Tag Archives: UCL

The yin and the yang of carbon nanotubes and toxicity

 

Illustration courtesy of the University College of London (UCL). Downloaded from http://www.ucl.ac.uk/news/news-articles/0113/130115-chemistry-resolves-toxic-concerns-about-carbon-nanotubes

Illustration courtesy of the University College of London (UCL). Downloaded from http://www.ucl.ac.uk/news/news-articles/0113/130115-chemistry-resolves-toxic-concerns-about-carbon-nanotubes

Researchers at the University College of London (UCL), France’s Centre national de la recherche scientifique (CNRS), and Italy’s University of Trieste have determined that carbon nanotube toxicity issues can be addressed be reducing their length and treating them chemically. From the Jan. 15,2013 news item on ScienceDaily,

In a new study, published January 15 [2013] in the journal Angewandte Chemie, evidence is provided that the asbestos-like reactivity and pathogenicity reported for long, pristine nanotubes can be completely alleviated if their surface is modified and their effective length is reduced as a result of chemical treatment.

First atomically described in the 1990s, carbon nanotubes are sheets of carbon atoms rolled up into hollow tubes just a few nanometres in diameter. Engineered carbon nanotubes can be chemically modified, with the addition of chemotherapeutic drugs, fluorescent tags or nucleic acids — opening up applications in cancer and gene therapy.

Furthermore, these chemically modified carbon nanotubes can pierce the cell membrane, acting as a kind of ‘nano-needle’, allowing the possibility of efficient transport of therapeutic and diagnostic agents directly into the cytoplasm of cells.

Among their downsides however, have been concerns about their safety profile. One of the most serious concerns, highlighted in 2008, involves the carcinogenic risk from the exposure and persistence of such fibres in the body. Some studies indicate that when long untreated carbon nanotubes are injected to the abdominal cavity of mice they can induce unwanted responses resembling those associated with exposure to certain asbestos fibres.

In this paper, the authors describe two different reactions which ask if any chemical modification can render the nanotubes non-toxic. They conclude that not all chemical treatments alleviate the toxicity risks associated with the material. Only those reactions that are able to render carbon nanotubes short and stably suspended in biological fluids without aggregation are able to result in safe, risk-free material.

Here’s a citation and link for this latest  research, from the ScienceDaily news item where you can also read the lead researcher’s comments about carbon nanotubes, safety, and unreasonable proposals to halt production,

Hanene Ali-Boucetta, Antonio Nunes, Raquel Sainz, M. Antonia Herrero, Bowen Tian, Maurizio Prato, Alberto Bianco, Kostas Kostarelos. Asbestos-like Pathogenicity of Long Carbon Nanotubes Alleviated by Chemical Functionalization. Angewandte Chemie International Edition, 2013; DOI: 10.1002/anie.201207664

The article is behind a paywall. I have mentioned long carbon nanotubes and their resemblance to asbestos fibres in several posts. The  Oct. 26, 2009 posting [scroll down about 1/3 of the way] highlights research which took place after the study where mice had carbon nanotubes injected into their bellies; in this second piece of research they inhaled the nanotubes.

ETA Jan. 21, 2013: Dexter Johnson gives context and commentary about this latest research into long multiwalled nanotubes (MWNTs) which he sums up as the answer to this question “What if you kept the MWNTs short?”  in a Jan. 18, 2013 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website)

COllaborative Network for Training in Electronic Skin Technology (CONTEST) looking for twelve researchers

The CONTEST (COllaborative Network for Training in Electronic Skin TechnologyCOllaborative Network for Training in Electronic Skin Technology) project was launched today in Italy. According to the Aug. 21, 2012 news item on Nanowerk,

“Flexible electronics” is one of the most significant challenges in the field of future electronics. The possibility of realizing flexible and bendable electronic circuits, that can be rolled up, twisted or inserted in films around objects, would introduce a range of infinite applications in multiple fields, including healthcare, robotics and energy.

In this area, the Fondazione Bruno Kessler of Trento will coordinate the CONTEST project (COllaborative Network for Training in Electronic Skin Technology), an Initial Training Network (ITN) Marie Curie project funded by the European Commission involving European research, academic and business players. These include seven full partners (Fondazione Bruno Kessler, Italy; ST Microelectronics, Italy; Technical University Munich, Germany; Fraunhofer EMFT, Germany; University College London, UK; Imperial College London, UK; and Shadow Robotics Company, UK) and two associate partners (University of Cambridge, UK, and University of Tokyo, Japan).

