Tag Archives: TCD

Multi-walled carbon nanotubes and blood clotting

There’s been a lot of interest in using carbon nanotubes (CNTs) for biomedical applications such as drug delivery. New research from Trinity College Dublin (TCD) suggests that multi-walled carbon nanotubes (MWCNTs) may have some limitations when applied to biomedical uses. From a Jan. 20, 2014 news item on Nanowerk (Note: A link has been removed),

Scientists in the School of Pharmacy and Pharmaceutical Sciences in Trinity College Dublin, have made an important discovery about the safety issues of using carbon nanotubes as biomaterials which come into contact with blood. The significance of their findings is reflected in their paper being published as the feature story and front page cover of the international, peer-reviewed journal Nanomedicine (“Blood biocompatibility of surface-bound multi-walled carbon nanotubes”).

A Jan. 19, 2015 TCD press release, which originated the news item, offers a good description of the issues around blood clotting and the research problem (nonfunctionalized CNTs and blood compartibility) the scientists were addressing (Note: Links have been removed),

When blood comes into contact with foreign surfaces the blood’s platelets are activated which in turn leads to blood clots being formed. This can be catastrophic in clinical settings where extracorporeal circulation technologies are used such as during heart-lung bypass, in which the blood is circulated in PVC tubing outside the body. More than one million cardiothoracic surgeries are performed each year and while new circulation surfaces that prevent platelet activation are urgently needed, effective technologies have remained elusive.

One hope has been that carbon nanotubes, which are enormously important as potentially useful biomedical materials, might provide a solution to this challenge and this led the scientists from the School of Pharmacy and Pharmaceutical Sciences in collaboration with Trinity’s School of Chemistry and with colleagues from UCD and the University of Michigan in Ann Arbour to test the blood biocompatibility of carbon nanotubes. They found that the carbon nanotubes did actually stimulate blood platelet activation, subsequently leading to serious and devastating blood clotting. The findings have implications for the design of medical devices which contain nanoparticles and which are used in conjunction with flowing blood.

Speaking about their findings, Professor Marek Radomski, Chair of Pharmacology, Trinity and the paper’s senior author said: “Our results bear significance for the design of blood-facing medical devices, surface-functionalised with nanoparticles or containing surface-shedding nanoparticles. We feel that the risk/benefit ratio with particular attention to blood compatibility should be carefully evaluated during the development of such devices. Furthermore, it is clear that non-functionalised carbon nanotubes both soluble and surface-bound are not blood-compatible”.

The press release also quotes a TCD graduate,

Speaking about the significance of these findings for Nanomedicine research, the paper’s first author Dr Alan Gaffney, a Trinity PhD graduate who is now Assistant Professor of Anaesthesiology in Columbia University Medical Centre, New York said: “When new and exciting technologies with enormous potential benefits for medicine are being studied, there is often a bias towards the publication of positive findings. [emphasis mine] The ultimate successful and safe application of nanotechnology in medicine requires a complete understanding of the negative as well as positive effects so that un-intended side effects can be prevented. Our study is an important contribution to the field of nanomedicine and nanotoxicology research and will help to ensure that nanomaterials that come in contact with blood are thoroughly tested for their interaction with blood platelets before they are used in patients.”

Point well taken Dr. Gaffney. Too often there’s an almost euphoric quality to the nanomedicine discussion where nanoscale treatments are described as if they are perfectly benign in advance of any real testing. For example, I wrote about surgical nanobots being used in a human clinical trial in a Jan. 7, 2015 post which features a video of the researcher ‘selling’ his idea. The enthusiasm is laudable and necessary (researchers work for years trying to develop new treatments) but as Gaffney notes there needs to be some counter-ballast and recognition of the ‘positive bias’ issue.

