Background: Gene therapy has experimented an increasing attention in the last decades, due to its enormous potential applications in the medical field. It can be defined as the use of genes or genetic material (DNA, RNA, oligonucleotides) to treat or prevent a disease state, generally a geneticbased one.Application: Other applications, like treating viral, bacterial or parasite infections or development of vaccines are gaining also interest. Efficient gene therapy is mainly dependent on the ability of the highly labile genetic material to reach the therapeutic target. For this purpose, different delivery systems have been designed and extensively investigated. Nanoparticles offer a broad range of possibilities in design, being prepared using biocompatible and biodegradable excipients, being therefore generally considered as safe. Conclusion: Oral delivery of the genetic material is also a great challenge, due to the complexity of this specific biological barrier. Special attention to all the intrinsic hazards for gene delivery due to the barrier must be taken into account during the particle design process. Particle design will also allow targeting to specific sites of the gastrointestinal tract. Solid lipid nanoparticles have been extensively studied in the oral drug delivery field, and also in gene delivery through other administration routes, but still not explored in oral gene delivery. In this manuscript, design considerations and particle-cell interaction mechanisms will be extensively reviewed, focusing on the oral route to encourage the scientific community to explore these valuable carriers for oral gene delivery.