Diagnostic Implementation of Fast and Selective Integrin-Mediated Adhesion of Cancer Cells on Functionalized Zeolite L Monolayers

The rapid and exact identification and quantification of specific biomarkers is a key technology for always achieving more efficient diagnostic methodologies. We present the first application of a nanostructured device constituted of patterned self-assembled monolayers of disk-shaped zeolite L coated with the cyclic integrin ligand c­[RGDfK] via isocyanate linker, to the rapid detection of cancer cells. With its high specificity toward HeLa and Glioma cells and fast adhesion ability, this biocompatible monolayer is a promising platform for implementation in diagnostics and personalized therapy formulation devices

Coverage-Dependent Disorder-to-Order Phase Transformation of a Uracil Derivative on Ag(111)

The self-organization of an angular bis­(uracil-ethynyl) benzene derivative is investigated on Ag(111) by means of scanning tunneling microscopy (STM) under ultrahigh vacuum (UHV) conditions. It is foundstarting at low submonolayer coveragethat upon increasing the molecular coverage a disorder-to-order phase transformation occurs. Specifically, at low and intermediate molecular coverage a glassy phase consisting of one-dimensional (1D) chains and 2D aggregates is observed, while close to a first complete molecular layer, a well-ordered 2D close-packed phase is revealed. The main driving forces responsible for the structure formation are (i) the high self-complementarity of the uracil (<b>U</b>) moiety, resulting in <b>U</b>–<b>U</b> homopairs through 2-fold CO···H–N H-bonds and (ii) the steric hindrance induced in the system by the alkyl chains. The delicate balance between the molecule–molecule and the molecule–substrate interactions leads to a complex phase behavior of the uracil derivative at the solid–vacuum interface. On the basis of this detailed study, we present a qualitative understanding of the peculiar phase behavior of the system

High Aspect Ratio Nanostructures Kill Bacteria <i>via</i> Storage and Release of Mechanical Energy

The threat of a global rise in the number of untreatable infections caused by antibiotic-resistant bacteria calls for the design and fabrication of a new generation of bactericidal materials. Here, we report a concept for the design of antibacterial surfaces, whereby cell death results from the ability of the nanofeatures to deflect when in contact with attaching cells. We show, using three-dimensional transmission electron microscopy, that the exceptionally high aspect ratio (100–3000) of vertically aligned carbon nanotubes (VACNTs) imparts extreme flexibility, which enhances the elastic energy storage in CNTs as they bend in contact with bacteria. Our experimental and theoretical analyses demonstrate that, for high aspect ratio structures, the bending energy stored in the CNTs is a substantial factor for the physical rupturing of both Gram-positive and Gram-negative bacteria. The highest bactericidal rates (99.3% for <i>Pseudomonas aeruginosa</i> and 84.9% for <i>Staphylococcus aureus</i>) were obtained by modifying the length of the VACNTs, allowing us to identify the optimal substratum properties to kill different types of bacteria efficiently. This work highlights that the bactericidal activity of high aspect ratio nanofeatures can outperform both natural bactericidal surfaces and other synthetic nanostructured multifunctional surfaces reported in previous studies. The present systems exhibit the highest bactericidal activity of a CNT-based substratum against a Gram-negative bacterium reported to date, suggesting the possibility of achieving close to 100% bacterial inactivation on VACNT-based substrata