This work investigates a sequential strategy to develop DNA-based hydrogel scaffolds with interpenetrating polymeric network. The scaffolds were formed via a two-step procedure. First, a covalently cross-linked DNA-based cryogel was formed by the chemical reaction between DNA strands and a bifunctional cross-linker, polyethylene glycol diepoxide at subzero temperatures. In the second step, alginate chains were absorbed into the preformed macroporous DNA cryogel network, followed by ionic cross-linking with divalent calcium ions. The individual and synergistic effects of covalent and ionic cross-linkings on mechanical and physical properties of the IPN cryogel were tested. The IPN cryogels were able to sustain large deformations higher than 95% of strain under compressive forces without exhibiting any failure. Addition of a physically cross-linked alginate network to the covalently linked DNA cryogel significantly enhanced its toughness and energy dissipation compared to the covalent network alone. The formulated hydrogels also exhibited excellent biocompatibility with human stem cells. Overall, this DNA-based IPN cryogel has the potential to be used as a biomaterial scaffold for a diverse range of tissue engineering applications.

中文翻译：

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以 DNA 为生物医学应用的主要网络制造坚韧的互穿网络冷冻凝胶

这项工作研究了开发具有互穿聚合物网络的基于 DNA 的水凝胶支架的顺序策略。通过两步程序形成支架。首先，通过 DNA 链与双功能交联剂聚乙二醇二环氧化物在零下温度下的化学反应形成共价交联的基于 DNA 的冷冻凝胶。在第二步中，海藻酸盐链被吸收到预先形成的大孔 DNA 冷冻凝胶网络中，然后与二价钙离子进行离子交联。测试了共价和离子交联对 IPN 冷冻凝胶的机械和物理性能的单独和协同影响。IPN 冷冻凝胶能够在压缩力下承受高于 95% 应变的大变形而不会出现任何故障。与单独的共价网络相比，将物理交联的海藻酸盐网络添加到共价连接的 DNA 冷冻凝胶中显着增强了其韧性和能量耗散。配制的水凝胶还表现出与人类干细胞的优异生物相容性。总体而言，这种基于 DNA 的 IPN 冷冻凝胶具有用作生物材料支架的潜力，可用于各种组织工程应用。