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About this Article
Written by: Simon Tse
Written on: November 1st, 2005
Tags: biomedical engineering, health & medicine
Thumbnail by: Illumin
About the Author
During the Fall 2005 semester, Simon was an engineering student at the University of Southern California.
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Planning for Future GenerationsWritten by: Kari Hernandez
The Inner Workings of Speech RecognitionWritten by: Seth Capistron
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Volume VIII Issue I > Applying Nanotechnology to the Battle Against Cancer
Nanotechnology is a developing field in engineering. The possibilities of nanotechnology currently seem endless with all of the things that can be solved on the nano scale. With that in mind, one of the currently most promising areas of research in the field is in the discipline of Biomedical Engineering. Focusing in on cancer treatments, research has shown that nanotechnology has the ability to develop cancer treatments that are more effective and have few to no side effects. These therapeutics would bring the fight against cancer to a new level and have the potential to change the way people view the fight against cancer.

Introduction

Imagine taking a standard size 12 point font period, dividing it into roughly 150,000 equally sized pieces, and manufacturing a device averaging the size of just one of these pint size pieces. Considering the potential use of such devices, nanotechnology research, especially within the medical field, is gaining momentum. In fact, an estimated $180 billion will be allotted to nanotechnology medical research by the year 2015 [1]. An important branch of this medical exploration lies in cancer diagnosis and treatment, and researchers are already on the brink of developing several nano-scale devices designed to detect and potentially battle different forms of cancer.

Cancer Formation

According to the American Cancer Society (ACS), approximately 1,373,910 individuals were diagnosed with cancer in 2005 while another 570,280 people died from the disease [2]. In fact, statistics indicate that approximately 40% of all individuals will develop some form of cancer within their lifetime [3], a startling fact considering the lack of a cure or even a comprehensive understanding of the disease. This risk, however, must be taken with the understanding that the use of or exposure to certain substances, including cigarettes and alcohol, can dramatically increase the likelihood of cancer formation; individuals living a healthy lifestyle can cut their chance of disease development in half [3].
Initially, decades of research concluded that the introduction of mutagens could be ascribed as the single cause of cancer. Mutagens invade a cell and attack a critical gene dubbed the "proto-oncogene", which is essentially a dormant version of cancer-causing genes [3]. When introduced to mutagenic chemicals, proto-oncogenes become activated, transforming into cancer-causing oncogenes. Cells containing oncogenes multiply uncontrollably and pass the oncogene on to daughter cells, thus creating a growing number of cancer cells [3]. A collection of the cancer cells constitutes a tumor.
However, more recent studies seem to disprove those initial conclusions. It appears that multiple processes, a series of critical mutations, are required for a cell's transformation into a cancer cell. These critical mutations primarily involve the deactivation of tumor suppression genes and the activation of oncogenes [3]. As the name indicates, a tumor suppression gene is a cell's line of defense against turning into a cancer cell. With the deactivation of the suppression gene, the oncogene will encourage rapid cell division and exponentially increase the probability of tumor development [3]. The mutated cell must now sustain itself within the body and continue to rapidly multiply before a tumor can officially develop.
Activation of the oncogene does not necessarily mean that an individual will develop cancer. The body provides multiple lines of defense against cancer formation. For example, certain white blood cells known as "natural killer" (NK) cells recognize and destroy the body's own mutated cells [3]. There are also certain enzymes in the body, such as N-acetyl transferases (NAT), which protect against natural mutagens. Such enzymes are also found in foods like celery and bean sprouts [3]. Unfortunately, some mutated cells are able to evade the body's natural defense mechanisms, generally leading to tumor formation. A nascent tumor must remain relatively small in order to receive sufficient nourishment and oxygen to survive [3]. As the tumor enlarges, it actually will develop its own peripheral circulation to provide essential nutrients [3].
Once self-sufficient, the tumor can further wreak havoc on the body by releasing cancerous cells thorough the body in a process known as metastasis. The mutated cells venture to other portions of the body through the circulation system, often creating secondary tumors. This is especially dangerous as an estimated 90% of cancer deaths are related to secondary tumors, whereas only 10% of deaths are due to the initial tumors [3. For example, prostate cancer migrates to the bones and breast cancer travels to the lungs [4].

Current Cancer Treatments

A better understanding of the causes of cancer has helped doctors develop several methods to fight the disease. Such treatments include surgery, radiotherapy, and chemotherapy. Surgery is used to remove relatively large tumors. However, surgery does not eliminate all cancer cells. The remaining cancer cells may cause recurring tumors. Therefore, surgery must be supplemented with other forms of treatment.
Radiotherapy can be used as a supplement to surgery to fight cancer. Radiotherapy uses a special kind of energy, ionizing energy, which is applied over a certain area that contains the tumor [5]. The ionizing energy damages the nuclear genetic material of the cancer cell, thereby preventing it from properly multiplying. Although sound in theory, radiotherapy can only work on the targeted area, meaning that if there are mutated cells outside the target area, they will not be eradicated by the treatment. This often means multiple treatments, along with the numerous side effects that accompany radiotherapy.
The most widely known form of cancer treatment is chemotherapy. Chemotherapy battles cancer by killing all cells experiencing high rates of cellular division, which includes cancer cells and some healthy cells from the bone marrow, GI Tract, and hair follicles [6]. The benefit of chemotherapy over radiotherapy is that chemotherapy works throughout the body, thus eliminating the initial and any secondary tumor sites. Chemotherapy is given in four different manners: intravenously, orally, topically, and through injection [6]. However, use of chemotherapy for the complete eradication of cancerous cells often falls short. Like radiotherapy, chemotherapy patients require multiple treatments to eliminate stray cancer cells. Unfortunately, chemotherapy treatments are notorious for side-effects, including extreme fatigue and hair loss.