Gliomas are primary tumors that originate in brain parenchyma. Symptoms and diagnosis are similar to those of other brain tumors. Treatment involves surgical excision, radiation therapy, and, for some tumors, chemotherapy. Excision rarely cures.
Meningiomas are benign tumors of the meninges that can compress adjacent brain tissue. Symptoms depend on the tumor's location. Diagnosis is by MRI with contrast agent. Treatment may include excision, stereotactic radiosurgery, and sometimes radiation therapy.
Pineal region tumors are usually germ cell tumors (eg, germinoma, choriocarcinoma, yolk-sac tumor, teratoma). Other primary pineal tumors include pineocytoma and the rare malignant pineoblastoma.
Most pituitary tumors are adenomas. Symptoms include headache and endocrinopathies; endocrinopathies result when the tumor produces hormones or destroys hormone-producing tissue. Diagnosis is by MRI. Treatment includes surgery or radiation therapy and correction of any endocrinopathy.
Primary brain lymphomas originate in neural tissue and are usually B-cell tumors. Diagnosis requires neuroimaging and sometimes CSF analysis, Epstein-Barr titers, or brain biopsy. Treatment includes corticosteroids, chemotherapy, and radiation therapy.
Spinal cord tumors may develop within the spinal cord parenchyma, directly destroying tissue, or outside the cord parenchyma, often compressing the cord or nerve roots. Symptoms include progressive back pain and neurologic deficits referable to the spinal cord or spinal nerve roots. Diagnosis is by MRI. Treatment may include corticosteroids, surgical excision, and radiation therapy.
Monday, September 22, 2008
MEDICINE
So medicines sound like a pretty good thing, right? In many cases they are — as long as they are used correctly. Too much of a medicine can be harmful, and old or outdated medicines may not work or can make people sick. Taking the wrong medicine or medicine prescribed for someone else is also very bad news. You should also always follow your doctor's instructions for taking medicine — especially for how long. If your doctor says to take medicine for 10 days, take it for the whole time, even if you start to feel better sooner. Those medicines need time to finish the job and make you better!
Friday, August 22, 2008
MIGRAIN HEADACHE
Signs and Symptoms
The headache from a migraine, classic or common, has the following characteristics:
- Throbbing, pounding, or pulsating pain
- Often, begins on one side of your head and may spread to both or stay localized
- Most intense pain is often concentrated around the temple(s) (side of the forehead)
- Commonly lasts from 6 to 48 hours
Accompanying symptoms that may precede or occur at the same time as the migraine include:
- Nausea and vomiting
- Dizziness described as lightheadedness or even vertigo (feeling like the room is spinning)
- Loss of appetite
- Fatigue
- Visual disturbances, like seeing flashing lights or zigzag lines, temporary blind spots (for example, loss of your peripheral vision), or blurred vision
- Eye pain
- Extreme sensitivitity to light (called photophobia)
- Parts of your body may feel numb, weak, or tingly
- Light, noise, and movement—especially bending over—make your head hurt worse; you want to lie down in a dark, quiet room
- Irritability
Symptoms that may linger even after the migraine has resolved:
- Feeling mentally dull, like your thinking is not clear or sharp
- Increased need for sleep
- Neck pain
Saturday, July 12, 2008
NEUTROPENIA
Neutropenia is a blood disorder that can affect anyone. Some people are born with it. It can happen after a viral infection. In some cases the cause can be a side effect of a drug, or exposure to certain poisons. People can get neutropenia when treated for cancer with chemotherapy drugs. Sometimes it happens for no known reason.
Blood is made up of billions of cells. There are many different types of blood cells, but most of the time you hear about two kinds - red cells and white cells. There are more red cells than any other type of blood cell. They are very important as they carry oxygen from your lungs to all parts of your body. White blood cells are just as important, but for a very different reason. One of their jobs is to protect you from infection. There are several kinds of white cells. Each has a special function.
Tuesday, July 8, 2008
CLUSTER HEADACHE
What Causes Cluster Headaches?
The exact cause of cluster headaches is not known. Many experts believe that cluster headaches and migraine headaches have a common cause that begins in the trigeminal nerve, a nerve that carries sensations from the head to the brain and that ends in the blood vessels that surround the brain. Other experts link cluster headaches to the hypothalamus, an area of the brain. Either explanation would account for the periodic nature of the headache.
What Are The Symptoms of Cluster Headaches?
Cluster headaches often occur with the following symptoms:
- Deep, stabbing pain around the temple or the eye
- Stuffy or runny nose
- Tearing and redness in one eye
- Droopy eyelid
How Are Cluster Headaches Treated?
People with cluster headaches usually receive drug therapies. These treatments may be classified as abortive or preventive.
Abortive treatments are directed at stopping or reducing the severity of an attack, and include:
- Inhalation of high-flow, concentrated oxygen
- Injection of Depo-Medrol
- Imitrex injection
- Dihydroergotoamine injection and ergotomine tartrate tablets
- Zomig, Zomig-ZMT, and Zomig nasal spray
- Maxalt, Maxalt-MLT
- Axert
- Deltasone
Preventive treatments are used to reduce the frequency and intensity of cluster headaches and improve the person's quality of life. Preventive drugs include:
- Blood pressure medications, such as beta-blockers and calcium channel blockers
- Antidepressants
- Anticonvulsants
- Periactin
- Nonsteroidal anti-inflammatory drugs (NSAIDs) such as Naprosyn
- Sansert
- Calan, Verelan, Covera-HS
- Eskalith, Lithane, Lithobid, Lithonate, Lithotabs
Surgeries including nerve blocks, ablative neurosurgical procedures and radiosurgery have helped some people with cluster headaches. Nerve blocks involve the injection of pain medicine into or around a nerve or the spine. Ablative neurosurgical procedures are operations that involve the removal or destruction of a part of the brain, the spinal cord, or a nerve. Radiosurgery, a type of surgery that uses radiant energy and does not involve cutting, recently has been used to provide a less invasive alternative for people who have persistent cluster headaches.
Some people with cluster headaches have been helped by alternative or complementary therapies such as chiropractic, acupuncture, osteopathic manipulation, and herbal remedies.
ALZHEIMER'S DISEASE
What is Alzheimer's disease?
Alzheimer's disease (AD) is a slowly progressive disease of the brain that is characterized by impairment of memory and eventually by disturbances in reasoning, planning, language, and perception. Many scientists believe that Alzheimer's disease results from an increase in the production or accumulation of a specific protein (beta-amyloid protein) in the brain that leads to nerve cell death.
The likelihood of having Alzheimer's disease increases substantially after the age of 70 and may affect around 50% of persons over the age of 85. Nonetheless, Alzheimer's disease is not a normal part of aging and is not something that inevitably happens in later life. For example, many people live to over 100 years of age and never develop Alzheimer's disease.
MELANOMA
What is melanoma?
