Liu Chun-Yen, Matsusaki Michiya, Akashi Mitsuru
Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
ACS Biomater Sci Eng. 2015 Aug 10;1(8):639-645. doi: 10.1021/acsbiomaterials.5b00015. Epub 2015 Jul 15.
In the field of tissue engineering, fabrication of millimeter- or centimeter-sized three-dimensional (3D) human tissues with controlled 3D cell density, 3D cell components, and 3D cell locations has been a goal of researchers. In this study, we fabricated collagen nanofiber layers of varying thicknesses on cell surfaces by previously reported collagen-coating techniques and then constructed millimeter-sized 3D human tissues, controlling the 3D cell-cell distance. In these 3D tissues, cells in the constructed 3D tissues kept a constant cell-cell distance after 24 h of incubation. Thickness of the obtained 3D tissues was controlled successfully by altering the number of cells seeded and coating times. The maximum thickness was over 2 mm when coating was carried out three times. Cell-cell distance was also controllable from approximately 15-30 μm. When cells coated once and twice with collagen nanofibers were used for the continuous construction of 3D tissues, millimeter-sized 3D tissues with areas of different cell density were obtained. The interfaces between higher and lower cell density areas were slightly mixed, but more than 80% viability was maintained after 4 days of incubation. The results suggested that stable millimeter-sized 3D tissues can be achieved using collagen nanofiber-coated cells. In addition, 3D tissues constructed by collagen-coated iPS-CM and human cardiac fibroblast were also successful.
在组织工程领域，制造具有可控三维细胞密度、三维细胞成分和三维细胞位置的毫米级或厘米级三维人体组织一直是研究人员的目标。在本研究中，我们通过先前报道的胶原包被技术在细胞表面制备了不同厚度的胶原纳米纤维层，然后构建了毫米级三维人体组织，控制三维细胞间距离。在这些三维组织中，构建的三维组织中的细胞在培养24小时后保持恒定的细胞间距离。通过改变接种细胞数量和包被次数成功控制了所得三维组织的厚度。当进行三次包被时，最大厚度超过2毫米。细胞间距离也可控制在约15 - 30微米。当用胶原纳米纤维包被一次和两次的细胞用于连续构建三维组织时，获得了具有不同细胞密度区域的毫米级三维组织。较高和较低细胞密度区域之间的界面略有混合，但在培养4天后仍保持超过80%的活力。结果表明，使用胶原纳米纤维包被的细胞可以实现稳定的毫米级三维组织。此外，由胶原包被的诱导多能干细胞来源的心肌细胞（iPS-CM）和人心脏成纤维细胞构建的三维组织也取得了成功。
