Synthesis of artificial cells via biocatalytic polymerisation-induced self-assembly

Abstract

Artificial cells are biomimetic microstructures that mimic functions of natural cells and find application, e.g., as microreactors, as building blocks for molecular systems engineering, and to host synthetic biology pathways. Here, we report enzymatically synthesised polymer-based artificial cells with the ability to express proteins. They are created by biocatalytic atom transfer radical polymerization-induced self-assembly (bioPISA). The metalloprotein myoglobin synthesises amphiphilic block copolymers that self-assemble into structures ranging from micelles over worm-like micelles to polymersomes and giant unilamellar vesicles (GUVs). The GUVs encapsulate cargo during the polymerisation, including enzymes, nanoparticles, microparticles, plasmids and cell lysate. The resulting artificial cells act as microreactors for enzymatic reactions and for osteoblast-inspired biomineralization, and could express proteins when fed with amino acids, as shown by the expression of the fluorescent protein mClover and of actin. Actin polymerises in the vesicles and alters the artificial cell’s internal structure by creating internal compartments. Thus, bioPISA-derived GUVs mimic bacteria as they are composed of a microscopic reaction compartment that contains genetic information which is able to express proteins upon induction. bioPISA not only is a powerful tool in the pursuit of artificial cells but also for the easy and highly efficient encapsulation of biological molecules under mild conditions and in biologically relevant media. Therefore, it could have significant implications for the development of biomaterials and drug-delivery systems, as well as for cell encapsulation, and the in-situ formation of nano-objects.