Mass culture of cell lines has long been fundamental to the manufacture of viral vaccines and many products of biotechnology. More recently it also has become an essential tool in stem cell research and tissue engineering. Most conventional petri dish based cell culture techniques produce monolayers cell growth that is missing essential cellular functions that are present in living organisms; gene expression, signaling and morphology can be different and this compromises its clinical relevance. It limits their potential to predict the cellular responses of real organisms. In order to develop cellular models that mimic the functions of living tissues, researchers have therefore been trying to move from two-dimensional to three-dimensional cultures. A recent example is a technique that uses magnetic levitation of cells in the presence of a hydrogel consisting of gold, magnetic iron oxide nanoparticles and filamentous bacteriophage. By spatially controlling the magnetic field while cells divide and grow, the geometry of the cell mass can be manipulated, and multicellular clustering of different cell types in co-culture can be achieved.
The concept of self-healing has become a popular theme in the field of material science. The whole concept of 'smart' materials that react on external impact - pH, humidity changes, or distortion of the coating integrity - and repair themselves has experienced a tremendous boost with the advent of nanotechnology. The nanoscale multilayer structure of a coating, in which the components are integrated and mutually reactive, is a main point in sophisticated and strong corrosion protection. Researchers have now proposed a new approach to self-healing polymer coating systems based on an electrospun coaxial healing agent. Electrospinning offers a number of unique opportunities. Most significantly, the location and concentration of the healing component can be spatially varied.
It has proven difficult to directly manufacture functional nanostructures and nanodevices with predetermined designs using bottom-up processes alone. So far, developing top-down machining techniques capable of fabricating structural/functional nanostructures and nanodevices appears to be indispensable, but mechanical machining tools with nanometer precision are still lacking. A grand challenge in nanotechnology is to machine three-dimensional nanostructures in a controllable and reproducible fashion. That begs the question if traditional top-down mechanical machining can also be realized at the nanoscale. So far, the conventional wisdom has been that traditional top-down mechanical machining like cutting and milling using a lathe is impossible at the nanoscale. Nanotechnologists considered most of the traditional top-down approaches as not applicable for fabricating nanostructure and nanodevices. However, as it turns out, there still is room at the bottom for traditional mechanical machining.
Bioethanol, unlike petroleum, is a form of renewable energy that can be produced from common agricultural feedstocks such as sugar cane or corn. Ethanol is already widely used in siome countries, mainly as biofuel additive for gasoline. The tremendous hype about bioethanol in the past few years has now been followed by a debate about how useful bioethanol actually can replace gasoline. Concerns about its production and use relate to the large amount of arable land required for crops, as well as the energy and pollution balance of the whole cycle of ethanol production. Recent developments with cellulosic ethanol production and commercialization may allay some of these concerns. It offers the promise that any plant material, from grass to wood, and not just edible crops, could be used in the production of ethanol fuels. Consequently, cellulosic ethanol could allow ethanol fuels to play a much bigger role in the future than previously thought. With regard to cellulosic production and commercialization, bioethanol production from woody biomass by enzymatic hydrolysis of cellulosic components and fermentation has attracted much attention.
Last year, NT-MDT Co. invited its AFM probe users to take part in an open contest of images obtained with their probes. Though equipment is important in gathering a great AFM image, the result also depends on the probe being used. The purpose of the contest was to compile the most intriguing images collected from ventures into the nano-universe with AFM tips. Another aim of the ProIMAGE Contest was to show a great variety of scientific and artistic results obtained with a wide range of specialized probes. A gallery of all images submitted to the contest, which now is closed, and the six winners can be seen on the ProIMAGE webpages. Here is a random selection of some visually stunning images from the 150 contest submissions.
Freshwater could become the oil of the 21st century - scarce, expensive and fought over. While over 70 per cent of the Earth's surface is covered by water, most of it is unusable for human consumption. Technological advances have made desalination and demineralization feasible - albeit expensive - solutions for increasing the world's supply of freshwater. However, nanotechnology- based water purification devices have the potential to transform the field of desalination. Researchers have now demonstrated a new, efficient and fouling-free desalination process based on the ion concentration polarization (ICP) phenomenon - a fundamental electrochemical transport phenomenon that occurs when an ion current is passed through ion-selective membranes - for direct desalination of sea water.
Materials that can produce electricity are at the core of piezoelectric research and the vision of self-powering machines and devices. With the emergence of nanotechnology and the use of nanomaterials, the field of piezoelectrics and nanopiezotronics has experienced a lot of new and interesting research efforts. A recent study, for instance, has demonstrated that the small vibrational energy waste generated in the environment from noise, wind power, running water, or water wave action can be scavenged or harvested as a driving force for direct water splitting. The researchers propose a new piezoelectrochemical mechanism for the direct conversion of mechanical energy to chemical energy and subsequently the splitting of water into hydrogen and oxygen.
Artificial photosynthesis can offer a clean and portable source of energy supply as durable as the sunlight. Using sunlight to split water molecules and form hydrogen fuel is one of the most promising tactics for kicking our carbon habit. Of the possible methods, nature provides the blueprint for converting solar energy in the form of chemical fuels. A natural leaf is a synergy of the elaborated structures and functional components to produce a highly complex machinery for photosynthesis in which light harvesting, photoinduced charge separation, and catalysis modules combined to capture solar energy and split water into oxygen and hydrogen efficiently. Chinese researchers have now demonstrated the design of an efficient, cost-effective artificial system to mimic photosynthesis by copying the elaborate architectures of green leaves, replacing the natural photosynthetic pigments with man-made catalysts and thereby realizing water splitting- a major advance in energy conversion.