Nanotechnology and the U.S. Food and Drug Administration
Nanotechnology is much in the news these days, heralded by some as a new technological revolution that is likely to reshape all aspects of society for the better, while others worry that a society reshaped by nanotechnology may experience significant risks as well as benefits. Nanoproducts are appearing on the shelves of local stores with increasing frequency.
What Is Nanotechnology?
Nanotechnology is not a single technology with only one or two uses or applications. Nanotechnology is a concept. The term “nanotechnology” is an umbrella term that refers to a variety of techniques for creating products, tools, and other devices that have or may have in the future a number of uses and applications in many different areas of life.
What unites all the different aspects of nanotechnology is that the raw materials and some of the products of nanotechnology are all extremely small in physical scale. Everyone knows how to use and manipulate matter at the “macro” scale, i.e., at the scale of the normal objects of daily life tables, automobiles, pots and pans, airplanes, etc. And most of us are at least generally familiar with the ways that scientists manipulate matter at the microscopic level of chemistry and biology the realm of cells, genes, and large molecules and atoms.
Nanoscience and nanotechnology focus on the manipulation of the most basic components of all matter atoms and molecules with great precision. “Nano” is a measurement (10-9 m), not a process, object or product. This is significant when thinking about the development and use of standards for nanotechnology. “Nanotechnology” refers to the science, technology, and engineering involved in manipulating matter at the nanometre level. A nanometre is the width of 10 hydrogen atoms lined up side-by-side. To put this in perspective, a human hair is about 80,000 nanometres wide; the head of a pin is about 1 million nanometres wide; a red blood cell is about 7,000 nanometres in diameter. Nanotechnology, as the use of the word has been “standardized” in the United States, involves manipulating the basic elements of matter (carbon, oxygen, magnesium, etc.) at a size of 100 nanometres or smaller. Nothing on the nanoscale can be seen with the naked eye. Very specialized instruments are required to manipulate matter at the nanoscale.
These structures can have very unusual properties that are unlike the properties of the same material as we know it at the macroscale. These unusual properties can be used to advantage. For example, extremely strong carbon nanotubes can be added to other materials (such as plastics), giving the plastic properties it didn’t have previously. The new plastic composite might be used to make a special product, such as a stronger, more durable prosthetic implant. A crystal of semiconductor material can be made to fluoresce at different frequencies that are solely a function of particle size over a very small range. These might be tagged with different antibodies to trace different stages of a disease or several disease states in a single diagnostic test.
Public health concerns focus on possible interactions between nanostructures and biological tissues and processes. For instance, recent research indicates that some nanostructures may accumulate within tissues and organs and can be taken up by individual cells. Research has shown that the introduction of nanoscale particles and structures into cells does not trigger the cell’s immune response in the way that introducing larger particles and structures will. The ability to get past the immune system may be desirable when trying to target specific cells with drugs, but it leaves unanswered what may happen when uninvited nanostructures enter. Some people fear that the very quality that makes nanostructures attractive as potential drug delivery mechanisms may turn out to be a health hazard. They urge accelerated research to discover the long-term health impacts of exposure to trillions of nanostructures in consumer products, work settings, and the environment. The extremely small size of nanostructures leads some to worry that the structures might enter the food chain undetected.
Developing Standards for Nanotechnology
Standards have long been recognized as the coin-of-the-realm for trade and commerce. Virtually no business transaction, construction, or regulatory process today occurs without the use of standards. The development of nanotechnology will be no exception. Enabling the academic research, industrial development, product regulation and, ultimately, penetration of nanotechnology-based products into consumer use will demand the development of standards for terminology, test methods, and product specifications.
The FDA has a long history of using standards to help manage the risks of the products we regulate. FDA believes that its participation in establishing ASTM Committee E56 on Nanotechnology is important, both as an indication of our engagement in assuring the safety of nanotechnology-based products and materials, and as a way to develop the tools for assessing and managing the risks of nanoproducts. FDA foresees that we must be a player and we believe that standards for nanotechnology will be an important asset to the risk management process.
How Will FDA-Regulated Products Be Impacted by Nanotechnology?
Nanotechnology is expected to dramatically affect a variety of consumer personal care products, medical treatments, and procedures.
