EAGER: High-Throughput Bioprinting of Vascularized Living Tissue

制造血管化活组织的能力将使药物筛选、组织修复和再生方面取得重大进展。组织工程传统上依赖于非细胞支架的使用。然而，由于缺乏稳定的、可灌注的脉管系统和无法复制复杂的多细胞结构，这种方法极大地限制了可以创建的组织的大小和复杂性。血管网络是活组织的核心，因为所有细胞必须居住在离营养供应几百微米的范围内才能生存。该奖项支持对一种新的增材制造工艺的科学研究，该工艺用于制造由细胞、细胞外基质和嵌入血管组成的三维血管化活组织。这项研究的结果将使3D活体组织在制药行业的药物安全性和毒性筛选中得到更广泛的应用，并最终用于组织修复和再生的医学。这项研究将建立在器官尺度上血管化活组织生物打印所需的基础科学认识。打印组织中细胞、细胞外基质和脉管系统之间复杂的相互作用将被确定。这些关系将通过通过活/死染色定量细胞活力作为不同细胞类型、浓度和细胞外基质组成的函数来建立。血管网络结构的影响，包括血管大小、间距和分支程度，对细胞活力和功能的影响也将通过活/死来量化，同时，血管通道的屏障功能将通过标准泄漏测试来测量，作为不同建筑图案的功能。最后，对于不同细胞类型、浓度和细胞外基质组成的细胞负载油墨，将确定喷嘴尺寸、设计和打印速度之间的关系，以确定在生物打印和长时间灌注过程中，通过活/死染色确定促进最大细胞活力的必要条件。

The ability to fabricate vascularized living tissues would enable critical advances in drug screening, tissue repair and regeneration. Tissue engineering has traditionally relied on the use of acellular scaffolds. However, this approach vastly limits the size and complexity of the tissues that can be created due to the lack of stable, perfusable vasculature and the inability to replicate intricate multicellular configurations. Vasculature networks are central to living tissues, since all cells must reside within several hundred micrometers of a nutrient supply to survive. This award supports scientific investigations on a new additive manufacturing process for fabricating three-dimensional, vascularized living tissues composed of cells, extracellular matrix, and embedded blood vessels. Results from this research will enable broader use of 3D living tissues in the pharmaceutical industry for drug safety and toxicity screening and, ultimately, in the medicine for tissue repair and regeneration.This research will establish the fundamental scientific understanding required for bioprinting of vascularized living tissue at organ scale. The complex interplay between cells, extracellular matrix, and vasculature in printed tissues will be determined. These relationships will be established by quantifying cell viability via live/dead staining as a function of varying cell type, concentration, and extracellular matrix composition. The effects of vascular network architecture, including blood vessel size, spacing, and degree of branching, on cell viability and function will also be quantified by live/dead and, concurrently, barrier function of the vascular channels will be measured by a standard leak test as a function of different architectural motifs. Finally, the relationship between nozzle size, design, and printing speed will be determined for cell-laden inks of varying cell type, concentration, and extracellular matrix composition to identify the requisite conditions that promote maximum cell viability, as determined by live/dead staining, during bioprinting and perfusion over long time periods.