Spherical Nucleic Acids*

Abstract

A historical perspective of the development of spherical nucleic acid (SNA) conjugates and other three-dimensional nucleic acid nanostructures is provided. The primary difference between SNAs and linear nucleic acids is that SNAs are dense, oriented spherical arrays of short oligonucleotides. SNA nanostructures are chemically quite sophisticated and can have markedly different properties depending upon the components and their placement within such structures. The oligonucleotides comprising SNAs consist of three main components: a particle attachment moiety, a spacer region, and a programmable recognition region. Initial studies conducted with DNA-gold nanoparticles have demonstrated the potential for utilizing SNA conjugates across a large number of disciplines. SNAs are entities with highly tailorable recognition properties by virtue of nucleic acid sequence. Importantly, the characteristic sharp melting of hybridized SNAs is a direct result of the collective behavior of the dense monolayer of oligonucleotides in the SNA shell.