Nanotechnology’s Small Problem

20 July 2008 (Last Updated July 20th, 2008 18:30)

Nanotechnology has the potential to transform the medical device industry but recent studies have questioned its safety. This has prompted calls for the industry to address the concerns raised before any real danger occurs, writes Catherine Lafferty.

Nanotechnology’s Small Problem

The nanotechnology revolution is here but for medical device makers the tiny technology which has the potential to transform the industry may also have the potential to sink it.

New studies have called into question nanotechnology's safety and led to calls for the industry, which has already used it in the development of devices, to address these concerns, as revelations it could be as dangerous as asbestos abound.

"Long, thin carbon nanotubes showed the same effects as long, thin asbestos fibres."

NANOTUBES EXPLAINED

The technology involves the creating and manipulating of common substances at the scale of the nanometre, or one billionth of a metre. It is invisible to the human eye and now a study, published in May 2008 in Nature Nanotechnology, suggests some types of carbon nanotubes could be as dangerous as asbestos if inhaled in large enough quantities.

With exposure to asbestos resulting in some of the worst occupational health disasters of the 20th century, the hype is understandable.

Carbon nanotubes are cylindrical sheets of graphite of atomic thickness which may be composed from a single layer of graphite or made up of multiple concentric layers of graphite, resulting in multi-walled carbon nanotubes.

Discovered almost 20 years ago they have been compared to spider silk thanks to their excellent properties of lightness, strength and electroconductivity. As strong as steel but as light as plastic they have been described as "the poster child for the nanotechnology revolution" and "the miracle material of the 21st century".

THE RESEARCH

Researchers led by Professor Keith Donaldson of Edinburgh University used recognised methods to examine whether specific types of nanotubes could potentially cause a cancer of lung lining, mesothelioma.

"The results were clear," said Donaldson. "Long, thin carbon nanotubes showed the same effects as long, thin asbestos fibres."

A similar study by researchers at Japan's National Institute of Health Sciences, published this year in the Journal of Toxicological Sciences found that mice injected with carbon nanotubes developed mesothelioma.

"By knowing the possible dangers of long, thin carbon nanotubes, we can work to control them."

Researchers pointed out that the studies are still a long way from demonstrating a causal link between exposure to carbon nanotubes and lung disease. Nonetheless, following the publication of the Japanese study, the Japanese Ministry of Health, Labour and Welfare issued a notice telling those involved in the industry, processes should be carried out under either sealed, unattended or automated conditions, or a local exhaust system should be installed.

The Edinburgh study however did come with some reassuring findings. It also found that short or curly nanotubes did not behave like asbestos. Moreover, in Donaldson's view, his research findings could ultimately be of benefit to the nanotechnology industry.

"By knowing the possible dangers of long, thin carbon nanotubes, we can work to control them," he said.

"It's a good news story, not a bad one. It shows that carbon nanotubes and their products could be made to be safe."

A WAKE-UP CALL

The study's co-author Andrew Maynard stresses the importance of the industry acting on the findings: "This is a wakeup call for nanotechnology in general and carbon nanotubes in particular," he says.

"As a society, we cannot afford not to exploit this incredible material, but neither can we afford to get it wrong – as we did with asbestos."

"As a society, we cannot afford not to exploit this incredible material, but neither can we afford to get it wrong – as we did with asbestos."

He emphasises the need for more targeted research on the subject, saying action needs to be taken to reduce levels of carbon nanotube exposure among workers and users.

Regulators, industries and consumers must know which types of carbon nanotubes are being used, where they are being used and what precautions must be taken to ensure safe use, he explains.

There is potentially a great deal at stake for the medical devices market. Industry experts maintain that nanotechnology holds great promise and is bound to be used more in the future.

RECENT DEVELOPMENTS

One recent example of a medical device designed using nanotechnology is Baxter's V-link Luer-activated device (LAD) with vital shield protective coating.

