Owing to its unique physiochemical properties similar to the extracellular matrix (ECM), three-dimensional (3D) crosslinked hydrogels are widely studied materials for tissue engineering. In this study, to mimic the ECM microenvironment, a two-step covalent cross-linking with hyaluronic acid and gelatin was performed to form an interpenetrating polymer network structure. Gelatin as the first network greatly improved the mechanical strength of the hydrogels, while a hyaluronic acid network as the second network improved the tenacity and biological activity. Compared with a single network hydrogel, the interpenetrating hydrogel system can further regulate the mechanical properties of the hydrogel by adjusting the ratio of the two components, thereby changing the proliferation, activity, and direction of cartilage differentiation of bone marrow mesenchymal stem cells (BMSCs). Not only that, with two culture methods for BMSCs on the surface and 3D wrapped in the double cross-linked hydrogels, they exhibited their potential to induce BMSCs to cartilage differentiation under the condition of 3D encapsulation of BMSCs and contact with BMSCs on its surface. As a scaffold material for cartilage tissue engineering, this double cross-linked hydrogel demonstrated its high feasibility and applicability in delivering BMSCs in vivo and repairing defects.

中文翻译：

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一种用于调节骨髓间充质干细胞生长和二维软骨分化的明胶-透明质酸双交联水凝胶。

由于其与细胞外基质 (ECM) 相似的独特理化性质，三维 (3D) 交联水凝胶是广泛研究的组织工程材料。在这项研究中，为了模拟 ECM 微环境，使用透明质酸和明胶进行两步共价交联，形成互穿聚合物网络结构。明胶作为第一个网络大大提高了水凝胶的机械强度，而透明质酸网络作为第二个网络提高了韧性和生物活性。与单一网络水凝胶相比，互穿水凝胶体系可以通过调节两种组分的比例来进一步调节水凝胶的力学性能，从而改变增殖、活性、骨髓间充质干细胞（BMSCs）的软骨分化方向和方向。不仅如此，通过表面和3D包裹在双交联水凝胶中的BMSCs两种培养方法，它们在3D包裹BMSCs并与表面BMSCs接触的条件下，表现出诱导BMSCs向软骨分化的潜力。作为软骨组织工程的支架材料，这种双交联水凝胶在输送骨髓间充质干细胞方面具有很高的可行性和适用性体内和修复缺陷。