Although hydrogels are extensively investigated as biomaterials due to their ability to mimic cellular microenvironments, they are often limited by their poor physical properties in response to mechanical loads, including weak gel strength, brittleness, and permanent deformation. Recently, interpenetrating polymer network (IPN) hydrogels have gained substantial attention for their use in investigating changes in encapsulated cell behaviors under mechanical stimulation. However, despite recent success in developing highly elastic IPN-structured hydrogels, it remains a great technical challenge to endow them with biocompatibility and biodegradability due to use of toxic chemicals, nonbiodegradable prepolymers, and harsh reaction conditions. In this study, we report on the synthesis and formation of highly elastic and tough IPN-structured hydrogels based on alginate and gelatin, which are biocompatible and biodegradable. Mechanical stimulation enhanced the proliferation and osteogenic differentiation of encapsulated human mesenchymal stem cells in the IPN-structured hydrogels. These new biocompatible, biodegradable, and tough elastomeric hydrogels provide an exciting platform for studying stem cell behaviors such as proliferation and differentiation under mechanical stimulation and may broaden the applications of hydrogels in the fields of tissue engineering and regenerative medicine.

中文翻译：

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高弹性和韧性的互穿聚合物网络结构的混合水凝胶，用于循环机械负荷增强的组织工程

尽管水凝胶由于其模仿细胞微环境的能力而被广泛研究为生物材料，但它们通常受到响应于机械负荷（包括弱的凝胶强度，脆性和永久变形）的不良物理性能的限制。近年来，互穿聚合物网络（IPN）水凝胶因其在研究机械刺激下胶囊化细胞行为的变化方面的研究而受到广泛关注。然而，尽管最近在开发高弹性IPN结构水凝胶方面取得了成功，但由于使用有毒化学药品，不可生物降解的预聚物和苛刻的反应条件，使其具有生物相容性和可生物降解性仍是一项巨大的技术挑战。在这项研究中，我们报道了基于藻酸盐和明胶的高弹性和高韧性IPN结构水凝胶的合成和形成，它们具有生物相容性和可生物降解性。机械刺激增强了IPN结构水凝胶中封装的人间充质干细胞的增殖和成骨分化。这些新的生物相容性，可生物降解和坚韧的弹性体水凝胶为研究干细胞行为（如在机械刺激下的增殖和分化）提供了令人兴奋的平台，并可能扩大水凝胶在组织工程和再生医学领域的应用。机械刺激增强了IPN结构水凝胶中封装的人间充质干细胞的增殖和成骨分化。这些新的生物相容性，可生物降解和坚韧的弹性体水凝胶为研究干细胞行为（如在机械刺激下的增殖和分化）提供了令人兴奋的平台，并可能拓宽水凝胶在组织工程和再生医学领域的应用。机械刺激增强了IPN结构水凝胶中封装的人间充质干细胞的增殖和成骨分化。这些新的生物相容性，可生物降解和坚韧的弹性体水凝胶为研究干细胞行为（如在机械刺激下的增殖和分化）提供了令人兴奋的平台，并可能扩大水凝胶在组织工程和再生医学领域的应用。