The V-Link with VitalShield, which received the Federal Drug Administration's approval in November 2007 and launched onto the US market in 2008, is the first needleless IV connector containing an antimicrobial coating.

The V-Link LAD with VitalShield protective coating is the first introduction of Baxter's newly developed Vital Infusion Systems product line, developed decrease risks associated with IV therapy.

NANOTECH'S POSSIBILITIES

According to Dr Sinead Keogh, senior executive, Irish Medical Devices Association, nanotechnology will provide huge opportunities not only to improve materials and medical devices but also to create new smart devices and technologies.

The technology is expected to accelerate scientific as well as economic activities in medical research and development with several medical devices, currently in use or being commercialised, already benefiting from its application.

"Industry experts maintain that nanotechnology holds great promise and is bound to be used more in the future."

Examples include: contrast agents incorporating nanoparticles for greatly improved imaging; bone replacement materials incorporating nanostructured materials allowing better integration in the body; nanostructured biomaterials for use in scaffolds for regenerative medicine; wound dressings incorporating antibacterial nanoparticles; orthopaedic implants with nanocontoured surfaces to improve fixation in bone.

Keogh emphasises the potential of nanotechnology to affect qualitative improvements in medical devices and hence patient care.

She says that the technology will eventually make a contribution towards improved efficiency and use of resources in an already stretched healthcare system.

These and other smart applications are expected to bring benefits in terms of early diagnosis, perhaps even at the stage of initial onset of a disease, more effective treatments, better prognosis and an earlier recovery for the patient.

NANOTECHNOLOGY GROWTH

While undoubtedly already of critical importance to the medical devices market, it is difficult to assess the size of the nanotechnology industry, Keogh says.

The National Science Foundation in the US has estimated that the global nanotechnology market will exceed $1t by 2010 but it is thought this may be on the conservative side.

"The market for nanomaterials alone was $0.12t in 2002, with this market growing at an annual rate of 15% to $0.37t by 2010."

According to Deutsche Bank, however, the market for nanomaterials alone was $0.12t in 2002, with this market growing at an annual rate of 15% to $0.37t by 2010.

While an estimate for the nanotools market is not currently available, The Department of Trade and Industry in the UK has concluded that, at present, 1% of all medical devices are nanotechnology enabled.

It has also estimated that this percentage will double every two years for the foreseeable future.

In Ireland the value of nanotechnology-enabled products exported by the medical devices sector is expected to grow to €0.6bn by 2010. It is similarly estimated that the value of nanotechnology-enabled products exported by the pharmaceutical sector will exceed €6.1bn by 2010. An analysis of the electronics and photonics sectors suggests that €4.5bn of all exports in 2010 will be nanotechnology enabled.

"Nanotechnologies are likely to offer a wide range of economic benefits," says Keogh. "However, unlocking this potential will require a responsible and co-coordinated approach to ensure that potential safety issues are being addressed at the same time as the technology is developing."

THE WAY FORWARD

While the debate over nanotechnology's safety has been prompted by the recent studies, Kevin Wilson of Medical Devices in Scotland is confident the industry will take steps to overcome such potential problems in nanotechnology.

"Medical device companies have demonstrated their willingness and ability to look at the distribution of particles in the operating theatre."

"Medical device companies have in the past demonstrated their willingness and ability to look at the distribution of particles in the operating theatre and developed techniques to limit the spread of particulates in the operating theatre," he says.

He cites the example of electrocautery devices, found to emit smoke plumes that potentially contained carcinogenic material.

"Medical device companies looked at technologies to reduce the amount of smoke in circulation by introducing vacuums to contain smoke spillage and developing better masking for staff."

If the nascent nanotechnology industry conscientiously addresses and is seen to address these health and safety concerns, public confidence will be maintained and research and development will continue to apace.

Current glitches would in time be viewed as very minor hurdles in what has been called the nanotechnology revolution.