Blog @ NanoVic - Nanotechnology Blog

Forget manipulating your chromosomes to make you better, faster, stronger…. What about just manipulating DNA to make you smile?

This image (credit to Paul Rothemund) shows a shape made by researchers from DNA. It was created a couple of years ago by researchers developing what has been termed Structural DNA Nanotechnology (SDN), but which might be easier to think of as DNA orgagami. It’s been known for decades that due to the way DNA molecules bind (via complementary base-pairing), it should be easy enough to engineer nanoscale shapes.

The company Nanorex developed the current method of using a very long DNA molecule as a base scaffold for attaching shorter DNA chains. The results are quite amazing and you can see some great examples of shapes and images here.

Nanorex have just announced at the recent 5^th Annual Foundations of Nanoscience conference in Utah the public release of their open-source software NE1 (Nano Engineering 1) for SDN research and education.

Holidaying in the city of Wollongong last week, I heard about the up-coming Asia Pacific Symposium on Nanobionics. Scheduled for 22-26 June 2008, the symposium aims to bring together clinicians, scientists, engineers and mathematicians in a collaborative environment to discuss the nanotechnology revolution and its impact on nanobionics. The Symposium will be hosted by the ARC Centre of Excellence for Electromaterials Science, which is headquarted at the University of Wollongong but which has additional nodes at Monash University, St Vincent’s Hospital and The Bionic Ear Institute. The program is diverse and looks very interesting, and includes a plenary presentation by Dr Graeme Clarke, the inventer of the cochlear implant. The bionic eye, one of the hot topics to emerge from the recent 2020 summit in the ACT, will be considered in a presentation by Associate Professor Gregg Suaning (University of New South Wales), entitled ‘Implantable Bionics: Considerations for Restoring Vision to the Blind’ . To learn more about the symposium visit www.electromaterials.edu.au

A new material has been developed that has been shown to heal spinal cord injuries in mice. The work has recently been published in the Journal of Neuroscience by Professor Samuel Stupp and his group at Northwestern University and describes a liquid material, which contains molecules that self-assemble into hollow, cylindrical nanofibers in vivo. These nanofibers then act as a scaffold by trapping cells, which facilitates growth of nerve fibers. The surface of the nanofibers also contains a material that inhibits the formation of scar tissue that can otherwise block nerve fibers and prevent their growth.

The liquid has been injected directly into the spinal cord of animals, restoring function to their previously paralyzed hind legs. The material then breaks down into nutrients in the body within three to eight weeks. I find these kinds of nanomaterials very exciting and worthwhile and can’t wait to see them in clinical use.

A recent newsletter from AZoNano.com features a round-up of movies that use principles of the ’small’ and nanotechnology  in their story lines. Apart from old favourites I Robot and Terminator 2 (and the cancelled screen adaption of Prey by Michael Crichton) nanotechnology in the movies seems to be fairly thinly spread. We’ve tried extending this list in the past, but it has not been a fruitful search. AZo Nano suggests Star Trek. Pictured is an example of  the Borg. Apparently the Borg originate from medical nano-machines, but you’ll have to trust Wikipedia for that!

The origins of the Borg seem to be cross-over with biotechnology, an area replete with film examples.  In fact Biotechnology Australia was able to compile a report on the portrayal of cloning in the movies and examine how this related to public attitudes on cloning.

Perhaps this leads us back to the myriad of technologies, applications, risks and benefits that fall under the term ‘nanotechnology’. It is our experience in education and public awareness that discussing the applications and then considering the technologies make most sense for most people. Nanotechnology on its own does not grip the imagination. Our search for nano-related movies will have to be much broader to capture the applications that might use nanotechnology. Anything else from Star Trek???

I’m sure most of you have had the rather nasty experience of food poisoning. For me, all it takes is catching a glimpse of one of my Aunt Judy’s chicken sandwiches to trigger my gag reflex. Ooohhh, the family Easter picnic 2005 will live with me forever.  Personal anecdotes aside, food-borne pathogens are an issue not only because they cause debilitating illness and death, but also because they are relatively slow to diagnose.  This is probably not so critical for the family picnic, but can save lives in the case of restaurants and establishments such as elderly residential facilities.  Current tests to detect Salmonella for example, can take up to 5 days to obtain a result and are relatively insensitive if only a low level of bacteria is present. A new nanotechnology-based biosensor has been developed to address this issue. As reported by Nanowerk, the American and Korean research team  fabricated a hetero-structured silicon/gold nanorod array by the glancing angle deposition (GLAD) thin film method and functionalized it with anti-Salmonella antibodies and organic dye molecules. The test works by amplification of the dye’s fluorescent signal when Salmonella is present.  Specifically, binding of Salmonella bacteria to gold nano-rod coupled antibodies enhances the fluorescence of the dye molecules which are immobilised on silicon.  The test is specific, sensitive and rapid, and can probably be adapted to suit detection of other food-borne pathogens as well.  Sounds good to me, Auntie Judy.

