Watching nanoscale assembly live

Ebola virus, Alzheimer's amyloid fibrils, tissue collagen scaffolds and cellular cytoskeleton are all filamentous structures that spontaneously assemble from individual proteins. Many protein filaments are well studied and are already finding use in regenerative medicine, molecular electronics and diagnostics. However, the very process of their assembly - protein fibrillogenesis - remains largely unrevealed. A better understanding of this process through direct observation is anticipated to offer new applications in biomedicine and nanotechnology while providing efficient solutions for pathogen detection and molecular therapy. The formation of protein filaments is highly dynamic and occurs over time and length scales that require fast measurements with nano-to-micrometer precision. Although many methods can meet these criteria the caveat is to measure in water and in real time. The challenge is compounded by the need to have a homogeneous assembly characterised by uniform growth rates of uniformly sized filaments. sequence of fluorescent micrographs showing a growing protein filament A shortened time-lapse sequence of fluorescent micrographs showing a growing protein filament (centre), with the bright round aggregate (left) used as a reference point. To tackle this challenge, an NPL team devised an archetypal fibrillogenesis model based on an artificial protein whose assembly was recorded in real time using super-resolution microscopy approaches. The findings have been published in Nature Publishing Group's ("Filming protein fibrillogenesis in real time"). Angelo Bella, Higher Research Scientist in NPL's Biotechnology Group explains: "By being able to continuously image the assembly from the start to maturation we established that protein monomers recruit at both ends of growing filaments at uniform rates in a highly cooperative manner." The study provides a measurement foundation for studying different macromolecular assemblies in real time and holds promise for engineering customised nano-to-microscale structures .
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New methods to control the size and chemical composition of nanoparticles

The Nanoparticles by Design Unit at the Okinawa Institute of Science and Technology Graduate University is constantly finding new ways to endow the tiniest of particles with more specific properties. They have developed methods to control the size and chemical composition of nanoparticles, and now they have found a way to control the degree of crystallinity, or the way that atoms align inside the nanoparticles. A nanoparticle’s crystallinity impacts its optical, magnetic, and electrical properties. Professor Mukhles Sowwan and the researchers in his unit Dr. Cathal Cassidy and Vidyadhar Singh have applied for a patent for their method, which describes exactly how to create semiconductor nanoparticles of varying crystallinity. Inducing Crystallinity in nanoparticles The yellow areas in this image are silver nanoclusters, which have monocrystalline structure and are used to induce crystallinity in an amorphous Silicon nanoparticle, the blue area. “Most scientists and even companies nowadays are using nanoparticles not optimized for their applications or devices,” explains Sowwan. “We hope, at a certain time, we will optimize the nanoparticles for specific applications.” To start though, the researchers in the Nanoparticles by Design Unit must figure out how to control a few basic characteristics of nanoparticles, such as crystallinity. A crystalline nanoparticle will have all of its atoms aligned in neat rows, while an amorphous nanoparticle will have more disordered atoms. A polycrystalline structure has atoms aligned in groups, which are also known as grains. Crystallinity is responsible for profound differences between products made of the same material. For example, soot is amorphous carbon, or carbon without any crystal grains, while diamonds are crystalline carbon. “It’s the first time to control the crystallinity and the number of crystallites of very small semiconductor nanoparticle,” Sowwan says, explaining that people have long known how to induce crystallinity in bulk semiconductor materials. But part of the reason why Sowwan can control certain characteristics is because of the experimental method he and his researchers use, based on a modified nanoparticle deposition system. One of the most important features of this system is the possibility to interact with or modify freshly formed semiconductor nanoparticles in flight before reaching a substrate. “That substrate is problematic,” explains Sowwan, “because it is always impacting the properties of the nanoparticle.” Following the steps described in the newly suggested method, nanoscientists expose these nanoparticles in flight to a beam of metal atoms. The metal atoms diffuse onto the surface of the nanoparticles and form metal nanoclusters, just a few nanometers wide, inducing crystallization in the product. The researchers can then selectively remove the metal nanoclusters with plasma cleaning, a fairly simple physical procedure, retaining only the intact semiconductor nanoparticles of desired crystallinity. The new patent will credit this method to OIST. “To use this method for commercial purposes, such as engineered nanoparticles in solar cells or for medical bio-imaging, the technology will have to be licensed from OIST,and academic researchers will have to credit us in their research.” Sowwan says this is one of many characteristics he would like to control in order to produce more specialized nanoparticles. At the end of the day, this is one new set of directions in the rulebook of how to customize a nanoparticle. For more information -- Patent application number: WO 2014141662 A1, Metal Induced Crystallization of Semiconductor Quantum Dots
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Scientist look for nanostructures that allow compatibility between metal, human bone tissues

