DNA delivery to the mitochondria sites using leader peptide conjugated polyethylenimine

Abstract

Some genetic diseases are associated with defects of the mitochondrial genome. Mitochondria gene therapy by direct DNA delivery to mitochondria has been suggested as atherapeutic option for the diseases. However, a few studies about DNA delivery to mitochondria have been reported and no definite delivery method is available. Although numerous viral and non-viral gene carriers ahve been developed, these carriers were designed for the delivery of DNA into the nucleus. Thus, mitochondrial gene therapy has been thought as theoretical and speculative. In this research, we hypothesized that mitochondrial leader peptide (LP) conjugated polyethylenimine (PEI) could delivery DNA to the mitochondrial sites. PEI-LP was synthesized by conjugation LP to PEI. The complex formation of PEI-LP with DNA was confirmed by a gel retardation assay. In vitro delivery tests into isolated mitochondria or living cells were performed with rhodamin-labeled DNA and PEI-LP. Mitochondria in living cells were counter-stained with Mitotrack green. The toxicity was measured by MTT assay.