Fibronectin immobilized by covalent conjugation or physical adsorption shows different bioactivity on aminated-PET
Fibronectin immobilized by covalent conjugation or physical adsorption shows different bioactivity on aminated-PET
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DOI：
10.1016/j.msec.2006.03.013
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发表时间：
2007-03
期刊：
影响因子：
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通讯作者：
Yue Zhang;C. Chai;Xuesong Jiang;S. Teoh;K. Leong
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文献类型：
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作者：
Yue Zhang;C. Chai;Xuesong Jiang;S. Teoh;K. Leong
为了控制细胞对合成表面的反应，细胞外基质(ECM)蛋白如纤维连接蛋白(FN)和胶原蛋白通常被固定在表面以促进这些配体和细胞受体之间的相互作用。在本研究中，我们比较了两种广泛使用的固定化技术：吸附和偶联技术制备的FN修饰的聚对苯二甲酸乙二醇酯(PET)的生物学性能。微米比辛酸(Micro-BCA)分析和原子力显微镜(AFM)分析表明，修饰后的表面形貌依赖于固定化方法。吸附方法保持了FN的致密构象，当FN形成单层膜时达到饱和。共价结合导致纤维连接蛋白的解折叠和纤维形成，形成多层纤维连接蛋白。通过对幼年仓鼠肾21(BHK21)细胞的黏附和对Arg-Gly-Asp(RGD)活性结构域的酶联免疫吸附试验(ELISA)的生物学特性表明，FN构象的不同导致了不同的生物活性。吸附维持了更活跃的RGD结构域，从而促进了细胞的黏附，而结合诱导了纤维形成并阻断了RGD的通路，从而随着FN表面密度的增加而抑制了细胞黏附。这项研究表明，除了选择黏附分子的性质外，固定化方式也可能显著影响表面的生物活性。
To manipulate the cellular response to synthetic surfaces, extracellular matrix (ECM) proteins such as fibronectin (FN) and collagen are often immobilized on the surface to promote interaction between these ligands and the cell receptors. In this study we compared the biological properties of FN-decorated polyethylene terephthalate (PET) produced by two widely used immobilization techniques: adsorption and conjugation. As revealed by the micro-bicinchoninic acid (micro-BCA) assay and AFM, the modified surface topography was dependent on the immobilization methods. Adsorption method preserved the compact conformation of FN, reaching saturation when a monolayer of FN was formed. Covalent conjugation induced FN unfolding and fibrillogenesis, forming multiple layers of FN. Biological characterization by adhesion of baby hamster kidney 21 (BHK21) cells and enzyme-linked immunosorbent assay (ELISA) for active Arg-Gly-Asp (RGD) domains suggested that the difference in conformation of FN led to different bioactivities. Adsorption maintained a more active RGD domain, thereby promoting cell adhesion, whereas conjugation induced fibrillogenesis and blocked the access of RGD, consequently suppressing cell adhesion as the surface density of FN increased. This study suggests that in addition to choosing the nature of the adhesion molecule, the mode of immobilization may also significantly influence the bioactivity of the surface.