Synthetic membranes, synthetic cells: Exploring the new frontier of cell engineering with polymers

Synthetic biology, historically rooted in reengineering natural cells, now embraces polymers as more than mere supports, but as key tools. Their inherent flexibility and customizability position polymers as ideal platforms for crafting cellular mimics and interfaces. Polymersomes highlight this potential: while nano-sized variants act as artificial organelles, their micro-sized counterparts serve as cell analogues. A non-classical approach was encasing E. coli in a Pluronic® membrane, which offers both protection and enhanced membrane modifiability. A further innovation came with S. cerevisiae, engineered to self-encapsulate through surface-expressed peroxidase, triggering bio-ATRP of conjugated polymers. Finally, the development of enzymatic PISA allowed cell lysates to be encapsulated, generating robust artificial cells that can express proteins, effectively substituting natural with synthetic membranes. Today, polymers stand as essential connectors, reshaping the boundaries of synthetic biology.