Getting back to the TCD research, here’s a link to and a citation for the paper (or counter-ballast),

Blood biocompatibility of surface-bound multi-walled carbon nanotubes by Alan M. Gaffney, MD, PhD, Maria J. Santos-Martinez, MD, Amro Satti, Terry C. Major, Kieran J. Wynne, Yurii K. Gun’ko, PhD, Gail M. Annich, Giuliano Elia, Marek W. Radomski, MD. January 2015 Volume 11, Issue 1, Pages 39–46 DOI: http://dx.doi.org/10.1016/j.nano.2014.07.005 Published Online: July 26, 2014

This paper is open access.

Monitoring health with graphene rubber bands

An Aug. 20, 2014 news item on Azonano highlights graphene research from the University of Surrey (UK) and Trinity College Dublin (Ireland),

Although body motion sensors already exist in different forms, they have not been widely used due to their complexity and cost of production.

Now researchers from the University of Surrey and Trinity College Dublin have for the first time treated common elastic bands with graphene, to create a flexible sensor that is sensitive enough for medical use and can be made cheaply.

An Aug. 15, 2014 University of Surrey press release (also on EurekAlert), which originated the news item, describes the innovation (Note: A link has been removed),

Once treated, the rubber bands remain highly pliable. By fusing this material with graphene – which imparts an electromechanical response on movement – the material can be used as a sensor to measure a patient’s breathing, heart rate or movement, alerting doctors to any irregularities.

“Until now, no such sensor has been produced that meets these needs,” said Surrey’s Dr Alan Dalton. “It sounds like a simple concept, but our graphene-infused rubber bands could really help to revolutionise remote healthcare – and they’re very cheap to manufacture.”

“These sensors are extraordinarily cheap compared to existing technologies. Each device would probably cost pennies instead of pounds, making it ideal technology for use in developing countries where there are not enough medically trained staff to effectively monitor and treat patients quickly.” [commented corresponding author, Professor Jonathan Coleman from Trinity College, Dublin]

Trinity College Dublin issued an Aug. 20, 2014 press release, which provides a little more technical detail and clarifies who led the team for anyone who may been curious about the matter,

The team – led by Professor of Chemical Physics at Trinity, Jonathan Coleman, one of the world’s leading nanoscientists – infused rubber bands with graphene, a nano-material derived from pencil lead which is 10,000 times smaller than the width of a human hair. This process is simple and compatible with normal manufacturing techniques. While rubber does not normally conduct electricity, the addition of graphene made the rubber bands electrically conductive without degrading the mechanical properties of the rubber. Tests showed that any electrical current flowing through the graphene-infused rubber bands was very strongly affected if the band was stretched. As a result, if the band is attached to clothing, the tiniest movements such as breath and pulse can be sensed.

The discovery opens up a host of possibilities for the development of wearable sensors from rubber, which could be used to monitor blood pressure, joint movement and respiration. Other applications of rubber-graphene sensors could be in the automotive industry (to develop sensitive airbags); in robotics, in medical device development (to monitor bodily motion), as early warning systems for cot death in babies or sleep apnoea in adults. They could also be woven into clothing to monitor athletes’ movement or for patients undergoing physical rehabilitation.

Professor Coleman said: “Sensors are becoming extremely important in medicine, wellness and exercise, medical device manufacturing, car manufacturing and robotics, among other areas. Biosensors, which are worn on or implanted into the skin, must be made of durable, flexible and stretchable materials that respond to the motion of the wearer. By implanting graphene into rubber, a flexible natural material, we are able to completely change its properties to make it electrically conductive, to develop a completely new type of sensor. Because rubber is available widely and cheaply, this unique discovery will open up major possibilities in sensor manufacturing worldwide.”

