Nanotechnology for Drug Delivery and Cancer Therapy

Introduction

With the development of nanotechnology, the formation and production of nanostructured materials with distinctive phenomena, and the utilization of these nanoscale structures in a vast range of fields like biology, chemistry, physics, engineering, computer science, and so on have become more frequent and have been increased day by day. Besides in the last decade, a wide range of profusion investigations has been applied in biomedical science, particularly in drug delivery systems, and diagnostic and therapeutic aspects of human health by using a combination of nanotechnology and biotechnology called nanobiotechnology, which deals with the implication and visualization of materials on the scale of 100 nm down to 1 nm (Faraji & Wipf, 2009). This is due to the fact that compared to the bulk materials, nano-scaled materials possess unique chemical, physical, magnetic, biochemical properties, which facilitate their surface to be modified easily in altered ways for gaining distinctive biological properties and functionalities with enhanced solubility under physiological conditions for accomplishing their specific biomedical applications (A. K. Gupta et al., 2007; Kasemo, 2002). Moreover, nanosized materials can easily be integrated into biomedical devices, and efficiently delivered into most biological systems to interact with different biomolecules both extracellularly and intracellularly. Due to possessing multi-functionality for instance, biocompatible nanostructured materials are considered as the smart biomaterial in tissue engineering (Kim et al., 2013). In such cases, titanium oxide (TiO₂) nanoparticles have been widely utilized for tissue engineering (Fei Yin et al., 2013). The biofluid of bone-substituting materials initiates its first interaction with a thin layer of TiO₂NPs which instinctively occurs on the top surface of metallic titanium (Feng et al., 2003; Hanawa, 2011). On the other hand, metallic nanoparticles can be used for facilitating the stimulation of cellular immune response i.e., T-helper 17 and T-helper 1 (Marques Neto et al., 2017). Similarly, through electrostatic interactions, oligonucleotide CpG-gold nanoparticle conjugates (CpG-Au@HBc VLP) and self-assembled engineered virus-like particles (VLP) were encapsulated for developing a characteristic immunostimulatory nanocomposite vaccine, where gold nanoparticles help to produce a cellular and humoral immune response by generating enhanced immunogenicity of virus-like particles and oligonucleotide CpG (Wang et al., 2016). By achieving access to most areas of the body and applying physical and chemical approaches for specific biological interaction of nanomaterials, particles at nano-level possess the potential to screen cells within the living system, identify and diagnose illness, and deliver target-specific therapeutics into the disease sites for treatment, which were previously considered as unachievable ways (Patra et al., 2008). Such as a tumor vascular targeting system is developed using a 200 nm-sized perfluorocarbon-based nanostructure, instantaneously capable of delivering drug molecules along with magnetic resonance imaging (MRI) and ultrasound distinction agents (Sumer & Gao, 2008). Moreover, another study also confirmed that polymeric micelles nanostructure of less than 100 nm-sized has possible multifunctional capacity in cancer therapy by detecting tumor cells through ultrasensitive MRI and affecting cancer cells through the release of pH-sensitive medications to target specific sites (Nasongkla et al., 2006). Additionally, nanomaterials are also found to retain various therapeutic applications i.e., for the treatment of tumor and cancer, photothermal therapy; for treating neurodegeneration, impaired or abnormal function of renal, hepatic and lung, cardiovascular disorders and other infectious diseases (J. Li et al., 2016). The nanomaterials commonly used to develop nanotechnology products for biomedical purposes are inorganic and metallic nanoparticles, carbon nanotubes, quantum dots (QDs), dendrimers, fullerenes, polymeric nanoparticles, liposomes, nanowires, nanoshells, nanofibers, nanocrystals, nanosuspension metallic surfaces etc. (Baetke et al., 2015; Canfarotta & Piletsky, 2014; Lalani et al., 2015; Rostami et al., 2014; Liu et al., 2016). A brief description of the biomedical applications of different nanoparticles and nanostructured materials is given by Table 1.