The question if certain engineered nanoparticles are toxic, and if yes to what degree, is still one of the major issues that hasn't been properly answered yet. Most studies in the literature thus far have focused on the environmental aspects of nanoparticle toxicity, and these studies have been conducted primarily on industrial or natural/incidental nanoparticles. However, engineered nanoparticles are at the forefront of the rapidly developing field of nanomedicine; and here they are deliberately injected into the body to perform a specific medical application: fluorescent agents for imaging; drug delivery vehicles; or therapeutic agents for the destruction of cancer cells (for instance in thermolysis); just to name a few. A brand new review article provides the first comprehensive summary of the properties of engineered nanoparticles which determine their interaction with components of the immune system. It concludes that nanoparticle-based therapeutics are no more intrinsically immunotoxic than traditional pharmaceuticals, such as biotechnology-derived or small molecules. Moreover, incorporation of traditional drugs into nanotechnology formulations frequently results in a decrease in immunotoxicity compared to the native drug. Although many questions still require thorough investigation, the available data suggest that nanoparticles can be engineered to become the next generation of biocompatible drug delivery platforms.
You might remember our Spotlight from a few months ago (25 years of scanning probe microscopy and no standards yet) where we gave an overview of how scanning probe microscopy has flourished over the past 25 years. The most versatile implementation of the scanned probe principle is the atomic force microscope (AFM). It has become one of the foremost tools for imaging, measuring and manipulating matter at the nanoscale. The essential part of an AFM is a microscale cantilever with a sharp tip (probe) at its end that is used to scan the specimen surface. The cantilever is typically silicon or silicon nitride with a tip radius of curvature on the order of nanometers. When the tip is brought into proximity of a sample surface, forces between the tip and the sample lead to a deflection of the cantilever according to Hooke's law. A multi-segment photodiode measures the deflection via a laser beam, which is reflected on the cantilever surface. Because there are so many promising areas in nanotechnology and biophysics which can be examined by AFM (force spectroscopy on DNA, muscle protein titin, polymers or more complex structures like bacteria flagella, 3-D imaging, etc. ) the availability of instruments is crucial, especially for new groups and young scientists with limited funds. The price tag of AFMs runs in the hundreds of thousand s of dollars, though. Until now, AFM heads are made of metal materials by conventional milling, which restricts the design and increases the costs. German researchers have shown that rapid prototyping can be a quicker and less costly alternative to conventional manufacturing.
Ever since Roman glass blowers made the Lycurgus cup, some 2,400 years ago, researchers and engineers have figured out to do all kinds of things with light, be it in optical fiber communications; the use of lasers for welding, cutting and surface modification of materials; photonic gyroscopes in aviation; or optical switches in computing. As a general field of science, photonics defines the knowledge devoted to the generation, transmission, detection, control and handling of light. One sub-domain, nanophotonics deals with the manipulation and emission of light using nanoscale material and devices. One of the sizzling hot topics within nanophotonics is plasmonics, which holds the promise of a class of subwavelength-scale optoelectronic components that could form the building blocks of a chip-based optical device technology that is scaleable to molecular dimensions. Here, we report on the latest achievements of a Spanish-French group of researchers that brings the exiting concept of an optically driven lab-on-a-chip closer.
Recent developments in spectroscopic techniques allow highly sensitive image detection both in vitro and in vivo on the individual cell level. These methods depend on nanometer-size particles as detection probes. One class of such particles, so-called nanocrystals or quantum dots (qdots), is very popular for constructing detection probes for biolabeling. Scientists have discovered that these nanocrystals can enable researchers to study cell processes at the level of a single molecule and may significantly improve the diagnosis and treatment of diseases such as cancers. Qdots are either used as active sensor elements in high-resolution cellular imaging, where the fluorescence properties of the qdots are changed upon reaction with the analyte, or in passive label probes where selective receptor molecules such as antibodies have been conjugated to the surface of the dots. Qdots could revolutionize medicine. Unfortunately, most of them are toxic. Ironically, the existence of heavy metals in qdots such as cadmium, a well-established human toxicant and carcinogen, poses potential dangers especially for future medical application, where qdots are deliberately injected into the body. As the use of nanomaterials for biomedical applications is increasing, environmental pollution and toxicity have to be addressed, and the development of a non-toxic and biocompatible nanomaterial is becoming an important issue. Researchers are now proposing the use of nanoscale diamond particles as a non-toxic alternative to heavy metal qdots.
