Tissue engineering aims to structurally and functionally regenerate damaged tissues, which requires the formation of new blood vessels that supply oxygen and nutrients by the process of angiogenesis. Stem cells are a promising tool in regenerative medicine due to their combined differentiation and paracrine angiogenic capacities. The study of their proangiogenic properties and associated potential for tissue regeneration requires complex in vivo models comprising all steps of the angiogenic process. The highly vascularized extraembryonic chorioallantoic membrane (CAM) of fertilized chicken eggs offers a simple, easy accessible, and cheap angiogenic screening tool compared to other animal models. Although the CAM assay was initially primarily performed for evaluation of tumor growth and metastasis, stem cell studies using this model are increasing. In this review, a detailed summary of angiogenic observations of different mesenchymal, cardiac, and endothelial stem cell types and derivatives in the CAM model is presented. Moreover, we focus on the variation in experimental setup, including the benefits and limitations of in ovo and ex ovo protocols, diverse biological and synthetic scaffolds, imaging techniques, and outcome measures of neovascularization. Finally, advantages and disadvantages of the CAM assay as a model for angiogenesis in tissue engineering in comparison with alternative in vivo animal models are described.

中文翻译：

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绒毛膜尿囊膜测定作为组织工程中血管生成的模型：专注于干细胞。

组织工程旨在在结构和功能上再生受损组织，这需要通过血管生成过程形成新的血管来供应氧气和营养。干细胞具有分化和旁分泌血管生成能力的组合，是再生医学中很有前景的工具。研究它们的促血管生成特性和相关的组织再生潜力需要复杂的体内模型包括血管生成过程的所有步骤。与其他动物模型相比，受精鸡蛋的高度血管化的胚外绒毛膜尿囊膜 (CAM) 提供了一种简单、易于获取且廉价的血管生成筛选工具。尽管 CAM 检测最初主要用于评估肿瘤生长和转移，但使用该模型的干细胞研究正在增加。在这篇综述中，详细总结了 CAM 模型中不同间充质、心脏和内皮干细胞类型和衍生物的血管生成观察结果。此外，我们关注实验设置的变化，包括卵内和卵外的优点和局限性协议、各种生物和合成支架、成像技术和新血管形成的结果测量。最后，描述了 CAM 测定作为组织工程血管生成模型与替代体内动物模型相比的优缺点。