Melanoma is a type of skin cancer. It begins in cells in the skin called melanocytes. To understand melanoma, it is helpful to know about the skin and about melanocytes—what they do, how they grow, and what happens when they become cancerous.
The skin
The skin is the body's largest organ. It protects against heat, sunlight, injury, and infection. It helps regulate body temperature, stores water and fat, and produces vitamin D.
The skin has two main layers: the outer epidermis and the inner dermis.
- The epidermis is mostly made up of flat, scalelike cells called squamous cells. Round cells called basal cells lie under the squamous cells in the epidermis. The lower part of the epidermis also contains melanocytes.
- The dermis contains blood vessels, lymphatic vessels, hair follicles, and glands. Some of these glands produce sweat, which help regulate body temperature. Other glands produce sebum, an oily substance that helps keep the skin from drying out. Sweat and sebum reach the skin's surface through tiny openings called pores.
Melanocytes and moles
Melanocytes produce melanin, the pigment that gives skin its natural color. When skin is exposed to the sun, melanocytes produce more pigment, causing the skin to tan, or darken.
Sometimes, clusters of melanocytes and surrounding tissue form noncancerous growths called moles. (Doctors also call a mole a nevus; the plural is nevi.) Moles are very common. Most people have between 10 and 40 moles. Moles may be pink, tan, brown, or a color that is very close to the person's normal skin tone. People who have dark skin tend to have dark moles. Moles can be flat or raised. They are usually round or oval and smaller than a pencil eraser. They may be present at birth or may appear later on—usually before age 40. They tend to fade away in older people. When moles are surgically removed, they normally do not return.
BOTULISM
What is botulism?
Botulism is a serious illness that causes flaccid paralysis of muscles. It is caused by a neurotoxin, generically called botulinum toxin, that is produced by the bacterium Clostridium botulinum. There are seven distinct neurotoxins (types A-G) that Clostridium botulinum produce, but types A, B, and E (rarely F) are the most common that produce the flaccid paralysis in humans. The other types mainly cause disease in animals. Most Clostridium species produce only one type of neurotoxin.
The recorded history of botulism begins in 1735, when the disease was first associated with German sausage (food-borne disease, or food poisoning after eating sausage). In 1870, a German physician by the name of Muller derived the name botulism from the Latin word for sausage. Clostridium botulinum bacteria were first isolated in 1895, and a neurotoxin that it produces was isolated in 1944 by Dr. Edward Schantz.
How many kinds of botulism are there?
There are three main kinds of botulism, which are categorized by the way in which the disease is acquired:
- Food-borne botulism is caused by eating foods that contain the botulinum neurotoxin.
- Wound botulism is caused by neurotoxin produced from a wound that is infected with the bacteria Clostridium botulinum.
- Infant botulism occurs when an infant consumes the spores of the botulinum bacteria. The bacteria then grow in the intestines and release the neurotoxin.
Three other kinds of botulism have been described but are seen rarely. The first is adult intestinal colonization that is seen in older children and adults with abnormal bowels. Only rarely does intestinal infection with the Clostridium botulinum bacteria occur in adults. Typically, the adult form of this intestinal botulism is related to abdominal surgical procedures. The second kind (injection botulism) is seen in patients injected with inappropriately high amounts of therapeutic neurotoxin (for example, Botox, Dysport), while the third kind (inhalation botulism) has occurred in laboratory personnel who work with the neurotoxins. All of these six kinds of botulism are potentially fatal.
How serious is botulism?
Botulinum neurotoxin is considered one of the most potent, lethal substances known. As little as about one nanogram/kg can be lethal to an individual, and scientists have estimated that about one gram could potentially kill one million people. All forms of botulism can be fatal and are considered medical emergencies. Food-borne botulism can be especially dangerous because many people can be poisoned by eating even small amounts of neurotoxin-contaminated food. A botulism outbreak is a public-health emergency that is reportable to the U.S. government.
How does botulism neurotoxin affect the body?
A neurotoxin actually paralyzes the nerves so that the muscles cannot contract. This happens when the neurotoxin enters nerve cells and eventually interferes with the release of acetylcholine so the nerve cannot stimulate the muscle to contract. Unless the nerve can regenerate a new axon that has no exposure to the neurotoxin, the interference at the neuromuscular junction is permanent. This is why it takes so long to recover from botulism and also why cosmetic and therapeutic uses of diluted neurotoxin can be effective for relatively lengthy time periods.
What kind of organism is Clostridium botulinum?
Clostridium botulinum is the name of bacteria commonly found in soil all over the world. The bacteria are considered to be anaerobic, which means these rod-shaped organisms grow best in low or absent oxygen levels. Clostridium form spores which allow the bacteria to survive in a dormant state until exposed to conditions that can support growth. There are seven types of botulism neurotoxin designated by the letters A through G. Only types A, B, E, and F cause illness in humans.Tuesday, July 1, 2008
MESOTHELIOMA
Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos. In this disease, malignant cells develop in the mesothelium, a protective lining that covers most of the body's internal organs. Its most common site is the pleura (outer lining of the lungs and chest cavity), but it may also occur in the peritoneum (the lining of the abdominal cavity) or the pericardium (a sac that surrounds the heart).
Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fibre in other ways, such as by washing the clothes of a family member who worked with asbestos. Unlike lung cancer, there is no association between mesothelioma and smoking.[1] Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).
The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis can be made with chest X-rays and a CT scan, and confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.
Signs and symptoms
Symptoms of mesothelioma may not appear until 20 to 50 years after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space are often symptoms of pleural mesothelioma.
Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.
These symptoms may be caused by mesothelioma or by other, less serious conditions.
Mesothelioma that affects the pleura can cause these signs and symptoms:
- chest wall pain
- pleural effusion, or fluid surrounding the lung
- shortness of breath
- fatigue or anemia
- wheezing, hoarseness, or cough
- blood in the sputum (fluid) coughed up (hemoptysis)
In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.
Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:
- abdominal pain
- ascites, or an abnormal buildup of fluid in the abdomen
- a mass in the abdomen
- problems with bowel function
- weight loss
In severe cases of the disease, the following signs and symptoms may be present:
- blood clots in the veins, which may cause thrombophlebitis
- disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
- jaundice, or yellowing of the eyes and skin
- low blood sugar level
- pleural effusion
- pulmonary emboli, or blood clots in the arteries of the lungs
- severe ascites
A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.
[edit] Diagnosis
Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient's medical history. A history of exposure to asbestos may increase clinical suspicion for mesothelioma. A physical examination is performed, followed by chest X-ray and often lung function tests. The X-ray may reveal pleural thickening commonly seen after asbestos exposure and increases suspicion of mesothelioma. A CT (or CAT) scan or an MRI is usually performed. If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe. For pleural fluid this is done by a pleural tap or chest drain, in ascites with an paracentesis or ascitic drain and in a pericardial effusion with pericardiocentesis. While absence of malignant cells on cytology does not completely exclude mesothelioma, it makes it much more unlikely, especially if an alternative diagnosis can be made (e.g. tuberculosis, heart failure).
