Using the world’s most advanced electron microscope, Eindhoven University of Technology researchers have, for the first time, captured high-resolution images of the earliest stages of bone formation. Utilizing the FEI Company’s cryoTitan microscope they imaged small clusters of calcium carbonate and showed that clusters consisting of around ten ions formed the basis for the process resulting in nucleation into larger, unstructured nanoparticles with an average diameter of around thirty nanometers through which the crystalline biominerals are formed.

The work, published in Science magazine offers increased understanding of bone, tooth and shell formation and could have important implications for creating industrial biomimetic materials.

Source: Nanowerk

Posted: March 13th, 2009 under Advanced materials, Advanced medtech, Nanomedicine.
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Researchers at the Cidetec-IK4 Research Centre at San Sebastian in Spain have developed a new type of electrochemical nanobiosensor capable of detecting mutations in DNA much more rapidly than before. The sensor technology also offers the possibility to be extended to the detection of other types of molecule.

The nanobiosensor comprises a nanotransistor, the cable of which is a carbon nanotube modified by a polymer that enables DNA to anchor. High selectivity can be achieved without the need to modify the DNA and the sensor is capable of detecting sequences, such as those implicated in particular genetic diseases directly.

Source: Basque Research

Journal reference: Nano Letters, 2009; 9 (2): 530

Cidetec-IK4

Posted: March 10th, 2009 under Advanced medtech, Nanomedicine, Nanotechnology.
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Researchers at Sandia National Laboratories, Livermore, California have succeeded in developing a device based on carbon nanotubes that can detect the entire visible spectrum of light and which may find potential uses in artificial retinas and other light gathering applications such as solar cells and miniature cameras for use in low light conditions. Earlier attempts at similar devices were only able to detect specific wavelengths.

The device utilizes carbon nanotubes decorated with three different types of chromophores, which are molecules that change shape in response to particular wavelengths of light… in the case of the Sandia research red, green and blue wavelengths. This change in shape alters the orientation of the chromophores in relation to the nanotube which, in turn, alters the conductivity of the nanotube to give a signal that can be measured. Because of their size, the nanotubes have intrinsically high resolution… around the diameter of each nanotube or 1nm.

The researchers believe that the process of manufacturing such devices could be scaled up and are also working on versions of the device that can detect infrared light, and which are more sensitive.

Source: MIT Technical Review

Posted: March 10th, 2009 under Advanced materials, Physics, Advanced medtech, Nanomedicine, Nanotechnology.
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Silk has been considered a useful material for some time for biological scaffold for some time, due to the fact that it is very strong and biocompatible. Researchers at Tuft’s University in the USA have now found that silkworm silk may also serve as an optical material for biosensors and other devices.

The team, led by Fiorenzo Omenetto, noted that a Tuft’s colleague, David Kaplan, was using the silk as a tissue engineering scaffold to build engineered corneal implants and wondered whether the material might also therefore be useful for optical devices. They found that the silk worked as well as traditional optical materials like glass and plastic and, in some cases, better, without the need for high temperature or harsh chemical processing enabling biosensing molecules such as proteins, antibodies and even enzymes to be easily attached.

The silk from the silkwork coccoons was extracted by the team into an aqueous solution providing an ideal medium into which to mix various biosensing molecules. A variety of moulds can then be used to create optical devices in different forms. A sample device incorporating haemoglobin and capable of sensing oxygen was constructed but the team believes that a whole variety of biosensing molecules could be utilised for a range of biosensing applications including glucose monitoring for diabetes, the detection of cancer markers, colour-changing sensors and sensors that can be incorporated into tissue-engineered devices to provide feedback about their performance.

Source: MIT Technology Review

Posted: January 12th, 2009 under Advanced materials, Advanced medtech, Nanomedicine.
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Researchers at Oxford University have succeeded in creating a molecular machine that can walk along a strand of DNA and which can be powered by nearby molecules. The design improves upon earlier attempts in that the walker can move in a definite direction, rather than randomly, and that the walker can stop or start according to the amount of available fuel.

The walker comprises two connected feet made from a sequence of DNA bases that attach to complementary sequences on the DNA track. As one foot attaches, the back foot is forced to lift off. The base sequences in the feet act as catalysts to release energy from the surrounding molecules to power the device.

Although some problems remain to be overcome, such as the DNA track becoming tangled, the team has hopes that the walker could be used to transport molecular loads in a “nanofactory”.

Source: New Scientist

Posted: January 12th, 2009 under Advanced materials, Advanced medtech, Nanomedicine.
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Collagen fibres in the natural cartilage protecting the knee are aligned in a parallel orientation. Achieving this configuration, and therefore optimum functionality, in a synthetic cartilage is not easy because collagen is a natural polymer that is difficult to control. Now a student at the Universitat Politècnica de Catalunya’s School of Industrial and Aeronautic Engineering at Terrassa has managed to achieve this desired effect using electrospun collagen nanofibres.