Here’s a link to and a citation for the paper,

Sensitive, High-Strain, High-Rate Bodily Motion Sensors Based on Graphene–Rubber Composites by Conor S. Boland, Umar Khan, Claudia Backes, Arlene O’Neill, Joe McCauley, Shane Duane, Ravi Shanker, Yang Liu, Izabela Jurewicz, Alan B. Dalton, and Jonathan N. Coleman. ACS Nano, Article ASAP DOI: 10.1021/nn503454h Publication Date (Web): August 6, 2014

Copyright © 2014 American Chemical Society

This paper is open access (I was able to open the HTML version this morning, Aug. 20, 2014). As well the researchers have made this image illustrating their work available,

[downloaded from http://pubs.acs.org/doi/full/10.1021/nn503454h]

[downloaded from http://pubs.acs.org/doi/full/10.1021/nn503454h]

The Irish mix up some graphene

There was a lot of excitement (one might almost call it giddiness) earlier this week about a new technique from Irish researchers for producing graphene. From an April 20, 2014 article by Jacob Aron for New Scientist (Note: A link has been removed),

First, pour some graphite powder into a blender. Add water and dishwashing liquid, and mix at high speed. Congratulations, you just made the wonder material graphene.

This surprisingly simple recipe is now the easiest way to mass-produce pure graphene – sheets of carbon just one atom thick. The material has been predicted to revolutionise the electronics industry, based on its unusual electrical and thermal properties. But until now, manufacturing high-quality graphene in large quantities has proved difficult – the best lab techniques manage less than half a gram per hour.

“There are companies producing graphene at much higher rates, but the quality is not exceptional,” says Jonathan Coleman of Trinity College Dublin in Ireland.

Coleman’s team was contracted by Thomas Swan, a chemicals firm based in Consett, UK, to come up with something better. From previous work they knew that it is possible to shear graphene from graphite, the form of carbon found in pencil lead. Graphite is essentially made from sheets of graphene stacked together like a deck of cards, and sliding it in the right way can separate the layers.

Rachel Courtland chimes in with her April 21,2014 post for the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers]) website (Note: A link has been removed),

The first graphene was made by pulling layers off of graphite using Scotch tape. Now, in keeping with the low-tech origins of the material, a team at Trinity College Dublin has found that it should be possible to make large quantities of the stuff by mixing up some graphite and stabilizing detergent with a blender.

The graphene produced in this manner isn’t anything like the wafer-scale sheets of single-layer graphene that are being grown by Samsung, IBM and others for high-performance electronics. Instead, the blender-made variety consists of small flakes that are exfoliated off of bits of graphite and then separated out by centrifuge. But small-scale graphene has its place, the researchers say. …

An April 22, 2014 CRANN (the Centre for Research on Adaptive Nanostructures and Nanodevices) at Trinity College Dublin news release (also on Nanowerk as an April 20, 2014 news item) provides more details about the new technique and about the private/public partnership behind it,

Research team led by Prof Jonathan Coleman discovers new research method to produce large volumes of high quality graphene.

Researchers in AMBER, the Science Foundation Ireland funded materials science centre headquartered at CRANN, Trinity College Dublin have, for the first time, developed a new method of producing industrial quantities of high quality graphene. …

The discovery will change the way many consumer and industrial products are manufactured. The materials will have a multitude of potential applications including advanced food packaging; high strength plastics; foldable touch screens for mobile phones and laptops; super-protective coatings for wind turbines and ships; faster broadband and batteries with dramatically higher capacity than anything available today.

Thomas Swan Ltd. has worked with the AMBER research team for two years and has signed a license agreement to scale up production and make the high quality graphene available to industry globally. The company has already announced two new products as a result of the research discovery (Elicarb®Graphene Powder and Elicarb® Graphene Dispersion).

Until now, researchers have been unable to produce graphene of high quality in large enough quantities. The subject of on-going international research, the research undertaken by AMBER is the first to perfect a large-scale production of pristine graphene materials and has been highlighted by the highly prestigious Nature Materials publication as a global breakthrough. Professor Coleman and his team used a simple method for transforming flakes of graphite into defect-free graphene using commercially available tools, such as high-shear mixers. They demonstrated that not only could graphene-containing liquids be produced in standard lab-scale quantities of a few 100 millilitres, but the process could be scaled up to produce 100s of litres and beyond.

