Recent progress of polymeric nanogels for gene delivery

With its nearly unrestricted possibilities, gene therapy attracts more and more significance in modern-day research. The only issue still seeming to hold back its clinical success is the actual effective delivery of genetic material. Nucleic acids are in general challenging to administer to their intracellular targets because of their unfavorable pharmaceutical characteristics. Polymeric nanogels present a promising delivery platform for oligonucleotide-based therapies, as the growing number of reports deliberated in this review represents. Within the scope of this article, recent progress in the use of nanogels as gene delivery vectors is summarized and different examples of modified, stimuli-responsive, targeted, and codelivering nanogels are discussed in detail. Furthermore, major aspects of successful gene delivery are addressed and critically debated in regard to nanogels, giving insights into what progress has been made and which key issues still need to be further approached.