{Author Name [first-name middle-name-initials last-name]}
{Institution Affiliation [name of Author’s institute]}
All drug delivery systems (DDS) use the nanostructures as drug containers. There are various types of these nanocontainers such as polymeric liposomal nanoparticles, carbon nanostructures, magnetic nanoparticles and polymeric micelles (Singh and Lillard, 2009; Zarogoulidis et al., 2012).
The mode of action of these nanostructures on the target site and the molecular proceedings occurring during this process provides a mechanistic foundation for drug discovery against cancerous developments. The several considerable points that an anti-cancer agent should have are targeted delivery to the impacted cells, least activity loss, selective killing of cancerous cells, controlled release of active drug forms and high efficiency with a minimal dose of the therapeutic agent as well as minimal side effects. DDS using nanocarriers fulfill all these conditions and deliver the drug in a selective way on the targeted site. The mechanism of its action on the target site starts with the drug accumulation as a carrier inside the cancerous tissue, where the drug is released using the permeability and retention effects of the tissues on frequent intervals. This scheme utilizes the damaged structure of blood vessels near the tumour site that facilitates the easy access to the target tissues adjacent to cancerous cells. The nano size of these drug particles is appropriate for intravenous release and site-specific targeting. This model increases the circulation time of the drug in the blood stream which also assists in extravasation (Werengowska-Ciecwierz et al., 2015; Bi, Zhang, and Dou, 2014).
Nanocarriers are made of macromolecular materials that are entrapped inside lipid or encapsulated or adsorbed on the particle surfaces. Nowadays double layered nanostructures are used for controlled drug delivery. This bilayer or multi-layered model is an excellent approach of using DDS for lung cancer treatments. The lamellar structure gives an appropriate interlayer spacing to the drug molecules for ion exchange process. For example in the case of layered double hydroxides (LDHs), an ionic species intercalate in the interlayer spaces (Figure 1) (Bi, Zhang, and Dou, 2014).
Figure 1: Demonstration of bilayered (LDHs) (Bi, Zhang, and Dou, 2014)
LDHs consists of positively charged brucite layers and an interlayer gallery that contain charged anions and water molecules. The centered cation placed in octahedra connects its hydroxide ions containing vertices to create two-dimensional sheets. Some of the most studies LDH may contain divalent and trivalent cations such as Mg2+, ZN2+, M3+, FE3+, and GA3+. The positioning of these cations influences the density of charge scattered on LDH sheets that play an important role in various physiochemical functions such as reactivity, bonding, and mobility of chemical species inside the gallery or on the surface (Bi, Zhang, and Dou, 2014). For example, Liposomes are self-assembling vesicles that constitute of double layers of lipid, and these bilayers enclose an aqueous core where hydrophilic drugs are enclosed. On the contrary lipophilic drugs are dissolved inside the lipid bilayer (Yu et al., 2010).
The major characteristics of these bilayer nanocarriers drug agents are morphological tenability, suitable biocompatibility, convenient synthesis and minimal toxicity. The synthesis of LDH requires the assembly of organic ions in the interlayer space between the galleries, where electrostatic interactions play a major role. The interactions between the charges determine the separation of the layers. Figure 2 shows the reaction process of biomolecules inside the layered nanocarriers.
Figure 2: Various reaction mechanisms to incorporate biomolecules into layered nanomaterials (Bi, Zhang, and Dou, 2014)
Recently nano-micelles are introduced for cancer targeting and tumour imaging in lung cancer cells (Guthi et al., 2009). Zarogoulidis et al. (2012) introduced pressurized-metered door inhalers for lung cancer chemotherapy which consists of an aqueous solution enclosed by a lipid bilayer (Zarogoulidis et al., 2012). References
Bi, X., Zhang, H., & Dou, L. (2014). Layered double hydroxide-based nanocarriers for drug
delivery. Pharmaceutics, 6(2), 298-332.
Guthi, J. S., Yang, S. G., Huang, G., Li, S., Khemtong, C., Kessinger, C. W., & Gao, J. (2009).
cells. Molecular pharmaceutics, 7(1), 32-40.
Werengowska-Ciećwierz, K., Wiśniewski, M., Terzyk, A. P., & Furmaniak, S. (2015). The
chemistry of bioconjugation in nanoparticles-based drug delivery system. Advances in
Condensed Matter Physics, 2015.
Singh, R., & Lillard, J. W. (2009). Nanoparticle-based targeted drug delivery. Experimental and
molecular pathology, 86(3), 215-223.
Yu, B., Tai, H. C., Xue, W., Lee, L. J., & Lee, R. J. (2010). Receptor-targeted nanocarriers for
therapeutic delivery to cancer. Molecular membrane biology, 27(7), 286-298.
Zarogoulidis, P., Chatzaki, E., Porpodis, K., Domvri, K., Hohenforst-Schmidt, W., Goldberg, E.
P., & Zarogoulidis, K. (2012). Inhaled chemotherapy in lung cancer: future concept of
nanomedicine. Int J Nanomedicine, 7, 1551-1572.
