Photoactivated metallodrugs: lighting the way to novel therapies

It is estimated that more than one in three of us will develop cancer in our lifetime, and for one in four it will be the cause of death. Scientists play an important role in combating this illness. Worldwide activities range from basic research into understanding the causes of cancer to the subject of this proposal, which is the development of new anticancer treatments.This research is concerned with the study of new drugs that have metal atoms as important constituents (metallodrugs), and which only become toxic to cancer cells upon irradiation of light (photoactivation). The combination of light-sensitive drugs and lasers as light sources means that the site of treatment can be carefully controlled, minimising side effects and avoiding killing healthy cells. To optimise the treatment, this research will also develop new ways to irradiate cancer cells using modern lasers with optical fibre delivery, thereby allowing any part of the body to be irradiated. In addition, new ways to deliver the drugs to the cancer cells will be studied. The drug-delivery method that will be investigated is the use of liposomes, which act as microscopic spherical containers. These can be used to store large amounts of the metallodrug and to preferentially bind to cancer cells by modifying the surface of the liposome. It may even be possible to burst open and release the drugs upon demand by activating light-sensitive molecules in the liposome.Modern science invariably requires increasingly sophisticated instrumentation and technology, and cancer research is no exception. The research described in this proposal is reliant on state of the art laser systems and advanced microscopes, which are available at the specialist COSMIC centre within the University of Edinburgh. This research will also involve close collaboration with biologists and clinicians, and the longer-term view would be for these photoactivated metallodrugs and liposome delivery systems to be in clinical trials in the next 5-10 years. In this respect, this area of research is well positioned to benefit from the rapidly expanding UK biotechnology sector, thereby maximising the potential for exploitation.