Gene therapy has been used as a potential approach to address the diagnosis and treatment of genetic diseases and inherited disorders. In this line, non-viral systems have been exploited as promising alternatives for delivering therapeutic transgenes and proteins. In this review, we explored how biological barriers are effectively overcome by non-viral systems, usually nanoparticles, to reach an efficient delivery of cargoes. Furthermore, this review contributes to the understanding of several mechanisms of cellular internalization taken by nanoparticles. Because a critical factor for nanoparticles to do this relies on the ability to escape endosomes, researchers have dedicated much effort to address this issue using different nanocarriers. Here, we present an overview of the diversity of nanovehicles explored to reach an efficient and effective delivery of both nucleic acids and proteins. Finally, we introduced recent advances in the development of successful strategies to deliver cargoes.

Gene therapy has been considered a promising strategy for treating several inherited diseases and acquired complex disorders. One crucial challenge yet to be solved to ensure the nanomaterials’ success in delivering gene therapies is their ability to escape from endosomes. To address this issue, we previously developed magnetite nanoparticles conjugated with the antimicrobial peptide Buforin II, which showed potent translocating and endosomal escape abilities in several cell lines. In this work, we propose developing new cell-penetrating nanoplatforms by interfacing graphene oxide (GO) with powerful translocating peptides to take advantage of already tested and unique peptides as well as the distinctive interactions of GO with the phospholipids of membranes and endosomes. GO was prepared by the modified Hummers’ method through the oxidation of graphite sheets. Next, the functionalization of GO was carried out by rendering pendant amine groups to the GO surface. Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR) were used to corroborate the successful functionalization of the nanoplatform. FTIR analysis exhibited the peaks related to the distinct carboxyl groups of GO and the Si–O bonds after silanization. TGA allowed us to estimate a silanization efficiency of 38%. Future work will be focused on conjugating Buforin II and assessing translocation efficiency by conducting uptake assays in liposomes and various cell lines. Additionally, endosomal escape will be determined via confocal microscopy by labeling the peptide with fluorescent molecules and examining colocalization with the fluorescent marker of endosomes, LysoTracker. By taking advantage of the exceptional qualities in terms of the physicochemical, electrical, and optical properties of GO, this study might provide novel strategies to overcome limitations commonly faced, such as low stability of the translocating biomolecules and endosomal entrapment.

The use of nanomaterials has recently emerged for the development of non-viral gene delivery systems to improve passing through biological barriers by surface modification, increase safeness and biocompatibility, and ultimately the efficacy for treating complex diseases. To successfully deliver genetic cargoes, the endosomal escape ability of these systems needs to be significantly