(Poly)cation-induced protection of conventional and wireframe DNA origami nanostructures. Issue 16 (11th April 2018)

• Record Type: Journal Article
• Authors: Ahmadi, Yasaman; De Llano, Elisa; Barišić, Ivan
• Is Part Of: Nanoscale. Volume 10:Issue 16(2018)
• Page Start: 7494
• Page End: 7504
• Publication Date: 2018-04-11
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c7nr09461b
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Gene-therapy inspired chitosan and polyethyleneimine coatings protect DNA nanostructures from enzymatic degradation but preserve the functionalization capability of the surface. Abstract : DNA nanostructures hold immense potential to be used for biological and medical applications. However, they are extremely vulnerable towards salt depletion and nucleases, which are common under physiological conditions. In this contribution, we used chitosan and linear polyethyleneimine for coating and long-term stabilization of several three-dimensional DNA origami nanostructures. The impact of the degree of polymerization and the charge density of the polymer together with the N/P charge ratio (ratio of the amines in polycations to the phosphates in DNA) on the stability of encapsulated DNA origami nanostructures in the presence of nucleases and in low-salt media was examined. The polycation shells were compatible with enzyme- and aptamer-based functionalization of the DNA nanostructures. Additionally, we showed that despite being highly vulnerable to salt depletion and nucleolytic digestion, self-assembled DNA nanostructures are stable in cell culture media up to a week. This was contrary to unassembled DNA scaffolds that degraded in one hour, showing that placing DNA strands into a spatially designed configuration crucially affect the structural integrity. The stability of naked DNA nanostructures in cell culture was shown to be mediated by growth media. DNA origami nanostructures kept in growth media were significantly more resistant towards low-salt denaturation, DNase I and serum-mediated digestion than when in a conventional buffer. Moreover, we confirmed that DNA origami nanostructures remain not only structurally intact but also fully functional after exposure to cell media. Agarose gel electrophoresis and negative stain transmission electron microscopy analysis revealed the hybridization of DNA origami nanostructures to their targets in the presence of serum proteins and nucleases. The structural integrity and functionality of DNA nanostructures in physiological fluids validate their use particularly for short-time biological applications in which the shape and structural details of DNA nanodevices are functionally critical.