Imagine a toothpaste that not only seeks out but actually repairs damage to tooth enamel. For those who dread their annual visit to the dentist, this may sound like science fiction. For people in Japan, it is a reality. Using nanoparticles, Japan's Sangi Company, Ltd., has sold more than 50 million tubes - and continues to expand its line of products containing nanoparticles. Scientists have learned to synthesize hydroxyapatite, a key component of tooth enamel, as nanosized crystals. When nano-hydroxyapatite is used in toothpaste, it forms a protective film on tooth enamel, and even restores the surface in damaged areas. Availability of similar products that claim to actually repair cavities is just around the corner. Unlikely as it seems at first blush, the $200 billion global cosmetics industry is one of the major players in the emerging field of nanotechnology. According to the Centre for the Study of Environmental Change at Lancaster University in Britain, the cosmetics industry already holds the largest number of patents for nanoparticles - and be it toothpaste, sunscreen, shampoo, hair conditioner, lipstick, eye shadow, after shave, moisturizer or deodorant, the industry is leading the way.
The last few years saw tremendous progress in the use of nanoparticles to enhance the in vivo efficiency of many drugs. Currently used pharmaceutical nanocarriers, such as liposomes, micelles, nanoemulsions, polymeric nanoparticles and many others demonstrate a broad variety of useful properties, such as for instance increased longevity in the blood, specific targeting to certain disease sites, or enhanced intracellular penetration. Some of these pharmaceutical carriers have already made their way into clinics, while others are still under preclinical development. In the next phase of developing nanocarriers, researchers are intrigued by the possibility to synthesize pharmaceutical nanocarriers that possess not only one but several properties. Such particles can significantly enhance the efficacy of many therapeutic and diagnostic protocols. A brandnew review paper considers current status and possible future directions in the emerging area of multifunctional nanocarriers with primary attention on the combination of such properties as longevity, targetability, intracellular penetration and contrast loading.
Artificial opals are gemstones that are of considerable scientific and technological interest as photonic crystals, as components of light sources, solar cells, and chemical sensors. They are conveniently made from periodic stackings of nanospheres. It would be exciting if one could fabricate optical cavities in these photonic crystals by removing, or adding high dielectric material to a single unit cell in the structure. These optical cavities would localize light that potentially enables the fabrication of high-resolution miniature on-chip sensors, or even qubits for quantum computers. Previously, such controlled modification of the nanostructure of a single colloid in an opal has not been achieved. Now, researchers in The Netherlands developed a method for realizing both single and arrays of material cavities, or defects, in individual colloids on the surface of silicon dioxide artificial opals by a focused ion beam milling technique. This research could ultimately lead to the fabrication of a photon-on-demand light source.
While the first reported fullerenes and nanotube structures were composed of carbon, it was soon recognized that a plethora of comparable inorganic candidates should also exist. A rich assortment of IF (inorganic fullerene-like structures, or IF for short) nanostructures have been synthesized, and are finding practical uses in tribology, photonics, batteries, and catalysis. On such inorganic molecule that can achieve fullerene-like nanostructures, cesium oxide, is particularly useful for a multitude of applications in photoemissive systems. Unfortunately, it is extremely reactive in the ambient atmosphere, so its production and handling require high vacuum and very pure inert conditions; which translates into problematic and expensive manufacturing and handling, which in turn limits its technological scope and device lifetime. In their quest for a relatively uncomplicated high-yield synthesis method for chemically stable cesium oxide IFs, scientists succeeded in exploiting highly concentrated solar radiation (ultrabright incoherent light) toward that end. This resulted in a simple, inexpensive, and reproducible photothermal procedure for synthesizing IF nanoparticles.
Wound healing is a complex process and has been the subject of intense research for a long time. Wound healing proceeds through an overlapping pattern of events including coagulation, inflammation, proliferation, and matrix and tissue remodeling. The holy grail for wound healing is accelerated healing without scars. Silver has been used for centuries to prevent and treat a variety of diseases. Its antibacterial effect may be due to blockage of the respiratory enzyme pathways and alteration of microbial DNA and the cell wall. In addition to its recognized antibacterial properties, some authors have reported on the possible pro-healing properties of silver. The use of silver in the past has been restrained by the need to produce silver as a compound, thereby increasing the potential side effects. Nanotechnology has provided a way of producing pure silver nanoparticles and this has provided a new therapeutic modality for use in burn wounds. Nonetheless, the beneficial effects of silver nanoparticles on wound healing remain unknown. A new study reports that silver nanoparticles can promote wound healing and reduce scar appearance.
Nano-this and nano-that. Nanotechnology moves into the public consciousness. This 'nanotrend' has assumed 'mega' proportions: Patent offices around the world are swamped with nanotechnology-related applications; investment advisors compile nanotechnology stock indices and predict a coming boom in nanotechnology stocks with estimates floating around of a trillion-dollar industry within 10 years; pundits promise a new world with radically different medical procedures, manufacturing technologies and solutions to environmental problems; nano conferences and trade shows are thriving all over the world; scientific journals are awash in articles dealing with nanoscience discoveries and nanotechnology breakthroughs. Nanotechnology has been plagued by a lot of hype, but cynicism and criticism have not been far behind. The media can run amok when news about potential health problems with nanoproducts surface (as recently happened with a product recall for a bathroom cleaner in Germany). These discussions around nanotechnology epitomize the contemporary processes of making the future present. An interesting approach to dealing with the lack of consensus in the views on nanotechnology identifies eight main nodes of nanotechnology discourse and describes these "islands" of discussion, examines their interactions and degrees of isolation from each other.
Carbon nanotubes (CNTs) have great potential applications in making ballistic-resistance materials. The remarkable properties of CNTs makes them an ideal candidate for reinforcing polymers and other materials, and could lead to applications such as bullet-proof vests as light as a T-shirt, shields, and explosion-proof blankets. For these applications, thinner, lighter, and flexible materials with superior dynamic mechanical properties are required. A new study by researchers in Australia explores the energy absorption capacity of a single-walled carbon nanotube under a ballistic impact. The result offers a useful guideline for using CNTs as a reinforcing phase of materials to make devices to prevent from ballistic penetration or high speed impact.
If current research is an indicator, wearable electronics will go far beyond just very small electronic devices. Not only will such devices be embedded on textile substrates, but an electronics device or system could become the fabric itself. Electronics textiles will allow the design and production of a new generation of garments with distributed sensors and electronic functions. Such e-textiles will have the revolutionary ability to sense, act, store, emit, and move (think biomedical monitoring functions or new man-machine interfaces) while leveraging an existing low-cost textile manufacturing infrastructure. Today, only a few steps towards new architectural possibilities of realizing circuit topologies that can be implemented with textile technique have been made: one an example of nonplanar devices and one of textile based devices. Researchers in Italy have now developed an organic field effect transistor (OFET) fully compatible with textile processing techniques.