Nucleic Acids Based Polyelectrolyte Complexes: Their Complexation Mechanism, Morphology, and Stability

Nucleic acids are a special class of negatively charged polymers, and they can complex with cationic small molecules and polymers to form polyelectrolyte complexes of rich morphology. The initial application focuses on gene delivery and typically involves the complexation of DNA with cationic surfactants and homopolymers. Recent research progress has extended to the complexation of nucleic acids with cationic block copolymers and ionic liquids, leading to the observation of unique morphology and stability characteristics and opening up opportunities for new application development. In this perspective article, we review the current understanding on the complexation behavior of nucleic acids with cationic species. We begin by discussing the phase behavior of DNA complexation with cationic surfactants and homopolymers. We then cover the more recent topic of nucleic acids interaction with cationic block copolymers and present the morphology and stability of complex micelles formed using both amphiphilic and hydrophilic block catiomers. Lastly, we examine DNA binding to ionic liquids and introduce new material applications involving ionic liquid stabilized DNA. We conclude the perspective by discussing a number of remaining challenges and future research topics in this exciting field.