Implants and Prosthetics Combining developments in nanoscale materials and biotechnologies may make it possible to create artificial organs and implants that are more like the original, through cell growth on artificial scaffolds or biosynthetic coatings that reduce rejection. These could include retinal and cochlear implants, nerve implants that can repair nerve damage, and replacements for damaged skin, tissue, or bone.
Diagnostics Developments in nanotechnology may lead to quicker diagnoses, while developments in genomics and nanotechnology may make available nanoscale sensors that can assess a patient’s genetic makeup quickly and precisely.
Drug Delivery Nanostructures may make it possible to deliver drugs with much greater precision and accuracy. These may be delivered within a cellular or molecular carrier, to protect them from antibodies and to control the timed release of the drugs. These developments are expected to greatly reduce side-effect problems with current medications, and are undergoing pre-clinical or clinical trials at the present. Eventually, it is hoped, laboratory-on-a-chip nanoscale devices and advanced drug delivery will permit permanent body implants, which would be able to continuously monitor various biochemical levels in the bloodstream and direct appropriate medications as indicated.
Personal Care Products Cosmetics and personal product manufacturers currently make use of nanostructures in some products such as shampoos, skin creams, sunscreens, etc. Cosmetics with nanostructures are able to deliver added medications where they are needed. Research is looking for ways that nanotechnology can be applied in the development of new foods capable of delivering specific nutrients or drugs, as well as flavor enhancement.
Powerful technologies, such as genetically modified foods, nuclear energy and nanotechnology often carry the prospect of significant societal impact. One response to such technologies is to surround them with regulatory structures intended to prevent or avoid the least desirable consequences of deploying the technology, while taking advantage of its benefits. The proponents of nanotechnology assert that these new technologies may well be revolutionary in their impact, and so the question of whether to regulate nanotechnology and, if so, how, is very relevant.
Risk Management As discussed earlier, the FDA paradigm for regulation of these products is based on the concept of “risk management,” i.e., risk identification, analysis and control. To implement risk management for nanotechnology products, we must acknowledge that the cells and molecules with which the FDA works every day are “nano” in size. In particular, every degradable medical device or injectable pharmaceutical generates particulates that transition through this size range during the processes of their absorption by the body. FDA has not found any adverse reactions related to the “nano” size of resorbable drug or medical device products. FDA regulates on a “product-by-product” basis.
Coordination of Policy with Other Government Agencies FDA coordinates policy in nanotechnology through regular discussions among the major experts from every organizational entity within the agency. In addition, several centers within FDA, e.g., the centers for drugs and medical devices, have organized similar regular discussion groups. The purpose of these meetings is to share experiences with product review, ensure that each center is aware of product guidance that may be developing elsewhere within the agency, and generally educate staff and policy makers about nanotechnology. Safety issues are identified and studied.
Similarly, FDA coordinates knowledge and policy with the other U.S. government agencies as a member of the Nanoscale Science and Engineering Technology Subcommittee of the President’s National Science and Technology Council Committee on Technology. Also, FDA and the National Institute for Occupational Safety and Health co-chair the National Nanotechnology Coordinating Office Working Group on Environmental and Health Issues to define new test methods and protocols for the safety of these products. Finally, FDA is a direct contributor to the evaluations of material toxicity supported by the National Institutes of Health’s National Institute of Environmental Health Sciences and the National Toxicology Program.
Current Issues in Nanotechnology
There are several issues under discussion in various forums regarding the FDA’s regulation of nanotechnology products. FDA expects many nanotechnology products that we regulate to span the regulatory boundaries between pharmaceuticals, medical devices and biologicals. These will be regulated as “combination products” for which the regulatory pathway has been established by statute. In such cases, FDA will determine the “primary” mode of action of the product. This decision will determine the regulatory framework for the product, whether a drug, medical device or biological product. The product application will be managed by the appropriate FDA center with consultations from the other centers.
It is valuable to repeat here that FDA has traditionally regulated many products with particulate materials in this size range. FDA believes that the existing battery of pharmacotoxicity tests is probably adequate for most nanotechnology products that we will regulate. Particle size is not the issue. As new toxicological risks that derive from the new materials and/or new conformations of existing materials are identified, new tests will be required.
FDA regulates products, not technology. For many of the products we regulate, standards are an integral part of the evaluation and management of risks to the public health. FDA strongly supports and participates in the development of standards for these products. The standards for nanoproducts to be developed in ASTM Committee E56 will be no exception. //