A gecko-inspired medical adhesive may have potential applications for sealing wounds and for replacement or augmentation of sutures or staples. 

US researchers have used a polymer poly(glycerol-co-sebacate acrylate) and modified the surface to mimic the nanotopography of gecko feet, which allows attachment to vertical surfaces.  Ideally these adhesives would also have the ability to deliver drugs or growth factors to promote healing.  The findings have been published in Proceedings of the National Academy of Sciences.

As a first demonstration, a gecko-inspired tissue adhesive from a biocompatible and biodegradable elastomer combined with a thin tissue-reactive biocompatible surface coating was been created. Tissue adhesion was optimized by varying dimensions of the nanoscale pillars, including the ratio of tip diameter to pitch and the ratio of tip diameter to base diameter. Coating these nanomolded pillars of biodegradable elastomers with a thin layer of oxidized dextran significantly increased the interfacial adhesion strength on porcine intestine tissue in vitro and in the rat abdominal subfascial in vivo environment.

Perhaps this might also lead to taking the ‘ouch’ out of removing bandaids from the skin!

Courtesy Atsushi Asano, Cornell University

While not quite on the nanoscale, an average human sperm on average is about 0.055 mm long, sperm have provided inspiration for how to power nano-sized devices. Energy to power the sperm tail (flagellum) comes from the mitochondria, the power stations of the cell, while the rear section of the tail or ‘principal piece’ gets it’s energy from glycolysis, the direct breakdown of glucose to produce energy. It’s this process that has inspired researchers at the Cornell NanoScale Science and Technology Facility to try and mimic this process to provide a power source for nanodevices. In sperm, the 10 enzymes required for glycolysis are attached to scaffolding proteins in the sperm tail, holding them in place in a unique conformation. Scientists engineered and tethered 3 of the 10 proteins to a gold surface covered in nickel ions, whilst retaining the enzymes activity. Researchers are now looking to extend the project to include all 10 protens necessary to complete a nano ‘power supply’.

Who would have thought that design would be so important to nanotechnology?  They may seem like very different disciplines, but, they actually go together hand-in-hand.  The importance of design became very apparent to us when we participated in the Design Victoria business immersion pilot program earlier this year, in which we discovered that design can play a very important role in shaping the development of a new technology, and in time, can also lead to a consumer-driven product.  We worked with a Melbourne-based industrial design firm, Charlwood Design, to design a prototype of an inhalation device for the delivery of insulin, based on our Pulmonary Drug Delivery project.  The results were outstanding, and the final product was sleek, sexy and compatible with the technology.  The development of the Pulmonary Delivery device is now being showcased on the newly launched Design Victoria website, leading the way on technology and design!

A nano-scale tool that distinguishes soft cancerous cells from stiffer normal ones could save lives by making it easier to diagnose cancer.  Researchers at UCLA have used an atomic force microscope to show that the surface of living cancer cells were more than 70 per cent softer than their healthy counterparts.  This measureable difference in elasticity held true across lung, breast and pancreatic cancers, and could provide a powerful means of detecting malignant cells that might otherwise escape notice.  The study has been pulished in the British Journal Nature Nanotechnology.

The researchers removed body fluid from suspected cancer patients and used atomic force microscopes to apply minute amounts of pressure on individual cells.  It was discovered malignant cells were four times as soft as normal tissue across all three types of cancer examined.

It all sounds very exciting and anything that will assist with earlier detection can only be good.

Researchers from the Northwestern University have shown that nanodiamonds are very effective at delivering chemotherapy drugs to cells without the negative effects associated with current drug delivery agents.  This is the first study to demonstrate the use of nanodiamonds in biomedicine.  Other applications where this model might be used could be fighting tuberculosis or viral infections.  The study has been published online by the journal Nano Letters.

One of the potential advantages is improved cancer treatment by limiting uncontrolled exposure of toxic drugs to the body.  The aggregated clusters of nanodiamonds were shown to be ideal for carrying a chemotherapy drug and shielding it from normal cells so as not to kill them, releasing the drug slowly only after it reached its cellular target.  Another advantage was that the nanodiamonds did not cause cell inflammation once the drug had been released, unlike materials currently being used.   Cell inflammation is a serious complication that can predispose a patient to cancer, block the activity of the cancer drug and even promote tumor growth.

I guess diamonds are therefore not just a girl’s best friend but could become man’s as well!