Nanostructures, by localized interactions with mammalian cells, can offer better efficacy and lower cell healing than conventional viral, biochemical, and electro-correction transfection techniques. In this perspective I describe the different stages of transfection and compare the transfection techniques based on their mechanisms. Focusing on the specific purposes of transfection, I also present how recent developments have developed in high aspect ratio nanostructures, with properties that go beyond existing viral, biochemical, and electroporation methods, as versatile techniques for delivering diverse cargo and. With different mammalian cell types for biomedical applications. Finally, I describe the challenges associated with transfections that need to be overcome to improve freight delivery efficiency and clinical translation.