A DNA nanostructure platform for directed assembly of synthetic vaccines

Safe and effective vaccines offer the best intervention for disease control. One strategy to maximize vaccine immunogenicity without compromising safety is to rationally design molecular complexes that mimic the natural structure of immunogenic microbes but without the disease-causing components. Here we use highly programmable DNA nanostructures as platforms to assemble a model antigen and CpG adjuvants together into nanoscale complexes with precise control of the valency and spatial arrangement of each element. Our results from immunized mice show that compared to a mixture of antigen and CpG molecules, the assembled antigen-adjuvant-DNA complexes induce strong and long-lasting antibody responses against the antigen without stimulating a reaction to the DNA nanostructure itself. This result demonstrates the potential of DNA nanostructures to serve as general platforms for the rational design and construction of a variety of vaccines.

Building a nanostructure with reversible motions using photonic energy

Recently, the specific hybridization of DNA molecules has been used to construct self-assembled devices, such as the mechanical device to mimic cellular protein motors in nature. Here, we present a new light-powered DNA mechanical device based on the photoisomerization of azobenzene moieties and toehold-mediated strand displacement. This autonomous and controllable device is capable of moving toward either end of the track, simply by switching the wavelength of light irradiation, either UV (365 nm) or visible (>450 nm). This light-controlled strategy can easily solve one main technical challenge for stepwise walking devices: the selection of routes in multipath systems. The principle employed in this study, photoisomerization-induced toehold length switching, could be further useful in the design of other mechanical devices, with the ultimate goal of rivaling molecular motors for cargo transport and macroscopic movement.

Cholesterol-Modified DNA Nanostructures Serve as Effective Non-Viral Carriers for Delivering siRNA to the Kidneys to Prevent Acute Kidney Injury

With the emergence of gene therapy utilizing viral vectors, the potential risks associated with these vectors have prompted increased attention toward non-viral alternatives. DNA nanotechnology enables the assembly of specific oligonucleotide chains into nanostructures possessing defined spatial configurations. Due to their inherent characteristics, DNA nanostructures possess natural advantages as carriers for regulating gene expression in a non-viral manner. Cholesterol modification can convert DNA nanostructures from hydrophilic materials to amphiphilic materials, thereby extending their systemic circulation time. In this study, the high-dimensional design and cholesterol modification are shown to prolong the systemic circulation half-life of DNA nanostructures in mice. Specifically, the tetrahedron structure modified with three cholesterol molecules (TDN-3Chol) exhibit excellent circulation time and demonstrate a preference for renal uptake. The unique characteristics of TDN-3Chol can effectively deliver p53 siRNA to the mouse renal tubular tissue, resulting in successful knockdown of p53 and demonstrating its potential for preventing acute kidney injury. Furthermore, TDN-3Chol is not exhibited significant toxicity in mice, highlighting its promising role as a non-viral vector for targeted gene expression regulation in the kidneys. The designed non-viral vector as a prophylactic medication shows potential in addressing the current clinical challenges associated with nephrotoxic drugs.