Camila Flor extruded collagen onto a nonconductive material placed between the two grounded electrospinning collecting plates and believes that the parallel orientation of the nanofibres may be related to the ratio of their diameter to the distance between the collecting plates.

To differentiate chondrocytes from stem cells into functional cartilage, the correct configuration of the scaffold material is important and Camila Flor’s work is an important step in engineering cartilage that might in future be used for knee protection in patients with protheses. The work is part of a larger project, under the supervision of Dr. Juan Hinestroza of Cornell University and funded by the Morgan Family Tissue Engineering Fund.

Source: Science Daily

Posted: November 19th, 2008 under Advanced medtech, Regenerative medicine, Nanomedicine.
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Nanotechnology is producing a wealth of new products based on utilising features and characteristics at the nanoscale including microelectronics and micromachines with moving parts. One problem at such a tiny scale is how to switch them on and off or control them as needed.

In a new study, Dr Harold Zandvliet and colleagues at the University of Twente in the
Netherlands have developed a nanoscale mechanical device, grown on a wafer of germanium, that can respond to a tiny electrical current from the tip of a scanning tunneling microscope to make two atom pairs move like the flippers of a nanoscale pinball machine. The researchers state that understanding the mechanism can provide insights into the opportunities for future atomic-scale devices.

Paper published in Nano Letters

Source: Nanotechnology Now

Posted: October 30th, 2008 under Advanced materials, Physics, Chemistry, Advanced medtech, Nanotechnology.
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Scientists from the John Innes Centre (UK), Institut Pasteur (France) and Scripps Research Institute (California, USA) have shown that a virus that withstands extreme conditions and that can infect bacteria living in temperatures of up to 80⁰C and pH 2-3, may be used as a stable nanobuilding block.

The virus, a rod-shaped rudivirus called SIRV2, infects the thermoacidiphilic bacterium Sulfolobus islandicus which is found in hot volcanic springs. The team subjected the virus to a variety of harsh environments within the laboratory and found that the viral capsule was able to withstand such conditions which make it a promising candidate as a viral nanoparticle (VNP), a form of particle that can self-assemble with high precision. To be suitable as a VNP, however, the particles must be amenable also to chemical or genetic modification and the team was able to successfully target modifications to both the ends and the body of the virus enabling it to be built up into layers or arrays.

The team thinks that the new VNP, by virtue of its stability under extreme conditions and possibility for alignment in different ways, may find useful applications in liquid crystal assembly, nanoscale templates, nanoelectronics, and biomedical applications.

Source: PhysOrg

Posted: October 28th, 2008 under Advanced materials, Advanced medtech, Nanotechnology.
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Structural DNA nanotechnology, where the nucleotides or base pairs of DNA, namely adenine (A) and thymine (T), and guanine (G) and cytosine (C) are made to self-fold into a number of different building blocks, and  is a fast-growing field within nanomedicine. Up until now, the technology has been somewhat limited by the need to synthesise all of the material from scratch. Now researchers at
Arizona State University’s Biodesign Institute, led by Hao Yan, have managed to harness the cell’s ability to copy DNA to make them into “factories” to replicate artificial DNA-based nanostructures.

The team started by taking two simple cross-shaped, four-armed shape nanostructures created from DNA, and placing them inside a phagemid, a virus-like particle infecting bacterial cells. Once inside the bacterial cell, the cell started reproducing the nanostructures. From a single infection and 1mL of cultured cells, the team found they could synthesise trillions of identical copies of the DNA nanostructures. Furthermore, the cells continued their other functions whilst tolerating the copied artificial nanostructures. Whilst acknowledging that this is an early step the team is excited that artificial structures can be copied by cells in this way which opens up the possibility of many exciting future applications

Original article at:  Small Times

Posted: October 23rd, 2008 under Advanced medtech, Nanomedicine, Nanotechnology.
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Direct interfacing of electrodes or sensors with the brain is becoming increasingly interesting to clinicians, both to treat illnesses like Parkinson’s disease and to interact with groups of cells in the brain in the case of providing patients like paraplegics with the ability to directly control interface devices like cursors or controls. In spite of the successes seen in trials, conventional electrodes have some drawbacks and limitations, such as deterioration over time and particular difficulties in receiving signals.

Researchers at the University of Texas Southwestern Medical Centre, led by Edward Keefer, have now developed electrodes, coated with carbon nanotubes that appear to be more efficient at sending and receiving electrical signals when interfaced with neurons while using less power and suffering from less noise. There are also hopes that, because of the degree of miniaturisation possible and low power requirements, the nanocoated electrodes might also find application in advanced prosthetic devices.

Read more at MIT Technology Review.

Posted: September 26th, 2008 under Advanced medtech, Nanomedicine, Nanotechnology.
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