Here, we demonstrate the ability of solid lipid nanoparticle-based non-viral vectors to increase the α-galactosidase A levels of the IMFE1 cell line, an in vitro model for target cells in Fabry disease. For this purpose, vectors containing the pR-M10-αGal A plasmid, which encodes the α-galactosidase A enzyme, were prepared; the in vitro transfection efficacy was studied in IMFE1 cells, and the results were confirmed by RT-PCR. The cellular uptake of the vectors, intracellular disposition of the plasmid, and probable endocytosis pathways of the nanoparticles were also analyzed. The vectors used for the studies carried protamine (P-DNA-SLN), dextran and protamine (D-P-DNA-SLN), or hyaluronic acid of two different molecular weights and protamine (HA150-P-DNA-SLN or HA500-P-DNA-SLN). The new formulations, which presented a particle size in the range of nanometers (from 218 nm to 348 nm) and a positive superficial charge, were able to increase α-galactosidase A activity up to 4-fold in comparison to non treated IMFE1 cells. The most efficient vectors were those that included HA, and no differences due to changes in the molecular weight of HA were detected. The observed lack of colocalization with each of the four different Nile Red-labeled vectors and transferrin or cholera toxin appears to indicate that clathrin- and caveolae-independent pathways may be involved in their cellular uptake. Additionally, colocalization with LysoTracker indicated that the formulations were exposed to lysosomal activity, which may be responsible for the release of the plasmid from the vector. In conclusion, we reveal the potential of SLN-based vectors to efficiently transfect an immortalized Fabry patient cell line.