Synergistic gene delivery by self-assembled nanocomplexes using fusion peptide and calcium phosphate

Gene therapy can be a promising therapeutic approach to cure the fundamental causes of incurable genetic diseases. Because virus carriers are costly and can cause inflammation and immunogenicity, efficient non-viral carriers need to be developed for broader gene therapy applications. Therefore, we designed novel synergistic nanocomplexes for efficient transfection incorporated by the fusion of nuclear localization signal and cell-penetrating peptides with calcium phosphate. Fusion peptides were able to package large plasmid DNAs into nanocomplexes spontaneously and efficiently. After optimization, S-R/CaP or S-S/CaP nanocomplexes significantly improved specific luciferase expression up to 2-fold compared to Lipofectamine® 2000. In addition, the large Cas9-encoding plasmids were transfected into HEK293T cells more efficiently than Lipofectamine® 2000. Furthermore, subcutaneously injected cells to mice maintained more stable protein expression until 10 days than Lipofectamine® 2000. Moreover, the biocompatibility was revealed by observing negligible cytotoxicity, histological difference, and inflammatory cytokine release. Consequently, the new chimeric strategy will be an efficient and safe gene carrier into cells and tissues to treat various genetic diseases through gene therapy.