Medical Device Link.

DESIGN

Nanomedicine defined

This new series of articles will examine the hurdles that will have to be overcome to bring new products that incorporate nanotechnology features to the market and into the health-care system. First, it is useful to review the definition of nanomedicine. The European Technology Platform on Nanomedicine defines it as:

“The application of nanotechnology in medicine. It exploits the improved and often novel physical, chemical, and biological properties of materials at the nanometric scale. Nanomedicine has potential impact on the prevention, early and reliable diagnosis and treatment of diseases.”¹

Another useful current definition is:

“Those practices of medicine, including prevention, diagnosis and therapy, that are based on interactions between the human body and materials and structures whose properties are defined at or around the nanometre scale.”²

According to Robert A. Freitas Jr, a leading researcher in the field of medical applications of nanotechnology, nanomedicine may be defined as:

“The monitoring, repair, construction and control of human biological systems at the molecular level, using engineered nanodevices and nanostructures.”³

Although subtly different, all of these definitions provide an understanding of the potential impact of nanomedicine. Common themes between them include:

• reference to the properties of materials or the ability to engineer materials at the nanoscale level
• diagnosis or monitoring of disease or of physiological condition
• treatment of disease or repair of tissues or biological systems.

It is clear that novel medical devices with characteristics at the nanolevel will often act with a different range of mechanisms from “classical” devices and will certainly interface with biological systems in a new way. These new modes of interaction bring new challenges.

Managing risk

In many cases the application of nanotechnology to a medical device may be an incremental innovation. This is the case, for example, in the use of nanocontoured surfaces on orthopaedic implants to improve cell growth and fixation in the bone. A risk management procedure will be performed as usual and it is unlikely that an innovation of this type would involve a change to the principal mode of action, classification or regulatory status of the device.In other cases, nanotechnology may have the effect of blurring traditional demarcation boundaries between, for example, medical device and pharmaceutical regulatory regimes and regulatory clarification has been required for coated stents. The application of nanotechnology may further obscure the main defining factors, that is, the principal intended mode of action and the ancillary effect. This erosion of the boundary between different regulatory regimes is a challenge and one that needs to be addressed, but that process should not delay innovative therapies reaching the patient.

More risk research

The author believes, as do many others, including, Maynard et al.,⁴ and Renn and Roco,⁵ that an effective and systematic risk-based approach is needed if emerging nano-industries are to survive and flourish, whatever the applicable regulatory regime. The risks posed by the various facets of nanomedicine are so diverse and specific that a single prescriptive approach is likely to be of little use and, indeed, may be counter-productive. In some cases such as the nanocontoured implant mentioned above, the risk profile may be relatively easy to characterise. In others such as those that may involve the release of novel nanoparticles in the body, there may be relatively less information available on the hazards and associated risks posed. Size of nanoparticle, surface area, surface chemistry, solubility and possibly shape may all play a role in determining the risk. As with all medical therapies, any risks must always be balanced against the benefits to the patient. Again, here, what may be acceptable in one situation, for example, critical surgery to save a life, may be unacceptable in another, for example, elective treatment for a nonlifethreatening condition.

Maynard et al., also state that, “Understanding and preventing risk often has a low priority in the competitive world of research funding.”⁴ They continue, “The science community needs to act now if strategic research is to support sustainable nanotechnologies, in which risks are minimised and benefits maximised.”

This is a crucial aspect that was reinforced in a recent news report that claimed that the United Kingdom Government is “failing” nanoscience.⁶ Included in that news item are comments from Professor Ann Dowling, chair of the working group that produced in 2004 a Government sponsored report by the Royal Society and Royal Academy of Engineering, which outlined possible opportunities and risks from developing nanotechnology. Dowling agreed that, “More targeted research to reduce the uncertainties around the health and environmental effects of nanomaterials must be funded, especially in light of the growing number of products on the market containing these manufactured ultra-small materials. This is a vital step to ensuring that nanotechnologies are well regulated and inspire the confidence of the public and investors.”

Professor Sir John Beringer, who chaired a Council for Science and Technology review of Government commitments made in 2005, in the same news item, said, “The Government made a very clear commitment that research needed to be done to understand more about the toxicology and possible risks that may arise from some of the nanotechnologies. But there has been virtually nothing done by Government to resolve this problem.”

Next steps

The pace of research in the domain of nanomedicine continues to accelerate and the technology holds great promise for exciting and improved products and therapies for patients. But the means and tools for adequately assessing the risk and benefit of these technologies must also evolve if that promise is to be realised. A number of stakeholders are involved in this, including industry, the European Commission, national governments, insurance bodies and nongovernmental organisations. However, there are a variety of different approaches.

A coordinated approach to risk management in medical nanotechnology will be required to provide a sound platform for further development and investment in medical nanotechnology. The Institute of Nanotechnology (www.nano.org.uk), a leading organisation working in this field, is actively trying to promote this coordination and collaboration. It takes as a starting point clinical needs balanced with patient safety and the requirement to get innovations to market in a fast-developing field. The author welcomes input from readers on this subject.

Richard Moore is Manager, Nanomedicine and Life Sciences, at The Institute of Nanotechnology, 6 The Alpha Centre Innovation Park, University of Stirling, Stirling FK9 4NF, UK, tel. +44 1786 447 520, e-mail: richard.moore@nano.org.uk.