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

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. 

Researchers from North Carolina State University and Texas A&M University have created materials that are stiff and can insulate against heat. This combination of properties is unusual and holds promise for the development of thermal insulation coatings for electronic devices. The researchers were working with a subset of a class of materials called two-dimensional hybrid organic-inorganic perovskites (2D HOIP). The researchers found at least three distinct 2D HOIP materials that became less thermally conductive as their stiffness increased.

Diabetic wounds, often resistant to conventional treatments, pose serious health risks to millions of people worldwide. Immune cells known as macrophages, which are supposed to help, end up causing inflammation instead, making it harder for the wound to heal properly and quickly. Now, researchers from the Icahn School of Medicine at Mount Sinai and The Ohio State University have designed a regenerative medicine therapy to speed up diabetic wound repair. Using lipid nanoparticles loaded with RNA encoding a signaling protein known as a cytokine, the therapy targeted dysfunctional macrophages while simultaneously reducing inflammation in diabetic wounds. "In preclinical models, we basically showed the therapy's ability to reprogram pro-inflammatory macrophages into reparative ones, leading to improved wound healing outcomes," said Yizhou Dong, one of the scientists involved in this study. 

A team of electrical engineering researchers from Penn State and the University of Nebraska-Lincoln has created an ultrathin optical element that can control the direction of polarized electromagnetic light waves. The optical element, akin to a glass slide, uses a forest of tiny, antenna-like nanorods that together create a metamaterial – a material engineered to have specific properties not typically found in nature. According to Christos Argyropoulos, one of the scientists involved in this study, the optical element can quickly image the molecular structure of pharmaceuticals, allowing scientists to better understand the nuances of drug behavior.