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

Researchers from Purdue University and ShanghaiTech University in China have developed a patent-pending method to synthesize high-quality, layered perovskite nanowires with large aspect ratios and tunable organic-inorganic chemical compositions. Layered metal halide perovskites, commonly called 2D perovskites, grow into large, thin sheets, but growth of one-dimensional forms of the materials is limited. The new method uses organic templating molecules that break the in-plane symmetry of layered perovskites and induce one-dimensional growth through secondary bonding interactions.

Researchers at The University of Texas at El Paso and Baylor College of Medicine are developing a new therapeutic approach that uses nanoparticles for the treatment of skin and lung fibrosis. Fibrosis is a condition in which the tissues in an organ become thicker and stiffer. For example, in the case of an autoimmune condition, the body kills cells called fibroblasts that help form connective tissue. The body then produces more collagen than it needs, which leads to fibrosis. The researchers focused on designing a nanoparticle that could modify the cells that are responsible for fibrosis development and progression so they no longer produce excess collagen.

Scientists from the University of North Carolina at Chapel Hill, North Carolina State University, and Purdue University have created innovative soft robots equipped with electronic skins and artificial muscles, allowing them to sense their surroundings and adapt their movements in real-time. The robots are designed to mimic the way muscles and skin work together in animals, making them more effective and safer to use inside the body. The electronic skin integrates various sensing materials – such as silver nanowires and conductive polymers – within a flexible base, closely replicating the complex sensory functions of real skin. "These soft robots can perform a variety of well-controlled movements, including bending, expanding and twisting inside biological environments," said Lin Zhang, one of the scientists involved in this study.

Engineers at the University of California San Diego have developed microscopic robots, known as microrobots, that can swim through the lungs to deliver cancer-fighting medication directly to metastatic tumors. To create the microrobots, researchers chemically attached drug-filled nanoparticles to the surface of green algae cells. The nanoparticles are made of tiny biodegradable polymer spheres, which are loaded with the chemotherapeutic drug doxorubicin and coated with red blood cell membranes. "This coating makes the nanoparticle look like a red blood cell from the body, so it will not trigger an immune response,” said Zhengxing Li, one of the researchers involved in this study.

The National Institute for Occupational Safety and Health (NIOSH) is celebrating the 20th anniversary of the NIOSH Nanotechnology Research Center (NTRC)! This blog post from NIOSH highlights NTRC activities in risk assessment of engineered nanomaterials. The small size of engineered nanomaterials (at least one dimension smaller than 100 nanometers) gives them unique and useful properties, but they could also pose a health risk to workers who produce or use these materials. NIOSH conducts risk assessments to estimate the likelihood and severity of adverse health effects in workers exposed to chemical substances, including nanomaterials. NIOSH risk assessments support the development of occupational safety and health recommendations. 

Researchers from the U.S. Department of Energy's Brookhaven National Laboratory and Oak Ridge National Laboratory; Stony Brook University; Chungnam National University in Daejeon, South Korea; and Mitsubishi Chemical Corporation in Yokohama, Japan, have uncovered new details of the reversible assembly and disassembly of a platinum catalyst. The researchers revealed how single platinum atoms on a cerium oxide support aggregate under reaction conditions to form active catalytic nanoparticles and then, surprisingly, disaggregate once the reaction is stopped. "Part of the definition of a catalyst is that it helps disassemble and reassemble reacting molecules to form new products," said Anatoly Frenkel, one of the scientists involved in this study. "But it was shocking to see a catalyst that also assembles and disassembles itself in the process."

Engineers from Arizona State University and Rutgers University have developed a multistep method that applies different nanomaterials to wounds at different times to support both early- and late-stage healing. The method outperformed a common wound dressing in a diabetic mouse model, closing wounds faster and producing more robust skin tissue. Also, the researchers' analysis suggests that their approach unexpectedly activated an immune cell population not normally seen in wounds that can resolve inflammation, which could be a new potential avenue to accelerate healing.

Imaging the hot turbulence of aircraft propulsion systems may now be possible with sturdy sheets of composite materials that twist light beams, according to researchers from the University of Michigan, the Air Force Research Laboratory, ARCTOS Technology Solutions (Beavercreek, OH), the Brazilian Center for Research in Energy and Materials in Campinas, Brazil, and the Federal University of São Carlos in Brazil. The key is arranging nanomaterials that don't twist light on their own onto layers that turn light waves into either left- or right-handed spirals, known as circular polarizations. "These low-cost optical materials afford modularity, which is crucial for optimizing solutions for a broad range of future technologies," said Richard Vaia, one of the researchers involved in this study.

Boston Children’s Hospital; the University of Louisville School of Medicine; Dartmouth College; Emory University; the University of Southampton in the United Kingdom; and Moderna, Inc. (Cambridge, MA) have successfully stimulated animals' immune systems to induce rare precursor B cells of a class of HIV broadly neutralizing antibodies. The researchers engineered immunogens – molecules used in vaccines that elicit a specific immune system response – on nanoparticles that mimic the appearance of a specific part of a protein found on the surface of HIV. These observations suggest that the promising immunization data (from mice and macaques) has the potential for translation to humans.

Engineers from Columbia University, the National Institute of Standards and Technology, the University of Montreal in Canada, and the National Institute for Materials Science in Tsukuba, Japan, have shown that an oxygen-free chemical vapor deposition (CVD) method can create high-quality graphene samples at scale. Their work directly demonstrates how trace oxygen affects the growth rate of graphene and, for the first time, identifies the link between oxygen and graphene quality. "We show that eliminating virtually all oxygen from the growth process is the key to achieving reproducible, high-quality CVD graphene synthesis," said James Hone, one of the scientists involved in this study.