By Usman Waheed, Quaid-i-Azam University, Islamabad & Abdul Sami, PMAS Arid Agriculture University, Rawalpindi
Nanomania, one could call it – the growing excitement and anxiety about super-small gadgets that might transform our world for better or worse. Two decades ago, techno-visionaries titillated the world with their prophecy of machines so small – measurable in nanometers, or billionths of a meter – that they’d be invisible to the naked eye. Nano-robots, they speculated, would patrol your bloodstream and attack viruses, cholesterol and tumors; or they’d clean up oil slicks and toxic spills; or they’d become micro-“spies” for monitoring enemy movements without being seen. This fiction remains a dream until carbon nanotubes, nanoparticles and other nanodevices were manufactured, opening a whole new era of research and rendering nanotech the greatest invention of the 21st century.
Nanotechnology is a highly multidisciplinary field that has been gaining attention, both from the scientific and political communities, for its exciting breakthroughs and promising developments. Nanomedicine, an offshoot of nanotechnology, refers to the monitoring, repair, construction and control of human biological systems at the molecular level, using engineered nanodevices and nanostructures. A nanometer is one-billionth of a meter, too small to be seen with a conventional lab microscope. It is at this size scale – about 100 nanometers or less – that biological molecules and structures inside living cells operate. Nanomedicine is a large industry, with over 200 companies and 38 products worldwide, a minimum of 3.8 billion dollars in nanotechnology R&D is being invested every year.
Nanotechnology has moved quickly from the realm of science fiction into clinical research. Pharmaceutical and biotechnology companies and government agencies are beginning to explore and test a variety of applications of nanotechnology in medicine. Nearly a dozen nanoparticle-based therapies or imaging devices are currently in clinical trials, are awaiting clinical trials. In recent years, the U.S. Food and Drug Administration (FDA) has approved numerous Investigational New Drug (IND) applications for nano-formulations, enabling clinical trials for breast, gynecological, solid tumor, lung, mesenchymal tissue, lymphoma, central nervous system and genito-urinary cancer treatments. Scientists have used emerging nanotechnology-based cancer treatments as a compelling example of what is possible when we gain mastery over materials at the scale of the atoms and molecules they are made of.
Nanotechnology has the possibility of revolutionizing the diagnosis and treatment of many diseases especially cancer. It can be used to reproduce or to repair damaged tissue. Nanotechnology can provide rapid and sensitive detection of cancer-related molecules, enabling scientists to detect molecular changes even when they occur only in a small percentage of cells. Nanotechnology also has the potential to generate unique and highly effective therapeutic agents. Researchers are developing customized nanoparticles that can deliver drugs directly to diseased cells in the body. When it’s perfected, this method should greatly reduce the treatment damage such as chemotherapy does to a patient’s healthy cells. The overall drug consumption and side-effects can be lowered significantly by depositing the active agent in the morbid region only and in no higher dose than needed. This highly selective approach reduces costs and human suffering. A targeted or personalized medicine reduces the drug consumption and treatment expenses resulting in an overall societal benefit by reducing the costs to the public health system in broader aspect.
The use of nanotechnology for diagnosis and treatment of cancer is hot area of research. There are several nanocarrier-based drugs available in the market. Nanotechnology has been harnessed to kill cancer cells without harming healthy tissue. The technique works by inserting submicroscopic, nano-size synthetic rods called carbon nanotubes into cancer cells. When the rods are irradiated to near-infra red light from a laser they heat up, killing the cell, while cells without rods are left unscathed.
Nanotechnology is being applied to cancer treatment in two broad areas:
1) DETECTION – high-throughput nanosensor devices for detecting the biological signatures of cancer. Combined, such technologies could lead to earlier diagnosis and better treatment for patients with cancer.
2) TARGETING – the development of nanovectors, such as nanoparticles, which can be loaded with drugs or imaging agents and then targeted to tumours.
Nanoparticles have been used successfully to smuggle a powerful cancer drug into tumor cells leaving healthy cells unharmed. Researchers believe the therapy could transform many cancers from killer into chronic, treatable diseases. The major goals in designing nanoparticles as a delivery system are to control particle size, surface properties and release of pharmacologically active agents in order to achieve the site-specific action of the drug at the therapeutically optimal rate and dose regimen. Several nanobiotechnologies mostly based on nanoparticles, have been used to facilitate drug delivery in cancer. The magic of nanoparticles mesmerizes everyone because of their multifunctional character and they have given us hope for the recovery from this disease.
In 2008, researchers presented data that suggested nanoparticle delivery of a p21, a known tumor suppressor protein, by the Antennapedia protein could pierce the outer layer of a cancer cell and successfully reduce malignant tumors. Although the research was conducted in mice, researchers speculated that it could be a promising therapeutic application for many carcinomas. Also in 2008, researchers found that green tea, a known cancer preventive agent, was more effective when delivered by a synthetic nanoparticle. Researchers tested the effect on prostate cancer cells and found a significant response that persisted for 48 to 72 hours. The past 30 years of innovation in nanotechnology has removed much of the “magic” to yield 21st century “smart bombs” capable of carrying a whole host of new anticancer drugs directly to tumors.
Apart from cancer, nanoparticle cream has also been shown to fight staph infections, burn dressing is coated with nanocapsules containing antibiotics, copper nanoparticles have been shown to have antimicrobial activity and kill microorganism by making pits in their glycocalyx.
As far as the other part of the picture is concerned, two major hurdles are subject of interest: one is the elements of immune system which is coordinated and disseminated throughout the body, a major challenge for researchers that they design and fabricate a nanomedicine which will either avoid immune cells or use them to achieve appropriate targeting without activation or suppression of immune function. Second major hurdle is toxicity and elimination of nanomedicine from the body. Many of the newer nanoparticles are designed to be non-toxic and eliminated from the body by either being ’small’, i.e., less than 8 nm in diameter to facilitate passage with the urine out of the kidneys, or to dissolve to a size that allows for elimination through the urinary flow.
Nanotechnology will radically change the way we diagnose, treat and prevent cancer to help meet the goal of eliminating suffering and death from cancer. Most of the nanotechnologies are promising and fit well with the current methods of treatment but research in the heads of toxic effects on the human body and elimination is inevitable.
It is true that almost any technology is subject to use, misuse, abuse, and accidents. Regardless of what technology we produce it is powerful when properly used, worsen when abused. Nanotechnology has tremendous potential to contribute to human flourishing in socially just and environmentally sustainable ways. However, nanotechnology is unlikely to realize its full potential unless its associated social and ethical issues are adequately attended. In same way transformational issues arise from nanotechnology’s potential (particularly in combination with other emerging technologies, such as biotechnology, information technology, computer science, cognitive science and robotics) to transform aspects of the human situation.
One question should be answered that will our society be able to muster the collective financial and moral courage to allow such extraordinarily powerful technology to be deployed for human betterment, with due regard to essential ethical considerations.
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