If cytology is positive or a plaque is regarded as suspicious, a biopsy is needed to confirm a diagnosis of mesothelioma. A doctor removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.
If the cancer is in the abdomen, the doctor may perform a laparoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary.
Risk factors
Working with asbestos is the major risk factor for mesothelioma. Mesothelioma is now known to occur in those who are genetically pre-disposed to it. A history of asbestos exposure exists in almost all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite.
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney.
The combination of smoking and asbestos exposure significantly increases a person's risk of developing cancer of the airways (lung cancer, bronchial carcinoma). The Kent brand of cigarettes used asbestos in its filters for the first few years of production in the 1950s and some cases of mesothelioma have resulted. Smoking modern cigarettes does not appear to increase the risk of mesothelioma.
Some studies suggest that simian virus 40 (SV40) may act as a cofactor in the development of mesothelioma.
Treatment
Treatment of malignant mesothelioma using conventional therapies has not proved successful and patients have a median survival time of 6 - 12 months after presentation[citation needed]. The clinical behaviour of the malignancy is affected by several factors including the continuous mesothelial surface of the pleural cavity which favours local metastasis via exfoliated cells, invasion to underlying tissue and other organs within the pleural cavity, and the extremely long latency period between asbestos exposure and development of the disease.
Surgery
Surgery, either by itself or used in combination with pre- and post-operative adjuvant therapies, has proved disappointing. A pleurectomy/decortication is the most common surgery, in which the lining of the chest is removed. Less common is an extrapleural pneumonectomy (EPP), in which the lung, lining of the inside of the chest, the hemi-diaphragm and the pericardium are removed. It is not possible to remove the entire mesothelium without killing the patient.
Saturday, June 21, 2008
NANOTECHNOLOGY
Nanotechnology refers to a field of applied science and technology whose theme is the control of matter on the atomic and molecular scale, generally 100 nanometers or smaller, and the fabrication of devices or materials that lie within that size range.
[edit] Overview
Nanotechnology is a highly multidisciplinary field, drawing from fields such as applied physics, materials science, interface and colloid science, device physics, supramolecular chemistry (which refers to the area of chemistry that focuses on the noncovalent bonding interactions of molecules), self-replicating machines and robotics, chemical engineering, mechanical engineering, biological engineering, and electrical engineering. Grouping of the sciences under the umbrella of "nanotechnology" has been questioned on the basis that there is little actual boundary-crossing between the sciences that operate on the nano-scale. Instrumentation is the only area of technology common to all disciplines; on the contrary, for example pharmaceutical and semiconductor industries do not "talk with each other". Corporations that call their products "nanotechnology" typically market them only to a certain industrial cluster.[1]
Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecular components which assemble themselves chemically by principles of molecular recognition. In the "top-down" approach, nano-objects are constructed from larger entities without atomic-level control. The impetus for nanotechnology comes from a renewed interest in Interface and Colloid Science, coupled with a new generation of analytical tools such as the atomic force microscope (AFM), and the scanning tunneling microscope (STM). Combined with refined processes such as electron beam lithography and molecular beam epitaxy, these instruments allow the deliberate manipulation of nanostructures, and lead to the observation of novel phenomena.
Examples of nanotechnology are the manufacture of polymers based on molecular structure, and the design of computer chip layouts based on surface science. Despite the promise of nanotechnologies such as quantum dots and nanotubes, real commercial applications have mainly used the advantages of colloidal nanoparticles in bulk form, such as suntan lotion, cosmetics, protective coatings, drug delivery,[2] and stain resistant clothing.
[edit] Origins
The first use of the concepts in 'nano-technology' (but predating use of that name) was in "There's Plenty of Room at the Bottom," a talk given by physicist Richard Feynman at an American Physical Society meeting at Caltech on December 29, 1959. Feynman described a process by which the ability to manipulate individual atoms and molecules might be developed, using one set of precise tools to build and operate another proportionally smaller set, so on down to the needed scale. In the course of this, he noted, scaling issues would arise from the changing magnitude of various physical phenomena: gravity would become less important, surface tension and Van der Waals attraction would become more important, etc. This basic idea appears plausible, and exponential assembly enhances it with parallelism to produce a useful quantity of end products. The term "nanotechnology" was defined by Tokyo Science University Professor Norio Taniguchi in a 1974 paper[3] as follows: "'Nano-technology' mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or by one molecule." In the 1980s the basic idea of this definition was explored in much more depth by Dr. K. Eric Drexler, who promoted the technological significance of nano-scale phenomena and devices through speeches and the books Engines of Creation: The Coming Era of Nanotechnology (1986) and Nanosystems: Molecular Machinery, Manufacturing, and Computation,[4] and so the term acquired its current sense. Engines of Creation: The Coming Era of Nanotechnology is considered the first book on the topic of nanotechnology. Nanotechnology and nanoscience got started in the early 1980s with two major developments; the birth of cluster science and the invention of the scanning tunneling microscope (STM). This development led to the discovery of fullerenes in 1986 and carbon nanotubes a few years later. In another development, the synthesis and properties of semiconductor nanocrystals was studied; This led to a fast increasing number of metal oxide nanoparticles of quantum dots. The atomic force microscope was invented six years after the STM was invented. In 2000, the United States National Nanotechnology Initiative was founded to coordinate Federal nanotechnology research and development.nano tecnology is the study of unicorns
[edit] Fundamental concepts
One nanometer (nm) is one billionth, or 10-9 of a meter. To put that scale in context, the comparative size of a nanometer to a meter is the same as that of a marble to the size of the earth.[5] Or another way of putting it: a nanometer is the amount a man's beard grows in the time it takes him to raise the razor to his face.[5]
Typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.12-0.15 nm, and a DNA double-helix has a diameter around 2 nm. On the other hand, the smallest cellular lifeforms, the bacteria of the genus Mycoplasma, are around 200 nm in length.
[edit] Larger to smaller: a materials perspective
A number of physical phenomena become pronounced as the size of the system decreases. These include statistical mechanical effects, as well as quantum mechanical effects, for example the “quantum size effect” where the electronic properties of solids are altered with great reductions in particle size. This effect does not come into play by going from macro to micro dimensions. However, it becomes dominant when the nanometer size range is reached. Additionally, a number of physical (mechanical, electrical, optical, etc.) properties change when compared to macroscopic systems. One example is the increase in surface area to volume ratio altering mechanical, thermal and catalytic properties of materials. Novel mechanical properties of nanosystems are of interest in the nanomechanics research. The catalytic activity of nanomaterials also opens potential risks in their interaction with biomaterials.
Materials reduced to the nanoscale can show different properties compared to what they exhibit on a macroscale, enabling unique applications. For instance, opaque substances become transparent (copper); inert materials become catalysts (platinum); stable materials turn combustible (aluminum); solids turn into liquids at room temperature (gold); insulators become conductors (silicon). A material such as gold, which is chemically inert at normal scales, can serve as a potent chemical catalyst at nanoscales. Much of the fascination with nanotechnology stems from these quantum and surface phenomena that matter exhibits at the nanoscale.
