Microelectronics and nanoelectronics technologies, combined with advances in chemistry, molecular biology, and medicine, will revolutionize diagnostics, patient monitoring, and medical procedures. The ultimate results, of course, are longer and healthier lives.
Electronics have brought greater efficiency and success to minimally invasive and even non-invasive treatments. Emphasis on early diagnosis, detection, and treatment of illnesses ensures a more efficacious approach to control at minimum patient discomfort.
Nowhere is this trend more pronounced than in medical drug delivery, which some market studies say will produce a multibillion-dollar market by the end of this decade. Targeted high-efficacy drug-delivery systems are indeed one of the most exciting areas of biomedicine, where the objective is to deliver drugs accurately to the areas of the body that need it the most, as well as minimize side effects.
So-called smart drugs are being formulated in many R&D facilities. Under investigation are the chemical and biological attributes of drug-delivery mechanisms, with the ultimate object of achieving in-vivo biocompatible drug-delivery systems that have high rates of efficacy and dosage concentration at the target cells.
Laboratory-on-a-chip DNA devices and microarrays already quickly and accurately analyze and deliver drug samples. Their success is due largely to advances in the fabrication of micro-electromechanical systems (MEMS) and microfluidic systems (Fig. 1).
Microfluidics involves etching silicon, glass, or polymer channels in MEMS devices. Through these channels flow liquids and gases that can be manipulated and controlled via switches and valves. This is instrumental in sample preparation, detection, analysis, and delivery of a wide range of drugs in point-of-care patient monitoring and therapeutic applications.
Such systems are generally worn by the patient or subcutaneously implanted under the skin, where the drugs are infused into the body. Researchers have gone to great lengths to minimize human discomfort during medication infusion. One experimental device uses RF energy to "blast" 50-µm wide openings in the skin as it administers drugs into the body.
Tomorrow's drug-delivery systems will be tinier as well as completely biocompatible with human tissue. Systems no bigger than a fingernail are under development for in-vivo delivery of therapeutic drugs in the treatment of heart diseases, diabetes, and cancer. These biodegradable systems will consist of polymers that the body can completely absorb. They won't require a power source or outside stimulus (Fig. 2).
Robert Langer, a researcher in the Chemical Engineering Department of the Massachusetts Institute of Technology, foresees the ability to load multiple drugs on one chip. These "pharmacy on a chip" devices would become an attractive medication-delivery method for patients who have to take several drugs daily, such as the elderly and those with AIDS.
Ultimately, nanotechnology will become the technology of choice for dispensing and monitoring therapeutic drugs. Under the U.S. National Science Foundation's National Nanotechnology Initiative, 2005 will usher in second-generation active nano-structures for targeted drugs and chemicals in biomedical applications. The era of nanomedicine will be upon us within a decade. Researchers envision that by 2015, nanotechnology will eliminate suffering and possibly death from cancer.
Presently, carbon nanotubes (CNTs) are assuming an important role as implants for studying the brain and retinal transplants. Though normally inert, CNTs can be functionalized at the tip of a probe molecule to enable a host of diagnostic and therapeutic functions.
Nanoparticles will get so small, they'll be used to replicate human organs. Tests have already shown that donor cells can be produced en masse, by ink-jet printing, to enable the successful self-assembly of "designer" tissues.
SENSORS TO PLAY A KEY ROLE
Sensors will be vital in state-of-the-art health care. Biosensor chips that will accurately identify medical ailments, monitor health, and detect viruses and biohazards are just on the horizon. Nanotechnology will impact the development of artificial muscles, bone replacement, bionic ears and eyes, and a host of other human parts and organs.
NASA is developing astrobiological sensors to study the origins of life. The technology also is being used in collaboration with the U.S. National Cancer Institute to develop sensors for cancer diagnostics. Efforts include probe molecules that will serve as signatures to identify leukemia cells, which would then attach to CNTs, and prototype biosensors for use as catheters.
Sensors also will be fundamental to prosthetics and orthotics. Wireless sensors are already tracking the forces at work in human joints, leading to improved devices. Experiments have shown that computerized sensors, incorporated into wearable robotic systems, can help the mobility of the disabled and the elderly.
IMPROVED DIAGNOSTICS THROUGH IMAGING
The tremendous strides in computing technology, coupled with advances in imaging technology, will provide very powerful imaging tools for identifying and treating all sorts of maladies.
A new cancer treatment that's already here is an example of what to expect in the next few years. Elekta Synergy from Swedish maker Elekta AB is being heralded as the most significant development in target-based radiotherapy systems in the last five years. Using 3D imaging, doctors can obtain cone-shaped computerized-tomography (CT) beam images of patients immediately before their treatment. It also permits precise targeting of cancer tumors to minimize damage to adjoining healthy tissue.
Even ultrasound imaging isn't beyond refinement. On the drawing board are ultrasound systems with better resolution that's 10 times better than what's available today.
New technology is also making inroads into the sometimes mysterious world of mental health. A new study of magnetic therapy's effect on depression, which afflicts millions worldwide, was launched early this year, involving hundreds of patients. It should prove pivotal in gaining approval by the U.S. Food and Drug Administration in a couple of years. The technique under study, known as transcranial magnetic stimulation, pulses magnetic energy to induce electric currents in specific regions of the brain. Physicians administer the pulses via a handheld device passed over the patient's head.
Though magnetic therapy for the treatment of depression has been tried for years, its results haven't been fully understood. But when combined with advances in coming nanotechnology-based neural brain probes and future advanced imaging techniques, a more accurate understanding of the treatment is bound to emerge. It will most likely do away with the drugs currently taken by depression patients.
There's no question that technology is poised to revolutionize health care. What remains unknown are the negative effects these advances will have on the well being of individuals and on society in general. After all, nano-based particles are so small, they can easily pass through the tiniest pores of human beings as well as the smallest cells in the air. It may require further study, lest the problems they solve bring new problems in need of solutions.