The CONTEST project page at the Fondazione Bruno Kessler website offers more details,

At the heart of the CONTEST programme lies the multidisciplinary research training of young researchers. The CONTEST network will recruit twelve excellent Early-Stage Researchers (e.g. PhD students) and two Experienced Researchers (e.g. Post-Doc fellows). Information for submitting applications is available at the project’s website: http://www.contest-itn.eu/.
CONTEST activities will be coordinated by Ravinder S. Dahiya, researcher at the Bio-MEMS Unit (BIO-Micro-Electro-Mechanical-Systems) of  the Center for Materials and Microsystems (Fondazione Bruno Kessler) and by Leandro Lorenzelli, head of the Bio-MEMS Unit.
“The disruptive flexible electronics technology – says Ravinder S. Dahiya – will create change and improve the electronic market landscape and usher in a new revolution in multifunctional electronics. It will transform to an unprecedented degree our view of electronics and how we, as a society, interact with intelligent and responsive systems.”
“The investigation, in a very multidisciplinary framework, of technological approaches for thin flexible components – explains Leandro Lorenzelli – will generate new paradigms and concepts for microelectronic devices and systems with new functionalities tailored to the needs of a wide range of applications including robotics, biomedical instrumentations and smart cities.”

Here’s more about the 12 researchers they’re recruiting, excerpted from the Job Openings page on the CONTEST project website (Note: I have removed some links),

We have been awarded a large interdisciplinary project on electronic skin and applications, called CONTEST (COllaborative Network for Training in Electronic Skin Technology). We are therefore looking for 12 excellent Early-Stage Researchers (e.g. PhD students) and 2 Experienced Researchers (e.g. Post-Doc), associated to:

  • Fondazione Bruno Kessler, Trento, Italy (2 Early-Stage Researcher positions on silicon based flexible sensors (e.g. touch sensors), electronic circuits and 1 Experienced Researcher position on system integration)  …,
  • ST Microelectronics, Catania, Italy (2 Early-Stage Researcher positions on chemical/physical sensors on flexible substrates, and metal patterned substrates for integrating flexible sensing elements)…,
  • Technical University Munich, Germany (3 Early-Stage Researcher positions on organic semiconductor based electronics devices and circuits, modeling of flexible devices and sensors … , and artificial skin in humanoids…,
  • Fraunhofer EMFT, Munich, Germany (1 Early-Stage Researcher position on assembly on film substrates and foil integration as well as 1 Experienced Researcher position on reliability and ESD issues of components during flex integration) … ,
  • University College London, UK (2 Early-Stage Researcher positions on organic semiconductor based interconnects, solutions processed sensors, alternative on-skin energy schemes, patterning of e-skin and stretchable interconnects using blends of graphene in polymeric materials …
  • Imperial College London, UK (1 Early-Stage Researcher position on human sensori-motor control and robotics) …, and
  • Shadow Robotics Company, UK (1 Early-Stage Researcher position on biorobotics and mechatronics) ….

Mobility rules apply to all these positions. Researchers can be of any nationality. They are required to undertake trans-national mobility (i.e. move from one country to another) when taking up their appointment. One general rule applies to the appointment of researchers: At the time of recruitment by the host organization, researchers must not have resided or carried out their main activity (work, studies, etc.) in the country of their host organization (i.e. recruiting institute) for more than 12 months in the 3 years immediately prior to the reference date. Short stays such as holidays and/or compulsory national service are not taken into account.

Good luck to all who apply! Priority will be given to applications received by Sept. 30, 2012.

Sniffing old books

I don’t know if it’s nano but this story about old books and their smell ‘speaks’ to me. Thanks to GrrlScientist for her May 1, 2012 posting about this interesting work on degradomics,

Every time I catch a whiff of that special old books smell, I am transported through time and space to the cool welcoming basement of The Strand Bookstore in New York City, where I spent many hot humid summer afternoons, searching for some used book I’ve never seen nor even heard of, or sitting on the cold concrete floor, reading. The smell of old books isn’t pleasant, exactly, but it is unmistakable — and powerfully evocative.

“A combination of grassy notes with a tang of acids and a hint of vanilla over an underlying mustiness,” writes an international team of chemists from University College London (UCL) and the University of Ljubljana (UL) in Slovenia in their scientific paper ([Material Degradomics: On the Smell of Old Books] doi:10.1021/ac9016049 [this paper is behind a paywall despite the fact the paper was published in 2009]).

