Department of Plastic and Hand Surgery, University Hospital of Erlangen, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Erlangen, Germany.
Department of Materials Science and Engineering for Metals, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
J Biomed Mater Res A. 2022 Sep;110(9):1551-1563. doi: 10.1002/jbm.a.37395. Epub 2022 Apr 28.
The arteriovenous (AV) loop model is a key technique to solve one of the major problems of tissue engineering-providing adequate vascular support for a tissue construct of significant size. However, the molecular and cellular mechanisms of vascularization and factors influencing the generation of new tissue in the AV loop are still poorly understood. We previously established a novel intravital microscopy approach to study these events. In this study, we implanted our observation chamber filled with two types of hydrogels such as fibrin and methacrylate gelatin (GelMA) and performed intravital microscopy (IVM) on days 7, 14, and 21. Initial microvessel formation was observed in GelMA on day 14, while the vessel network showed clear indicators of network rearrangement and maturation on day 21. No visible microvessels were observed in fibrin. The chambers were explanted on day 21. Histological examination revealed higher numbers of microvessels in GelMA compared to fibrin, while the AV loop was thrombosed in all fibrin constructs, possibly due to matrix degradation. GelMA proved to be an ideal matrix for IVM studies in the AV loop model due to its slow degradation and transparency. This IVM model can be employed as a novel tool for live and thus faster comprehension of crucial events in the tissue regeneration process, which can improve tissue engineering application.
动静脉（AV）环模型是解决组织工程的一个主要问题的关键技术——为具有显著尺寸的组织构建体提供足够的血管支持。然而，血管生成的分子和细胞机制以及影响 AV 环中新组织生成的因素仍知之甚少。我们之前建立了一种新的活体显微镜方法来研究这些事件。在这项研究中，我们植入了充满两种水凝胶（纤维蛋白和甲基丙烯酰化明胶（GelMA）的观察室，并在第 7、14 和 21 天进行了活体显微镜检查（IVM）。第 14 天在 GelMA 中观察到初始微血管形成，而在第 21 天，血管网络显示出明显的网络重排和成熟迹象。在纤维蛋白中未观察到可见的微血管。第 21 天取出腔室。组织学检查显示 GelMA 中的微血管数量明显多于纤维蛋白，而所有纤维蛋白构建体中的 AV 环都发生了血栓形成，可能是由于基质降解。GelMA 因其缓慢的降解和透明度而被证明是 AV 环模型中 IVM 研究的理想基质。这种 IVM 模型可以作为一种新的工具，用于活体观察，从而更快地理解组织再生过程中的关键事件，从而提高组织工程的应用。