Various scientific projects performed at the Research Center for Advanced Materials (Cimav), Unit Monterrey, in the north of Mexico, aimed at one goal: conducting research and apply the knowledge in the development of biomedical implants, since the ones existing in the domestic market come generally from foreign manufacture. Currently this center, part of the National Council for Science and Technology (CONACYT) and located at the Park of Research and Technological Innovation (PIIT), works on the study of novel materials, coating systems and specific properties to use in the manufacture of hip and knee implants, and, in the future, of dental parts. It is the combination of research focused on nanostructured materials with biocompatible and antibacterial properties. In this regard, Ana Maria Arizmendi Morquecho, Cimav scholar, explains that the challenge is to find appropriate measures to improve the compatibility of a metal structure with the chemical composition of bone tissue and human bone's nanostructures. biomedical implant "We use a ceramic material which is compatible with the bone, in this case hydroxyapatite, which is used as a matrix and nanoparticles from other materials are used to reinforce it and provide improvements to the bicompatibility, joint wear and mechanical properties" , explains Arizmendi Morquecho. (Image courtesy of Investigación y Desarrollo) "The biocompatibility is the ability of a material to be in contact with a living being without adverse effects, therefore represents one of the most important properties in the manufacture of a biomedical implant. Currently the knee and hip implants are complex systems made of titanium alloy substrates, which require a coating compatible with bone tissue and physiological fluids using nanotechnology; to achieve this intermediate coating deposition techniques of new synthesized materials are used. "We use a ceramic material which is compatible with the bone, in this case hydroxyapatite, which is used as a matrix and nanoparticles from other materials are used to reinforce it and provide improvements to the bicompatibility, joint wear and mechanical properties" , explains Arizmendi Morquecho. She reiterates that the materials are increasingly complex and functional, since it is needed of them to be resistant to wear, having improved mechanical properties and may be compatible with the human body simultaneously, in addition to abide to public health requirements. The researcher at Cimav explains that due to the complexity of the system for the knee implant, scientific work is completed in parts: research is focused on the coating that will join the the metal substrate (titanium alloy) to the bone, the study of polymeric biomaterials which will be in contact with the articulation and both focused with the entire system compatibility with body fluids. "Each research is a graduate level thesis and participation of a multidisciplinary group of researchers that ultimately come together for the same product, a final component. The next stage of the project is to validate in vitro and in vivo synthesized material at a laboratory level, for which the link with other entities such as medical schools and academic institutions specialized in this type of testing is necessary. It's important to note that compatibility tests are standardized under sanitary policies and those entities are responsible for validation in our developments ." The materials specialist refers that the aforementioned research has led to ten scientific papers published in scientific journals. To get to the finished product, Cimav has vinculated with higher education institutions and other technology research centers, but still needs to find domestic companies interested in manufacturing the final component. In this regard, Arizmendi Morquecho notes that the advantage of working in the PIIT is the ease of linking with other institutions nationally and globally that have other technologies, additional infrastructure and can be useful for obtaining the final product . "The science-technology-innovation ecosystem is a necessity in the region, so the creation of the PIIT is a path we must take to move faster. Doing research is not everything, business participation is required and the participation of a governmental entity to offer innovative and necessary products for the national population. Everything has to do with the momentum of the innovation ecosystem in the state," she concludes.
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