A new European project on the emerging discipline of nanobiotechnology aims to tackle the thorny issue of safety as well as develop new materials for drug delivery and other medical uses, reports Phil Taylor.
While the field is still in its infancy, the use of nanoscale materials for drug delivery has the potential to transform the pharmaceutical industry, raising the prospect that diseases such as cancer could be treated at the same time as they are diagnosed, according to Ian Bruce, professor of nanobiotechnology at the University of Kent, which is co-ordinating the project.
In an interview, he noted that companies such as Philips and GE Healthcare are already working on the development of nanomaterials that can be injected into a patient, hone in on an area of disease such as a malignant tumour and reveal on a scanner the precise location and extent of the lesion. It is a small leap to imagine this same material carrying a drug that could be activated by an external force such as magnetism or heat and tackle the tumour the moment it is detected, providing a rapid, non-invasive therapy.
Of course, other delivery vehicles such as liposomes are already being directed towards diseases cells and tissues using antibodies, but there are potential advantages in the use of nanomaterials such as silica and carbon nanotubes, including that they tend to have a high loading capacity for drugs and can be designed to hold onto their payload until needed.
One project that will receive backing by the project - funded by the European Commission, industry and the Chinese government to the tune of €15.6 million - is looking at using a patient's red blood cells as a carrier for a drug-loaded nanomaterial. This has the advantage of shielding the nanomaterial from factors in the body - such as the patient's own immune system - that could interfere with its activity. This work is being conducted at the University of Urbino in Italy.
However, one of the primary aims of the Novel and Improved Nanomaterials, Chemistries and Apparatus for Nano-Biotechnology (NACBO) project will be to conduct toxicology experiments on nanomaterials, said Prof Bruce.
The safety of nanotechnology has been under scrutiny for some time. It first emerged in the 1980s when Eric Drexler, senior research fellow of the Molecular Engineering Research Institute in the US and a long-standing researcher in the area of nanoscale machines, published a book warning of self-replicating nanomachines that could go out of control - creating what has now become the infamous 'grey goo'.
Drexler has since revised his stance - now maintaining that self-replicating machines are unnecessary to advance the field - but other studies have since warned of different dangers, focusing on the impact of nanoparticles entering the body, and it is this element which is causing the greatest concern as the use of nanotechnology in the healthcare field advances.
Last year, a study was reported showing that inhaled nano-sized particles accumulate in the nasal cavities, lungs and brains of rats, raising concerns that this build-up could lead to harmful inflammation and a risk of brain damage or other central nervous system disorders. And it is well established that carbon 'buckyballs' - a spherical form of the element that has properties attractive for drug delivery - are toxic to cells.
With this in mind, a proportion of the NACBO's funding - albeit only around 5-7 per cent of the total - will be directed towards studies of the in vitro and in vivo toxicology of nanomaterials, and also whether the size of the particles affects their toxicity, in the same way that asbestos is safe when encountered in a sheet, but causes cancer when inhaled as a dust.
The bulk of the funding is going on projects looking at the design and development of nanomaterials, and about €3m of the total is directed at drug delivery applications.
Keeping up with the US
Finally, another primary agenda behind the new project is to coordinate Europe's efforts in nanotechnology and nanobiotechnology and compete with the US, which is often reported to have a leading role in the sector, and Asia.
While this may well be true for nanotechnology in its broadest sense, in nanobiotechnology the situation is more ambiguous, said Bruce. "For biotechnology applications the crux of the issue is interface science - working out how nanomaterials interact with their environment in order to carry out a function - and in this respect Europe, Asia and the US are all strong."
It is far too early to say if nanobiotechnology will live up to its promise in drug delivery, noted Bruce, but the new project should accelerate the work that will answer this question.