Particle characterisation in drug delivery

The use of materials in nano-scale dimensions is proving to be a promising approach to overcome drug delivery challenges. ‘Nanomedicine’ technologies are gradually achieving commercial success and reaching the clinic. Sub-micron nanocarriers have the potential to ferry the therapeutic to its site of action and in this process overcome the biological barriers and achieve targeted drug delivery, controlled or stimuli-responsive delivery and protect the therapeutic from biological milieus. Many different types of nanocarriers have been described, including polymeric nanoparticles (NPs), liposomes, solid lipid NPs, micelles, dendrimers and metal NPs among other systems (the terms ‘nanomedicine’, ‘NP’ and ‘nanocarriers’ are used herein to describe all nanosystems). Of particular interest are nanocarriers with the ability to act selectively and target cell internalisation processes, guiding the therapeutic into subcellular regions. NP features important in dictating their drug delivery performance, including targeted delivery and cellular trafficking, are their size, shape and surface characteristics such as surface charge, chemistry and the distribution of ligands.