News from the NNI Community - Research Advances Funded by Agencies Participating in the NNI

Engineers at the University of Illinois Urbana-Champaign have developed a method to visualize structures of small molecules clearly. The method is adapted from a technique, called cryogenic electron microscopy, which is used to capture high-quality images of the structures of larger molecules. But unlike large molecules, the imaging signals from small molecules are easily overwhelmed by their surroundings. So, the engineers used graphene – a single layer of carbon atoms that form a tight, hexagon-shaped honeycomb lattice – to temper the small molecules’ environment.

Researchers from The University of Texas at Austin and Xi’an Jiaotong University in China have created the first ever solid-state optical nanomotor. The nanomotor is less than 100 nanometers wide, and it can rotate on a solid substrate under light illumination and serve as a fuel-free and gear-free engine to convert light into mechanical energy. Nanomotors serve as a middle ground in scale between molecular machines at the smaller end and micro-engines at the larger end.

Researchers at Georgia State University have developed a new universal flu vaccine that offers broad defense against different strains of the influenza B virus. The double-layered protein nanoparticle vaccine, which is constructed with a stabilized portion of the influenza virus, induced broadly reactive immune responses and conferred robust and sustained cross-immune protection against the virus. The nanoparticle vaccine was tested in cell culture and in mice. 

Researchers from Tufts University describe some of the latest advances in wearable electronic devices and systems that are being developed using electrospinning – the fabrication of nanofibers with tunable properties from a polymer base – and showcase advantages electrospun materials have over conventional bulk materials. For example, their high surface-to-volume ratio endows them with enhanced porosity and breathability. Also, conductive electrospun nanofibers provide high-surface-area electrodes, enabling flexibility, rapid charging, and high energy storage.

Researchers at Penn State have combined laser writing and responsive sensor technologies to fabricate the first highly customizable microscale gas sensing devices. The researchers developed a process that enables the simultaneous creation and integration of metal oxides directly into sensor platforms. Metal oxides react to various compounds, triggering the sensing mechanism. With laser writing, the researchers dissolve metal salts in water, then focus the laser into the solution. The high temperature decomposes the solution, leaving behind metal oxide nanoparticles that can be sintered onto the sensor platform.

Researchers at the National Institute of Standards and Technology have discovered an unexpected property in a material called "SeedGel": Its temperature determines which color of light can pass through it.  In other words, shine white light at the gel, and depending on the gel's temperature, only a specific wavelength, or color, will pass through it. The material begins as a transparent fluid made of water and liquid solvents, with silica nanoparticles added. If this mix is heated to a certain temperature, the liquids and nanoparticles form a physical gel, which initially remains transparent but then its internal structure changes: the liquids form interlocking microscopic channels, with the nanoparticles confined within these channels. 

Researchers at Arizona State University and the Institute of Biophysics of the Czech Academy of Sciences have used crystallography techniques to describe the characteristics of 36 basic variants of the Holliday junction, which forms when two segments of double stranded DNA cross each other. The researchers showed that the effectiveness of a given Holliday junction for the construction of crystalline nanoarchitectures depends not only on the arrangement of the four nucleotide pairs forming the junction but also on sequences forming the junction's four protruding arms. In the case of the 36 variants of the Holliday junction, some DNA sequences acted to enhance the crystallization process of these forms, while six of the 36 Holliday junction variants failed to form crystals. 

Researchers from Rice University, Technion-Israel Institute of Technology, NASA Langley Research Center, the National Institute of Aerospace, and BNNT Materials, LLC, have reported that boron nitride nanotubes can assemble themselves into liquid crystals under the right conditions. These liquid crystals are easier to process than the tangled nanotubes that usually form in solution. Boron nitride nanotubes are like carbon nanotubes, but with alternating boron and nitrogen atoms, instead of carbon in their hexagonal lattices. 

As they grow, solid tumors surround themselves with a thick, hard-to-penetrate wall of molecular defenses. Getting drugs past that barricade is notoriously difficult. Now, scientists from the University of Texas Southwestern Medical Center and the University of Texas at Arlington have developed nanoparticles that can break down the physical barriers around tumors to reach cancer cells. Once inside, the nanoparticles released their payload: a gene editing system that alters DNA inside the tumor, blocking its growth, and activating the immune system.

Researchers from the University of Pittsburgh and Princeton University have unexpectedly discovered that two-dimensional polymer sheets can rise and rotate in spiral helices without the application of external power. Through computational modeling, the researchers placed passive, uncoated polymer sheets around a circular, catalytic patch within a fluid-filled chamber and then added hydrogen peroxide to initiate a catalytic reaction. They noticed that the polymer sheets autonomously self-assembled into a tower-like structure.