Transverse Relaxivity Changes after Layer-by-Layer Encapsulation of Multicomponent DNA Templated Nanostructures

Abstract

We examine the effects on transverse proton relaxivity after layer-by-layer encapsulation of one-dimensional (1D), DNA templated nanostructures for potential applications as magnetic resonance imaging contrast agents. Multicomponent DNA templated nanostructures made with gold−iron oxide and gold−cobalt iron oxide were electrostatically encapsulated by polyelectrolytes (PSS and PAH) and ligands (RGD peptide) in order to stabilize the DNA nanostructure. Transverse relaxivity was measured by 300 MHz H1 nuclear magnetic resonance (NMR) spectroscopy. The results indicate that the transverse proton relaxivity was greater for 1D DNA-templated nanostructures when compared to zero-dimensional (0D) nanoparticles, but relaxivity decreased after the layer-by-layer encapsulation.