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

Researchers from North Carolina State University, Arizona State University, Jeonbuk National University in South Korea, and Sungkyunkwan University in South Korea have discovered that liquid metal composites can spontaneously grow over four times in volume when exposed to water, while retaining metallic conductivity similar to their starting material. This growth occurs because water infiltration promotes oxidation reactions that generate porous gallium oxyhydroxide while freeing hydrogen gas. This gradually accumulating gas exerts internal pressure that expands the liquid metal composite further – much like bread dough rising from the byproducts of yeast fermentation.

Researchers at the University of Michigan have developed a new fabrication process for helical metal nanoparticles that provides a simpler, cheaper way to rapidly produce a material essential for biomedical and optical devices. "One of our motivators is to drastically simplify manufacturing of complex materials that represent bottlenecks in many current technologies," said Nicholas Kotov, one of the scientists involved in this study. 

Researchers at the National Institute of Standards and Technology (NIST) and colleagues from the Joint Quantum Institute, a research partnership between NIST and the University of Maryland, have developed standards and calibrations for optical microscopes that allow quantum dots to be aligned with the center of a photonic component to within an error of 10 to 20 nanometers. Such alignment is critical for chip-scale devices that employ the radiation emitted by quantum dots to store and transmit quantum information.

Materials scientists at Rice University are shedding light on the intricate growth processes of 2D crystals, paving the way for controlled synthesis of these materials with unprecedented precision. The researchers have developed a custom-built miniaturized chemical vapor deposition system to observe and record the growth of 2D molybdenum disulfide crystals in real time. Through the use of advanced image processing and machine learning algorithms, the researchers were able to extract valuable insights from the real-time footage, including the ability to predict the conditions needed to grow very large, single-layer molybdenum disulfide crystals.

Researchers from the Johns Hopkins Kimmel Cancer Center have found that targeting a non-encoding stretch of RNA may help shrink tumors caused by an aggressive type of brain cancer in children. A previous study showed that a long noncoding stretch of RNA contributes to the growth of brain tumors by attaching to a piece of DNA that increases expression of cancer-causing genes. In this study, the researchers developed an intravenous treatment that uses cerium oxide nanoparticles and that ultimately blocks the noncoding stretch of RNA from binding to the piece of DNA to stop the resulting cascade of cancer-gene expression. 

By wrapping a carbon nanotube with a ribbon-like polymer, researchers from Duke University, the University of Pittsburgh, and the University of North Carolina, Chapel Hill, were able to create nanotubes that conduct electricity when struck with low-energy light. The approach takes a metallic nanotube, which always lets current through, and transforms it into a semiconducting form that can be switched on and off. The secret lies in special polymers that wind around the nanotube in an orderly spiral, "like wrapping a ribbon around a pencil," said the study’s first author Francesco Mastrocinque.

Researchers from Pennsylvania State University have developed a "GPS nanoparticle" that, after being injected intravenously, can home in on cancer cells to deliver a genetic punch to the protein implicated in tumor growth and spread. The researchers showed that this nanoparticle works for basal-like breast cancers, which are characterized by aggressive, quickly growing tumors that shed cancer cells, which then spread elsewhere in the body.

Researchers from Carnegie Mellon University and the University of Pittsburgh are providing guidance on the design of lipid nanoparticles for safe use during pregnancy. Lipid nanoparticles are the delivery vehicles that bring messenger RNA into cells. The researchers are studying how changes during pregnancy (for example, immune system changes) alter nanoparticle behavior, compared to non-pregnant people. So far, the researchers have shown that the inclusion of different lipids in a nanoparticle alters its chemistry, which in turn changes the way the immune system responds.

Researchers from the Massachusetts Institute of Technology and Harvard Medical School have shown that a type of nanoparticle called a metal organic framework can provoke a strong immune response by activating the innate immune system – the body’s first line of defense against any pathogen – through cell proteins called toll-like receptors. In a study of mice, the researchers showed that this metal organic framework could successfully encapsulate and deliver part of the SARS-CoV-2 spike protein, while also acting as an adjuvant once the metal organic framework is broken down inside cells. An adjuvant is a molecule that helps to boost the immune system’s response to a protein.

Researchers from Rice University and Florida State University have shown that changing the structure of the oxide layer that coats aluminum nanoparticles modifies their catalytic properties. The researchers elucidated the structure of the native oxide layer on aluminum nanoparticles and showed that heating the nanoparticles to temperatures of up to 500 degrees Celsius (932 degrees Fahrenheit) in different gases can change the structure of the aluminum oxide layer. One of the effects of this heating was to make the aluminum nanoparticles better at facilitating the conversion of carbon dioxide into carbon monoxide and water.