Drug delivery represents one of the last boxes to tick in the drug discovery project map. Perhaps it shouldn’t be that way, but it frequently is. If, however, you consider that without this, even the most potent and useful compounds will die a death. The death may be a clean one if the company strictly complies with go/no go decision points on its project map, or lingering and painful if the compound has a sufficiently powerful, political champion within the company. Modern approaches in the field of drug delivery have the potential to transform molecules, that would be difficult to advance in development, from dead as a duck into world beaters. This month’s offering features three excellent articles that highlight how nanotechnology has become an essential part of modern drug discovery by transforming certain aspects of drug delivery.
The first article in this month’s offering is entitled: “Strategies for the enhanced intracellular delivery of nanomaterials”, by Cláudia Azevedo, Maria Helena Macedo and Bruno Sarmento of The University of Porto, Portugal. In this article, the authors review the most up-to-date developments in the field of intracellular delivery and the mechanisms that facilitate the efficient transit of drugs functionalized to nanomaterials to their targets. By such techniques and approaches, it is now possible to obtain novel nanomaterials that retain biological (in vitro) activity yet have significantly improve properties, such as the avoidance of lysosomal degradation and ability to reach their target. This field, combining biology, chemistry and pharmacy has the potential massively to improve the ability of promising compounds to become effective drugs.
Following on from this is the article by Ryan F. Donnelly and Eneko Larrañeta of Queen’s University Belfast, UK entitled: “Microarray patches: potentially useful delivery systems for long-acting nanosuspensions”. The authors review a field that is important not only for efficiency of drug molecules, but also for patient compliance. The controlled release of more and more clinically important compounds require injection, generally, but not exclusively intramuscularly. As I’m sure you are more than aware, a significant number of patients have an almost phobic aversion to hypodermic needles. This, of course has associated issues such as injury, infection and disposal and can hinder the introduction of useful molecules, particularly in developing countries. One useful approach for delivery of such preparations is through the introduction of the compound via dissolving microneedles as microarray patches. These devices are capable of delivering of delivering microparticles into skin and they are minimally invasive and require no follow up (with respect to removal and disposal). As such, they are capable of enhancing compliance (especially in a needle averse population). The review covers various aspects of development of these systems.
The remaining article in this month’s offering is, perhaps not really an application of drug delivery per se but makes a nice bridge between the two previous articles. It is from Vijay Mishra, Akshay Patil, Sourav Thakur and Prashant Kesharwani, entitled: “Carbon dots: emerging theranostic nanoarchitectures”. Theranostics (therapeutic diagnostics) is a term that has been in use for perhaps 75 years from the use of radioactive isotopes of iodine salts to diagnose and treat thyroid cancer. Modern theranostics are significantly more sophisticated than this (but do not confuse sophistication with value). Kesharwani and colleagues discuss carbon dots and how they may have the potential to be of great value as theranostics in the field of oncology. Their reproducible size and shape and other physical properties, such as biocompatibility, photoluminescence and electron transfer abilities make them attractive structures for the diagnosis and drug delivery of molecules to a variety of cancer types. The advantage of drug delivery and ability to bioimage within a single structure is a great advantage of this approach.
Steve Carney was born in Liverpool, England and studied Biochemistry at Liverpool University, obtaining a BSc.(Hons) and then read for a PhD on the Biochemistry and Pathology of Connective Tissue Diseases in Manchester University, in the Departments of Medical Biochemistry and Histopathology. On completion of his PhD he moved to the Kennedy Institute of Rheumatology, London, where he worked with Professor Helen Muir FRS and Professor Tim Hardingham, on the biochemistry of experimental Osteoarthritis. He joined Eli Lilly and Co. and held a number of positions in Biology R&D, initially in the Connective Tissue Department, but latterly in the Neuroscience Department. He left Lilly to take up his present position as Managing Editor, Drug Discovery Today, at Elsevier. Currently, he also holds an honorary lectureship in Drug Discovery at the University of Surrey, UK. He has authored over 50 articles in peer-reviewed journals, written several book chapters and has held a number of patents. On the media front, Dr. Carney has been busy on some hush-hush projects that will be reported on later in the year.