Gold nanoparticles (GNPs) can be easily synthesized using various techniques, depending on the required shape and size (Perez-Juste et al., 2005). Their surfaces can also be simply modified and attached with several molecules, such as antibody, protein, carbohydrate, and lipid (Di Pasqua et al., 2009; Pissuwan et al., 2007). According to the review by Dykman and Khlebtsov (2011), many shapes of GNPs have been applied in biomedical applications, such as spherical and rod shapes (Fig. 7.1). However, it seems that spherical and rod-shaped GNPs are the most common shapes used in biomedical applications. Spherical GNPs can be synthesized by chemical reduction, and rod-shaped GNPs are generally synthesized by the seed-mediated synthesis method. The difference in shape and size of GNPs leads to different optical properties and cellular uptakes that can increase the wide use of GNPs in modern biomedical applications both in vitro and in vivo (Kim et al., 2015). For example, they can be applied as a potential tool for the diagnosis of various diseases (Mieszawska et al., 2013; Pissuwan et al., 2008). Due to their surface plasmon property, the light absorbed by GNPs can be converted into heat, which makes gold nanoparticles suitable for photothermal therapy (Huang and El-Sayed, 2011; Pissuwan et al., 2006). Rod-shaped GNPs or gold nanorods (GNRs) are especially well-known for having high photothermal efficiency. Their optical absorption can also be tuned to the near-infrared region, which can reduce the risk of healthy tissue damage from light exposure because of the low light absorption of biological tissues at nearinfrared wavelengths. Besides this decent property, GNRs also have strong surface
Monitoring and Evaluation of Biomaterials and their Performance in vivo. http://dx.doi.org/10.1016/B978-0-08-100603-0.00007-9
Copyright © 2017 Elsevier Ltd. All rights reserved.
Figure 7.1 SRod and spherical shapes of gold nanoparticles.
plasmon absorption and a high light-scattering ability that make them useful in therapeutic, diagnostic, and imaging applications (Pissuwan et al., 2008).