Engineering Living Functional Materials

Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, that are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered ‘living functional materials’ and ‘living materials-synthesis platforms’, which incorporate both living systems and inorganic components, could transform the functionality and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms into a synthesis platform that could organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles^1,2. Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the characteristic properties of living systems and to interface living systems with inorganic materials. Such hybrids possess novel properties enabled by living systems while retaining desirable functionalities of inorganic materials. These systems, as living functional materials and as living materials-synthesis platforms, provide a radically different paradigm of materials function and synthesis: materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are synthesized in a distributed, bottom-up, autonomous, and environmentally sustainable manner.

References:
1. Chen, A. Y. et al. Synthesis and patterning of tunable multiscale materials with engineered cells. Nat Mater (Forthcoming 2014).
2. Chen, A. Y., Seker, U. O. S., Lu, M. Y., Citorik, R. J. & Lu, T. Synthesizing and Patterning Tunable Multiscale Materials with Engineered Biofilms. bioRxiv, doi:10.1101/002659 (2014).