3D Bioprinted Engineered Living Materials for Continuous Organophosphorus Compound Detoxification

Abstract

Engineered living materials (ELMs) are a rapidly emerging class of materials, demonstrating
a wide range of functionalities, including responsive morphing, self-healing, and bio-catalysis.
3D bioprinted hydrogels have been used for the fabrication of high resolution,
compartmentalised, and load-bearing structures suitable for hosting microbial metabolism,
and accordingly represent an ideal environment for ELMs. The interactions between material
frameworks, such as hydrogels, and encapsulated life are now beginning to be investigated.
Herein, by 3D printing a hydrogel-encapsulated population of Escherichia coli, a chemically
inducible, metabolically active, microbial ELM was fabricated. The material was characterised
using a wide range of techniques, including fluorescence microscopy and cryogenic electron
microscopy. Toxic organophosphorus compound (OPC) detoxifying capabilities were
conveyed to the material through inducible expression of Agrobacterium radiobacter
phosphotriesterase (arPTE). The reaction diffusion process occurring at the interface of the
OPC detoxifying ELM was investigated using continuous fluorescence imaging of Coumaphos
hydrolysis.. Principal component analysis was then used to uncover spatial and temporal
features within this data, with relevance for future optimisation of catalytic microbial ELM
structures. To further demonstrate the applicability of this 3D printable microbial ELM, the
material was incorporated into an entirely 3D printed flow reactor, demonstrating effective,
cyclical detoxification of an OPC solution at high flow rate.
Looking towards the future of ELM design, a novel, 3D printable, contractile-thermosensitive,
double-network hydrogel was used to create thermo-responsive OPC degrading bioreactors,
capable of autonomously controlling their performance.

Date of Award	5 Dec 2023
Original language	English
Awarding Institution	University of Bristol
Supervisor	Adam W Perriman (Supervisor) & Valeska Ting (Supervisor)