Jones Caroline N, Lee Ji Youn, Zhu James, Stybayeva Gulnaz, Ramanculov Erlan, Zern Mark A, Revzin Alexander
Department of Biomedical Engineering, University of California, Davis, California 95616, USA.
Anal Chem. 2008 Aug 15;80(16):6351-7. doi: 10.1021/ac8007626. Epub 2008 Jul 22.
The microarray format is being used extensively for combinatorial screening of cellular interactions with proteins, small molecules, or biomaterials. The utility of microarray-based cell cultivation approaches may be enhanced further by incorporating biosensing elements alongside the cell-adhesive ligands to enable local detection of secreted cellular products. The concept of combining cells and sensing elements in the same microarray is demonstrated in the present paper with hepatocytes serving as a model cellular system. Robotic microarraying was employed to print arrays of 300-mum-diameter collagen (I) spots alongside the antibody (Ab) spots specific to liver proteins: albumin and alpha1-antitrypsin (alpha1-AT). Protein microarrays were printed onto poly(ethylene glycol) hydrogel-coated glass slides, thus eliminating nonspecific adsorption of cells or proteins. When incubated with printed microarrays, hepatocytes became localized on collagen (I) domains but did not attach on Ab spots or elsewhere on hydrogel-coated glass substrates. Liver-specific proteins secreted by hepatocytes were captured on Ab domains in the immediate vicinity of the cells, detected with a sandwich immunofluorescent assay and quantified using a microarray scanner. Importantly, hepatic albumin and alpha1-AT production detected in the microarray was comparable to enzyme-linked immunosorbent assay measurements of these proteins. In the future, the juxtaposition of sensing Ab regions with cell arrays will be particularly useful for the detection of local appearance or loss of phenotype of cells interacting with the printed components of the cellular microenvironment.
微阵列形式正被广泛用于对细胞与蛋白质、小分子或生物材料之间相互作用的组合筛选。通过将生物传感元件与细胞黏附配体结合，以便能够对分泌的细胞产物进行局部检测，基于微阵列的细胞培养方法的实用性可能会进一步提高。本文以肝细胞作为模型细胞系统，展示了在同一微阵列中结合细胞和传感元件的概念。采用机器人微阵列技术打印直径为300微米的胶原蛋白（I）斑点阵列，以及针对肝脏蛋白质白蛋白和α1-抗胰蛋白酶（α1-AT）的抗体（Ab）斑点。将蛋白质微阵列打印到聚（乙二醇）水凝胶包被的载玻片上，从而消除细胞或蛋白质的非特异性吸附。当与打印好的微阵列一起孵育时，肝细胞定位于胶原蛋白（I）区域，但不会附着在抗体斑点或水凝胶包被的玻璃基质的其他位置。肝细胞分泌的肝脏特异性蛋白质在细胞紧邻的抗体区域被捕获，通过夹心免疫荧光测定法进行检测，并使用微阵列扫描仪进行定量。重要的是，微阵列中检测到的肝脏白蛋白和α1-AT产量与这些蛋白质的酶联免疫吸附测定结果相当。未来，传感抗体区域与细胞阵列的并置对于检测与细胞微环境的打印成分相互作用的细胞的局部表型出现或丧失将特别有用。