Inhalation, or respiratory, therapy is a fairly old discipline of medicine that dates back to ancient times (and not always for purely therapeutic effects; witness the hookah). In the late 18th century, earthenware inhalers became popular for the inhalation of air drawn through infusions of plants and other ingredients and about 50 years ago the first pressurized metered dose inhaler was put on the market. Especially people suffering from asthma are very familiar with inhalers - devices that help deliver a specific amount of medication to the lungs. The delivery of drugs via the pulmonary route is a potentially effective form of therapy not only for asthma but also for for patients with other chronic diseases, including the debilitating hereditary disease, cystic fibrosis, type I diabetes (insulin is absorbed well through the lungs), and recently lung cancer. During inhalation therapy the drugs are delivered in aerosol form, meaning that very small particles of the drug are suspended in air (liquid particles make mist, solid particles make fume or dust). Unfortunately, state the-of-the-art aerosol delivery technologies do not allow to target aerosols to specific regions of the lung. Researchers in Germany now have show that aerosols containing magnetic nanoparticles can be guided inside the lungs and thus offer a potential new route for lung cancer treatment.
If you have been an investor in nanotechnology companies and been lured by the promised riches, the picture doesn't look very pretty right now. We have updated our Nanotechnology Stock Index Performance chart, that we first showed six months ago, and the performance gap between the Dow Jones and the nanotechnology index funds has widened significantly (it looks even worse if you replace the Dow Jones industrial Index with a broad market index such as the Russell 2000). Of course, individual nanotechnology stocks have done better, but then, some have done much worse. That brings us to the question: What will it take for nanotechnology, taken as a set of enabling technologies, to realize its disruptive potential and create value for nanotechnology companies? An interesting answer can be found in an analysis of the recent Unidym and Carbon Nanotechnologies merger. Growth in the sector through consolidation may enable the creation of companies with the critical mass necessary to finally get public investors really excited about nanotechnology.
Finding out how much power all the computers in the U.S., not to mention the world, are using seems to be an impossible task. We tried. The latest data from the Department of Energy (DoE) for household computer use is from 2001, for office use, from 1999. This is strange because when you do some back of the envelope calculations you arrive at some pretty staggering numbers. An estimated 1 billion computers in 2008 will use some 200 billion kWh of electricity (that's roughly what all households in New York City combined use over five years), generating about 127 million tonnes of CO2 in the process. And that's just for desktop and laptop computers, not including peripherals or the billions of chips used in other electronic devices. Researchers are now proposing to build a fully mechanical computer based on nanoelectromechanical (NEMS) components that would use considerably less energy. Inspired by a classical mechanical computer design from 200 years ago, the main motivation behind constructing such a computer is threefold: (1) mechanical elements are more robust to electromagnetic shocks than current dynamic random access memory (DRAM) based purely on complimentary metal oxide semiconductor (CMOS) technology, (2) the power dissipated can be orders of magnitude below CMOS and (3) the operating temperature of such an NMC can be an order of magnitude above that of conventional CMOS. Today, such a mechanical computer is only a hypothetical device. However, any effort to reduce the power consumption of computers, and not increase them as happens with every new chip generation, seems like a worthwhile effort.
Just a few days ago we ran a Spotlight on nanobionics that addressed some of the issues of bridging the interface between electronics and biology. Today we'll take a look at some leading edge research in the field of neural engineering - an emerging discipline that uses engineering techniques to investigate the function and manipulate the behavior of the central or peripheral nervous systems. Neural engineering is highly interdisciplinary and relies on expertise from computational neuroscience, experimental neuroscience, clinical neurology, electrical engineering and signal processing of living neural tissue, and encompasses elements from robotics, computer engineering, neural tissue engineering, materials science, and nanotechnology. In order for neural prostheses to augment or restore damaged or lost functions of the nervous system they need to be able to perform two main functions: stimulate the nervous system and record its activity. To do that, neural engineers have to gain a full understanding of the fundamental mechanisms and subtleties of cell-to-cell signaling via synaptic transmission, and then develop the technologies to replicate these mechanisms with artificial devices and interface them to the neural system at the cellular level. The first steps toward precise, informative and biocompatible neural interfaces have been made already.