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

Liver fibrosis has remained challenging to treat using RNA therapies due to a lack of delivery systems for targeting activated liver-resident cells called fibroblasts. Both the solid fibroblast structure and the lack of specificity or affinity to target these fibroblasts have impeded current lipid nanoparticles from entering activated liver-resident fibroblasts, and thus they are unable to deliver RNA therapeutics. Now, researchers at the University of Pennsylvania have found a new way to synthesize ligand-tethered lipid nanoparticles, increasing their selectivity and allowing them to target liver fibroblasts. 

Chemists usually make materials by finding the best conditions to target a single product. For example, nanoparticles have been engineered to produce scratch-proof eyeglasses and transparent sunscreen. A research team at Penn State University has flipped this approach on its head by purposely using unoptimized conditions to produce many products at once. This approach allowed them to discover novel nanoparticles, which combine many different materials in various arrangements. They then analyzed these nanoparticles to develop new guidelines that allowed them to make high-yield samples of the most interesting types of new nanoparticles.

Chemists at the University of Oregon have found a way to make carbon-based molecules with a unique structural feature: interlocking rings. These linked-together molecules have interesting properties that can be “tuned” by changing their size and chemical makeup. For example, the researchers made three interlocked rings, as well as a rod-like structure with multiple rings that can slide up and down. The advance grew out of previous work on nanohoops, rings of carbon atoms that are a pared-back variation of long, skinny carbon nanotubes.

Scientists from Northwestern University, the University of Arizona, Washington University in St. Louis, and North Carolina State University have developed a wireless, battery-free implant capable of monitoring dopamine signals in the brain in real time in small animal models – an advance that could help improve our understanding of the role neurochemicals play in neurological disorders. The implant, which records dopamine activity in freely behaving subjects (without the need for bulky or prohibitive sensing equipment) includes a carbon nanotube-based sensor with sensitivities among the highest recorded so far.

Researchers from Columbia University, Harvard University, the University of Virginia, the University of Rhode Island, Amherst College, and Barnard College have discovered a new form of carbon, called graphullerene, made from fullerene molecules that are assembled together in a way that is reminiscent of graphene. 

Researchers at Cornell University want to revolutionize how polymer nanoparticles are manufactured by using a novel combination of artificial intelligence (AI) and production techniques. As nanoparticles are being synthesized, the researchers will incorporate liquid crystals that leave an “optical fingerprint” to be read by computer vision. The resulting data will be used to train a neural network to identify information about the polymer nanoparticles and then used for real-time, automated decision-making during the assembly process.

Researchers from Pennsylvania State University and Zhejiang University have proposed that super-lubricity – a state in which friction between two contacting surfaces nearly vanishes -- may be found in water vapor and vapor in phenol (a family of organic compounds). The researchers used a silicon oxide probe on a surface of graphene to demonstrate how this might be possible. They found that super-low friction can be increased 25 times by water vapor and 45 times by phenol vapor. 

Cellulose nanocrystals—bio-based nanomaterials derived from natural resources such as plant cellulose—are valuable for their use in water treatment, packaging, tissue engineering, electronics, and antibacterial coatings. Though the materials provide a sustainable alternative to non-bio-based materials, transporting them in liquid taxes industrial infrastructures and leads to environmental impacts. Now, a team of Penn State chemical engineering researchers studied the mechanisms of drying the nanocrystals and proposed nanotechnology to make the nanocrystals highly redispersible in aqueous mediums to make them easier to store and transport. 

Since 2014, 37 budding engineers and technicians in the semiconductor industry have completed an internship program at the National Institute of Standards and Technology’s NanoFab facility, which provides researchers with rapid access to state-of-the-art nanoscale measurement and fabrication tools and methods, along with technical expertise. This article describes the experiences of four of these interns.

A new kind of solar panel, developed at the University of Michigan, has achieved 9% efficiency in converting water into hydrogen and oxygen – mimicking a crucial step in natural photosynthesis. Outdoors, it represents a major leap in the technology, nearly 10 times more efficient than solar water-splitting experiments of its kind. The outstanding result comes from two advances: the ability to concentrate the sunlight without destroying the semiconductor that harnesses the light, and the use of a semiconductor catalyst -- made of indium gallium nitride nanostructures, grown onto a silicon surface – that improves itself with use.