Gene delivery into mammalian cells: an overview on existing approaches employed in vitro and in vivo.

Delivery of nucleic acids into cells is one of the central techniques underpinning molecular biology research and is also a critical process for in vivo applications such as gene therapy, vaccination, and drug development. Delivery of plasmid DNA enables expression of recombinant genes, while delivery of siRNA is used to downregulate gene expression. Over the last 40 years, multiple different methods of nucleic acid delivery have been developed. These include viral methods and non-viral methods, which can be further subdivided into mechanical, physical, and chemical methods. Here we describe the principal delivery methods, including their advantages, disadvantages, and suitability for particular applications.