Mechanisms and Application of Micropunctured Induced Angiogenesis for the Rapid Perfusion of Intraoperative Bioprinted Flaps

项目总结/摘要 这些进展已经允许在体外产生薄的血管化的替代移植物，但缺乏连续的血管化的替代移植物。 并且可折叠的脉管系统限制了尺寸的平移和放大。关于效用的知识很少 手术方法，以促进植入的工程组织迅速吻合。我们的长期目标 是发展外科策略，增加厚工程皮瓣的血管整合;这将 提供更多的临床相关性。本提案的目的是确定一个国家的机制和影响， 用于工程化脂肪的快速血管化的协调的手术和增材制造方法 皮瓣，这将适用于软组织重建。我们开发了一种创新的显微外科手术 策略，称为“血管微穿刺”，其增加大鼠受体的血管生成能力 血管，以便快速灌注相邻放置的不可折叠的薄工程化移植物。这导致 在24小时内的移植物灌注和新血管化加倍。如果与标准血管 插入导管（例如隐静脉），可用于延长受体蒂，它提供了一个 易于翻译的厚皮瓣工程方法。我们的核心假设是血管微穿刺 并且受体脉管系统的延长能够使厚脂肪的直接吻合和快速灌注 在术中用脂肪细胞/内皮祖细胞球体生物打印的皮瓣。基本原理是 这些研究的完成将揭示如何最好地优化互补策略， 同时进行原位组织工程。我们的中心假设将通过三个具体目标进行检验：1）证明 微穿刺通过允许立即单核细胞/巨噬细胞外渗来诱导血管生成; 2） 耐缺氧血管化脂肪移植物的高通量生物打印和体外测试; 3）协调 原位厚皮瓣生成和手术诱导的快速灌注。我们将使用新的方法来实现这些目标。 来自外科和工程科学的组合技术，包括最近开发的 显微手术和抽吸辅助生物打印方法。这项研究意义重大，因为它 将整合这些先进技术，在术中组装并快速灌注厚的工程皮瓣; 与通常描述的薄工程移植物相比，这是一个值得注意的进步。预期的结果是， 微穿刺诱导的血管生成将被确定和实验技术， 将确定工程组织融合。这些结果将产生积极的影响， 为大体积软组织缺损开发新的可移植重建方法奠定了基础。

PROJECT SUMMARY/ABSTRACT Advances have allowed for the in vitro creation of thin vascularized replacement grafts but lack of a continuous and anastomosable vasculature limits translation and scale-up of size. There is little knowledge about the utility of surgical approaches in facilitating prompt inosculation of implanted engineered tissues. Our long-term goal is to develop surgical strategies which augment the vascular integration of thick engineered flaps; which would offer more clinical relevance. The objective of this proposal is to define the mechanisms and impact of a coordinated surgical and additive manufacturing approach for the rapid vascularization of an engineered adipose flap, which would be applicable for soft tissue reconstruction. We have developed an innovative microsurgical tactic, termed “vascular micropuncture”, which increases the angiogenic capabilities of the rat recipient vasculature in order to quickly perfuse an adjacently placed un-anastomosable thin engineered graft. This results in graft perfusion within 24 hours and a doubling of neovascularization. If combined with standard vascular interposition conduits (e.g. saphenous vein), which can be used to lengthen the recipient pedicle, it offers an easily translatable approach for thick flap engineering. Our central hypothesis is that vascular micropuncture and lengthening of the recipient vasculature can enable direct inosculation and rapid perfusion of a thick adipose flap that is intraoperatively bioprinted with adipocyte/endothelial progenitor cell spheroids. The rationale is that completion of these studies will reveal how to best optimize complementary tactics for the inosculation of concurrently engineered in situ flaps. Our central hypothesis will be tested by three specific aims: 1) Demonstrate that micropuncture induces angiogenesis by allowing for immediate monocyte/macrophage extravasation; 2) High-throughput bioprinting and in vitro testing of a hypoxia-resistant vascularized adipose graft; 3) Coordinated in situ thick flap generation and surgically induced rapid perfusion. We will pursue these aims using novel combinatorial techniques from both the surgical and engineering sciences, including recently developed microsurgical and aspiration assisted bioprinting approaches. This proposed research is significant because it will integrate these advances to intraoperatively assemble and rapidly perfuse a thick engineered flap; a noteworthy advance from the often-described thin engineered graft. The expected outcome is that mechanisms of micropunctured induced angiogenesis will be identified and experimental techniques for augmenting engineered tissue inosculation will be determined. These results will have a positive impact by laying the foundation in developing new and translatable reconstructive approaches for large volume soft tissue loss.