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

Silver has long been used to thwart the spread of illness, and in recent years, silver nanoparticles have been incorporated into many products, including odor-resistant clothes, makeup, food packaging, and sports equipment. Despite their ubiquity, little is known about their environmental toxicity or how it might be mitigated. So, researchers at Oregon State University and the Oregon Nanoscience and Microtechnologies Institute (Corvallis, OR) have taken a key step toward closing the knowledge gap with a study that indicates silver nanoparticles' shapes and surface chemistries play key roles in how they affect aquatic ecosystems.

Researchers from Oregon State University and Funai Microfluidic Systems (Lexington, KY) have developed a novel technique for the aerosolization of inhalable nanoparticles that can be used to carry messenger RNA (mRNA) to the lungs of patients with inherited lung diseases. The findings are important because the current nebulization method for nanoparticles subjects them to shear stress, hindering their ability to encapsulate the genetic material and causing them to aggregate in certain areas of the lungs rather than spread out evenly, the researchers said. "We utilized a novel microfluidic chip that helps in generation of plumes that carry nanoparticles and does not cause any shear stress," said Gaurav Sahay, a scientist who led this study. "This device is based on the similar idea of an ink-jet cartridge that generates plumes to print words on paper." 

Researchers from Columbia University and the National Institute for Materials Science in Tsukuba, Japan, have used commercially available tabletop lasers to create tiny, atomically sharp nanostructures, or nanopatterns, in samples of a layered two-dimensional (2D) material. Rather than damaging the underlying atomic structure, the lasers broke the crystal lattice cleanly apart. According to Cecilia Chen, a scientist who led this study, the effect was visible under the microscope and looked like unzipping a zipper.

Researchers at the University of Miami Miller School of Medicine have developed a nanoparticle that can penetrate the blood-brain barrier. Their goal is to kill primary breast cancer tumors and brain metastases in one treatment, and their research shows the method can shrink breast and brain tumors in laboratory studies. Brain metastases are tumors that have spread from other parts of the body to the brain. The nanoparticle is coupled with two drugs that take aim at cancer's energy sources. One of these drugs is a modified version of a classic chemotherapy drug, cisplatin; the other drug targets a mitochondrial protein and inhibits a different kind of energy called glycolysis.

Chemists and bioengineers from Rice University and the University of Houston have developed a novel fabrication process to create aligned nanofiber hydrogels that mimic the aligned structure of muscle and nerve tissues. "Our findings demonstrate that our method can produce aligned peptide nanofibers that effectively guide cell growth in a desired direction," said Adam Farsheed, a scientist who led this research effort. "This is a crucial step toward creating functional biological tissues for regenerative medicine applications."

Scientists from the U.S. Department of Energy's Oak Ridge National Laboratory and the University of Central Florida have demonstrated that small changes in the isotopic content of two-dimensional (2D) semiconductor materials can influence their optical and electronic properties. The scientists grew 2D crystals of atomically thin molybdenum disulfide using molybdenum atoms of different masses. They noticed small shifts in the color of light emitted by the crystals after they were stimulated by light. "Unexpectedly, the light from the molybdenum disulfide with the heavier molybdenum atoms was shifted farther to the red end of the spectrum, which is opposite to the shift one would expect for bulk materials," said Kai Xiao, one of the scientists involved in this study.

Researchers at Penn State have made borophene, the atomically thin version of boron, potentially more useful by imparting chirality – or handedness – on it. Chirality refers to similar but not identical physicality, like left and right hands. The researchers found that certain amino acids, like cysteine, would bind to borophene in distinct locations, depending on their chiral handedness. Also, when the chiralized borophene was exposed to mammalian cells in a dish, their handedness changed how they interacted with cell membranes and entered cells.

Researchers from the University of Wyoming, Pennsylvania State University, Northeastern University, the University of Texas at Austin, Colorado State University, and the National Institute for Materials Science in Tsukuba, Japan, have created an innovative method to control tiny magnetic states within ultrathin, two-dimensional (2D) van der Waals magnets – a process akin to how flipping a light switch controls a bulb. "Our research could lead to the development of novel computing devices that are faster, smaller and more energy-efficient and powerful than ever before,” said Jifa Tian, one of the scientists involved in this study. “Our research … sets the stage for new, powerful computing platforms, such as probabilistic computers.” 

Researchers from Rutgers University and Xi'an University of Architecture and Technology in China have found that people walking through a space where a consumer product containing nanoparticles was recently sprayed stirred residual specks off carpet fibers and floor surfaces, projecting them some three to five feet in the air. Gediminas Mainelis, the scientist who led this study, said that while it's still too early to gauge the long-term effects of these particles on people's health, the results are important to contemplate. "At this point, it's more about increasing awareness, so that people know just what they are using," he said.

Researchers from the University of Michigan, the University of California at Berkeley, Cornell University, the U.S. Department of Energy’s Argonne National Laboratory and Lawrence Berkeley National Laboratory (Berkeley Lab), and Dow Chemical have accomplished high-resolution, efficient 3D chemical imaging for the first time at the one-nanometer scale. Up to this point, nanomaterial researchers have had to choose between imaging 3D structure or 2D chemical distribution. This time, the researchers developed a process to collect 3D images at every tilt angle as well as chemical images every few tilts. A multi-modal algorithm then takes the information for both signal types and outputs the 3D structure and chemistry. This research work was done in part at the Molecular Foundry, a nanoscience user facility that is part of Berkeley Lab.