Microtissue Engineered Constructs with Living Axons for Targeted Nervous System Reconstruction
Microtissue Engineered Constructs with Living Axons for Targeted Nervous System Reconstruction
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DOI：
10.1089/ten.tea.2011.0534
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发表时间：
2012-11-01
影响因子：
4.1
通讯作者：
Smith, Douglas H.
中科院分区：
文献类型：
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作者：
Cullen, D. Kacy;Tang-Schomer, Min D.;Smith, Douglas H.
作为许多神经疾病和损伤的共同特征，轴突通路的丧失可以对功能产生毁灭性的影响。在这里，我们展示了一种新的策略，使用可移植的微型结构来恢复受损的轴突路径，该结构由水凝胶管中的活神经元和轴突束组成。这些水凝胶微导管是通过迭代过程开发的，以支持神经元存活和定向轴突生长。设计包括中空的琼脂糖管，提供一个相对坚硬的外壳，通过中央软胶原基质引导受约束的单向轴突生长，总尺寸为250微米内径×500微米外径，延伸至几厘米。外壳还被设计为在构建物移植期间为神经元/轴突培养提供结构支持。利用微导管优化的神经元培养条件，将分离的背根节神经元接种于微导管一端的胶原蛋白中。在接下来的一周里，高分辨率共聚焦显微镜显示，神经元存活下来，胞体保持在原始播种部位的紧密簇状。此外，还发现神经元的轴突生长旺盛，轴索束沿内胶原管呈纵向投射，长度超过5 mm。值得注意的是，这一一般几何学概括了轴突束的解剖结构。因此，这些结构可能有助于修复受损的轴突投影，因为它提供了一座可移植的活轴突桥梁。此外，该结构的小尺寸使微创移植到神经系统潜在敏感区域的后续研究成为可能。
As a common feature of many neurological diseases and injury, the loss of axon pathways can have devastating effects on function. Here, we demonstrate a new strategy to restore damaged axon pathways using transplantable miniature constructs consisting of living neurons and axonal tracts internalized within hydrogel tubes. These hydrogel microconduits were developed through an iterative process to support neuronal survival and directed axon growth. The design included hollow agarose tubes providing a relatively stiff outer casing to direct constrained unidirectional outgrowth of axons through a central soft collagen matrix, with overall dimensions of 250 mu m inner diameter x500 mu m outer diameter and extending up to several centimeters. The outer casing was also designed to provide structural support of neuronal/axonal cultures during transplantation of the construct. Using neuron culture conditions optimized for the microconduits, dissociated dorsal root ganglia neurons were seeded in the collagen at one end of the conduits. Over the following week, high-resolution confocal microscopy demonstrated that the neurons survived and the somata remained in a tight cluster at the original seeding site. In addition, robust outgrowth of axons from the neurons was found, with axon fascicles constrained in a longitudinal projection along the internal collagen canal and extending over 5 mm in length. Notably, this general geometry recapitulates the anatomy of axon tracts. As such, these constructs may be useful to repair damaged axon projections by providing a transplantable bridge of living axons. Moreover, the small size of the construct permits follow-on studies of minimally invasive transplantation into potentially sensitive regions of the nervous system.