[edit] Simple to complex: a molecular perspective
Modern synthetic chemistry has reached the point where it is possible to prepare small molecules to almost any structure. These methods are used today to produce a wide variety of useful chemicals such as pharmaceuticals or commercial polymers. This ability raises the question of extending this kind of control to the next-larger level, seeking methods to assemble these single molecules into supramolecular assemblies consisting of many molecules arranged in a well defined manner.
These approaches utilize the concepts of molecular self-assembly and/or supramolecular chemistry to automatically arrange themselves into some useful conformation through a bottom-up approach. The concept of molecular recognition is especially important: molecules can be designed so that a specific conformation or arrangement is favored due to non-covalent intermolecular forces. The Watson-Crick basepairing rules are a direct result of this, as is the specificity of an enzyme being targeted to a single substrate, or the specific folding of the protein itself. Thus, two or more components can be designed to be complementary and mutually attractive so that they make a more complex and useful whole.
Such bottom-up approaches should be able to produce devices in parallel and much cheaper than top-down methods, but could potentially be overwhelmed as the size and complexity of the desired assembly increases. Most useful structures require complex and thermodynamically unlikely arrangements of atoms. Nevertheless, there are many examples of self-assembly based on molecular recognition in biology, most notably Watson-Crick basepairing and enzyme-substrate interactions. The challenge for nanotechnology is whether these principles can be used to engineer novel constructs in addition to natural ones.
[edit] Molecular nanotechnology: a long-term view
Molecular nanotechnology, sometimes called molecular manufacturing, is a term given to the concept of engineered nanosystems (nanoscale machines) operating on the molecular scale. It is especially associated with the concept of a molecular assembler, a machine that can produce a desired structure or device atom-by-atom using the principles of mechanosynthesis. Manufacturing in the context of productive nanosystems is not related to, and should be clearly distinguished from, the conventional technologies used to manufacture nanomaterials such as carbon nanotubes and nanoparticles.
When the term "nanotechnology" was independently coined and popularized by Eric Drexler (who at the time was unaware of an earlier usage by Norio Taniguchi) it referred to a future manufacturing technology based on molecular machine systems. The premise was that molecular-scale biological analogies of traditional machine components demonstrated molecular machines were possible: by the countless examples found in biology, it is known that sophisticated, stochastically optimised biological machines can be produced..
It is hoped that developments in nanotechnology will make possible their construction by some other means, perhaps using biomimetic principles. However, Drexler and other researchers[6] have proposed that advanced nanotechnology, although perhaps initially implemented by biomimetic means, ultimately could be based on mechanical engineering principles, namely, a manufacturing technology based on the mechanical functionality of these components (such as gears, bearings, motors, and structural members) that would enable programmable, positional assembly to atomic specification (PNAS-1981). The physics and engineering performance of exemplar designs were analyzed in Drexler's book Nanosystems.
But Drexler's analysis is very qualitative and does not address very pressing issues, such as the "fat fingers" and "Sticky fingers" problems. In general it is very difficult to assemble devices on the atomic scale, as all one has to position atoms are other atoms of comparable size and stickyness. Another view, put forth by Carlo Montemagno,[7] is that future nanosystems will be hybrids of silicon technology and biological molecular machines. Yet another view, put forward by the late Richard Smalley, is that mechanosynthesis is impossible due to the difficulties in mechanically manipulating individual molecules.
This led to an exchange of letters in the ACS publication Chemical & Engineering News in 2003.[8] Though biology clearly demonstrates that molecular machine systems are possible, non-biological molecular machines are today only in their infancy. Leaders in research on non-biological molecular machines are Dr. Alex Zettl and his colleagues at Lawrence Berkeley Laboratories and UC Berkeley. They have constructed at least three distinct molecular devices whose motion is controlled from the desktop with changing voltage: a nanotube nanomotor, a molecular actuator, and a nanoelectromechanical relaxation oscillator.
An experiment indicating that positional molecular assembly is possible was performed by Ho and Lee at Cornell University in 1999. They used a scanning tunneling microscope to move an individual carbon monoxide molecule (CO) to an individual iron atom (Fe) sitting on a flat silver crystal, and chemically bound the CO to the Fe by applying a voltage.
[edit] Current research
[edit] Nanomaterials
This includes subfields which develop or study materials having unique properties arising from their nanoscale dimensions.[10]
- Interface and Colloid Science has given rise to many materials which may be useful in nanotechnology, such as carbon nanotubes and other fullerenes, and various nanoparticles and nanorods.
- Nanoscale materials can also be used for bulk applications; most present commercial applications of nanotechnology are of this flavor.
- Progress has been made in using these materials for medical applications; see Nanomedicine.
[edit] Bottom-up approaches
These seek to arrange smaller components into more complex assemblies.
- DNA nanotechnology utilizes the specificity of Watson-Crick basepairing to construct well-defined structures out of DNA and other nucleic acids.
- Approaches from the field of "classical" chemical synthesis also aim at designing molecules with well-defined shape (e.g. bis-peptides[11]).
- More generally, molecular self-assembly seeks to use concepts of supramolecular chemistry, and molecular recognition in particular, to cause single-molecule components to automatically arrange themselves into some useful conformation.
[edit] Top-down approaches
These seek to create smaller devices by using larger ones to direct their assembly.
- Many technologies descended from conventional solid-state silicon methods for fabricating microprocessors are now capable of creating features smaller than 100 nm, falling under the definition of nanotechnology. Giant magnetoresistance-based hard drives already on the market fit this description,[12] as do atomic layer deposition (ALD) techniques. Peter Grünberg and Albert Fert received the Nobel Prize in Physics for their discovery of Giant magnetoresistance and contributions to the field of spintronics in 2007.[13]
- Solid-state techniques can also be used to create devices known as nanoelectromechanical systems or NEMS, which are related to microelectromechanical systems or MEMS.
- Atomic force microscope tips can be used as a nanoscale "write head" to deposit a chemical upon a surface in a desired pattern in a process called dip pen nanolithography. This fits into the larger subfield of nanolithography.
[edit] Functional approaches
These seek to develop components of a desired functionality without regard to how they might be assembled.
- Molecular electronics seeks to develop molecules with useful electronic properties. These could then be used as single-molecule components in a nanoelectronic device.[14] For an example see rotaxane.
- Synthetic chemical methods can also be used to create synthetic molecular motors, such as in a so-called nanocar.
[edit] Speculative
These subfields seek to anticipate what inventions nanotechnology might yield, or attempt to propose an agenda along which inquiry might progress. These often take a big-picture view of nanotechnology, with more emphasis on its societal implications than the details of how such inventions could actually be created.