Minister for Research and Innovation Sean Sherlock, TD commented; “Professor Coleman’s discovery shows that Ireland has won the worldwide race on the production of this ‘miracle material’. This is something that USA, China, Australia, UK, Germany and other leading nations have all been striving for and have not yet achieved. This announcement shows how the Irish Government’s strategy of focusing investment in science with impact, as well as encouraging industry and academic collaboration, is working.”

Here’s a link to and a citation for the researchers’ paper,

Scalable production of large quantities of defect-free few-layer graphene by shear exfoliation in liquids by Keith R. Paton, Eswaraiah Varrla, Claudia Backes, Ronan J. Smith, Umar Khan, Arlene O’Neill, Conor Boland, Mustafa Lotya, Oana M. Istrate, Paul King, Tom Higgins, Sebastian Barwich, Peter May, Pawel Puczkarski, Iftikhar Ahmed, Matthias Moebius, Henrik Pettersson, Edmund Long, João Coelho, Sean E. O’Brien, Eva K. McGuire, Beatriz Mendoza Sanchez, Georg S. Duesberg, Niall McEvoy, Timothy J. Pennycook, et al. Nature Materials (2014) doi:10.1038/nmat3944 Published online 20 April 2014

This article is mostly behind a paywall but there is a free preview available through ReadCube Access.

For anyone who’s curious about AMBER, here’s more from the About Us page on the CRANN website (Note: A link has been removed),

In October 2013, a new Science Foundation Ireland funded research centre, AMBER (Advanced Materials and BioEngineering Research) was launched. AMBER is jointly hosted in TCD [Trinity College Dublin] by CRANN and the Trinity Centre for Bioenineering, and works in collaboration with the Royal College of Surgeons in Ireland and UCC. The centre provides a partnership between leading researchers in materials science and industry and will deliver internationally leading research that will be industrially and clinically informed with outputs including new discoveries and devices in ICT, medical device and industrial technology sectors.

Finally, Thomas Swan Ltd. can be found here.

2.5M Euros for Ireland’s John Boland and his memristive nanowires

The announcement makes no mention of the memristor or neuromorphic engineering but those are the areas in which  John Boland works and the reason for his 2.5M Euro research award. From the Ap. 3, 2013 news item on Nanowerk,

Professor John Boland, Director of CRANN, the SFI-funded [Science Foundation of Ireland] nanoscience institute based at Trinity College Dublin, and a Professor in the School of Chemistry has been awarded a €2.5 million research grant by the European Research Council (ERC). This is the second only Advanced ERC grant ever awarded in Physical Sciences in Ireland.

The Award will see Professor Boland and his team continue world-leading research into how nanowire networks can lead to a range of smart materials, sensors and digital memory applications. The research could result in computer networks that mimic the functions of the human brain and vastly improve on current computer capabilities such as facial recognition.

The University of Dublin’s Trinity College CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices) April 3, 2013 news release, which originated the news item,  provides details about Boland’s proposed nanowire network,

Nanowires are spaghetti like structures, made of materials such as copper or silicon. They are just a few atoms thick and can be readily engineered into tangled networks of nanowires. Researchers worldwide are investigating the possibility that nanowires hold the future of energy production (solar cells) and could deliver the next generation of computers.

Professor Boland has discovered that exposing a random network of nanowires to stimuli like electricity, light and chemicals, generates chemical reaction at the junctions where the nanowires cross. By controlling the stimuli, it is possible to harness these reactions to manipulate the connectivity within the network. This could eventually allow computations that mimic the functions of the nerves in the human brain – particularly the development of associative memory functions which could lead to significant advances in areas such as facial recognition.

