Defects in the formation of microvascular networks, which provide oxygen and nutrients to cells, are the main reason for the engraftment failure of clinically applicable engineered tissues. Inflammatory responses and immunomodulation can promote the vascularization of the engineered tissues. We developed a capillary construct composed of a gelatin methacrylate-based cell-laden hydrogel framework complexed with interleukin-4 (IL-4)-loaded alginate-chitosan (AC) microspheres and endothelial progenitor cells (EPCs) and RAW264.7 macrophages as model cells. The AC microspheres maintained and guided the EPCs through electrostatic adhesion, facilitating the formation of microvascular networks. The IL-4-loaded microspheres promoted the polarization of the macrophages into the M2 type, leading to a reduction in pro-inflammatory factors and enhancement of the vascularization. Hematoxylin and eosin staining and immunohistochemical analysis revealed that, without IL-4 or AC microspheres, the scaffold was less effective in angiogenesis. We provide an alternative and promising approach for constructing vascularized tissues.

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评估负载白细胞介素 4 的海藻酸钠-壳聚糖微球对工程组织微血管化的支持

为细胞提供氧气和营养的微血管网络的形成缺陷是临床适用的工程组织植入失败的主要原因。炎症反应和免疫调节可以促进工程组织的血管化。我们开发了一种毛细血管结构，由基于明胶甲基丙烯酸酯的细胞负载水凝胶框架与负载白介素 4 (IL-4) 的藻酸盐壳聚糖 (AC) 微球和内皮祖细胞 (EPC) 以及 RAW264.7 巨噬细胞复合而成，作为模型细胞。AC 微球通过静电粘附维持和引导 EPC，促进微血管网络的形成。负载 IL-4 的微球促进巨噬细胞极化为 M2 型，导致促炎因子的减少和血管化的增强。苏木精和伊红染色和免疫组织化学分析表明，如果没有 IL-4 或 AC 微球，支架在血管生成中的效果较差。我们为构建血管化组织提供了一种替代且有前景的方法。