Nanobioengineering group, Institute for Bioengineering of Catalonia, Baldiri i Reixac 10-12, 08028 Barcelona, Spain.
J Biomed Mater Res A. 2011 Aug;98(2):245-56. doi: 10.1002/jbm.a.33089. Epub 2011 May 27.
Cellular microarray developments and its applications are the next step after DNA and protein microarrays. The choice of the surface chemistry of the substrates used for the implementation of this technique, that must favor proper protein immobilization while avoiding cell adhesion on the nonspotted areas, presents a complex challenge. This is a key issue since usually the best nonfouling surfaces are also the ones that retain immobilized the smallest amounts of printed protein. To quantitatively assess the amount of protein immobilization, in this study several combinations of fluorescently labeled fibronectin (Fn*) and streptavidin (SA*) were microspotted, with and without glycerol addition in the printing buffer, on several substrates suitable for cellular microarrays. The substrates assayed included chemically activated surfaces as well as Poly ethylene oxide (PEO) films that are nonfouling in solution but accept adhesion of proteins in dry conditions. The results showed that the spotted Fn* was retained by all the surfaces, although the PEO surface did show smaller amounts of immobilization. The SA*, on the other hand, was only retained by the chemically activated surfaces. The inclusion of glycerol in the printing buffer significantly reduced the immobilization of both proteins. The results presented in this article provide quantitative evidence of the convenience of using a chemically activated surface to immobilize proteins relevant for cellular microarray applications, particularly when ECM proteins are cospotted with smaller factors which are more difficult to be retained by the surfaces.
细胞微阵列的发展及其应用是继 DNA 和蛋白质微阵列之后的下一步。用于实施该技术的基底的表面化学的选择是一个复杂的挑战，必须有利于适当的蛋白质固定化，同时避免非斑点区域的细胞黏附。这是一个关键问题，因为通常最好的非粘性表面也是保留固定化的打印蛋白质量最少的表面。为了定量评估蛋白质固定化的量，在这项研究中，在几种适用于细胞微阵列的基底上，分别用和不用打印缓冲液中的甘油，微点了几种荧光标记的纤维连接蛋白（Fn*）和链霉亲和素（SA*）的组合。所测定的基底包括化学活化表面以及聚环氧乙烷（PEO）薄膜，这些薄膜在溶液中是无粘性的，但在干燥条件下可以接受蛋白质的黏附。结果表明，尽管 PEO 表面的固定化量较小，但所有表面都保留了点样的 Fn*。另一方面，SA*仅被化学活化表面保留。在打印缓冲液中加入甘油显著降低了两种蛋白质的固定化。本文提供的结果提供了定量证据，证明使用化学活化表面来固定与细胞微阵列应用相关的蛋白质是方便的，特别是当细胞外基质蛋白与更难以被表面保留的较小因子共同点样时。