- Molecular nanotechnology is a proposed approach which involves manipulating single molecules in finely controlled, deterministic ways. This is more theoretical than the other subfields and is beyond current capabilities.
- Nanorobotics centers on self-sufficient machines of some functionality operating at the nanoscale. There are hopes for applying nanorobots in medicine[15][16][17], but it may not be easy to do such a thing because of several drawbacks of such devices.[18] Nevertheless, progress on innovative materials and methodologies has been demonstrated with some patents granted about new nanomanufacturing devices for future commercial applications, which also progressively helps in the development towards nanorobots with the use of embedded nanobioelectronics concept.[19][20]
- Programmable matter based on artificial atoms seeks to design materials whose properties can be easily and reversibly externally controlled.
- Due to the popularity and media exposure of the term nanotechnology, the words picotechnology and femtotechnology have been coined in analogy to it, although these are only used rarely and informally.
[edit] Tools and techniques
The first observations and size measurements of nano-particles were made during the first decade of the 20th century. They are mostly associated with the name of Zsigmondy who made detailed studies of gold sols and other nanomaterials with sizes down to 10 nm and less. He published a book in 1914.[21] He used ultramicroscope that employs a dark field method for seeing particles with sizes much less than light wavelength.
There are traditional techniques developed during 20th century in Interface and Colloid Science for characterizing nanomaterials. These are widely used for first generation passive nanomaterials specified in the next section.
These methods include several different techniques for characterizing particle size distribution. This characterization is imperative because many materials that are expected to be nano-sized are actually aggregated in solutions. Some of methods are based on light scattering. Other apply ultrasound, such as ultrasound attenuation spectroscopy for testing concentrated nano-dispersions and microemulsions.[22]
There is also a group of traditional techniques for characterizing surface charge or zeta potential of nano-particles in solutions. These information is required for proper system stabilzation, preventing its aggregation or flocculation. These methods include microelectrophoresis, electrophoretic light scattering and electroacoustics. The last one, for instance colloid vibration current method is suitable for characterizing concentrated systems.
Next group of nanotechnological techniques include those used for fabrication of nanowires, those used in semiconductor fabrication such as deep ultraviolet lithography, electron beam lithography, focused ion beam machining, nanoimprint lithography, atomic layer deposition, and molecular vapor deposition, and further including molecular self-assembly techniques such as those employing di-block copolymers. However, all of these techniques preceded the nanotech era, and are extensions in the development of scientific advancements rather than techniques which were devised with the sole purpose of creating nanotechnology and which were results of nanotechnology research.
There are several important modern developments. The atomic force microscope (AFM) and the Scanning Tunneling Microscope (STM) are two early versions of scanning probes that launched nanotechnology. There are other types of scanning probe microscopy, all flowing from the ideas of the scanning confocal microscope developed by Marvin Minsky in 1961 and the scanning acoustic microscope (SAM) developed by Calvin Quate and coworkers in the 1970s, that made it possible to see structures at the nanoscale. The tip of a scanning probe can also be used to manipulate nanostructures (a process called positional assembly). Feature-oriented scanning-positioning methodology suggested by Rostislav Lapshin appears to be a promising way to implement these nanomanipulations in automatic mode. However, this is still a slow process because of low scanning velocity of the microscope. Various techniques of nanolithography such as dip pen nanolithography, electron beam lithography or nanoimprint lithography were also developed. Lithography is a top-down fabrication technique where a bulk material is reduced in size to nanoscale pattern.
The top-down approach anticipates nanodevices that must be built piece by piece in stages, much as manufactured items are made. Scanning probe microscopy is an important technique both for characterization and synthesis of nanomaterials. Atomic force microscopes and scanning tunneling microscopes can be used to look at surfaces and to move atoms around. By designing different tips for these microscopes, they can be used for carving out structures on surfaces and to help guide self-assembling structures. By using, for example, feature-oriented scanning-positioning approach, atoms can be moved around on a surface with scanning probe microscopy techniques. At present, it is expensive and time-consuming for mass production but very suitable for laboratory experimentation.
In contrast, bottom-up techniques build or grow larger structures atom by atom or molecule by molecule. These techniques include chemical synthesis, self-assembly and positional assembly. Another variation of the bottom-up approach is molecular beam epitaxy or MBE. Researchers at Bell Telephone Laboratories like John R. Arthur. Alfred Y. Cho, and Art C. Gossard developed and implemented MBE as a research tool in the late 1960s and 1970s. Samples made by MBE were key to the discovery of the fractional quantum Hall effect for which the 1998 Nobel Prize in Physics was awarded. MBE allows scientists to lay down atomically-precise layers of atoms and, in the process, build up complex structures. Important for research on semiconductors, MBE is also widely used to make samples and devices for the newly emerging field of spintronics.
Newer techniques such as Dual Polarisation Interferometry are enabling scientists to measure quantitatively the molecular interactions that take place at the nano-scale.
[edit] Applications
As of April 24, 2008 The Project on Emerging Nanotechnologies claims that over 609 nanotech products exist, with new ones hitting the market at a pace of 3-4 per week.[23] The project lists all of the products in a database. Most applications are limited to the use of "first generation" passive nanomaterials which includes titanium dioxide in sunscreen, cosmetics and some food products; Carbon allotropes used to produce gecko tape; silver in food packaging, clothing, disinfectants and household appliances; zinc oxide in sunscreens and cosmetics, surface coatings, paints and outdoor furniture varnishes; and cerium oxide as a fuel catalyst.[24]
The National Science Foundation (a major source of funding for nanotechnology in the United States) funded researcher David Berube to study the field of nanotechnology. His findings are published in the monograph “Nano-Hype: The Truth Behind the Nanotechnology Buzz". This published study (with a foreword by Mihail Roco, Senior Advisor for Nanotechnology at the National Science Foundation) concludes that much of what is sold as “nanotechnology” is in fact a recasting of straightforward materials science, which is leading to a “nanotech industry built solely on selling nanotubes, nanowires, and the like” which will “end up with a few suppliers selling low margin products in huge volumes." Further applications which require actual manipulation or arrangement of nanoscale components await further research. Though technologies branded with the term 'nano' are sometimes little related to and fall far short of the most ambitious and transformative technological goals of the sort in molecular manufacturing proposals, the term still connotes such ideas. Thus there may be a danger that a "nano bubble" will form, or is forming already, from the use of the term by scientists and entrepreneurs to garner funding, regardless of interest in the transformative possibilities of more ambitious and far-sighted work.
