Polyelectrolyte multilayers generated in a microfluidic device with pH gradients direct adhesion and movement of cells
Polyelectrolyte multilayers generated in a microfluidic device with pH gradients direct adhesion and movement of cells
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DOI：
10.1039/c1lc20408d
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发表时间：
2011-01-01
期刊：
影响因子：
6.1
通讯作者：
Groth, T.
中科院分区：
文献类型：
--
作者：
Kirchhof, K.;Andar, A.;Groth, T.
本研究以聚乙烯亚胺、肝素和壳聚糖为原料，在pH值为5、7和9的条件下制备了多层膜。水接触角和石英微天平测量结果表明，所得到的多层材料在润湿行为、层质量和机械性能方面存在差异。然后在梯度生成微流控（mu FL）装置内形成多层膜。将pH值为5的聚乙烯亚胺或肝素溶液引入一个进口，将pH值为9的相同溶液引入另一个进口。通过pH敏感荧光团和共聚焦激光扫描显微镜，可以在微室内看到多层形成过程中建立的pH梯度。通过这种设置，可以预期在不同pH值下显示的多层膜的性质可以在mu FL器件内以梯度方式实现。在mFL装置内形成的多层细胞上播种和培养的成骨细胞系MG-63的行为支持了这一假设。观察到更多的细胞粘附和扩散在多层膜上，而在pH 5下构建的多层膜上的细胞数量较少，体积较小。这些结果与MG-63细胞在离散pH值形成的多层膜上播种的行为一致。特别有趣的是，在6小时的培养过程中，细胞开始从pH为5的多层迁移到pH为9的多层。总的来说，提出的多层形成设置应用pH梯度导致表面，促进细胞的迁移。
In this study, multilayers from polyethylene imine, heparin and chitosan are prepared at three different pH values of 5, 7 and 9. Water contact angle and quartz microbalance measurements show that resulting multilayers differ in terms of wetting behaviour, layer mass and mechanical properties. The multilayer is then formed within a gradient generation microfluidic (mu FL) device. Polyethylene imine or heparin solutions of pH 5 are introduced into one inlet and the same solutions but at pH 9 into another inlet of the mu FL device. The pH gradient established during the multilayer formation can be visualized inside the microchamber by pH sensitive fluorophores and confocal laser scanning microscopy. From this setup it is expected that properties of multilayers displayed at distinct pH values can be realised in a gradient manner inside the mu FL device. Behaviour of the osteoblast cell line MG-63 seeded and cultured on top of multilayers created inside the mFL device support this hypothesis. It is observed that more cells adhere and spread on multilayers build-up at the basic side of the mu FL channel, while those cells on top of multilayers built at pH 5 are fewer and smaller. These results are consistent with the behaviour of MG-63 cells seeded on multilayers formed at discrete pH values. It is particularly interesting to see that cells start to migrate from multilayers built at pH 5 to those built at pH 9 during 6 h of culture. Overall, the presented multilayer formation setup applying pH gradients leads to surfaces that promote migration of cells.