Novel branching membrane translocational peptide as gene delivery vector.

A fragment of HIV-tat protein, RKKRRQRRR, has been shown to have membrane penetration and nuclear localization properties, which are critical attributes of gene therapy agents. In this study, we designed a series of arborizing tat peptides, containing 1-8 tat moieties, and evaluated them as transfection enhancers in a variety of cell lines. We found that all compounds complexed with plasmid DNA, but only the molecule containing 8 tat-peptide chains shows significant transfection capabilities. Using rhodamine labeled plasmid and eight tat-peptide complex, we were also able to demonstrate intracellular delivery of the complex by fluorescence microscopy.