Non-viral gene delivery systems: hurdles for bench-to-bedside transformation.

Biologist and Nobel Prize winner James Watson's quote, "We used to think that our fate was in our stars, but now we know that, in large measure, our fate is in our genes", represents the initial food for thought that revolutionized the way medications and active pharmaceutical ingredients are defined (Rocholl 1996). This fate engraved in the genetic material, as mentioned in Watson's quote, fueled a tremendous revolution wave in gene therapy. Gene therapy is a promising technology for treating genetic and acquired diseases by modulating the expression of a specific gene in the pathological cells. This is achieved by introducing a DNA sequence or other nucleic acid material or oligonucleotides to the target cell (Kay, 2011). Moreover, gene therapy contributes to correction of genetic defects, expression of therapeutic proteins, and inhibition of the synthesis of malignant proteins. In this review article, different non-viral gene delivery systems and their applications are discussed in detail. We reviewed and tabulated over 90 papers and 50 patents from 2006 to date discussing non-viral gene delivery technologies, innovation, and bench-to-bedside transformation. Furthermore, we are going to shed light on the lack of standardization in the design and characterization of non-viral gene delivery systems worldwide, which is a major concern in this research's field. This review would aid in getting an eagle eye view through non-viral gene delivery technologies during the past 20 years. Such a view, capturing the advances, the hurdles, and experimental details, would aid expert researchers in tuning their experimentation strategies and help newcomers better initially design their studies to generate solid and comprehensive results that can be reliable and reproducible.