Small-scale production of biologics has great potential for enhancing the accessibility of biomanufacturing. By exploiting cell–material feedback, we have designed a concise platform to achieve versatile production, analysis and purification of diverse proteins and protein complexes. The core of our technology is a microbial swarmbot, which consists of a stimulus-sensitive polymeric microcapsule encapsulating engineered bacteria. By sensing the confinement, the bacteria undergo programmed partial lysis at a high local density. Conversely, the encapsulating material shrinks responding to the changing chemical environment caused by cell growth, squeezing out the protein products released by bacterial lysis. This platform is then integrated with downstream modules to enable quantification of enzymatic kinetics, purification of diverse proteins, quantitative control of protein interactions and assembly of functional protein complexes and multienzyme metabolic pathways. Our work demonstrates the use of the cell–material feedback to engineer a modular and flexible platform with sophisticated yet well-defined programmed functions.
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All data generated or analyzed during the current study are available from the corresponding author on reasonable request.
All code used in this study is available from the author upon reasonable request.
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We thank M. Lynch for plasmid constructs, insightful comments and suggestions; D.A. Tirrell, Y. Zhang and F. Sun for plasmid constructs; K. Zhu and K. Luginbuhl for insightful suggestions; J. Decker for useful suggestions; and P. Li, B. Chen, Q. Hu, X. Peng and Y. Zhang for assistance in revision. This study was partially supported by the U.S. Army Research Office under grant W911NF-14-1-0490 (to L.Y.), the National Institutes of Health (grant R01-GM098642 to L.Y. and grant R35GM127042 to A.C.), the Office of Naval Research (grant N00014-12-1-0631 to L.Y.), Beijing Municipal Natural Science Foundation (grant 5182017 to Z.L.) and a David and Lucile Packard Fellowship to L.Y.
The authors declare no competing interests.
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Supplementary Tables 1–3 and Supplementary Figures 1–18
Oscillatory behavior of engineered cells was observed on the microfluidic device.
Capsules carrying engineered bacteria shrunk with cell growth.
Capsules carrying engineered bacteria swelled slightly before shrinking with cell growth.
Oscillations of the capsule size in the culture chamber were observed under microscopy.
Periodic accumulation of fluorescence in the assay chamber were observed under microscopy.
Response of chitosan capsules to periodic change in pH.
Alginate capsules maintain the same size at varied chemical conditions.