Shape-memory hydrogels (SMHs) have been used for various biomedical applications, such as injectable scaffolds in noninvasive procedures and as carriers for drugs and stem cells. However, most SMH studies have investigated properties related to shape recovery rather than bioactivities governed by hydrogel micro/nanostructure. In this study, one of the main structural proteins in tissues and organs, collagen, was incorporated into SMHs, and by varying the fabrication procedure, two different collagen-based SMHs were obtained. The first was a collagen Cryo-gel that could immediately recover its programmed shape. The second was a fibrous collagen gel (F-gel) fabricated by collagen fibrillation that required more time for recovery but possessed a much higher shape fixity ratio and better supported cell adhesion and growth in vitro. To combine the advantages of the two hydrogels, we fabricated a new collagen-based biocomposite that incorporated fibrillated collagen and photo-crosslinkable methacrylated collagen (Col-ma). A collagen/Col-ma ratio of 5:5 was the most favorable for shape recovery and cellular activity.

中文翻译：

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基于胶原蛋白的形状记忆生物复合材料

形状记忆水凝胶 (SMH) 已用于各种生物医学应用，例如无创手术中的可注射支架以及药物和干细胞的载体。然而，大多数 SMH 研究调查了与形状恢复相关的特性，而不是水凝胶微/纳米结构控制的生物活性。在这项研究中，组织和器官中的主要结构蛋白之一，胶原蛋白，被纳入 SMHs，并通过改变制造程序，获得了两种不同的基于胶原蛋白的 SMHs。第一个是胶原蛋白冷冻凝胶，可以立即恢复其编程形状。第二种是通过胶原纤维化制备的纤维胶原凝胶 (F-gel)，它需要更多的恢复时间，但具有更高的形状固定率，更好地支持体外细胞粘附和生长。为了结合这两种水凝胶的优点，我们制造了一种新的基于胶原蛋白的生物复合材料，其中包含原纤维化胶原蛋白和可光交联的甲基丙烯酸化胶原蛋白 (Col-ma)。5:5 的胶原蛋白/Col-ma 比例最有利于形状恢复和细胞活性。