Despite significant progress in the fabrication of prevascularized networks over the past decade, a number of challenges remain. One of the most relevant issues is the lack of three-dimensional (3D) structures, which limits the clinical applications of the engineered scaffolds. Another problem is the complexity of prevascularized networks in engineered scaffolds, which is still less than that of human tissues, especially in the case of mature and bulk tissues. Thus, there is still the need to develop more flexible methods to better simulate the structure of natural tissues. In this work, we used a versatile sacrificial template method to fabricate bulk scaffolds with spatial prevascularized networks. Soft poly(vinyl alcohol) (PVA) filaments were used to print the sacrificial template, and the receiving platform was a stepped shaft, allowing the sacrificial template to have a complex 3D structure. The obtained template was embedded into gelatin and microbial transglutaminase (mTG). The inner PVA template could be extracted from the enzymatic cross-linking system, and an engineered scaffold with spatial prevascularized networks was obtained. In vitro experiments demonstrated that the fabrication process is biocompatible with cells.

中文翻译：

---

具有空间预血管化网络的工程支架的表征，用于大量组织的再生。

尽管在过去十年中在血管形成前网络的制造方面取得了重大进展，但仍然存在许多挑战。最相关的问题之一是缺乏三维（3D）结构，这限制了工程支架的临床应用。另一个问题是工程支架中的血管形成前网络的复杂性，仍然比人体组织的复杂性要低，尤其是在成熟和块状组织的情况下。因此，仍然需要开发更灵活的方法来更好地模拟天然组织的结构。在这项工作中，我们使用了一种多功能的牺牲模板方法来制造具有空间血管前网络的散装支架。使用柔软的聚乙烯醇（PVA）细丝打印牺牲模板，接收平台为阶梯状轴，允许牺牲模板具有复杂的3D结构。将获得的模板嵌入明胶和微生物转谷氨酰胺酶（mTG）中。可以从酶促交联体系中提取内部PVA模板，并获得具有空间血管前网络的工程支架。体外实验表明，制备过程与细胞具有生物相容性。