Here’s an entertaining video about this work,

Not all old books are deteriorating and expelling gases. There are some very old books that are in pretty good condition. The problem arises with the paper production techniques of the 19th and 20th centuries. We put a lot of acid in our papers and that’s what’s breaking down the material. From GrrlScientist’s May 1, 2012 posting,

The one factor that speeds a book’s death more rapidly than any other is acidity: paper that is too acidic significantly decreases a book’s lifespan. These papers are cheap and easy to mass produce. This explains why a newspaper clipping left in the pages of a book creates an ugly orange-brown stain on the book’s pages. But books have also been printed on acidic paper. Many of the books now crowding onto shelves in used bookstores were published in the 19th and 20th centuries; yellowing books with brown spots and crackling bindings that were mass printed on cheap paper that was too acidic. These books are aging rapidly whilst much older books are still in good shape because the paper they were printed on was much purer.

The paper’s lead author, Matija Strlič, is a senior lecturer at the University College of London (UCL) and he has a research interest that I did not realize existed, Heritage Smells,

Research interests span multi-disciplinary research linked to cultural heritage. The focus of these efforts are the development of new scientific tools and methods of study of heritage materials, collections and their interactions with the environment. Among the pioneering contributions are the development of degradomics, use of Near Infrared Spectrometry with chemometric data analysis in heritage science, use of chemiluminometry for studies of degradation of organic heritage materials, and studies of emission and absorption of volatile degradation products in heritage collections. My current research interests include development and use of damage functions and integrated modeling of heritage collections.

Presently, Matija Strlic is the Principal Investigator of the UK AHRC/EPSRC Science and Heritage Programme project Collections Demography (2010-2013) and a Co-Investigator on Heritage Smells! (2010-2013).  He is also involved in  several other projects, including the EU projects POPART (2009-2012, “Preservation of plastic artefacts in museum collections”) and TEACH (2009-2011, “Technologies and tools to prioritize assessment and diagnosis of air pollution impact on immovable and movable cultural heritage”), and UK Technology Strategy Board-funded project Heritage Intelligence (2009-2011).
In the past few years he has been  involved in other large collaborative projects: coordination of SurveNIR (2005-2008, “Near Infrared Tool for Collection Surveying”), scientific coordination of Papylum (2001-2004, “Chemiluminescence – a novel tool in paper conservation studies”), and participation in PaperTreat (2005-2008, “Evaluation of mass deacidification processes”), InkCor (2002-2005, “Stabilisation of iron-gall ink containing paper”) and MIP (2002-2005, “Metals in paper”). He co-coordinated the 8th European Conference on Research for Protection, Conservation and Enhancement of Cultural Heritage, Ljubljana, Slovenia, 10-13 November 2008.

Our paper is crumbling, eh? That means song sheets with the notations from composers such as Beethoven, etc.; original editions of important books of literature and nonfiction; drawings and prints by important artists; and scientific and other research papers; in other words,  historical documents of all kinds will be disappearing unless researchers can find a solution to the problem.

Body parts nano style

In early July 2011, there were reports of a new kind of transplant involving a body part made of a biocomposite. Andemariam Teklesenbet Beyene underwent a trachea transplant that required an artificial windpipe crafted by UK experts then flown to Sweden where Beyene’s stem cells were used to coat the windpipe before being transplanted into his body.

It is an extraordinary story not least because Beyene, a patient in a Swedish hospital planning to return to Eritrea after his PhD studies in Iceland, illustrates the international cooperation that made the transplant possible.

The scaffolding material for the artificial windpipe was developed by Professor Alex Seifalian at the University College London in a landmark piece of nanotechnology-enabled tissue engineering. Tim Harper in his July 25, 2011 posting provides more details about the scaffolding,

A team led by Professor Alexander Seifalian (UCL Division of Surgery & Interventional Science; professor of nanotechnology and regenerative medicine at University College London, UK), whose laboratories are headquartered at the Royal Free Hospital, created a glass mold of the patient’s trachea from X-ray computed tomography (CT) scans of the patient. In CT, digital geometry processing is employed to generate a 3D image of the inside of an object from a large series of 2D X-ray images taken around one single axis of rotation.

Then, they manufactured a full size y-shaped trachea scaffold at Professor Seifalian’s laboratories. The scaffold of the trachea was built using a novel nanocomposite polymer developed and patented by Professor Seifalian. Professor Seifalian worked together with Professor Paolo Macchiarini at Karolinska Institutet, Stockholm, Sweden (who also holds an Honorary appointment at UCL).

Professor Seifalian and his team used a porous novel nanocomposite polymer to build the y-shaped trachea scaffold. The pores were millions of little holes, providing this way a place for the patient’s stem cells to grow roots. The team cut strips of the novel nanocomposite polymer and wrapped them around the glass mold creating this way the cartilage rings that conferred structural strength to the trachea.

