Enhancing in vitro selection techniques to assist the discovery, understanding and use of inorganic binding peptides

Reflecting the increasing interest in combinatorial approaches, peptide phage display has seen an unprecedented expansion in a wide range of research areas. Its application to the discovery and analysis of metal binding peptides has opened up new research directions and largely contributed to the nanotechnology field. The rationale behind the need to identify such peptides varies depending on the final aim of the research and its application. Therefore, the possibility to modify the selection technique according to the different requirements would allow for a more systematic approach to be adopted and would ultimately provide substantial benefits. Although the standard panning method can be virtually applied to any target, its use for the identification of metal binding peptides does not provide the characteristics and the flexibility required for an efficient and tailored selection. Here we report on the development of a new panning method that can contribute to a faster, versatile and more informative analysis. Through the use of rolling-circle amplification, polymerase reaction and wild type phage, we have converted the standard selection technique into a more dynamic process in which adjustments can be evaluated and made consistently with the need of the experiment. The successfulness of the improved method is demonstrated in a number of panning experiments with different inorganic targets. The modifications applied to each selection are described and comparisons between the results obtained are made in order to extensively assess and evaluate the impact of the new process. The importance of tailoring the screening method to the specific objectives of a study is also considered. New binder sequences for the materials included in the investigation are identified; their sequences and distinctive characteristics are reported and their ability to act as templates for the nucleation of inorganic material is demonstrated and discussed.

Design and Synthesis of Functional Silsesquioxane-Based Hybrids by Hydrolytic Condensation of Bulky Triethoxysilanes

This paper presents a short overview of recent advances in the design and synthesis of organic-inorganic hybrids using silsesquioxane-based nanoparticles having nanometer size, relatively narrow size distribution, high functionalities, and various characteristic features, mainly focusing on our recent researches related to the subject. A highlight of this paper is the water-soluble silsesquioxane-based nanoparticles, including hydroxyl-functionalized and cationic silsesquioxanes, which were synthesized via the one-step condensation of the bulky triethoxysilane precursors. The design and synthesis of R-SiO1.5/SiO2and R-SiO1.5/TiO2hybrids by hydrolytic cocondensation of a triethoxysilane precursor and metal alkoxides are briefly introduced. This paper also deals with recent results in stimuli-responsive hybrids based on the water-soluble silsesquioxane nanoparticles and fluorinated and amphiphilic silsesquioxane hybrids.