Originally Published EMDM November 2005
INDUSTRY NEWS
NanoEurope Explores the Future of Medical Technology
Robert Lyng
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| Multiphysics simulation developed by Comsol shows the heat field caused by a current flowing through an electric probe designed to treat malignant tissue. |
"Small is beautiful" could well have been the motto of the third annual NanoEurope conference and trade show held at the Olma Messe in the picturesque town of St. Gallen, Switzerland. The three-day event, from 13 to 15 September, hosted approximately 90 exhibitors as well as a wide-ranging and comprehensive conference. Dozens of papers were presented, some of which addressed life science issues.
Trends in drug delivery, molecular imaging, implant coatings, and the development of nanocomposite and ceramic materials were touched on by Ineke Malsch. She heads Malsch TechnoValuation (Utrecht, Netherlands), a consultancy devoted to the intersection of emerging technologies and larger societal issues. One flash point, she noted, involves the fears raised by nanotechnology and its possible risks, which will inevitably play a major role in its regulation. The risks, according to Malsch, include the potential of these minute materials to permeate the blood-brain barrier, and the possible toxicity of man-made nanoparticles. In a recent study on attitudes toward nanotechnology, Malsch determined that 75% of those questioned rated human exposure to free nanoparticles or other nanostructures as an urgent hazard. The environmental release of nanoparticles was considered an imminent hazard by 40% of respondents, while 20% cited the life cycle of nanomaterials.
Joachim Grossman of Süd-Chemie (Munich) presented a paper on his company’s Nanofil additives at the conference. These materials have potential applications in a number of sectors, including the medical arena.
Nanofil additives are produced from natural high-purity layered silicate (called Bentonite) based on the mineral montmorrillonite. In its natural state, the material is hydrophilic and organophobic, but it can also be engineered to be hydrophobic. Exfoliation of organically modified montmorrillonite in monomers and polymers results in so-called organoplates, making it possible to achieve a very fine and homogeneous dispersion of Nanofil.
The additive can be 50X thinner than conventional layered fillers like kaolin, talc, or mica. Fully exfoliated Nanofil varies between 100 and 500 nm diam with a layer thickness of only 1 nm. The layer’s unique structure results in an unusually high aspect ratio of more than 100. Polymers reinforced with nanocomposite additives are only slightly denser than unfilled polymers, yet because of the small particle size and high aspect ratio, a very low concentration of Nanofil can yield significant improvements in a polymer’s mechanical and thermal properties as well as its barrier characteristics. Improved stiffness (without loss of impact strength) and transparency, a reduction in permeability and shrinkage, and increased solvent resistance are among the benefits, according to the firm.
Sol-gel technology was discussed by Harry Kopola from VTT Electronics, a government-funded research institute in Tampere, Finland. These highly printable materials are manipulated at the molecular level through the addition of a catalytic acid and other chemicals. Sol-gel products are biocompatible and provide the highest possible fluorescence when antibodies are photogravure-printed onto them, noted Kopola. In another form, the material accommodates fluidic channels for multianalytical applications.
Arthroscopic SFM May Aid in Osteoarthritis Detection
The promise of nanotechnology was also in full display on the show floor. One interesting development was showcased at the stand of the Swiss Nationaler Forschungsschwerpunkt,“Nanowissenschaften” (National Centre of Competence in Research (NCCR), “Nanoscale Sciences”). The centre includes numerous scientific and engineering faculties from the universities of Basel, Neuchâtel, Zürich, and Lausanne, and partners from the IBM research laboratory and Swiss Federal Institute of Technology. Medical nanotechnology projects are led by professor Ueli Aebi at the University of Basel. The centre’s most ambitious current medical research involves the development of an arthroscopic scanning force microscope (SFM) for in situ cartilage inspection of knee and hip joints. This technology may enable early detection of osteoarthritis, a disease affecting millions of people.
The device uses a cantilever with a 20-nm tip for indentation testing. This allows imaging of the individual collagen fibres while the soft glycosamino-glycon moiety between the hard fibres is probed. Quantitative ex vivo evaluations of the technique are currently being conducted by arthroscopically performing cylindrical punch biopsies approximately 7 mm long and 2 mm diam. Veronica Cerletti, NCCR scientific manager, estimates that it will be about another five years before the system is on the market for in situ scanning.
So-called molecular machines are being explored at the Competence Centre Nanoanalysis, a network centered around the physics departments of the universities of Hamburg, Munich, and Münster, and the Excellence Network NanoBioTechnology in Munich. Stefan Lichtenhalter of the Adolf Butenandt Institute of the Ludwig Maximilians University in Munich heads the molecular neurodegeneration group. It aims to develop new therapeutic approaches to the treatment of Alzheimer’s disease.
The group’s attention is focused on proteins that act as a molecular machine within the cell and play an important role in the pathogenesis of Alzheimer’s disease. The molecular machine consists of different proteins and causes ecto-domain shredding of other membrane proteins, thereby regulating intercellular communication. This process is also important in embryonic development, in the functioning of the immune system, and possibly in cancer formation. Identifying and ultimately regulating the proteins in the machine is one of the main goals of the research.
Wolfgang J. Parak, also of the University of Munich, heads the Bio-Quantum Dots Group, which is researching hybrid nanomaterials and their applications. By controlling the shape and size of a broad spectrum of colloidal nanoparticles, the group is developing a material that has both magnetic and fluorescent properties. The group’s strategies to attain this goal include chemically synthesizing a nanocomposite material, linking two different nanomaterials with DNA, and incorporating two different nanomaterials in polymer capsules. Potential applications include the use of semiconductor nanoparticles as single-electron transistors to build a complete circuit, developing a new generation of biosensors by conjugating particles with biological molecules, and embedding functional particles in polymer capsules for exact drug targeting.
Doing the Math
Elsewhere on the show floor, FEI (Hillsboro, OR, USA) treated attendees to a demonstration of its 3-D imaging software for medical technology. Its DualBeam product combines a scanning electron microscope with a focused ion beam (FIB) in a single unit. The FIB serves as a “nanoscalpel,” enabling high-precision slicing to reveal a sample’s 3-D structure. Xplore3D is the company’s complete 3-D imaging product for transmission electron microscopes, using electron tomography and single-particle analysis for imaging at the nanolevel.
The recognition that traditional mathematical analysis has expanded into virtually every area of science and engineering was a theme at the stand of Comsol (Burlington, MA, USA) and FEMLAB GmbH (Zürich, Switzerland). The use of models enables engineers to account simultaneously for multiple physical properties, noted the companies. For example, it is possible to study electrical fields in a medical device, the resulting heat, and its effects on human tissue within one integrated environment. Their programs can be run on a standard office PC and can be applied in such areas as localized treatment, dose planning, and nanoscale drug delivery.
Small, indeed, may be beautiful, but the general attitude among speakers, exhibitors, and visitors was that the future of nanotechnology is the next big thing.
Copyright ©2005 European Medical Device Manufacturer