Commenting Professor John Boland said, “This funding from the European Research Council allows me to continue my work to deliver the next generation of computing, which differs from the traditional digital approach.  The human brain is neurologically advanced and exploits connectivity that is controlled by electrical and chemical signals. My research will create nanowire networks that have the potential to mimic aspects of the neurological functions of the human brain, which may revolutionise the performance of current day computers.   It could be truly ground-breaking.”

It’s only in the news release’s accompanying video that the memristor and neuromorphic engineering are mentioned,

I have written many times about the memristor, most recently in a Feb. 26, 2013 posting titled, How to use a memristor to create an artificial brain, where I noted a proposed ‘blueprint’ for an artificial brain. A contested concept, the memristor has attracted critical commentary as noted in a Mar. 19, 2013 comment added to the ‘blueprint’  post,

A Sceptic says:

….

Before talking about blueprints, one has to consider that the dynamic state equations describing so-called non-volatile memristors are in conflict with fundamentals of physics. These problems are discussed in:

“Fundamental Issues and Problems in the Realization of Memristors” by P. Meuffels and R. Soni (http://arxiv.org/abs/1207.7319)

“On the physical properties of memristive, memcapacitive, and meminductive systems” by M. Di Ventra and Y. V. Pershin (http://arxiv.org/abs/1302.7063)

Namdiatream; a European multimodal diagnostics project

I’ve written about lab-on-a-chip projects, point-of-care diagnostics, and other such initiatives on several occasions, most recently in a Mar. 1, 2013 posting about a technique where powder is used to make the diagnostic device more portable. This time it was a Europe-wide project described in a Mar. 4, 2013 news item on Nanowerk,which caught my attention (Note: A link has been removed),

The plan of the EU-funded consortium Nanotechnological toolkits for multi-modal disease diagnostics and treatment monitoring (Namdiatream) is not to cure cancer, per se, but to boost the sensitivity of diagnostics and the ability to monitor progress during treatment. They focused on three types – breast, prostate and lung cancer.

… The prototype devices being developed during the four-year project will detect common cancer cells much earlier and, with timely treatment, improve the chances of recovery.

According to the project leader, Professor Yuri Volkov of Trinity College Dublin’s School of Medicine, the portable nanodevices are based on innovative lab-on-a-chip, -bead and -wire technologies applicable in different settings – clinical, research, or point of care (i.e. hospitals). These lab-on-x technologies exploit the photo-luminescent (‘glow-in-the-dark’ light emitting), plasmonic (‘light-on-a-wire’), magnetic and unique optical properties of nanomaterials.

Volkov offers some insight into how the project started and its current state of evolution (from the news item),

This is ground-breaking work made possible thanks to advanced technology but also to EU funding for cross-border investigations. Teams across Europe were doing related but fragmented research, suggests Prof. Volkov. This risked leaving a team dangling if their approach failed or lacked funding.

“So we integrated our research and identified joint strengths to help one another develop the best technological approaches in case something didn’t work in one, or synergies were identified, thereby increasing the chances of wider success.”

At its half-way stage, notes Prof. Volkov, Namdiatream underwent a natural evolution when it became clear that by merging and refocusing work in some areas – i.e. in fluorescent nanomaterial technology and magnetic nanowire barcodes – it would speed up industrial implementation efforts.

“Now, work on the preclinical prototype devices is well under way,” he confirms. But one of the many remaining challenges is to calibrate their sensitivity, so that they do not give false readings, for instance.

The Namdiatream (Nanotechnological Toolkits for Multi-Modal Disease Diagnostics and Treatment Monitoring) home page offers more detail about the project,

Namdiatream is a truly interdisciplinary and Pan-european consortium that builds around 7 High-Tech SMEs [small to medium enterprises], 2 Multinational industries and 13 academic institutions. NAMDIATREAM will develop nanotechnology-based toolkit to enable early detection and imaging of molecular biomarkers of the most common cancer types and of cancer metastases, as well as permitting the identification of cells indicative of early-stage disease onset. The project is built on the innovative technology concepts of super-sensitive “lab-on-a-bead”, “lab-on-a-chip” and “lab-on-a-wire” nano-devices.

