Catching a virus in a molecular net.

A metal-organic molecular net composed of tannic acid (TA) and iron(iii) was constructed around the brome mosaic virus (BMV) particle to determine whether the added net could act as a transport barrier for water, and if the net could stabilize the virus in physically or chemically challenging environments. This new virus engineering strategy is expected to provide benefits both in the study and technological applications of viruses. For instance, a virus wrapped in a thin molecular layer could be extracted from solution either in air or vacuum, and its structure, composition and even internal dynamics could be interrogated by methods not compatible with a liquid environment. Atomic force microscopy (AFM) studies of Fe(iii)-TA coated BMV in liquid and in air supported a marked resistance to dehydration when compared to wtBMV. Native charge detection mass spectrometry (CDMS), was employed to estimate the number of molecules in the molecular net which wrapped the virus. The CDMS data suggested that less than one molecular monolayer wrapped the virus. Additionally, it was found, that this very thin molecular coat was sufficient to render the coated viruses resistant to storage conditions that typically lead to virus disassembly over time. A temporary coat imparting increased resistance to disassembly could be useful in adding time delay control or alleviate required storage conditions of engineered viruses for therapeutic purposes.

Nanoindentation of Isometric Viruses on Deterministically Corrugated Substrates.

It has been just over 100 years since inventor Joseph Coyle perfected the egg carton-a package format that has known very little changes since its first appearance ( Dhillon , S. B. C. Inventor Created Better Way to Carry Eggs. In The Globe and Mail Vancouver , 2013 ). In this article, we extend Coyle's old idea to the study of mechanical properties of viruses. Virus stiffness, strength, and breaking force obtained by force spectroscopy atomic force microscopy (AFM) provide the knowledge required for designing nanocontainers for applications in biotechnology and medicine, and for understanding the fundamentals of virus-host interaction such as virus translocation from one cellular compartment to another. In previous studies, virus particles adsorbed on flat surfaces from a physiological buffer were subjected to directional deformation by a known force exerted via a microscopic probe. The affinity between the virus shell and surface is required to be strong enough to anchor particles on the substrate while they are indented or imaged, yet sufficiently weak to preserve the native structure and interactions prior deformation. The specific question addressed here is whether an experimental scheme characterized by increased contact area and stable mechanical equilibrium under directional compression would provide a more reliable characterization than the traditional flat substrate approach.