UCL Division of Surgery and Interventional Sciences, Tissue Repair and Engineering Centre, Brockley Hill, Stanmore Campus, London HA74LP, UK.
J Control Release. 2010 Sep 15;146(3):309-17. doi: 10.1016/j.jconrel.2010.05.037. Epub 2010 Jun 9.
The full sequence of signals leading to new blood vessel formation is a physiological response to tissue hypoxia through upregulation of angiogenic factor cascades. Controlled initiation of this mechanism for therapeutic/engineered angiogenesis must rely on precisely localized hypoxia. Here we have designed a 3D in vitro model able to test the effect and predictability of spatially positioned local hypoxic stimuli using defined cell depots within a 3D collagen matrix. Cell-mediated hypoxia was engineered using human dermal fibroblasts (HDFs), to generate a local population of Hypoxia-Induced Signaling (HIS) cells. HIS cell depots released angiogenic factors which induced directional endothelial cell (EC) migration and tubule formation in a spatially defined assay system. Non-hypoxic baseline control cultures induced minimal EC migration with little tubule formation. Furthermore, depots of HIS cells, positioned in the core of 3D collagen constructs directed host vessel in-growth deep into the implant by 1 week, which was at least 7 days earlier than in non-hypoxia pre-conditioned constructs. The functionality of in vivo vascularisation was verified by real-time monitoring of O2 levels in the core of implanted constructs. These findings establish the angiogenic potential of HIS cells applicable to in vitro tissue modeling, implant vascularization and engineering predictable angiogenic therapies.
导致新血管形成的完整信号序列是组织缺氧通过上调血管生成因子级联反应的生理反应。为了治疗/工程血管生成而控制该机制的启动必须依赖于精确的局部缺氧。在这里,我们设计了一种 3D 体外模型,该模型能够使用 3D 胶原基质中的定义细胞库来测试空间定位局部缺氧刺激的效果和可预测性。使用人真皮成纤维细胞 (HDF) 设计了细胞介导的缺氧,以产生局部缺氧诱导信号 (HIS) 细胞群。HIS 细胞库释放的血管生成因子在空间定义的分析系统中诱导定向内皮细胞 (EC) 迁移和管腔形成。非缺氧基线对照培养物诱导的 EC 迁移很少,管腔形成也很少。此外,HIS 细胞库位于 3D 胶原构建物的核心位置,可在 1 周内将宿主血管引导至植入物内部,比非缺氧预处理构建物至少早 7 天。通过实时监测植入物核心中的 O2 水平,验证了体内血管生成的功能。这些发现确立了 HIS 细胞的血管生成潜力,适用于体外组织建模、植入物血管化和工程化可预测的血管生成疗法。