Delivery of epidrugs.

Inhibitors of epigenetic targets have entered clinical trials with some success, in particular for combined therapies. Like many other chemotherapeutics these new classes of molecules have dose-limiting toxicities and highly active metabolism in vivo resulting in lower efficacy than expected. This review presents drug delivery strategies proposed to prolong epigenetic inhibitor effects while reducing toxicities and metabolic clearance. Inspired from the work done in cancer-targeted strategies, prodrugs and nanoparticle-based drug delivery systems are discussed in a comprehensive way, detailing the chemical and physiological principles of the selected releasing method and, when available, how epigenetic chemistry can be exploited.