Nahmias Yaakov, Schwartz Robert E, Verfaillie Catherine M, Odde David J
Department of Biomedical Engineering, University of Minnesota, Minneapolis, 55455, USA.
Biotechnol Bioeng. 2005 Oct 20;92(2):129-36. doi: 10.1002/bit.20585.
One of the principal limitations to the size of an engineered tissue is oxygen and nutrient transport. Lacking a vascular bed, cells embedded in an engineered tissue will consume all available oxygen within hours while out branching blood vessels will take days to vascularize the implanted tissue. One possible solution is to directly write vascular structures within the engineered tissue prior to implantation, reconstructing the tissue according to its native architecture. The cell patterning technique, laser-guided direct writing (LGDW), can pattern multiple cells types with micrometer resolution on arbitrary surfaces, including biological gels. Here we show that LGDW can pattern human umbilical vein endothelial cells (HUVEC) in two- and three-dimensions with micrometer accuracy. By patterning HUVEC on Matrigel, we can direct their self-assembly into vascular structures along the desired pattern. Finally, co-culturing the vascular structures with hepatocytes resulted in an aggregated tubular structure similar in organization to a hepatic sinusoid. This capability can facilitate studies of tissue architecture at the single cell level, and of heterotypic interactions underlying processes such as liver and pancreas morphogenesis, differentiation, and angiogenesis.
工程组织大小的主要限制之一是氧气和营养物质的运输。由于缺乏血管床，嵌入工程组织中的细胞会在数小时内消耗所有可用的氧气，而向外生长的血管则需要数天时间才能使植入组织血管化。一种可能的解决方案是在植入前直接在工程组织内构建血管结构，根据其天然结构重建组织。细胞图案化技术，即激光引导直接写入（LGDW），可以在包括生物凝胶在内的任意表面上以微米分辨率对多种细胞类型进行图案化。在这里，我们展示了LGDW可以在二维和三维空间中以微米精度对人脐静脉内皮细胞（HUVEC）进行图案化。通过在基质胶上对HUVEC进行图案化，我们可以引导它们沿着所需图案自组装成血管结构。最后，将血管结构与肝细胞共培养，形成了一种聚集的管状结构，其组织结构类似于肝血窦。这种能力有助于在单细胞水平上研究组织结构，以及研究肝脏和胰腺形态发生、分化和血管生成等过程背后的异型相互作用。
