Nanoscale objects are typically internalized by cells into membrane-bounded endosomes and fail to access the cytosolic cell machinery. Whereas some biomacromolecules may penetrate or fuse with cell membranes without overt membrane disruption, no synthetic material of comparable size has shown this property yet. Cationic nano-objects pass through cell membranes by generating transient holes, a p...

century. The process involved polishing a silver coated copper plate, made photo sensitive by exposure to halogens, then exposed to light, and finally coated with gold. This complex, intricate process has yielded some of the most iconic images of the 19 th century. Unfortunately, in some instances plate interaction with storage materials have yielded objects ranging from pristine to disfigured....

In this paper, we present an analysis of electromagnetic scattering from arbitrarily shaped three-dimensional (3D) conducting objects coated with dielectric materials. The integral equation treated here is the combined field integral equation (CFIE). The objective of this paper is to illustrate that only the CFIE formulation is a valid methodology in removing defects, which occur at a frequency...

In recent years, fluorescence microscopy has enabled researchers to observe the dynamics of clathrin-coated pit (CCP) assembly in real time. The assembly dynamics of CCPs shows striking heterogeneity. Some CCPs are long-lived (productive CCPs); they bind cargo and grow in size to form clathrin-coated vesicles. In contrast, other CCPs (abortive CCPs) are relatively short-lived and disassemble we...

Actin polymerization has been shown to be sufficient to propel curved objects, for example beads and vesicles coated with the Listeria monocytogenes protein ActA. Recent studies suggest that actin polymerization on flat surfaces can also provide the propulsive force to push them forward.

We use multipolar expansions to find the force on a gold coated sphere above a gold substrate; we study both an empty gold shell and a gold coated polystyrene sphere. We find four characteristic separation ranges. In the first region, which for the empty gold shell occurs for distances, d, smaller than the thickness of the coating, the result agrees with that on a solid gold sphere and varies a...

The formation of clathrin-coated pits at the plasma membrane requires the concerted action of many different molecules. The real challenge lies in determining the hierarchy of these interactions. We are using assays in both intact and permeabilized cells to dissect the temporal requirements for clathrin-coated vesicle formation, and also to examine the role of phosphorylation of the coat proteins.

The precise sequence of events promoting clathrin-coated vesicle assembly is still debated. In this issue, Kadlecova et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201608071) test structural models using quantitative microscopy in living cells to investigate the hierarchy and temporal importance of molecular events required for clathrin-coated pit initiation.