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

Researchers from The Johns Hopkins University School of Medicine, the Van Andel Institute in Grand Rapids, MI, and the Chinese Academy of Sciences have discovered that a mouse protein, called STELLA, disrupts cancer-causing chemical changes to genes associated with human colorectal cancer cells. First, the researchers found the part of the protein, or peptide, that was required to activate tumor suppressor genes in human colorectal cancer cells. Then, they designed a lipid nanoparticle – an ultratiny drug delivery vehicle made of fatty molecules – to deliver the messenger RNA (mRNA) that codes for this peptide to cells. The therapy performed well in mice, activating tumor suppressor genes and impairing tumor growth. Next, the researchers plan to test this therapy on human patients through clinical trials.

Researchers from the Massachusetts Institute of Technology, Purdue University, Stanford University, Rice University, and the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, Argonne National Laboratory, and Oak Ridge National Laboratory have described how a type of quasiparticle, called a polaron, behaves in tellurene, a nanomaterial made up of tiny chains of tellurium atoms. A polaron forms when charge-carrying particles such as electrons interact with vibrations in the atomic or molecular lattice of a material. The researchers had hypothesized that as tellurene transitions from bulk to nanometer thickness, polarons change from large, spread-out electron-vibration interactions to smaller, localized interactions. Computations and experimental measurements backed up this scenario.

Researchers from Columbia University, the University of Chicago, the University of Vienna in Austria, Politecnico di Milano in Italy, and Universita Degli Studi Dell’ Aquila in Italy have created a device that can generate photon pairs more efficiently than previous methods while being less prone to error. To create the device, the researchers used thin crystals of a van der Waals semiconducting transition metal called molybdenum disulfide. Then, they layered six of these crystal pieces into a stack, with each piece rotated 180 degrees relative to the crystal slabs above and below. As light travels through this stack, a phenomenon called quasi-phase-matching manipulates properties of the light, enabling the creation of paired photons. "We believe this breakthrough will establish van der Waals materials as the core of next-generation nonlinear and quantum photonic architectures,” said James Schuck, one of the scientists involved in this study.

Researchers from Georgia Tech and the University of California Riverside have developed biosensors made of iron oxide nanoparticles and special molecules called cyclic peptides that recognize tumor cells better than current biosensors. The cyclic peptides respond only when they encounter two specific types of enzymes – one secreted by the immune system, the other by cancer cells. In animal studies, the biosensors distinguished between tumors that responded to a common cancer treatment that enhances the immune system from tumors that resisted treatment.

Researchers from the U.S. Department of Energy’s Argonne National Laboratory and the University of Cambridge have unveiled the existence of an intriguing link between ferroelectric domain walls and electron interactions in a type of van der Waals 2D material. A domain wall is a boundary or interface separating regions inside a material that exhibit different orientations of ferroelectric polarization. The link discovered by the researchers gives rise to a new type of superconductivity that is unique to these 2D materials. "We showed that places like domain walls, typically associated with irregularities and potentially harmful for things like superconductivity, can indeed be helpful for superconductivity," said Gaurav Chaudhary and Ivar Martin, the two authors of this study.

Most cancers occur when there is an imbalance of cellular growth and inhibition, causing cells to grow rapidly and form tumors in the body. In the case of prostate cancer, no therapies exist to simultaneously correct tumor growth and restore tumor suppression. To restore this balance, researchers from Brigham and Women's Hospital, which is part of Harvard Medical School, have used lipid nanoparticles to deliver messenger RNA (mRNA) and small interfering RNA (siRNA) to human prostate cancer cells. This approach was successful in preclinical models, holding promise for suppressing tumor growth in patients. 

Researchers from Stanford University; the IBM T.J. Watson Research Center in Yorktown Heights, NY; the Korea Electronics Technology Institute in Seongnam-si, South Korea; and Ajou University in Suwon, South Korea, have shown that niobium phosphide can conduct electricity better than copper in films that are only a few atoms thick. Many researchers have been working to find better conductors for nanoscale electronics, but so far the best candidates have had extremely precise crystalline structures, which need to be formed at very high temperatures. The niobium phosphide films made in this study are the first examples of non-crystalline materials that become better conductors as they get thinner, and they can be created at lower temperatures. 

Researchers from Carnegie Mellon University have found a way to control the size and structure of active colloids while yielding more than 100 times the amount created by earlier fabrication methods. The team's active colloids are linked together using DNA nanostructures – an innovation that makes them flexible, agile, and responsive to signals in their environment. Typically, DNA nanotechnology can only be studied using expensive equipment. In this case, because the DNA is attached to the colloid particles, researchers can observe any nanoscale phenomenon – such as the DNA structures changing shape – in real time by observing changes in the colloid's movement under a microscope.

Researchers from the U.S. Department of Energy's SLAC National Accelerator Laboratory, Stanford University, and the University of California, Davis, have developed a new software tool that can provide more quantitative details about the structure of the active sites in single atom catalysts in much less time, compared to current methods. Normally, a catalyst uses an inert support to stabilize nanometer-sized clusters of metal atoms, or metal nanoparticles. To maximize the use of each metal atom, researchers also use single atom catalysts, where individual metal atoms are dispersed onto the support. In reality, catalysts usually have both single atoms and nanoparticles, and the new software tool determines the fractions of these two forms.

Scientists from Oregon State University; the Molecular Foundry at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory; Columbia University; and the Autonomous University of Madrid, Spain, have discovered luminescent nanocrystals that can be quickly toggled from light to dark and back again. "Normally, luminescent materials give off light when they are excited by a laser and remain dark when they are not," said Artiom Skripka, one of the scientists involved in this study. "In contrast, we were surprised to find that our nanocrystals live parallel lives. Under certain conditions, they show a peculiar behavior: They can be either bright or dark under exactly the same laser excitation wavelength and power."