Mixed Alkanethiol Monolayers on Submicrometric Gold Patterns: A Controlled Platform for Studying Cell–Ligand Interactions

Abstract

Nanoscale organization of surface ligands often has a critical effect on cell-surface interactions. We have developed an experimental system that allows a high degree of control over the 2-D spatial distribution of ligands. As a proof of concept, we used the developed system to study how T-cell activation is independently affected by antigen density and antigen amount per cell. Arrays of submicrometer gold islands at varying surface coverage were defined on silicon by electron beam lithography (EBL). The gold islands were functionalized with alkanethiol self-assembled monolayers (SAMs) containing a small antigen, 2,4,6-trinotrophenyl (TNP), at various densities. Genetically engineered T-cell hybridomas expressing TNP-specific chimeric T-cell antigen receptor (CAR) were cultured on the SAMs, and their activation was assessed by IL-2 secretion and CD69 expression. It was found that, at constant antigen density, activation increased monotonically with the amount of antigen, while at constant antigen amount activation was maximal at an intermediate antigen density, whose value was independent of the amount of antigen.

Antigen-Dependent Integration of Opposing Proximal TCR-Signaling Cascades Determines the Functional Fate of T Lymphocytes

“…First, before applying CTLs to peptide-pulsed target cells, the peptide is washed away so only the defined peptide levels, as measured by the HLA-A2-restricted peptide-specific Abs, are present on the cell surface. Second, we (19) showed previously that hyporesponsiveness to high Ag doses also was observed in assays in which the pMHC was covalently immobilized to a surface and, thus, CTLs cannot capture the peptides.…”

Highly Sensitive Chemical Detection with Tunable Sensitivity and Selectivity from Ultrathin Platinum Nanowires

“…Our results demonstrate successful integration of separation and detection in a hybrid structure at molecular level, indicating promising potential for ligand engineering of metal nanostructures for a variety of chemical sensing applications. Moreover, similar ligand functionalization could be potentially used for other purposes such as molecular recognition, through incorporating other techniques such as grafting of a recognition motif or molecular imprinting …”

Degradation of alkanethiol self‐assembled monolayers in mesenchymal stem cell culture

“…Alkanethiol self-assembled monolayers (SAMs) have been used extensively to formulate surfaces with unique functionalities for studies involving cell culture. 2,3,[14][15][16][17] These unique functionalities arise from the synthesis of alkanethiols with various head groups 18,19 and chain lengths, 19 which have been shown to influence cell behavior. More recently, development of single-cell protein patterns using various alkanethiol SAM patterning approaches has been explored as a method of examining the effects of geometry on stem cell differentiation.…”

“…Investigating how to best optimize the cellular microenvironment in order to promote the desired stem cell response is an active area of research. Alkanethiol self‐assembled monolayers (SAMs) have been used extensively to formulate surfaces with unique functionalities for studies involving cell culture . These unique functionalities arise from the synthesis of alkanethiols with various head groups and chain lengths, which have been shown to influence cell behavior.…”