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

Researchers from the University of Connecticut; Harvard University; the Massachusetts Institute of Technology; RTX BBN Technologies in Arlington, VA; and the National Institute for Materials Science in Tsukuba, Japan, have discovered that electrons in twisted trilayer graphene behave unlike those described by Bardeen-Cooper-Schrieffer theory of paired electrons. However,  twisted trilayer graphene shares properties with high-temperature cuprates, in which electrons also pair up, but differently from traditional superconductors. Many previous studies in graphene are limited in describing superconductivity, because those experiments focus on the properties of single electrons rather than electron pairs, says Pavel Volkov, one of the researchers involved in this study. "What matters is that electrons form pairs, and somehow you want to probe the properties of those pairs to be able to study superconductivity,” he says.

Researchers at the University of Pennsylvania have demonstrated that ferumoxytol, an U.S. Food and Drug Administration-approved iron oxide nanoparticle formulation, greatly reduces infection in patients diagnosed with apical periodontitis. The researchers showed that topical applications of ferumoxytol in combination with hydrogen peroxide potently disrupt biofilms – dense, sticky communities of bacteria that attach to surfaces and cause infections. The researchers treated 44 patients with periapical periodontitis and found that patients who received ferumoxytol/hydrogen peroxide achieved a 99.9% reduction in bacterial counts without experiencing any adverse effects.

Researchers from Cedars-Sinai Cancer; Caltech; California State University, Northridge; and Technion-Israel Institute in Haifa, Israel, have designed nanobioparticles that can cross the protective blood–brain barrier and deliver therapy directly into cancerous tumor cells. The findings could help clinicians target brain tumors previously unreachable by chemotherapy. The investigators conducted experiments using a unique blood-brain barrier "organ chip." When investigators flowed the nanobioparticles through the blood vessel portion of the chip, they saw that it crossed over and accumulated in the brain matter. 

Researchers from the University of Pennsylvania, Rutgers University, and East China University of Science and Technology in Shanghai have shown that a combination of messenger RNA (mRNA) and a new lipid nanoparticle could help heal damaged lungs. The researchers matched up mRNA with just one unique lipid nanoparticle – ionizable amphiphilic Janus dendrimers – which are organ-specific. When it reaches the lung, the mRNA instructs the immune system to create transforming growth factor beta, a signaling molecule that is used to repair tissue. “This research marks the birth of a new mRNA delivery platform,” said 2023 Nobel laureate Drew Weissman, a co-author of the study. “While using other lipid nanoparticles works great to prevent infectious diseases, … this new platform does not have to be stored at such extremely cold temperatures and is even easier to produce.” 

Researchers from Baylor College of Medicine and Pennsylvania State University have discovered that Zika virus builds a series of tiny tubes, called tunneling nanotubes, that facilitate the transfer of viral particles to neighboring uninfected cells. The tiny conduits also provide a means to transport RNA, proteins and mitochondria, a cell’s main source of energy, from infected to neighboring cells. “Altogether, we show that Zika virus uses a tunneling strategy to covertly spread the infection in the placenta while hijacking mitochondria to augment its propagation and survival,” said Indira Mysorekar, one of the scientists involved in this study. “We propose that this strategy also protects the virus from the immune response.” 

Using the nanostructures and microstructures found on Morpho butterfly wings, scientists at the University of California San Diego have developed a simple and inexpensive way to analyze cancerous tissues. Fibrosis, the accumulation of fibrous tissue, is a key feature of many diseases, including cancer, and evaluating the extent of fibrosis in a biopsy sample can help determine whether a patient’s cancer is in an early or advanced stage. The researchers discovered that by placing a biopsy sample on top of a Morpho butterfly wing and viewing it under a standard microscope, they can assess whether a tumor’s structure indicates early- or late-stage cancer – without the need for stains or costly imaging machines.

Researchers from Penn State; Columbia University; the National Renewable Energy Laboratory in Golden, CO; TUD Dresden University of Technology in Germany; King’s College London; Radboud University in the Netherlands; the University of Chemistry and Technology Prague in the Czech Republic; and the University of Regensburg in Germany have identified a surface exciton – an excited electron and the hole it leaves behind – in chromium sulfide bromide, a layered magnetic semiconductor. Cooling chromium sulfide bromide down to around –223 degrees Fahrenheit brings it to a ground state, or the state of lowest energy. This transforms it into an antiferromagnetic system, in which the magnetic moments – referred to as “spin” – of the system’s particles align in a regular, repeating pattern. This antiferromagnetic ordering ensures that each layer alternates its magnetic alignment. As a result, excitons tend to stay in the layer with the same spin. Like cars on alternating one-way streets, these established boundaries keep excitons confined to the layer with which they share the same spin directions. 

Researchers at North Carolina State University have demonstrated a new technique that uses light to tune the optical properties of quantum dots. The researchers placed green-emitting perovskite quantum dots in a solution containing either chlorine or iodine. The solution was then run through a microfluidic system that incorporated a light source. The microfluidic environment enabled precise reaction control by ensuring uniform light exposure across small solution volumes, approximately 10 microliters per reaction droplet. The light triggered reactions that made the green-emitting perovskite quantum dots move closer to the blue end of the spectrum when chlorine was present in the solvent and closer to the red end of the spectrum when iodine was present in the solvent.

Researchers from Rice University; the Massachusetts Institute of Technology; Carnegie Mellon University; the National University of Singapore; Southern University of Science and Technology in Shenzhen, China; and Osaka University in Japan have found a two-dimensional (2D) carbon material that is tougher than graphene and resists cracking. Carbon-derived materials, such as graphene, are among the strongest on Earth, but once established, cracks propagate rapidly through them, making them prone to sudden fracture. The new carbon material, called a monolayer amorphous carbon, is both strong and tough. Like graphene, this material is also a 2D material, but unlike graphene, in which atoms are arranged in an ordered lattice, this material incorporates both crystalline and amorphous regions. "This unique design prevents cracks from propagating easily, allowing the material to absorb more energy before breaking," said Bongki Shin, one of the researchers involved in this study.

Scientists at the Icahn School of Medicine at Mount Sinai have developed a lipid nanoparticle system that can deliver messenger RNA (mRNA) to the brain via intravenous injection – a challenge that has long been limited by the protective nature of the blood-brain barrier. The system takes advantage of natural transport mechanisms within the blood-brain barrier that move nanoparticles across the blood-brain barrier. The findings, in mouse models and isolated human brain tissue, show the potential of this system for future treatments for Alzheimer’s disease, amyotrophic lateral sclerosis, brain cancer, and drug addiction.