The future of nanotechnology

THE ELEMENT

Nanotechnology is the manipulation of materials on an atomic or molecular scale and can involve the usage of nanoparticles, which are microscopic particles with at least one dimension less than 100 nanometers. Examples of prevalent nanomaterials include carbon based nanoparticles such as the buckminsterfullerene, graphene sheets and nanotubes, liposomes and metal based nanoparticles such as silver or gold. Nanotechnology, despite not being used yet on a larger scale, has huge potential implications in fields such as drug delivery, improving air quality and increasing the energy efficiency of products.

Much of the research going into nanotechnology is focused on drug delivery systems whose efficacy is thereby drastically improved by modification or usage of nanoparticles. These tiny particles have the capacity to mitigate huge problems such as targeting cancer cells with excellent precision, permitted by their extremely high surface area to volume ratio compared to the same mass of material in a larger form. This allows drug delivery to have reduced toxicity, improved efficacy and enhanced distribution. Nanoparticle drug delivery systems, on account of their minute size, can easily penetrate across barriers in small capillaries into single cells, for example the blood brain barrier, which allows the specific drug to accumulate at the targeted locations in the body more successfully. Therefore this reduces the toxicity of the therapeutic agent as well as decreasing the drugs side effects and increasing treatment efficacy. The impact of the drugs side effects are reduced by nanoparticles not releasing the medicine till they reach the target cell or tissue, which prevents the drugs from damaging healthy tissues around the tumour, which are the cause of side effects. Furthermore, the therapeutic agents can be packed into nanoparticles that are unidentifiable by the human immune system essentially giving them “stealth mode” properties which allow antiviral drugs to target for example, human immunodeficiency virus (HIV) infected cells.

For example, cancer chemotherapy cytostatic drugs damage both malignant and normal cells alike. However nano drug delivery, such as nanoshells coated with gold, selectively target malignant breast cancer cells only. This is done by combining infrared optical activity with properties of gold colloid, which allows the particle, of size smaller than 75 nanometers in diameter, to absorb and scatter the incidence of light.

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THE ELEMENT

Antibodies to breast cancer can be directly attached to gold nanoshells, which strongly absorbs infrared light in contrast to normal tissue which is transparent to it. The nanoshellantibody complex binds strongly to cancerous cells only where an infrared laser will then heat up the nanoshells thereby destroying the cancer cells.

Nanotechnology is also being used to treat and improve the quality of air and water through separation and filtration, bioremediation and disinfection. This is vital as only 30% of all water on Earth is not trapped in ice or glaciers and only 0.08% of this is clean water, hence providing adequate safe and clean water is often a challenge. Remediation is the process to remove, minimise or neutralise the water contaminants that damage human health or ecosystems. Traditional methods of remediation such as extraction and oxidation are less effective, expensive and timeconsuming. In contrast, an advanced method that can be used is nanomaterials which have enhanced affinity, capacity and selectivity for heavy metals and other contaminants in water. Using nanomaterials has wide ranging advantages including their higher reactivity, larger surface contact and better disposal capabilities. An example of this would be remediation using nanosized semiconductor photocatalysts. This is achieved through using materials such as titanium dioxide (TiO2), iron (III) oxide (Fe2O3) and zinc oxide (ZnO) which can serve as photocatalysts. In relation to air and water remediation, these photocatalysts are able to oxidise organic pollutant molecules into non toxic materials by light. At a sufficient level of light, the charge will be transferred from the valence band to the conduction band causing the surrounding substance to be oxidised. Nanotechnology has allowed semiconductor photocatalysts, such as those described above, to be modified in terms of reactivity and selectivity. Titanium dioxide is often used for remediation due to its low levels of toxicity, high photoconductivity and photostability as well as it’s easy availability and inexpensive nature. It has been trialed to remove contaminators from groundwater such as 1,1-dicholorethane, cis-1,1dischloroethane and toulene (methylbenzene). The surface of the TiO2 catalyst, which is developed using nanotubes, is proven to be more effective at eliminating organic materials in relation to the usual structure of TiO2. In effect, nanotechnology has an abundance of uses and provides more sophisticated and targeted solutions which are vital to mitigating prevalent environmental and health issues.

By Clara Gilardi

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References and Further reading: Yunus, Ian Sofian, et al. “Nanotechnologies in Water and Air Pollution Treatment.” Environmental Technology Reviews, vol. 1, no. 1, Nov. 2012, pp. 136–148, 10.1080/21622515.2012.733966.

ALMEIDA, A, and E SOUTO. “Solid Lipid Nanoparticles as a Drug Delivery System for Peptides and Proteins .” Advanced Drug Delivery Reviews, vol. 59, no. 6, 10 July 2007, pp. 478–490, 10.1016/j.addr.2007.04.007.

“Types and Preparation of Nanomaterials.” AZoNano.com, 17 Nov. 2015, www.azonano.com/ article.aspx?ArticleID=4147.

“Nanotechnology in the Chemical Industry.” Nano Magazine - Latest Nanotechnology News, nanomagazine.com/news/2018/6/27/ nanotechnology-in-the-chemicalindustry.

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