ABSTRACT
Wang, Zhang, and Rahman, 2007) to target cells with a specific membrane thickness. For example, gram-negative bacteria have thinner cell membranes than human cells, allowing these bacteria cells to be targeted without affecting normal cells. iii. The fact that they can embed in the cell membrane and form an open channel spanning the entire membrane (Lopez, Nielsen, Moore, and Klein, 2004; Hilder, Gordon, and Chung, 2010). iv. Their drastically enhanced flow of water and ions compared to biological ion channels, which will be highlighted in Section 6.2. v. The ability to modify their surface chemistry to target specific
cells, such as specific bacteria or cancer cells. For example, folate receptors are often expressed in large numbers on cancer cells compared to healthy cells. Nanoparticles with
folate receptor targeting have been successfully delivered to folate receptor-expressing cells (Hilgenbrink and Low, 2005). In Section 6.2, we highlight recent work that illustrates the ability of various nanotubes to mimic the function of biological ion channels and thus their enormous potential in the development of novel nanoscale devices and products. Our computational work has shown that it is possible to design a nanotube with the ability to either reject all charged particles or selectively reject positive or negative ions. In mimicking the function of biological ion channels, we may be able to fabricate nanoscale devices for various applications, including desalination, water purification, and ultrasensitive detection. Water shortage and water contamination are important global challenges. Over a third of the world’s population lives in a region where water is scarce (Elimelech and Phillip, 2011), and about one-sixth of the population doesn’t have access to safe drinking water (Botes and Cloete, 2010). Nanotube-based applications may provide significant benefits to both industry and local communities, such as through more efficient desalination membranes and improved access to safe drinking water. Nanotube-based devices may also enable the detection of very small concentrations of contaminants in water, such as heavy metals and bacteria. In addition, we may be able to design new pharmaceutical products for the treatment of bacterial infections, cancer, cystic fibrosis, and many other diseases. Section 6.3.1 examines the positive potential impacts of nanotube-based devices for a secure and sustainable future. Unfortunately, since nanotubes can affect cells, they could also have negative health and environmental risks, and issues such as safe handling and disposal will need to be carefully considered. To facilitate the development of these nanotube-based devices, it is vital that we have an in-depth understanding of their impact on global health and the environment. Section 6.3.2 examines the negative implications of developing a nanotube-based device that mimics biological ion channels. The dissemination of their impact will enable policy makers and the public to make informed decisions and have a better understanding of the technology that may result from such research.
