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

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.

Addressing UK skills demand: The most important impact of the CDT will be to train a new generation of Chemical Biology PhD graduates (~80) to be future leaders of enterprise, molecular technology innovation and translation for academia and industry. They will be able to embrace the life science's industrialisation thereby filling a vital skills gap in UK industry. These students will be able to bridge the divide between academia/industry and development/application across the physical/mathematical sciences and life sciences, as well as the human-machine interfaces. The technology programme of the CDT will empower our students as serial inventors, not reliant on commercial solutions.
CDT Network-Communication & Engagement: The CDT will shape the landscape by bringing together >160 research groups with leading players from industry, government, tech accelerators, SMEs and CDT affiliates. The CDT is pioneering new collaboration models, from co-located prototyping warehouses through to hackathons-these will redefine industry-academic collaborations and drive technology transfer.
UK plc: The technologies generated by the CDT will produce IP with potential for direct commercial exploitation and will also provide valuable information for healthcare and industry. They will redefine the state of the art with respect to the ability to make, measure, model and manipulate molecular interactions in biological systems across multiple length scales. Coupled with industry 4.0 approaches this will reduce the massive, spiralling cost of product development pipelines. These advances will help establish the molecular engineering rules underlying challenging scientific problems in the life sciences that are currently intractable. The technology advances and the corresponding insight in biology generated will be exploitable in industrial and medical applications, resulting in enhanced capabilities for end-users in biological research, biomarker discovery, diagnostics and drug discovery.
These advances will make a significant contribution to innovation in UK industry, with a 5-10 year timeframe for commercial realisation. e.g. These tools will facilitate the identification of illness in its early stages, minimising permanent damage (10 yrs) and reducing associated healthcare costs. In the context of drug discovery, the ability to fuse the power of AI with molecular technologies that provide insight into the molecular mechanisms of disease, target and biomarker validation and testing for side effects of candidates will radically transform productivity (5-10 yrs). Developments in automation and rapid prototyping will reduce the barrier to entry for new start-ups and turn biology into an information technology driven by data, computation and high-throughput robotics. Technologies such as integrated single cell analysis and label free molecular tracking will be exploitable for clinical diagnostics and drug discovery on shorter time scales (ca.3-5 yrs).
Entrepreneurship & Exploitation: Embedded within the CDT, the DISRUPT tech-accelerator programme will drive and support the creation of a new wave of student-led spin-out vehicles based on student-owned IP.
Wider Community: The outreach, responsible research and communication skill-set of our graduates will strengthen end-user engagement outside their PhD research fields and with the general public. Many technologies developed in the CDT will address societal challenges, and thus will generate significant public interest. Through new initiatives such as the Makerspace the CDT will spearhead new citizen science approaches where the public engage directly in CDT led research by taking part in e.g hackathons. Students will also engage with a wide spectrum of stakeholders, including policy makers, regulatory bodies and end-users. e.g. the Molecular Quarter will ensure the CDT can promote new regulatory frameworks that will promote quick customer and patient access to CDT led breakthroughs.