Platinum nanoparticles are now being considered in the next generation of automotive catalytic converters because the very high surface area of nanoparticles could reduce the amount of platinum required.[25] However, some concerns have been raised due to experiments demonstrating that they will spontaneously combust if methane is mixed with the ambient air.[26] Ongoing research at the Centre National de la Recherche Scientifique(CNRS) in France may resolve their true usefulness for catalytic applications.[27] Nanofiltration may come to be an important application, although future research must be careful to investigate possible toxicity.[28]
In 1999, the ultimate CMOS transistor developed at the Laboratory for Electronics and Information Technology in Grenoble, France, tested the limits of the principles of the MOSFET transistor with a diameter of 18 nm (approximately 70 atoms placed side by side). This was almost one tenth the size of the smallest industrial transistor in 2003 (130 nm in 2003, 90 nm in 2004, 65 nm in 2005 and 45 nm in 2007). It enabled the theoretical integration of seven billion junctions on a €1 coin. However, the CMOS transistor, which was created in 1999, was not a simple research experiment to study how CMOS technology functions, but rather a demonstration of how this technology functions now that we ourselves are getting ever closer to working on a molecular scale. Today it would be impossible to master the coordinated assembly of a large number of these transistors on a circuit and it would also be impossible to create this on an industrial level.[29]
[edit] Cancer
The small size of nanoparticles endows them with properties that can be very useful in oncology, particularly in imaging. Quantum dots (nanoparticles with quantum confinement properties, such as size-tunable light emission), when used in conjunction with MRI (magnetic resonance imaging), can produce exceptional images of tumor sites. These nanoparticles are much brighter than organic dyes and only need one light source for excitation. This means that the use of fluorescent quantum dots could produce a higher contrast image and at a lower cost than today's organic dyes used as contrast media.
Another nanoproperty, high surface area to volume ratio, allows many functional groups to be attached to a nanoparticle, which can seek out and bind to certain tumor cells. Additionally, the small size of nanoparticles (10 to 100 nanometers), allows them to preferentially accumulate at tumor sites (because tumors lack an effective lymphatic drainage system). A very exciting research question is how to make these imaging nanoparticles do more things for cancer. For instance, is it possible to manufacture multifunctional nanoparticles that would detect, image, and then proceed to treat a tumor? This question is under vigorous investigation; the answer to which could shape the future of cancer treatment.[30]A promising new cancer treatment that may one day replace radiation and chemotherapy is edging closer to human trials. Kanzius RF therapy attaches microscopic nanoparticles to cancer cells and then "cooks" tumors inside the body with radio waves that heat only the nanoparticles and the adjacent (cancerous) cells.
[edit] Regulation
 | It has been suggested that this section be split into a new article. (Discuss) |
The nanotechnology label is used on an increasing number of commercially available products – from socks and trousers to tennis racquets and cleaning cloths. The emergence of such nanotechnologies, and their accompanying industries, have been met by calls for increased community participation and effective regulatory arrangements.[31] Yet despite such calls, there is currently no comprehensive regulation to oversee research and the commercial application of nanotechnologies.[32] Nor is there any comprehensive labeling for products that contain nano-particles, or that are derived from nano-processes.
Limited nanotechnology labeling and regulation are expected to exacerbate the potential human and environmental health and safety issues associated with nanotechnology.[33] The development of comprehensive regulation of nanotechnology will be vital to ensure that the potential risks associated with the research and commercial application of nanotechnology do not overshadow its supposed benefits.[34] Regulation will also be required to meet community expectations about responsible development of nanotechnology, as well as ensuring that public interests are included in shaping the development of nanotechnology.[35]
[edit] Definitions: ‘Newness’, Size and Mass
[edit] ’Newness’
The question of whether nanotechnology represents something ‘new’ must be answered to decide how best nanotechnology should be regulated. Given its novelty, there is a strong argument that nanotechnology should be defined as ‘new’, and as such that it be regulated via comprehensive nanotechnology specific regulatory regimes.[36] The Royal Society[37] recommended that the UK government assess chemicals in the form of nanoparticles or nanotubes as new substances. Subsequent to this, in 2007 a coalition of over forty groups called for nanomaterials to be classified as new substances, and regulated as such.
Despite these recommendations, chemicals comprising nanoparticles that have previously been subject to assessment and regulation may be exempt from regulation, regardless of the potential for different risks and impacts. In contrast, nanomaterials are often recognised as ‘new’ from the perspective of intellectual property rights (IPRs), and as such are commercially protected via patenting laws. There is an inconsistency here; nanomaterials are legally defined as ‘new’ via IPRs, however they are not recognized as such from the perspective of health and safety regulations.
[edit] Size
Regulation of nanotechnology will require a definition of the size, in which particles and processes are recognized as operating at the nano-scale. The size-defining characteristic of nanotechnology is the subject of significant debate, and varies to include particles and materials in the scale of at least 100 to 300 nanometers (nm). Friends of the Earth Australia recommend defining nanoparticles up to 300 nanometers (nm) in size. They argue that “particles up to a few hundred nanometers in size share many of the novel biological behaviours of nanoparticles, including novel toxicity risks”, and that “nanomaterials up to approximately 300nm in size can be taken up by individual cells”. The UK Soil Association define nanotechnology to include manufactured nanoparticles where the mean particle size is 200 nm or smaller. The U.S. National Nanotechnology Initiative define nanotechnology as “the understanding and control of matter at dimensions of roughly 1 to 100 nm.
[edit] Mass Thresholds
Regulatory frameworks for chemicals tend to be triggered by mass thresholds.[38] This is certainly the case for the management of toxic chemicals in Australia through the National pollutant inventory. However, in the case of nanotechnology, nanoparticle applications are unlikely to exceed these thresholds (tonnes/kilograms) due to the size and weight of nanoparticles. As such, the Woodrow Wilson International Centre for Scholars question the usefulness of regulating nanotechnologies on the basis of their size/weight alone. They argue, for example, that the toxicity of nano-participles is more related to surface area than weight, and that emerging regulations should also take account of such factors.
[edit] Assessment
There is significant debate related to the circumstances in which it is necessary and appropriate to assess new substances prior to their release into the market, community and environment. The 2004 report by the UK Royal Society and Royal Academy of Engineers[39] noted that existing UK regulations did not require additional testing when existing substances were produced in nanoparticulate form. The Royal Society, however, recommended that such regulations were revised so that “chemicals produced in the form of nanoparticles and nanotubes be treated as new chemicals under these regulatory frameworks” (p.xi).
[edit] Managing Risks: Human and Environmental Health and Safety
[edit] Human Health and Safety
Calls for tighter regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks associated with nanotechnology. The Royal Society identifies the potential for nanoparticles to penetrate the skin, and recommend that the use of nanoparticles in cosmetics be conditional upon a favorable assessment by the relevant European Commission safety advisory committee. Andrew Maynard[40] also reports that ‘certain nanoparticles may move easily into sensitive lung tissues after inhalation, and cause damage that can lead to chronic breathing problems’.
