ABSTRACT
Nanoscale materials are having direct and indirect impacts on the wellbeing of society. Nanotechnology is an emerging interdisciplinary area that is expected to have a wide range of implications in all fields of science and technology, such as material science, mechanics, electronics, optics, medicine, plastics, energy, and aerospace, etc. Nanoparticles are of current interest because of an emerging understanding of their possible effects on human health and environmental sustainability, and also owing to the increased output of man-made nanoparticles into the environment.
In the case of drug delivery systems, nanoparticle delivery systems have been proposed as colloidal drug carriers. The key advantages of nanoparticles are (1) improved bioavailability by enhancing aqueous solubility, (2) increasing resistance time in the body (i.e., increasing half-life for clearance, increasing specificity for its cognate receptors), and (3) targeting drugs to specific locations in the body (i.e., their site of action). This results in concomitant reduction in the quantity of the drug required and dosage toxicity, enabling the safe delivery of toxic therapeutic drugs and the protection of non-target tissues and cells from severe side effects. It is increasingly used in different applications, including drug-carrier systems and to pass organ barriers such as the blood–brain barrier, cell membrane, etc. They are based on biocompatible lipids and provide sustained effects by either diffusion or dissolution.
Nanoparticles are used in many different applications and are created by many different processes. The fundamental issue of nanotechnology lies in the fact that the properties of materials change dramatically when their size is reduced to the nanometer range. However, research is going on to synthesize nanostructured and nanophasic materials, and characterizing these nano-sized materials is also an emerging field posing lots of challenges to scientists and technologists.
The formal definition of a nanoparticle is a “nano-object with all three external dimensions in the nanoscale”. Nanoparticles are a type of colloidal drug delivery system comprising particles with a size range from 10 to 1,000 nm in diameter. Their origins and properties are highly varied, making their study a rich branch of analytical science. Chemical properties of interest for nanoparticles include total chemical composition, mixing state (internal/external), surface composition, electrochemistry, and oxidation state, etc. Physical properties of interest include number and mass concentration, size, surface area, total mass, morphology, and optical properties, etc. Because of their very high surface area to mass ratio and high surface curvature, nanoparticles may be particularly chemically active.27
The origins and properties of nanoparticles are highly varied, making their study a rich branch of analytical science. It is important to have robust analytical approaches for characterizing nanoparticles to maximize the benefits from them while mitigating their impact. The development and characterization of nanoscale entities have motivated an upsurge in research activities on the discovery and invention of techniques to allow a better regulation on morphology, size, and dimensions in the nano-range. The present chapter represents the basics of various nanoparticles applied as drug delivery devices with their benefits, as well as the properties of the materials applied in their fabrication. It also encompasses the applications and principles of different analytical techniques used in nanoparticle characterization.
