multicellular spheroids. Guided by the patterns, 3D spheroids with narrow size distribution, tunable size, and high cell viability were successfully obtained. The patterned PHEMA films reported here exhibited a lot of advantages. The patterning method was quite simple and required no template or special equipment. They were synthesized in commercial cell culture plates. Particularly, thanks to the clean nature of the DA reaction, no low molecular weight monomer, cross-linker, initiator, or catalyst, which were potentially cytotoxic, was involved in the film synthesis, and no byproduct was produced and left in the film. The resulting films presented a high biocompatibility, allowing the avoidance of the tedious washing step. The films synthesized here were expected to have high potential for massive production of well-defined multicellular spheroids.
三维（3D）多细胞球体是新一代细胞模型，然而，由于其生成困难，其应用受到严重限制。 在这里，图案化的聚（2-羟乙基甲基丙烯酸酯）（PHEMA）水凝胶膜被合成用于其生成。 在这里，不是在交联剂存在下聚合 HEMA 单体，而是通过呋喃功能化的线性 PHEMA、PHEMA-呋喃和马来酰亚胺功能化的线性 PHEMA、PHEMA-马来酰亚胺之间的 Diels-Alder（DA）反应来合成 PHEMA 膜。 选择 75°C 的热处理温度进行交联反应。 通过红外光谱确认了 DA 反应的发生。 使用这种方法，成功地在细胞培养板的孔中合成了具有光滑表面的交联 PHEMA 膜。 通过简单地加水使它们溶胀来对膜进行图案化。 通过调整前体线性聚合物中的呋喃和马来酰亚胺含量，成功获得了高度有序的、蜂窝状的褶皱图案。 使用图案化的水凝胶膜来生成多细胞球体。 通过图案的引导，成功获得了具有窄尺寸分布、可调尺寸和高细胞活力的 3D 球体。 这里报道的图案化 PHEMA 膜具有许多优点。 图案化方法非常简单，不需要模板或特殊设备。 它们是在商业细胞培养板中合成的。 特别是，由于 DA 反应的清洁性质，没有涉及可能具有细胞毒性的低分子量单体、交联剂、引发剂或催化剂，并且没有副产物产生并留在膜中。 所得膜具有高生物相容性，可避免繁琐的洗涤步骤。 预计这里合成的膜具有大规模生产定义明确的多细胞球体的巨大潜力。
