Dept. of Biomedical Engineering, Columbia University, New York, NY 10032, USA.
Biotechnol Prog. 2010 Mar-Apr;26(2):565-72. doi: 10.1002/btpr.337.
The requirements for engineering clinically sized cardiac constructs include medium perfusion (to maintain cell viability throughout the construct volume) and the protection of cardiac myocytes from hydrodynamic shear. To reconcile these conflicting requirements, we proposed the use of porous elastomeric scaffolds with an array of channels providing conduits for medium perfusion, and sized to provide efficient transport of oxygen to the cells, by a combination of convective flow and molecular diffusion over short distances between the channels. In this study, we investigate the conditions for perfusion seeding of channeled constructs with myocytes and endothelial cells without the gel carrier we previously used to lock the cells within the scaffold pores. We first established the flow parameters for perfusion seeding of porous elastomer scaffolds using the C2C12 myoblast line, and determined that a linear perfusion velocity of 1.0 mm/s resulted in seeding efficiency of 87% +/- 26% within 2 hours. When applied to seeding of channeled scaffolds with neonatal rat cardiac myocytes, these conditions also resulted in high efficiency (77.2% +/- 23.7%) of cell seeding. Uniform spatial cell distributions were obtained when scaffolds were stacked on top of one another in perfusion cartridges, effectively closing off the channels during perfusion seeding. Perfusion seeding of single scaffolds resulted in preferential cell attachment at the channel surfaces, and was employed for seeding scaffolds with rat aortic endothelial cells. We thus propose that these techniques can be utilized to engineer thick and compact cardiac constructs with parallel channels lined with endothelial cells.
工程化临床规模的心脏构建物的要求包括中等灌注（以维持整个构建物体积中的细胞活力）和保护心肌细胞免受流体剪切力的影响。为了协调这些相互冲突的要求，我们提出使用多孔弹性支架，其阵列中的通道提供了介质灌注的通道，并通过在通道之间的短距离内进行对流和分子扩散的组合，为细胞提供有效的氧气传输。在这项研究中，我们研究了在没有我们之前用于将细胞锁定在支架孔内的凝胶载体的情况下，用心肌细胞和内皮细胞对有通道的构建物进行灌注接种的条件。我们首先使用 C2C12 成肌细胞系建立了多孔弹性体支架灌注接种的流动参数，并确定线性灌注速度为 1.0mm/s 可在 2 小时内实现 87% +/- 26%的接种效率。当将这些条件应用于新生儿大鼠心肌细胞的有通道支架的接种时，也可获得 77.2% +/- 23.7%的高效细胞接种。当将支架堆叠在灌注盒中的彼此顶部时，可获得均匀的空间细胞分布，有效地在灌注接种期间封闭通道。当对单个支架进行灌注接种时，细胞优先附着在通道表面，并且可以用于接种大鼠主动脉内皮细胞的支架。因此，我们提出这些技术可用于工程化具有平行通道的厚而紧凑的心脏构建物，并在通道内排列内皮细胞。
