DNA hydrogel-based gene editing and drug delivery systems

Deoxyribonucleic acid (DNA) is a promising synthesizer for precisely constructing almost arbitrary geometry in two and three dimensions. Among various DNA-based soft materials, DNA hydrogels are comprised of hydrophilic polymeric networks of crosslinked DNA chains. For their properties of biocompatibility, porosity, sequence programmability and tunable multifunctionality, DNA hydrogels have been widely studied in bioanalysis and biomedicine. In this review, recent developments in DNA hydrogels and their applications in drug delivery systems are highlighted. First, physical and chemical crosslinking methods for constructing DNA hydrogels are introduced. Subsequently, responses of DNA hydrogels to nonbiological and biological stimuli are described. Finally, DNA hydrogel-based delivery platforms for different types of drugs are detailed. With the emergence of gene therapy, this review also gives future prospects for combining DNA hydrogels with the gene editing toolbox.