[Targeting mitochondria: innovation from mitochondrial drug delivery system (DDS) to mitochondrial medicine]

Mitochondrial dysfunction has been implicated in a variety of human diseases, including cancer and neurodegenerative disorders. Effective medical therapies for such diseases will ultimately require the targeted delivery of therapeutic agents to mitochondria. This will likely be achieved through innovations in the areas of the nanotechnology of intracellular trafficking. Mitochondrial delivery systems for a variety of cargoes have been repored to date. However, only a limited number of approaches are available for delivering macromolecules directly to mitochondria. We previously reported on the construction of a MITO-Porter, a liposome-based carrier that introduces macromolecular cargos into mitochondria via membrane fusion. Using the green fluorescence protein as a model macromolecule in conjunction with analysis by confocal laser scanning microscopy, we were able to confirm the mitochondrial delivery of a macromolecule by the MITO-Porter. Moreover, we reported that the Dual Function MITO-Porter (DF-MITO-Porter) could efficiently deliver cargo to mitochondria, through endosomal and mitochondrial membranes via step-wise membrane fusion. Here, We will present our findings on the development of our mitochondrial drug delivery system, and discuss our attempts regarding mitochondrial gene delivery and therapy. Finally, We will discuss the potential use of mitochondrial drug delivery systems in mitochondrial medicine.