Characterizing chemical signaling between engineered "microbial sentinels" in porous microplates

Area of Science:

• Biomaterials Engineering
• Synthetic Biology
• Chemical Engineering

Background:

• Living materials integrate engineered cells with material scaffolds for advanced functions.
• Designing these materials is challenging due to limited understanding of intracellular signaling transport.
• Porous scaffolds are crucial for cell communication and function within living materials.

Purpose of the Study:

• To develop and characterize a porous microplate system for studying molecular transport in living materials.
• To quantify the diffusion and adsorption parameters of various signaling molecules within hydrogel barriers.
• To enable the design of living materials with predictable cellular communication.

Main Methods:

• Development of a porous microplate with hydrogel barriers (60% porosity, 1.6 tortuosity).
• Characterization of molecular diffusion (dyes, antibiotics, inducers, quorum signals) between microplate wells.
• Construction of a sentinel Escherichia coli strain with sensors for multiple inducers and quorum signals.
• Quantification of signaling distances and response times using finite element modeling.

Main Results:

• Molecular diffusion of various signaling molecules was successfully characterized across hydrogel barriers.
• The engineered sentinel strain responded to inducers diffusing up to 14 mm.
• Adsorption coefficients for signaling molecules in hydrogels were determined, ranging from 0 to 0.1 mol m⁻³.
• Signaling distances were found to be influenced by hydrogel adsorption properties.

Conclusions:

• The developed porous microplate system effectively facilitates and quantifies molecular transport for living materials.
• Derived transport parameters and adsorption coefficients are crucial for designing predictable living material systems.
• This research provides foundational data for advancing applications in pathogen remediation, computation, and biofilm engineering.