Enzyme-Encapsulation and Performance of Nucleic Acid Nanoparticles

Chemical warfare countermeasures are crucial to 21st century military and civilian defense. While protective enzymes are available to neutralize a range of lethal compounds, including most nerve agents such as sarin, molecular carriers that enable both their in vivo prophylactic use and their environmental dissemination for purposes of remediation are either unavailable or severely limited. Major goals of molecular carriers are to protect biocatalytic activity for programmed durations of days to weeks, and inhibition of immune recognition and clearance in vivo. DNA nanotechnology offers the unique ability to program highly structured, nanometer-scale virus-like particles (VLPs) on the 10-100 nanometer-scale with fully controllable size, geometry, and chemical composition, as well as biodegradation properties, using the principle of scaffolded DNA origami. These VLPs can be used to encapsulate single or multiple distinct chemical warfare conversion enzymes with controlled copy numbers to enhance their enzymatic activity, as well as stability, in vivo in Soldiers and civilians, and in the environment. In particular, enzymes such as organophosphorus acid anhydrolase can be used to neutralize organophosphate G-type nerve agents including sarin, which are deadly compounds that Soldiers might be exposed to on the front lines of the battlefield, or civilians and diplomats might be exposed to on domestic or foreign soil. Because DNA origami is composed of nucleic acids, it is a naturally biodegradable material through nuclease activity, which can be tuned to offer controllable degradation timescales in vivo and environmentally. In this project, the Bathe research group explores principles of fabricating DNA origami VLP-encapsulated enzyme systems as hybrid protein-nucleic-acid vehicles for countermeasures against chemical warfare agents. Activity and neutralization of these agents will be investigated in vitro in mouse and human serum, blood, and in cell models, in vivo in animal models, as well as in simulated models for environmental dissemination. This project will form the basis for novel nanotechnological countermeasures that may be deployed on the battlefield for warfighter protection from diverse chemical warfare agents, and might also be extended to include biological warfare agents.