Virus-Based Devices: Prospects for Allopoiesis.

The assembly line is a commonly invoked example of allopoiesis, the process whereby a system produces a different system than itself. In this sense, virus production in plants is an instance of bio-enabled bottom-up allopoiesis because the plant host can be regarded as a programmable assembly line for the virus. Reprogramming this assembly line and integrating it into a larger lineup of chemical manipulations has seen a flurry of activity recently, with more sophisticated systems emerging every year. The field of virus nanomaterials now has several subdisciplines that focus on virus shells as assemblers, scaffolds for molecular circuitry, chemical reactors, magnetic and photonic beacons, and therapeutic carriers. A case in point is the work reported by Brillault et al. in this issue of ACS Nano. They show how two types of animal virus coat proteins can be simultaneously expressed and efficiently assembled in plants into a complex virus-like particle of well-defined stoichiometry and composition. Such advances, combined with the promise of scalability and sustainability afforded by plants, paint a bright picture for the future of high-performance virus-based nanomaterials.