Nonviral Regenerative Gene Therapy of Mammalian Cutaneous Damages

The rate and character of superficial tissue regeneration after wounds, burns, and other traumas depend on cell proliferation within the damaged area. The acceleration of wound healing via the stimulation of cell proliferation and extracellular matrix synthesis is one of the most important tasks of modern medicine. There are gene therapy approaches to wound treatment, such as the transfer of genes that encode mitogenic growth factors to the wound area. The most important step in the development of the gene therapy approaches is the design of gene delivery tools. Despite the high efficiency of viral vectors, the nonviral approaches have some advantages (low toxicity, low immunogenity, safety, and the absence of side effects). Among the nonviral gene delivery tools molecular conjugates are the most popular due to their efficiency, simplicity, and the capacity for targeted gene transfer. In the present work, we have developed two molecular conjugates, NLS-TSF7 and NLS-TSF12, which consist of the modified signal of the nuclear localization of the T-antigen of the SV40 virus (cationic part) and the peptide ligands of the mammalian transferrin receptor (ligand part). Those conjugates bind to plasmid DNA via the formation of polyelectrolytic complexes and are able to deliver plasmid DNA into cells that express transferrin receptors through receptor-mediated endocytosis. The transfer of the expression vector of the luciferase gene in the complex with the molecular conjugate NLS-TSF7 to murine surface tissues led to about the 100-fold increase of luciferase activity in comparison with the transfer of the free expression vector. The treatment of mice with incised wounds with complexes of the expression vector of the synthetic human gene that encodes insulin-like growth factor 1 with molecular conjugate NLS-TSF7 led to the acceleration of wound healing in comparison with mice treated with the free expression vector. The obtained results confirm the high efficiency of the developed approach to regenerative gene therapy for treating the superficial tissue damage of mammals.