Advancing bacterial 3D printing for the production of next-generation bio-materials

Lead Research Organisation: Imperial College London
Department Name: Dept of Chemistry

Abstract

Natural and engineered bacteria possess extraordinary biosynthetic capabilities. These can serve
almost any application imaginable: from functionalised bacterial cellulose patches for antimicrobial
wound dressing to bacterial self-healing concrete or the use of bacteria to make nacre-inspired
composite materials. The ability to harness such great manufacturing potential into customised
designs with defined three-dimensional shape and composition remains, however, largely elusive.



Current 3D bacterial printing approaches rely on the use of scaffolds or conventional layer-by-layer
additive manufacturing strategies to shape their designs, often resulting in unsophisticated structures
with restricted geometries and monotonous physico-chemical and mechanical properties. In contrast,
one-body yet heterogeneous composite materials with seamless transitions between disparate
properties (functionally graded composite materials) have long been a holy grail for designers and
engineers.
The project supervisors have devised and are currently developing a novel enabling platform for the
3D printing of new classes of bio-materials with radically enhanced properties and functionalities. This
new platform technology employs a series of CAD-programmed light cues to activate gene expression
of engineered cells "at will" at specific xyz coordinates, which allows for seamless changes in the
spatial composition of the composite bio-material. Engineered cells are conveniently embedded into
a translucent, bio-compatible matrix that provides additional capabilities and that can be easily
removed once the printing process is finished. The final success of this approach will depend not only
on overcoming the optical challenges (i.e. diffraction, dispersion, etc.) posed by the use of light but
also on our ability to achieve exquisite control over a number of biology-related aspects of the project.



This project will build on ongoing efforts to bridge the gap between synthetic biology and 3D printing
technology and will focus on further developing the necessary biological tools for the effective
manufacturing of bio-materials in 3D. In the initial phases of the project, less-sophisticated, simple
proof-of-concept structures will be generated. This will help identify and delimit expected and also
unexpected challenges for the production of more complex composite materials. Next steps will
include, but not be limited to, optimisation of biosynthetic pathways in the working chassis; finding
appropriate illumination regimes to improve printing efficiencies; incorporation of biomolecular
feedback control into genetic designs (e.g. incorporation of positive feedback loops could help
improve printing efficiency); development of efficient secretion systems and alternative "secretion"
strategies (e.g. enzyme display for extracellular biosynthesis of one or more constituents of the
composite material); bio-material engineering (e.g. through incorporation of bacterial amyloids) and
functionalisation (e.g. silver nanoparticles); integration of mathematically-modelled light-driven gene
expression systems into 3D printing software for truly computer-guided bio-fabrication; etc. Finally,
resultant next-generation 3D bio-materials will be analysed for their physico-chemical and mechanical
behaviour and compared with existing bio-materials.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023518/1 01/10/2019 31/03/2028
2279913 Studentship EP/S023518/1 01/10/2019 31/12/2022 Andreas Hadjimitsis