Polycation-mediated gene delivery: challenges and considerations for the process of plasmid DNA transfection

The process of gene delivery has increasingly become a focus in biomedical research due to the growing demand by an ageing global population for targeted therapies of genetic related diseases, such as cancer, immunodeficiencies, and cystic fibrosis. In light of the safety issues that viral vectors still face in progressing through clinical trials, polycations have alternatively attracted keen attention, due to their lower safety risks and ability to interact with cells more effectively and with more stability, compared with other chemically designed nonviral vectors. In this review, a reflection of the literature pertaining to various types of polycations designed and optimized is presented, including the obstacles they face in facilitating plasmid DNA transfection. In order to design new polycations or optimize current ones that will be successful-both economically and for use in future clinical therapies-further in vivo research is needed to fully elucidate the mechanisms of each stage in the delivery process.