Carbon nanotubes – characterized by their lightweight and incredible strength – are frequently likened to asbestos, due to their needle like fiber shape. In a recent study that introduced carbon nanotubes into the abdominal cavity of mice, results demonstrated that long thin carbon nanotubes showed the same effects as long thing asbestos fibers, raising concerns that exposure to carbon nanotubes may lead to mesothelioma (cancer of the lining of the lungs caused by exposure to asbestos).[41]
Given the risks identified with carbon nanotubes, effective and rigorous regulation will be required to determine if, and under what circumstances, carbon nanotubes are manufactured, as well as ensuring their safe handling and disposal.[42]
The Woodrow Wilson Centre’s Project on Emerging Technologies conclude that there is insufficient funding for human health and safety research, and as a result there is currently limited understanding of the human health and safety risks associated with nanotechnology. While the US National Nanotechnology Initiative reports that around four percent (about $40 million) is dedicated to risk related research and development, the Woodrow Wilson Centre estimate that only around $11 million is actually directed towards risk related research. They argued in 2007 that it would be necessary to increase funding to a minimum of $50 million in the following two years so as to fill the gaps in knowledge in these areas.[43]
The potential for workplace exposure was highlighted by the 2004 Royal Society report,[44] which recommended a review of existing regulations to assess and control workplace exposure to nanoparticles and nanotubes. The report expressed particular concern for the inhalation of large quantities of nanoparticles by workers involved in the manufacturing process.
Stakeholders concerned by the lack of a regulatory framework to assess and control risks associated with the release of nanoparticles and nanotubes have drawn parallels with bovine spongiform encephalopathy (‘mad cow’s disease), thalidomide, genetically modified food),[45] nuclear energy, reproductive technologies, biotechnology, and asbestosis. In light of such concerns, the Canadian based ETC Group have called for a moratorium on nano-related research until comprehensive regulatory frameworks are developed that will ensure workplace safety.
[edit] Environmental Health and Safety
Environmental assessment is justified as nanoparticles present novel (new) environmental impacts. Scrinis[46] raises concerns about nano-pollution, and argues that it is not currently possible to “precisely predict or control the ecological impacts of the release of these nano-products into the environment.” Ecotoxicological impacts of nanoparticles and the potential for bioaccumulation in plants and microorganisms remain under-researched. The capacity for nanoparticles to function as a transport mechanism also raises concern about the transport of heavy metals and other environmental contaminants. A May 2007 Report to the UK Department for Environment, Food and Rural Affairs noted concerns about the toxicological impacts of nanoparticles in relation to both hazard and exposure. The report recommended comprehensive toxicological testing and independent performance tests of fuel additives. Of the US$710 million spent in 2002 by the U.S. government on nanotechnology research, only $500,000 was spent on environmental impact assessments. Risks identified by Uskokovic (2007)[47] include: self-replicating nanobots aggressively or through slowly rising supremacy wiping out the whole biosphere; further destabilising the already endangered diversity of the biosphere or extending the existing gap between the rich and poor.
In early 2008, The UK's largest organic certifier, the Soil Association, announced that its organic standard would exclude nanotechnology, recognizing the associated human and environmental health and safety risks. It is likely that other organic certifiers will also follow suite. The Soil Association was also the first to declare organic standards free from genetic engineering.
[edit] Life Cycle Responsibility
The Royal Society report[48] identified a risk of nanoparticles or nanotubes being released during disposal, destruction and recycling, and recommended that “manufacturers of products that fall under extended producer responsibility regimes such as end-of-life regulations publish procedures outlining how these materials will be managed to minimize possible human and environmental exposure” (p.xiii). Reflecting the challenges for ensuring responsible life cycle regulation, the Institute for Food and Agricultural Standards has proposed standards for nanotechnology research and development should be integrated across consumer, worker and environmental standards. They also propose that NGOs and other citizen groups play a meaningful role in the development of these standards.
[edit] Democratic Governance
It is now widely recognized that government has a responsibility to provide opportunities for the public to be involved in the development of new forms of science and technology).[49] Community engagement can be achieved through various means or mechanisms. Rowe et al. (2005)[50] identify traditional approaches such as referenda, consultation documents, and advisory committees that include community members and other stakeholders. Other conventional approaches include public meetings and “closed” dialog with stakeholders. More contemporary engagement processes that have been employed to include community members in decisions about nanotechnology include citizens' juries and consensus conferences.
The Better Regulation Task Force's 2003 report[51] recommended that the UK Government: 1. enable, through an informed debate, the public to consider the risks for themselves, and help them to make their own decisions by providing suitable information; 2. be open about how it makes decisions, and acknowledge where there are uncertainties; 3. communicate with, and involve as far as possible, the public in the decision making process; 4. ensure it develops two-way communication channels; and 5. take a strong lead over the handling of any risk issues, particularly information provision and policy implementation.
These recommendations were accepted in principle by the UK Government. Noting that there was “no obvious focus for an informed public debate of the type suggested by the Task Force”, the UK government's response was to accept the recommendations. By contrast, Leach and Scoones (2006, p. 45)[52] argue that since that “most debates about science and technology options involve uncertainty, and often ignorance, public debate about regulatory regimes is essential.”
The Royal Society's 2004 report[53] identified two distinct governance issues:
- the “role and behaviour of institutions” and their ability to “minimise unintended consequences” through adequate regulation and
- the extent to which the public can trust and play a role in determining the trajectories that nanotechnologies may follow as they develop.
Community education, engagement and consultation tend to occur “downstream”: once there is at least a moderate level of awareness, and often during the process of disseminating and adapting technologies. “Upstream” engagement, by contrast, occurs much earlier in the innovation cycle and involves: “dialogue and debate about future technology options and pathways, bringing the often expert-led approaches to horizon scanning, technology foresight and scenario planning to involve a wider range of perspectives and inputs.”[54] Daniel Sarewitz Director of Arizona State University’s Consortium on Science, Policy and Outcomes, argues that “by the time new devices reach the stage of commercialization and regulation, it is usually too late to alter them to correct problems.”[55]
[edit] New Regulatory Framework or Adapt Existing Arrangements
There is significant debate about who is responsible for the regulation of nanotechnology. While some non-nanotechnology specific regulatory agencies currently cover some products and processes (to varying degrees) – by “bolting on” nanotechnology to existing regulations – there are clear gaps in these regimes.[56] This enables some nanotechnology applications to literally “slip through the cracks” without being covered by any regulations. An example of this has occurred in the US, and involves nanoparticles of titanium dioxide for use in sunscreen. In this case, the Federal Drug Administration reviewed the immediate health effects of exposure to nanoparticles of titanium dioxide for consumers. However, they did not review its impacts for aquatic ecosystems when the sunscreen rubs off, and nor did the EPA, or any other agency.[57] Such gaps in regulation are likely to continue alongside the development and commercialization of increasingly complex second and third generation nanotechnologies.