After the scaffold construct was finished, it was taken to Karolinska Institutet where the patient’s stem cells were seeded by Professor Macchiarini’s team.

Harper goes on to provide more details and insight into what makes this event such an important one.

Meanwhile, Dexter Johnson’s (Nanoclast blog in the IEEE website) July 21, 2011 posting poses a question,

While the nanocomposite scaffold is a critical element to the artificial organ, perhaps no less important was the bioreactor used to grow the stem cells onto it, which was developed at Harvard Bioscience.

If you needed any evidence of how nanotechnology is not only interdisciplinary, but also international, you could just cite this case: UK-developed nanocomposite for the scaffolding material, US-based bioreactor in which the stem cells were grown onto the scaffolding and a Swedish-based medical institute to perform the transplant.

So I ask, which country or region is going to get rich from the breakthrough?

It’s an interesting question and I don’t think I would have framed it in quite that fashion largely because I don’t tend to think of countries or regions getting wealthy from biomedical products since pharmaceutical companies tend to be internationally based. Is Switzerland richer for Novartis?

I suppose I’m a product of the Canadian landscape from which I spring so I think of trees and mines as making a country or region richer as they are inextricably linked to their environment but pharmaceuticals or biomedical appliances can be manufactured anywhere. Consequently, a synthetic organ could be manufactured anywhere once the technology becomes easily available. Who gets rich from this development? I suspect that will be a person or persons if anyone but, not a region or a country.

Getting back to Beyene, here are more details from the July 7, 2011 BBC News article by Michelle Roberts,

Dr Alex Seifalian and his team used this fragile structure [the scaffold] to create a replacement for the patient, whose own windpipe was ravaged by an inoperable tumour.

Despite aggressive chemotherapy and radiotherapy, the cancer had grown to the size of a golf ball and was blocking his breathing. Without a transplant he would have died.

During a 12-hour operation Professor Macchiarini removed all of the tumour and the diseased windpipe and replaced it with the tailor-made replica [now covered with tissue grown from the patient’s bone marrow tricked into growing like cells found in a trachea].

And, importantly, Mr Beyene’s body will accept it as its own, meaning he will not need to take the strong anti-rejection drugs that other transplant patients have to.

Professor Macchiarini said this was the real breakthrough.

“Thanks to nanotechnology, this new branch of regenerative medicine, we are now able to produce a custom-made windpipe within two days or one week.

“This is a synthetic windpipe. The beauty of this is you can have it immediately. There is no delay. This technique does not rely on a human donation.”

He said many other organs could be repaired or replaced in the same way.

A month on from his operation, Mr Beyene is still looking weak, but well.

Sitting up in his hospital bed, he said: “I was very scared, very scared about the operation. But it was live or die.”

My best wishes to Beyene and his family who are also pioneers.

 

Growing into your prosthetics

Fusing skin to metal is the secret to making prosthetics more comfortable and usable. In a July 13, 2011 posting, GrrlScientist at the Guardian Science blogs highlights this pioneering research,

… thanks to the work of Professor Gordon Blunn, Head of University College London’s Centre for Bio-Medical Engineering, and his colleagues, including Dr Noel Fitzpatrick, a veterinary surgeon. Professor Blunn has been developing groundbreaking metal prosthetic implants that provide comfort and improved mobility for amputee humans and animals.

… They found that in antlers, the bone structure under the skin is very different to that of the exposed bone.

“It was very porous, with lots of tiny holes, which the dermis [the inner layer of skin] webs its way into”, explained Professor Blunn. [emphasis mine]

This observation led to their breakthrough development, known as Intraosseous Transcutaneous Amputation Prosthesis (ITAP), which uses a layer of porous and bioactive (hydroxyapatite-coated) surfaces that encourage adhesion by living tissues. This living “seal” prevents bacterial infections, thereby allowing surgeons to provide amputees with securely-attached limbs that carry weight in a natural way.

Currently, battery-powered sensors allow human amputees to consciously control the movement of downstream portions of the prosthetic limb, such as flexing the hand on a prosthetic arm.

As an excuse for including this item here on the blog and until I hear otherwise, I choose to think of those tiny holes as being at the nanoscale . Plus, I’ve written about prosthetics and human enhancement a number of times.  Here’s the first in a four-part series on Robots and Human Enhancement, July 22, 2009 posting.

As for Blunn’s work, GrrlScientist includes a video and pictures as well as more details about it.