A tiny technology with a big medical impact

2008-10-14

It will kill 1,419 Canadians every week in 2008. Estimates suggest another 166,400 Canadians will be diagnosed this year alone; 39 per cent of Canadian women, and 45 per cent of men will acquire it over their lifetimes.[1]

Cancer, which remains an incurable disease, is the leading cause of early death in Canada according to the Canadian Cancer Society.

Traditionally, treatments such as chemotherapy and radiation cause various adverse side-effects. During treatment, along with the destruction of cancer tissue, damage is also done to surrounding healthy tissue. New advances in science, in the domain of nanotechnology, have the potential to make a significant impact on the treatment and diagnosis of cancer while reducing some of the traditional obstacles to treatment.

Nanotechnology is a collective term that refers to the science of manipulating particles between 1-100 nanometres (nm). Measurements are so microscopic, that one single double-helix strand of DNA is approximately 2.5 nm wide and one red blood cell is approximately 8,000 nm long.

Even in the early stages of research and development, cancer researchers see nanotechnology as key to improving the way doctors and specialists diagnose and treat cancer and other diseases. Since the body’s biological processes that play factors in disease often occur at the nanoscale, scientists believe integrating nanotechnology in medicine is not only a natural progression, but possibly an effective one.

One major medical advantage to integrating nanoparticles into cancer treatment is the improvement in drug delivery. The cancer research community has long established that nanosize particles can collect in tumors. In the past, certain drug particles have been prevented from reaching the cell because the particles were too large to fit through the small channels and pumps within the membrane of human cells. Nanoparticle-based drug treatments, which coat a nanoparticle with a hydrophilic layer, allow a once insoluble drug to bypass the cell’s filters, thereby reaching the cell body to dispense treatment.

Nano-engineered drug strategies are able to actively target cancerous tissue, without destroying any surrounding healthy tissue. Because cancerous cells often display behaviour which is distinguishable from that of surrounding healthy tissue, such as in the form of mutated cellular proteins, antibodies can be attached to nanoparticles and tailored to actively target only those cells displaying characteristics that signal cancer. The ability to focus the drug at the site of the tumor is also expected to decrease negative side effects including nausea, and weight and hair loss.

On the diagnostic side, machinery used to diagnose cancer is also becoming more efficient and effective as a result of nanotechnology.

"Every piece of hardware used for cancer diagnosis, especially MRIs, and CAT scans will change dramatically," says Dr. Roland Hosein, chair of Canada’s advisory committee to the International Organization for Standardization (ISO) committee that is developing standards on nanotechnology (ISO/TC 229).

"They [diagnostic machinery] are becoming faster, smarter, and invariably cheaper with the introduction of nanotechnology."

With all of the potentially effective strategies to treat cancer, Dr. Clive Willis, vice-chair of the Canadian advisory committee to ISO/TC 229, who also helped found NanoQuébec, stops short of saying nanotechnology could deliver a cure for cancer.

"There probably won’t be a silver bullet cure for cancer, just because of the nature of the disease," says Willis. "But nanotechnology is one of the areas for delivering new treatments very specifically and effectively. It will certainly be one of the technologies involved in the treatment of cancer."

The effectiveness of manipulating matter at the nanoscale is derived from the idea that when it comes to nanoparticles, strength is in small numbers. When matter is broken down at the nanoscale, different characteristics are evident. At this size, performance is more enhanced than in its larger form.  In addition, certain functionality (chemical, physical or biological) can be added to make the nanoparticle behave in a pre-determined way.

"In a number of potential applications, the key is the uniformity of small size. Smaller particles form a more uniform pattern. Each particle will have a greater surface area and involve a different strength in its bonding," says Willis. "It’s the collective effect of the whole that makes the particles better."

With all of the possible advances in medicine that nanotechnology could deliver, the technology’s potential good also comes with potential risk.

A report released by the Council of Canadian Academies, an organization which provides independent assessments of science in the public interest, suggests more research is needed. The report says the risk is related to the uncertainty of the change in properties that take place when existing compounds are reduced to such a small scale.  Chemical reactions involving nano-sized particles take place more quickly, which could possibly mean a more reactive and higher toxicity than in the compound’s original form.

Though Willis agrees that the research in this field is relatively limited, he says the research being conducted globally is helping to define the hazards and therefore to manage the risk.

 "Many of the materials we are engineering at the nanoscale, we have used before. If they were toxic, we would know about it by now, unless there is a specific change of toxicity because of the size," says Willis. "With such new materials, sure the potential is there for risk and we must be vigilant in ensuring responsible use."

Canadian experts and researchers are actively working alongside their global counterparts to develop standards in nanotechnology in order to provide guidance for regulators, researchers, developers, manufacturers and users.

ISO chose four working areas to be established before any industry-specific standards could begin development. The four areas are: terminology and nomenclature; measurement and characterization; health, safety and environmental aspects of nanotechnologies; and lastly, material specifications.

"This area needs language," says Hosein. "It needs terminology and definitions in order to create the foundation for language. Measurement methods must be developed for the user community to characterize the materials. Plus you also have to develop systems to protect employee and public health and the environment."

Developing standards in nanotechnology can be complicated since nanotechnology is not considered a sector in itself. Because its impact spans various sectors, ranging from cosmetics to forestry, consensus among industry, stakeholders and researchers is that standards should be developed before nanotechnology is made available commercially across multiple industries.

"We saw that it was important to take early action with standards, in order to create a scientific-based standard description covering the whole field," says Willis.

In the field of biotechnology, he recalls that standards were developed afterwards, which caused problems later-on in the commercialization of that technology.

"We didn’t want the same thing to happen in nanotechnology, simply because we haven’t taken early steps," says Willis.

From incorporating nanoparticles into cosmetics (which is already happening), to manufacturing lighter-weight and stronger composites to create more durable and sustainable materials, this small science is en-route to make a large impact on just about every sector of the market. 

"Nanotechnology will allow us to be more efficient across the board in a way we haven’t been before," says Willis. "When we see it applied across the traditional industrial sectors, we are going to see a lot of differences—niche products tailored to optimally respond to their specific applications. It’s going to be very different, but incrementally different. I don’t see that in 10 to 15 years we’re going to have a world we had not envisaged before because of nanotechnology.”

Willis is confident that nanotechnology’s benefits outweigh any risk, provided the industry understands and manages the risks.

"Even in its early stages, we are seeing so much promise and we haven’t really engineered the field yet," he says. "It’s exciting and really going to change our lives for the better."

[1] 2008. Canadian Cancer Society. General Cancer Stats for 2008. (www.cancer.ca)

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This article first appeared in Volume 35 of CONSENSUS Magazine, 2008.  The information it contains was accurate at the time of publication but has not been updated or revised since, and may not reflect the latest updates on the topic.  If you have specific questions or concerns about the content, please contact the Standards Council of Canada.

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