Nanotechnology is a very fascinating yet seemingly daunting field of interest. Simply stated, nanotechnology refers to the study of devices (or devices with critical components) that range in size from 1 to 1,000 nm1. Such microscopic devices have found applications in various fields, one of which is in medical diagnostics and treatment.
A particular application is in the field of oncology. Although various treatments for cancer such as surgery, radiation therapy and chemotherapy2 are readily available nowadays, each still has its own limitations. Both radiation therapy3 and chemotherapy4 give rise to side effects because both are not as targeted as they ideally should be. That is, they kill cancer cells but unavoidably also cause damage to nearby cells that are otherwise healthy.
It is for this reason that nanotechnology plays a promising role in the treatment of cancers. The use of such devices can possibly allow for drug treatments to be delivered directly to and only to cancer cells, thereby decreasing the risk for serious side effects and offering the chance for an improved quality of life for chemotherapy patients.5
However, to state the current limitations of cancer treatment and the potentials that nanotechnology offers in this way would make things sound too simple. This is where review articles therefore prove truly useful because they provide a more detailed picture of how such a technology aids and continually improves current methods. Although reading fact sheets from academic institutions and articles from science magazines do provide laymen with a general idea of the applications of nanotechnology in the field of medicine, review articles give a more in-depth discussion of the potentials and current limitations of the technology and hence allows for a deeper appreciation of how scientists in the field continually strive to improve nanodevices to meet the needs and keep up with the discoveries in cancer biology.
As was stated, despite the growing number of anticancer drugs being developed, current chemotherapy treatments are largely limited by the inherent toxicity of these drugs which, acting in a non-targeted manner, lead to serious side effects in patients.5 Doxorubicin, for instance, is a drug that is employed for treating metastatic breast cancers but also puts long-term users at risk for severe heart damage.5,6 However, when the drug is encapsulated in a liposome – minute structures composed of an outer wall of lipids enclosing a water core7 – the drug can be released in a controlled manner so that it doesn’t reach levels high enough to cause toxic effects.8
A liposome is just one type of what are known as nanovectors – nano-sized structures that can either be solid or hollow so that they can contain the toxic anticancer drugs (or other chemical agents, e.g. for diagnostic purposes)7 until the intended targets are reached, upon which these toxic chemicals are then released. Rather than simply being vehicles for transporting drugs, what nanovectors also offer are opportunities for more targeted therapies by way of attaching targeting “appendages” on their surfaces. These moieties are responsible for recognizing only cancer cells so that the toxic anticancer drugs will only be delivered to them, sparing healthy cells and thus minimizing the serious side effects of chemotherapy. Additionally, the use of such nanovectors will also allow for higher doses and possibly even cocktails of drugs to be delivered, making chemotherapy more effective yet doing away with the necessity of repeated administrations.1
Again, however, this is but a simple picture of the whole business of the oncological applications of nanotechnology. It would take more than reading several review articles or research papers but rather a more in-depth study of the biology of the human body and of cancer to fully understand the hurdles being faced in the search for better cancer treatment methods. For instance, the impenetrability of the blood-brain barrier to most substances makes it an obstacle for some treatments, but there have already been reports on nanoparticles having been able to overcome this barrier.9
Nevertheless, other barriers still exist which challenge the potential of nanoparticles. There is also the need for better permeation of the vascular endothelium, overcoming the increased osmotic pressure in lesions so that drugs can be delivered deeper into them, as well as avoiding being eliminated by the reticulo-endothelial system.10
Likewise, a deeper understanding of the chemistry of these nanoparticles and how interact favorably (or otherwise) with the human body will be necessary to comprehend how they may be able to actually realize their potentials in improving cancer treatment.
Indeed, nanotechnology is a very interesting topic but it would definitely require a lot of reading and studying to comprehend and truly appreciate its role in overcoming the complexities of successfully treating cancer.
1. Mauro Ferrari, “Cancer Nanotechnology : Opportunities and Challenges,” Nature Reviews 5 (2005): 162.
2. National Cancer Institute, “National Cancer Institute: Cancer Topics,” US National Institutes of Health [Website]; available from http://www.cancer.gov/cancertopics/treatment/types-of-treatment.
3. Radiation therapy involves killing cancer cells with ionizing radiation. (Ibid)
4. Chemotherapy is a treatment method which uses drugs to kill cancer cells. (Ibid)
5. Gorka Orive, Rosa Maria Hernandez, Alicia R. Gascon, and Jose Luis Pedraz, “Micro and nano drug delivery systems in cancer therapy: Review Article,” Cancer Therapy 3 (2005): 131.
6. Medline Plus, “Drugs and Supplements, ” US National Library of Medicine [Website]; available from http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682221.html.
7. Ferrari, 161.
8. Orive, 132.
9. Ibid, 134.
10. Ferrari, 163.
Ferrari, Mauro. “Cancer Nanotechnology: Opportunities and Challenges.” Nature Reviews 5 (2005): 161-71.
Medline Plus. “Drugs and Supplements. ” US National Library of Medicine. Website.
Available from http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682221.html.
National Cancer Institute. “National Cancer Institute: Cancer Topics.” US National Institutes of Health. Website. Available from http://www.cancer.gov/cancertopics/treatment/types-of-treatment.
Orive, Gorka, Rosa Maria Hernandez, Alicia R. Gascon, and Jose Luis Pedraz. “Micro and nano drug delivery systems in cancer therapy: Review Article.” Cancer Therapy 3 (2005): 131-38.