Just imagine if the information on 1000 compact discs could be packed into the space of a wristwatch! That is where the field of nanotechnology is currently headed. Although nanotechnology is estimated to be at about the same level of development as the computer/information technology of the 1950s, it is expected to become one of the strategic and dominant technologies in the next 10 to 20 years. Nanotechnology will have an almost endless string of applications in biotechnology, biology, and biomedicine. One day, the concept of creating an implantable nanosensor to watch for the signature molecules of cancer will no longer be dismissed as the wishful thinking of wide-eyed dreamers.
Nanotechnology has created a growing sense of excitement due to the ability to create and utilize materials, devices, and systems through the control of matter on the nanometer scale (1 to 50 nm). This bottom-up approach requires less material and causes less pollution. Nanotechnology has had several commercial applications in advanced laser technology, hard coatings, photography, pharmaceuticals, printing, chemical-mechanical polishing, and cosmetics. Soon, there will be lighter cars using nanoparticle-reinforced polymers, orally applicable insulin, artificial joints made from nanoparticulate materials, and low-calorie foods with nanoparticulate taste enhancers.
The advancement of biotechnology has been facilitated by the availability of enabling technologies such as laser tweezers, optical traps, and nano-pokers as well as the atomic force, scanning electron, and scanning tunneling microscopes. These tools enable the biotechnologist to have better understanding, characterization, and control of living cells. Bioinspired nanodevices and materials are currently formed by self-assembly, molecular imprinting, or other patterning techniques. Nanoreactors prepared from reversed micelles are capable of producing well defined, nano-sized crystallites or manipulating individual protein molecules. Perhaps, biotechnological applications of nanoscience/technology are not as advanced as nonbiotech counterparts. However, nanobiotechnology presents a promising R&D frontier with a tremendous future impact in the following areas:
Drug delivery: Half of useful drugs are hydrophobic, and reducing the size of the drug particles to the nanoscale can significantly enhance the administration of such drugs. Highly porous nanomaterials are ideal candidates for controlled drug delivery.
Gene therapy: Successful gene therapy is dependent upon the development of safe and efficient gene vectors. Nonviral vectors, nanoparticles, complexes between lipids, or polymers with DNA have been proposed as alternatives to viruses used to incorporate specific genes into target cells. Significant advances in nanotechnology will soon perfect the preparation of such DNA nanoparticles.
Nanobiosensors/DNA nanochips: Nanobiosensors have several immediate applications in generic research to monitor the inherent nanoscale components of living cells. They are also envisioned for the detection of chemical and biological threats such as pollutants, microbial contamination, viruses, communicable and genetic diseases, and cancer. DNA array technology itself might play an important role in enabling nanofabrication. Rapid and sensitive drug screening, one of the limiting factors in combinatorial chemistry for drug discovery and development, is another important application of nanobiosensors. Chip-sized biodevices could revolutionize the detection and management of illness. For example, a nanosensor can be combined with a nanoscale drug delivery system to dispense optimum amounts of drugs to maximize their efficacy.
Nano-total analysis systems (nano-TAS): These nanosystems are also known as "nanolabs-on-chips," which are distinguished from simple sensors because they conduct a complete analysis: reaction, separation, and detection on a single nanochip. They consist of three important elements: a nanofluidic system, a separation scheme (normally electrophoresis), and a detection element. With the ability to make chemical and biological information faster and cheaper, nanolabs-on-chips in array may profoundly change the current practice in clinical diagnostics, genome sequencing, environmental monitoring, food safety, and other areas of the public interest.
Nanoscale bioprocesses for bioremediation: Novel properties of nanocrystals such as TiO2 that show promise as photocatalysts can be used in combination with microorganisms to break down toxic pollutants to clean up a variety of waste streams. Nanoscale scavengers are able to capture heavy metals in contaminated sites.
There are, however, several problems associated with the commercialization of nanotechnology. One well-known citation is the superior performance of transistors made from carbon nanotubes. Unfortunately, it is almost impossible to mass-produce such transistors for making computer chips. Similarly, formidable challenges still remain in the synthesis and processing of drug-carrier nanoparticles at the commercial scale. Another critical issue is the integration of nanostructures or nanodevices with the larger, human-scale systems or platforms around them so that they can be used as components of electronic devices, sensors, etc. Nanostructures are often unstable due to their small constituent sizes and high chemical activity. Therefore, a real challenge is to increase the thermal, chemical, and structural stability of these materials and the devices made therefrom. Last but not least, the biggest problem nanotechnology could encounter towards commercialization is the costs of manufacturing. With myriad nanomaterials or nanostructures in hand, there is no question that more and more nano-objects with novel or enhanced properties will be developed. However, technical feasibility and commercial viability are two different things. One of the key factors is the identification of promising areas for future research and commercial development. The complexity of nanosystems begs for strong, interdisciplinary research programs to aid this process. Several potential applications of the technology are still in an embryonic phase, and the government must play an important role to sustain the research effort required for establishing the scientific and technological infrastructure.
As a very broad and interdisciplinary area of R&D, nanobiotechnology draws upon all disciplines from engineering, physics, chemistry, biology/microbiology, biomedicine, materials science, and mathematics. It is of utmost importance to educate a new breed of researchers who can work and think across several disciplines. The challenge for nanotechnology will be to foster more interdisciplinary collaborations and get more young people interested in science and engineering. Therefore, it is essential to create a series of interdisciplinary centers of excellence and research chairs at Canadian universities to conduct research and train graduate students. Such centers will serve as a vehicle to foster on-campus interaction through interdisciplinary research involving multiple departments. These centers should carry out long-term nanoscience and engineering research leading to fundamental discoveries of novel applications, processes, phenomena, and enabling tools. For moving toward nanoscience/technology, there is an urgent need for the university planners to develop pertinent research, policy, and curricula. Numerous workshops and symposia with specific objectives must be organized to spur and encourage the government, private foundations, and industries to support research and education in nanotechnology. Of course, both federal and provincial funding agencies are expected to play an important role in fostering the research and development in this important area. They must have a "national nanotechnology initiative" to support basic research and an "implementation plan" to assess their strategic investment in nanotechnology. Government laboratories are then expected to pursue applications of nanotechnology in support of the government's policy in collaboration with universities and industry.
Dr. John H. Luong is the head of the biosensor technology group at the Biotechnology Research Institute, National Research Council Canada. He received a Ph.D. degree in chemical engineering from McGill University in 1979. He has seven patents and over 170 research papers. He is a member of the New York Academy of Sciences, the American Institute of Chemical Engineers, the American Chemical Society, and the American Association for the Advancement of Science.