Biological Engineered Living Materials: Growing Functional Materials with Genetically Programmable Properties

Abstract

Natural biological materials exhibit remarkable properties: self-assembly from simple raw materials, precise control of morphology, diverse physical and chemical properties, selfrepair and the ability to sense-and-respond to environmental stimuli. Despite having found numerous uses in human industry and society, the utility of natural biological materials is limited. But, could it be possible to genetically program microbes to create entirely new and useful biological materials? At the intersection between microbiology, material science and synthetic biology, the emerging field of biological Engineered Living Materials (ELMs) aims to answer this question. Here we review recent efforts to program cells to produce living materials with novel functional properties, focussing on microbial systems that can be engineered to grow materials and on new genetic circuits for pattern formation that could be used to produce the more complex systems of the future.

Modular Thermal Control of Protein Dimerization

“…cellular functions 26 , as well as previous work on temperaturecontrolled transcription 12 . We anticipate that as external control of protein signaling becomes needed in more complex settings, such as cellular therapy 27 and engineered living materials 28 , this will provide a role for temperature-based control modalities that offer spatiotemporal specificity and penetration depth beyond those afforded by systemic drug delivery and optical methods 1,8 . We anticipate that the coiled-coil structure of TlpA will facilitate future use of TlpA-based thermomers to control a variety of protein functions.…”

Controlling spatiotemporal pattern formation in a concentration gradient with a synthetic toggle switch

“…Future work will reveal if the TS properties are conserved when incorporated in more complex (synthetic) gene regulatory networks, for example when combined with the repressilator (Elowitz and Leibler, 2000, Potvin-Trottier et al, 2016, Santos-Moreno and Schaerli, 2019a to yield the AC-DC network (Perez-Carrasco et al, 2018, Verd et al, 2019, Balaskas et al, 2012, Panovska-Griffiths et al, 2013. Moreover, the here established engineering guidelines on how to control patterning with a synthetic TS will be valuable for future synthetic pattern formation, for example in the context of engineered living materials based on bacterial biofilms (Gilbert and Ellis, 2018, Nguyen et al, 2018, Moser et al, 2019, Cao et al, 2017.…”

“…Synthetic biology aims to engineer living organisms with standardized and modular circuits that perform their functions in a programmable and predictable way (Brophy and Voigt, 2014, Cameron et al, 2014, Purcell and Lu, 2014. In addition to the promise of providing new technologies for medical and industrial applications (Gilbert and Ellis, 2018, Kitada et al, 2018, Nielsen and Keasling, 2016, Xie and Fussenegger, 2018, recapitulating biological processes synthetically provides a route to understanding the basic necessary mechanisms underpinning biological functions and dissect their properties and limitations Collins, 2018, Li et al, 2018).…”

“…The rise of synthetic biology has successfully allowed to build synthetic systems able to explore core patterning principles (reviewed in (Santos-Moreno and Schaerli, 2019b, Luo et al, 2019, Davies, 2017, Ebrahimkhani and Ebisuya, 2019). In addition, synthetic pattern formation is also an attractive technology for the engineering of living materials (Gilbert and Ellis, 2018, Nguyen et al, 2018, Moser et al, 2019, Cao et al, 2017 and tissues (Davies and Cachat, 2016, Healy and Deans, 2019, Webster et al, 2016.…”

Cell-in-the-loop pattern formation with optogenetically emulated cell-to-cell signaling

“…Spatial patterning is crucial for the proper functioning of diverse multicellular biological systems from slime molds [1] to developing embryos. The ability to synthetically engineer multicellular patterning will facilitate advances in designing microbial communities [2] [3] [4], creating synthetic biomaterials [5] [6], and programming tissue and organ growth [7] [8] [9] [10], among other applications [11]. While recent efforts to synthetically engineer multicellular patterning have met with success (see [12], [13], [14] for reviews), relatively few of these efforts [15] [16] have been guided by quantitative mathematical theory beyond numerical simulation.…”