Some NGOs, including Friends of the Earth, are calling for the formation of a separate nanotechnology specific regulatory framework for the regulation of nanotechnology. In Australia, Friends of the Earth propose the establishment of a Nanotechnology Regulatory Coordination Agency, overseen by a Foresight and Technology Assessment Board. The advantage of this arrangement is that it could ensure a centralized body of experts that are able to provide oversight across the range of nano-products and sectors. It is also argued (Bowman and Hodge 2006[58]) that a centralized regulatory approach would simplyfing the regulatory environment, thereby supporting industry innovation. A National Nanotechnology Regulator could coordinate existing regulations related to nanotechnology (including intellectual property, civil liberties, product safety, occupation health and safety, environmental and international law). Regulatory mechanisms could vary from "hard law at one extreme through licensing and codes of practice to ‘soft’ self-regulation and negotiation in order to influence behaviour" (Bowman and Hodge 2006[59], p. 1068).
Rather than adopt a new nano-specific regulatory framework, however, the United States’ Food and Drug Administration (FDA) convenes an ‘interest group’ each quarter with representatives of FDA centers that have responsibility for assessment and regulation of different substances and products. This interest group ensures coordination and communication.[60]
In 2004, the United Kingdom Government commissioned the Royal Society and Royal Academy of Engineering[61] to provide independent advice concerning areas where regulation should be considered. The formation of national nanotechnology regulatory bodies may also assist in establishing global regulatory frameworks.[62]
[edit] Self-regulation
The Self-policing wiki notes that self-regulation attempts may well fail, due to the inherent conflict of interest in asking any organization to police itself. If the public becomes aware of this failure, an external, independent organization is often given the duty of policing them, sometimes with highly punitive measures taken against the organization. The Food and Drug Administration note that they only regulate on the basis of voluntary claims made by the product manufacturer. If no claims are made by a manufacturer, then the FDA may be unaware of nanotechnology being employed.[63]
[edit] International Law
There is no international regulation of nanoproducts or the underlying nanotechnology.[64] Nor are there any internationally agreed definitions or terminology for nanotechnology, no internationally agreed protocols for toxicity testing of nanoparticles, and no standardized protocols for evaluating the environmental impacts of nanoparticles.[65]
It is likely that products that are produced using nanotechnologies will enter international trade. For this reason, it is argued that it will be necessary to harmonize nanotechnology standards across national borders. There is concern that some countries, most notably developing countries, will be excluded from international standards negotiations. The Institute for Food and Agricultural Standards note that “developing countries should have a say in international nanotechnology standards development, even if they lack capacity to enforce the standards". (p. 14).[66]
Concerns about monopolies and concentrated control and ownership of new nanotechnologies were raised in community workshops in Australia in 2004.[67]
[edit] Precautionary approach
The Royal Society and Royal Academy of Engineering (2004)[68] recommended that existing regulation be modified to support a precautionary basis because “the toxicity of chemicals in the form of free nanoparticles and nanotubes cannot be predicted from their toxicity in a larger form and… in some cases they will be more toxic than the same mass of the same chemical in larger form.”
In January 2008, a coalition of over 40 civil society groups endorsed a statement of principles[69] calling for precautionary action related to nanotechnology.
[edit] Social Justice and Civil Liberties
Concerns are frequently raised that the claimed benefits of nanotechnology will not be evenly distributed, and that any benefits (including technical and/or economic) associated with nanotechnology will only reach affluent nations.[70] The majority of nanotechnology research and development - and patents for nanomaterials and products - is concentrated in developed countries (including the United States, Japan, Germany, Canada and France). In addition, most patents related to nanotechnology are concentrated amongst few multinational corporations, including IBM, Micron Technologies, Advanced Micro Devices and Intel.[71] It is unlikely that developing countries will have access to the infrastructure, funding and human resources required to support nanotechnology research and development. This is likely to exacerbate such inequalities.
The agriculture and food industries demonstrate the concentration of nanotechnology related patents. Patents over seeds, plant material, animal and other agri-food techniques are already concentrated amongst a few corporations. This is anticipated to increase the cost of farming, by increasing farmers' input dependence. This is likely to marginalize poorer farmers, including those living in developing countries.[72]
Producers in developing countries will also be disadvantaged by the replacement of natural products (including rubber, cotton, coffee and tea) by developments in nanotechnology. These natural products are important export crops for developing countries, and many farmers' livelihoods depend on them. Their substitution with industrial nano products will negatively impact the economies of developing countries, that have traditionally relied on these export crops.[73]
It is proposed that nanotechnology can only be effective in alleviating poverty and aid development "when adapted to social, cultural and local institutional contexts, and chosen and designed with the active participation by citizens right from the commencement point" (Invernizzi et al 2008, p. 132).[74]
[edit] Health and environmental concerns
Some of the recently developed nanoparticle products may have unintended consequences. Researchers have discovered that silver nanoparticles used in socks to reduce foot odor are being released in the wash with possible negative consequences.[75] Silver nanoparticles, which are bacteriostatic, may then destroy beneficial bacteria which are important for breaking down organic matter in waste treatment plants or farms.[76]
A study at the University of Rochester found that when rats breathed in nanoparticles, the particles settled in the brain and lungs, which lead to significant increases in biomarkers for inflammation and stress response.[77]
A major study published more recently in Nature nanotechnology suggests some forms of carbon nanotubes – a poster child for the “nanotechnology revolution” – could be as harmful as asbestos if inhaled in sufficient quantities. Anthony Seaton of the Institute of Occupational Medicine in Edinburgh, Scotland, who contributed to the article on carbon nanotubes said "We know that some of them probably have the potential to cause mesothelioma. So those sorts of materials need to be handled very carefully." [78]. In the absence of specific nano-regulation forthcoming from governments, Paull and Lyons (2008) have called for an exclusion of engineered nanoparticles from organic food.[79]
[edit] Implications
Due to the far-ranging claims that have been made about potential applications of nanotechnology, a number of serious concerns have been raised about what effects these will have on our society if realized, and what action if any is appropriate to mitigate these risks.
One area of concern is the effect that industrial-scale manufacturing and use of nanomaterials would have on human health and the environment, as suggested by nanotoxicology research. Groups such as the Center for Responsible Nanotechnology have advocated that nanotechnology should be specially regulated by governments for these reasons. Others counter that overregulation would stifle scientific research and the development of innovations which could greatly benefit mankind.
Other experts, including director of the Woodrow Wilson Center's Project on Emerging Nanotechnologies David Rejeski, have testified[80] that successful commercialization depends on adequate oversight, risk research strategy, and public engagement. More recently local municipalities have passed (Berkeley, CA) or are considering (Cambridge, MA) - ordinances requiring nanomaterial manufacturers to disclose the known risks of their products.
The National Institute for Occupational Safety and Health is conducting research on how nanoparticles interact with the body’s systems and how workers might be exposed to nano-sized particles in the manufacturing or industrial use of nanomaterials. NIOSH offers interim guidelines for working with nanomaterials consistent with the best scientific knowledge. [81]
Longer-term concerns center on the implications that new technologies will have for society at large, and whether these could possibly lead to either a post scarcity economy, or alternatively exacerbate the wealth gap between developed and developing nations. The effects of nanotechnology on the society as a whole, on human health and the environment, on trade, on security, on food systems and even on the definition of "human", have not been characterized or politicized.
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