Choi Seong Ying, Habimana Olivier, Flood Peter, Reynaud Emmanuel G, Rodriguez Brian J, Zhang Nan, Casey Eoin, Gilchrist Michael D
University College Dublin, College of Engineering and Architecture, School of Mechanical and Materials Engineering, Ireland.
University College Dublin, College of Engineering and Architecture, School of Chemical and Bioprocess Engineering, Ireland.
Colloids Surf B Biointerfaces. 2016 Sep 1;145:46-54. doi: 10.1016/j.colsurfb.2016.04.032. Epub 2016 Apr 19.
Two polymers, polymethylmethacrylate (PMMA) and cyclic olefin copolymer (COC), containing a range of nano- to micron- roughness surfaces (Ra 0.01, 0.1, 0.4, 1.0, 2.0, 3.2 and 5.0μm) were fabricated using electrical discharge machining (EDM) and replicated using micro injection moulding (μIM). Polymer samples were characterized using optical profilometry, atomic force microscopy (AFM) and water surface contact angle. Cell adhesion tests were carried out using bacterial Pseudomonas fluorescens and mammalian Madin-Darby Canine Kidney (MDCK) cells to determine the effect of surface hydrophobicity, surface roughness and stiffness. It is found that there are features which gave insignificant differences (feature-dependent effect) in cell adhesion, albeit a significant difference in the physicochemical properties (material-dependent effect) of substrata. In bacterial cell adhesion, the strongest feature-dependence is found at Ra 0.4μm surfaces, with material-dependent effects strongest at Ra 0.01μm. Ra 0.1μm surfaces exhibited strongest feature-dependent effects and Ra 5.0μm has strongest material-dependent effects on mammalian cell adhesion. Bacterial cell adhesion is found to be favourable to hydrophobic surfaces (COC), with the lowest adhesion at Ra 0.4μm for both materials. Mammalian cell adhesion is lowest in Ra 0.1μm and highest in Ra 1.0μm, and generally favours hydrophilic surfaces (PMMA). These findings can be used as a basis for developing medical implants or microfluidic devices using micro injection moulding for diagnostic purposes, by tuning the cell adhesion on different areas containing different surface roughnesses on the diagnostic microfluidic devices or medical implants.
使用放电加工（EDM）制造了两种聚合物，聚甲基丙烯酸甲酯（PMMA）和环烯烃共聚物（COC），它们具有一系列从纳米到微米级的粗糙度表面（Ra分别为0.01、0.1、0.4、1.0、2.0、3.2和5.0μm），并通过微注塑成型（μIM）进行复制。使用光学轮廓仪、原子力显微镜（AFM）和水表面接触角对聚合物样品进行表征。使用荧光假单胞菌和哺乳动物的马-达二氏犬肾（MDCK）细胞进行细胞粘附试验，以确定表面疏水性、表面粗糙度和硬度的影响。结果发现，尽管基质的物理化学性质存在显著差异（材料依赖性效应），但在细胞粘附中存在一些差异不显著的特征（特征依赖性效应）。在细菌细胞粘附中，在Ra 0.4μm的表面发现最强的特征依赖性效应，在Ra 0.01μm时材料依赖性效应最强。Ra 0.1μm的表面对哺乳动物细胞粘附表现出最强的特征依赖性效应，而Ra 5.0μm对其具有最强的材料依赖性效应。发现细菌细胞粘附有利于疏水表面（COC），两种材料在Ra 0.4μm时粘附力最低。哺乳动物细胞在Ra 0.1μm时粘附力最低，在Ra 1.0μm时最高，并且通常倾向于亲水表面（PMMA）。通过调节诊断微流控装置或医疗植入物上不同表面粗糙度区域的细胞粘附，这些发现可作为使用微注塑成型开发用于诊断目的的医疗植入物或微流控装置的基础。
