Establishing true-to-life functionality in synthetic cells is a global grand challenge that traverses multiple fields including synthetic biology, bioengineering and origins of life research. However, advancing the spontaneous bottom-up construction of artificial cells with high organisational complexity and diverse functionality remains an unresolved issue at the interface between living and non-living matter.
The transitioning from inert capsule-based technologies to dynamical micro-compartmentalized entities capable of autonomous cytomimetic behaviour requires breakthrough advances in functional integration and on-board energization of multiplexed micro-systems. To date, the engineering of synthetic cellular systems (protocells) has been mainly approached using self-assembled vesicles, semi-permeable microcapsules and membrane-less or coated coacervate micro-droplets. These compartments provide a controllable medium for the encapsulation and exchange of biological and non-biological components that are experimentally selected to demonstrate single functions such as gene expression, enzyme catalysis and ribozyme activity within the synthetic cell models. Achieving high organisational and functional complexity in these constructs is methodological demanding due to difficulties in establishing sufficient compositional diversity and chemical complementarity by conventional methods of micro-compartmentalization under close-to-equilibrium conditions. These limitations restrict the structural and chemical complexity of current protocell models, inhibit the implementation of integrated componentry, and impede the development of energized cytomimetic systems.
To address this challenge, a living material assembly process based on the capture and on-site processing of spatially segregated bacterial colonies within individual coacervate micro-droplets is developed for the endogenous construction of membrane-bounded, molecularly crowded, compositionally, structurally and morphologically complex synthetic cells. The bacteriogenic protocells inherit diverse biological components, exhibit multi-functional cytomimetic properties and can be endogenously remodelled to include a spatially partitioned DNA/histone nucleus-like condensate, membranized water vacuoles and a self-supporting 3D network of F-actin proto-cytoskeletal filaments. The ensemble is biochemically energized by self-sustainable ATP production derived from implanted live E. coli cells to produce a cellular bionic system with amoeba-like external morphology and integrated life-like properties. Our results demonstrate a novel bacteriogenic strategy for the bottom-up construction of functional protoliving micro-devices and provide opportunities for the fabrication of new synthetic cell modules and augmented living/synthetic cell constructs with potential applications in engineered synthetic biology and biotechnology.