Interestingly, this too was on the home page,

The ETP Nanomedicine documents point out that nanotechnology has yet to deliver practical solutions for the patients and clinicians in their struggle against common, socially and economically important diseases such as cancer. Therefore NAMDIATREAM results will firstly aim to deliver to the diagnostic and medical imaging device companies involved in the consortium, and the clinical and academic partners. This could further provide the basis for cancer therapeutics as it will be possible to accurately assess the kinetics of cancer cell destruction during the course of appropriate therapy.

Better beer in plastic bottles

This innovation in beer bottling was developed in Ireland and I’m pretty sure the Irish have themselves braced for the humourous comments sure to follow given the legends about the Irish and beer.

Here’s more about the nanotechnology-enabled plastic beer bottles from the Sept. 18, 2012 news item on Nanowerk,

Scientists at CRANN [Centre for Research on Adaptive Nanostructures and Nanodevices], the Science Foundation Ireland-funded nanoscience institute based at Trinity College Dublin, have partnered with world-leading brewing company SABMiller on a project to increase the shelf life of bottled beer in plastic bottles. The new deal will see SABMiller invest in the project over a two year period.

Professor Jonathan Coleman and his team in CRANN are using nanoscience research methods to develop a new material that will prolong the shelf-life of beer in plastic bottles. Current plastic bottles have a relatively short shelf life, as both oxygen and carbon dioxide can permeate the plastic and diminish the flavour.

The new material, when added to plastic bottles will make them extremely impervious, meaning that oxygen cannot enter and that the carbon dioxide cannot escape, thus preserving the taste and ‘fizz’.

The Sept. 18, 2012 CRANN news release does not include many more details about the technology,

The team will exfoliate nano-sheets of boron nitride, each with a thickness of approximately 50,000 times thinner than one human hair. These nano-sheets will be mixed with plastic, which will result in a material that is extremely impervious to gas molecules. The molecules will be unable to diffuse through the material and shelf life will be increased.

As well as increasing the shelf life of the beer itself, less material is required in production, reducing cost and environmental impact.

If you are lucky enough to have a subscription or have some other access to Science magazine, you can read more about Coleman’s and his team’s work on boron nitride and thin films. Here’s the citation and abstract for the article,

Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials by Jonathan N. Coleman, Mustafa Lotya, Arlene O’Neill, Shane D. Bergin, Paul J. King, Umar Khan,  Karen Young, Alexandre Gaucher, Sukanta De, Ronan J. Smith, Igor V. Shvets, Sunil K. Arora, George Stanton, Hye-Young Kim, Kangho Lee, Gyu Tae Kim, Georg S. Duesberg, Toby Hallam, John J. Boland, Jing Jing Wang, John F. Donegan, Jaime C. Grunlan, Gregory Moriarty, Aleksey Shmeliov, Rebecca J. Nicholls, James M. Perkins, Eleanor M. Grieveson, Koenraad Theuwissen, David W. McComb, Peter D. Nellist, and Valeria Nicolosi in Science 4 February 2011: Vol. 331 no. 6017 pp. 568-571 DOI: 10.1126/science.1194975

If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. We show that layered compounds such as MoS2, WS2, MoSe2, MoTe2, TaSe2, NbSe2, NiTe2, BN, and Bi2Te3 can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solutions, we can prepare hybrid dispersions or composites, which can be cast into films. We show that WS2 and MoS2 effectively reinforce polymers, whereas WS2/carbon nanotube hybrid films have high conductivity, leading to promising thermoelectric properties.

This announcement comes during Ireland’s Nanoweek 2012 (Sept. 14 – 21, 2012) which I mentioned along with other nano-themed events currently taking place in Ireland in my Sept. 14, 2012 posting.