Adsorption and Stability of Streptavidin on Cluster-Assembled Nanostructured TiOx Films

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• 作者：Luca Giorgetti ; Gero Bongiorno ; Alesssandro Podestà ; Giuseppe Berlanda ; Pasquale Emanuele Scopelliti ; Roberta Carbone ; Paolo Milani
• 刊名：Langmuir
• 出版年：2008
• 出版时间：October 21, 2008
• 年：2008
• 卷：24
• 期：20
• 页码：11637-11644
• 全文大小：301K
• 年卷期：v.24,no.20(October 21, 2008)
• ISSN：1520-5827

文摘

The study of the adsorption of proteins on nanostructured surfaces is of fundamental importance to understand and control cell−surface interactions and, notably, cell adhesion and proliferation; it can also play a strategic role in the design and fabrication of nanostructured devices for postgenomic and proteomic applications. We have recently demonstrated that cluster-assembled nanostructured TiO_x films produced by supersonic cluster beam deposition possess excellent biocompatibility and that these films can be functionalized with streptavidin, allowing the immobilization of biotinylated retroviral particles and the realization of living-cell microarrays for phenotype screening. Here we present a multitechnique investigation of the adsorption mechanisms of streptavidin on cluster-assembled TiO_x films. We show that this nanostructured surface provides an optimal balance between adsorption efficacy and protein functionality. By using low-resolution protein arrays, we demonstrate that a layer of adsorbed streptavidin can be stably maintained on a cluster-assembled TiO_x surface under cell culture conditions and that streptavidin retains its biological activity in the adsorbed layer. The adsorption mechanisms are investigated by atomic force microscopy in force spectroscopy mode and by valence-band photoemission spectroscopy, highlighting the potential role of the interaction of the exposed carboxyl groups on streptavidin with the titanium atoms of the nanostructured surface.