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

University of Texas at Dallas scientists have discovered a previously unknown "housekeeping" process in kidney cells that ejects unwanted content, resulting in cells that rejuvenate themselves and remain functioning and healthy. The scientists focused on gold nanoparticles, which are used as imaging agents, and investigated how they are filtered by the kidneys and cleared from the body through urine. "In the field of nanomedicine, we want to minimize accumulation of nanoparticles in the body as much as possible," said Jie Zheng, one of the scientists involved in this study. “We don't want them to get stuck in the kidneys, so it's very important to understand how nanoparticles are eliminated from the proximal tubules.”

Researchers at Washington University in St. Louis have pioneered a new technique that will enable higher-resolution imaging of very small objects, such as neurons. The technique uses ultrabright fluorescent markers, called plasmonic-fluors, that are constructed from a nanoparticle of gold wrapped in a silver shell, which is then covered with a layer of light-emitting markers, called fluorophores. Interactions between the gold-silver nanoparticle and the fluorophores causes the fluorophores to emit more photons than they normally would. As a result, the plasmonic-fluor is nearly four orders of magnitude brighter than the fluorescent markers would be on their own. 

Rice University scientists have used light-activated molecular machines to trigger intercellular calcium wave signals, revealing a powerful new strategy for controlling cellular activity. "Most of the drugs developed up to this point use chemical binding forces to drive a specific signaling cascade in the body," said Jacob Beckham, the lead author on the study. "This is the first demonstration that, instead of chemical force, you can use mechanical force – induced, in this case, by single-molecule nanomachines – to do the same thing, which opens up a whole new chapter in drug design."

Researchers at Columbia University have shown that tiny organic transistors enabled an implanted device to acquire and transmit neurophysiologic brain signals while simultaneously providing power to the implanted device. The researchers used advanced nanofabrication techniques to miniaturize and densify these transistors at sub-micrometer scales. The researchers also demonstrated that these implants can be made soft and conformable and can record and transmit high-resolution neural activity from both outside, on the surface of the brain, as well as inside, deep within the brain. 

Researchers at the Massachusetts Institute of Technology have created a technique that allows individual halide perovskite nanocrystals to be grown on-site where needed with precise control over location to within less than 50 nanometers. The researchers used this technique to create arrays of nanoscale light-emitting diodes (LEDs) – tiny crystals that emit light when electrically activated. Such arrays could have applications in optical communication and computing, lensless microscopes, new types of quantum light sources, and high-density, high-resolution displays for augmented and virtual reality.

Researchers from Oregon State University; Columbia University; the U.S. Department of Energy’s Pacific Northwest National Laboratory; and Chemspeed Technologies AG in Switzerland have demonstrated the potential of an inexpensive nanomaterial to scrub carbon dioxide from industrial emissions. The nanomaterial, known as a metal-organic framework, can intercept carbon dioxide molecules through adsorption as flue gases make their way through smokestacks. Unlike other metal-organic frameworks, this one works well in damp conditions and prefers carbon dioxide to nitrogen, which is important because nitrogen oxides are an ingredient in flue gases. 

Researchers at the National Institute of Standards and Technology have designed a method that uses a high-intensity laser to blast microscale projectiles into a small sample at velocities that approach the speed of sound. The system analyzes the energy exchange between the microscale projectiles and the sample of interest at the micro level and then uses scaling methods to predict the puncture-resistance of the sample material against larger energetic projectiles, such as bullets encountered in real-world situations. The researchers used this new method to evaluate several materials, including a widely used compound for bulletproof glass, a novel nanocomposite, and the strong, all-carbon nanomaterial known as graphene.

Chemists at Clemson University have constructed a novel two-dimensional electrically conductive metal-organic framework – a breakthrough that could help advance modern electronics and energy technologies. Metal-organic frameworks are nano-sized architectures that look like miniature buildings made of metal ions linked by organic ligands. The structures are mostly hollow and porous, so they can store guest molecules, catalyze chemical reactions, and deliver drugs in a controlled manner. The conductivity of the new metal-organic framework is 10 to 15 times higher than the parent metal-organic framework.  

During the infamous Terra Nova Expedition to Antarctica in 1911, British geologist Thomas Griffith Taylor made a mysterious discovery at the rocky base of the glacier that now bears his name: a waterfall of what appeared to be blood. Now, using powerful transmission electron microscopes, researchers at Johns Hopkins University; the Planetary Science Institute in Tucson, AZ; Mount Holyoke College in South Hadley, MA; and the College of Charleston in Charleston, SC, have examined solids in samples of Blood Falls' water and found an abundance of tiny, iron-rich nanospheres that oxidize, turning the water seemingly gory.

Researchers at New York University Abu Dhabi have developed a new rapid testing method for COVID-19 – an adhesive bandage that relies on gold nanoparticles to quickly detect antibodies in the bloodstream produced as a result of a COVID-19 infection. On the surface of the nanoparticles are molecules called antigens that recognize the antibodies with high specificity and sensitivity. A color change indicates a person’s infection status – not infected or infected with an immune response – within minutes.