Figure 5.

Schematic representation of two strategies/delivery systems developed for mitochondrial gene therapy (MTS-CPPs/pND1 [104] and PEI-TAT-DQA/pND1 [87]) and the most relevant achieved results. The delivery systems demonstrated the ability to target and transfect mitochondria in HeLa cells, a result confirmed by confocal microscopy (Mitochondria were labeled with Mitotracker, the plasmid encapsulated in the systems was labeled with FITC, and nuclei were stained with DAPI). These systems were also able to mediate the delivery of the mitochondrial ND1 gene directly into the mitochondria and the production of the respective protein after transfection of HeLa cells, an achievement demonstrated by the quantification of ND1 using the Elisa kit. Data were analyzed by one-way ANOVA. Data analysis was conducted with GraphPad Prism v.8.01 (GraphPad Software, Inc., San Diego, CA, USA). A p-value below 0.05 was considered statistically significant; *** p < 0.001 and **** p < 0.0001. The images of the results were adapted from [87,104]. Schematic representation created at BioRender.com.