Endothelial cells guided by immobilized gradients of vascular endothelial growth factor on porous collagen scaffolds
Endothelial cells guided by immobilized gradients of vascular endothelial growth factor on porous collagen scaffolds
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DOI：
10.1016/j.actbio.2011.05.002
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发表时间：
2011-08-01
影响因子：
9.7
通讯作者：
Radisic, Milica
中科院分区：
文献类型：
--
作者：
Odedra, Devang;Chiu, Loraine L. Y.;Radisic, Milica
组织工程学中的一个关键挑战是克服支架内部由于氧气和营养物质的有限扩散而导致的细胞死亡。我们在这里假设，将生长/存活因子的梯度从多孔支架的外围固定到中心，将引导内皮细胞进入支架内部，从而克服坏死的核心。用三种方法之一将蛋白质固定在多孔胶原支架上，用于心血管组织工程。这些蛋白质首先用1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/sulfo N-羟基琥珀酰亚胺活化，然后通过三种方法之一应用到支架上，以建立梯度：灌流(流动法)、使用源和汇(源-汇法)或通过在支架中心注入5亩L溶液(点源法)。由于点源方法的高度重复性和易于应用，它还被用于VEGF-165梯度的形成，其中在支架上沿径向形成类似于2ngml(-1)mm(-1)的梯度，直径12 mm，厚度2.5 mm。与均匀固定的血管内皮生长因子165(具有相同的总血管内皮生长因子浓度)和不含血管内皮生长因子的对照组相比，血管内皮生长因子165梯度引导更多的内皮细胞深入支架中心。所有支架(包括对照组)都产生了相同数量的细胞，但值得注意的是，VEGF-165梯度支架中心的细胞密度更高。因此，我们得出结论，血管内皮生长因子-165梯度促进了细胞向支架内的迁移，而不是增殖。这些梯度支架为未来的体内组织工程研究奠定了基础。(C)2011 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
A key challenge in tissue engineering is overcoming cell death in the scaffold interior due to the limited diffusion of oxygen and nutrients therein. We here hypothesize that immobilizing a gradient of a growth/ survival factor from the periphery to the center of a porous scaffold would guide endothelial cells into the interior of the scaffold, thus overcoming a necrotic core. Proteins were immobilized by one of three methods on porous collagen scaffolds for cardiovascular tissue engineering. The proteins were first activated with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/sulfo N-hydroxysuccinimide and then applied to the scaffold by one of three methods to establish the gradient: perfusion (the flow method), use of a source and a sink (the source-sink method) or by injecting 5 mu l of the solution at the center of the scaffold (point source method). Due to the high reproducibility and ease of application of the point source method it was further used for VEGF-165 gradient formation, where an similar to 2 ng ml(-1) mm(-1) gradient was formed in a radial direction across a scaffold, 12 mm in diameter and 2.5 mm thick. More endothelial cells were guided by the VEGF-165 gradient deep into the center of the scaffold compared with both uniformly immobilized VEGF-165 (with the same total VEGF concentration) and VEGF-free controls. All scaffolds (including the controls) yielded the same number of cells, but notably the VEGF-165 gradient scaffolds demonstrated a higher cell density in the centre. Thus we concluded that the VEGF-165 gradient promoted the migration, but not proliferation, of cells into the scaffold. These gradient scaffolds provide the foundation for future in vivo tissue engineering studies. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.