Lipophilicity of Cationic Ligands Promotes Irreversible Adsorption of Nanoparticles to Lipid Bilayers.

A mechanistic understanding of the influence of the surface properties of engineered nanomaterials on their interactions with cells is essential for designing materials for applications such as bioimaging and drug delivery as well as for assessing nanomaterial safety. Ligand-coated gold nanoparticles have been widely investigated because their highly tunable surface properties enable investigations into the effect of ligand functionalization on interactions with biological systems. Lipophilic ligands have been linked to adverse biological outcomes through membrane disruption, but the relationship between ligand lipophilicity and membrane interactions is not well understood.

Influence of Sensor Coating and Topography on Protein and Nanoparticle Interaction with Supported Lipid Bilayers.

Supported lipid bilayers (SLBs) have proven to be valuable model systems for studying the interactions of proteins, peptides, and nanoparticles with biological membranes. The physicochemical properties (, topography, coating) of the solid substrate may affect the formation and properties of supported phospholipid bilayers, and thus, subsequent interactions with biomolecules or nanoparticles. Here, we examine the influence of support coating (SiO SiN) and topography [sensors with embedded protruding gold nanodisks for nanoplasmonic sensing (NPS)] on the formation and subsequent interactions of supported phospholipid bilayers with the model protein cytochrome and with cationic polymer-wrapped quantum dots using quartz crystal microbalance with dissipation monitoring and NPS techniques.

Interfacial water and ion distribution determine ζ potential and binding affinity of nanoparticles to biomolecules.

The molecular features that dictate interactions between functionalized nanoparticles and biomolecules are not well understood. This is in part because for highly charged nanoparticles in solution, establishing a clear connection between the molecular features of surface ligands and common experimental observables such as ζ potential requires going beyond the classical models based on continuum and mean field models. Motivated by these considerations, molecular dynamics simulations are used to probe the electrostatic properties of functionalized gold nanoparticles and their interaction with a charged peptide in salt solutions.

Peroxymonosulfate Oxidizes Amino Acids in Water without Activation.

A variety of peptidic and proteinaceous contaminants (e.g., proteins, toxins, pathogens) present in the environment may pose risk to human health and wildlife.

Tracking the Invasion of Small Numbers of Cells in Paper-Based Assays with Quantitative PCR.

Paper-based scaffolds are an attractive material for culturing mammalian cells in a three-dimensional environment. There are a number of previously published studies, which utilize these scaffolds to generate models of aortic valves, cardiac ischemia and reperfusion, and solid tumors. These models have largely relied on fluorescence imaging and microscopy to quantify cells in the scaffolds.