Bacterial Surface Biosensor for Cell-Impermeable Target Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Gram-negative bacteria are limited in their ability to sense and respond to cell-impermeable molecules, hindering their use in diagnostic and therapeutic applications.

Innovation Solution

Engineered bacterial cells with a heterologous target-specific binding peptide in the outer membrane transport protein, an inducible promoter, and a repressible promoter system that allows for increased expression of proteins or bioactive RNA molecules in response to extracellular targets and compounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If Gram-negative bacteria are used as diagnostic or therapeutic agents, then their therapeutic potential is improved, but their ability to sense and respond to cell-impermeable molecules deteriorates

Engineering Contradiction:

Improvetherapeutic potentialVSAvoidability to sense cell-impermeable molecules

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces an outer membrane transport protein as an intermediary component that enables Gram-negative bacteria to detect cell-impermeable molecules. The transport protein spans the outer membrane and has a binding domain that specifically interacts with target molecules, translating extracellular signals into intracellular responses that trigger therapeutic action.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The bacterial cell is segmented into functional modules: an outer membrane transport protein with binding domain for target recognition, a signaling pathway for signal transduction, and a therapeutic payload delivery system. This modular architecture allows independent optimization of each function while maintaining overall system versatility.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If an outer membrane transport protein with heterologous binding peptide is introduced, then the ability to detect specific targets is improved, but the device complexity increases

Engineering Contradiction:

Improvetarget detection abilityVSAvoidbacterial system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The outer membrane transport protein is engineered to perform multiple functions: it maintains its native role in compound uptake while simultaneously serving as a target detection sensor through the added heterologous binding peptide. This multi-functionality reduces the need for separate sensing and therapeutic components, thereby limiting complexity increase.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The binding affinity and specificity of the transport protein are modified by introducing heterologous peptides with specific binding characteristics. By changing the binding parameters of the protein rather than adding entirely new components, the system achieves enhanced target detection with minimal complexity increase.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If compound internalization is inhibited by target binding, then target detection sensitivity is improved, but the loss of compound internalization increases

Engineering Contradiction:

Improvedetection sensitivityVSAvoidcompound internalization

Core Design Contradiction:

Measurement precisionVSLoss of substance

Solution Approach 1:

The system employs feedback control where target binding to the transport protein generates a detectable signal that regulates subsequent compound internalization. The binding event itself modulates the transport activity, creating a feedback loop that enhances detection sensitivity while controlling compound uptake to minimize loss.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances the bacterial cells' ability to detect and respond to cell-impermeable targets by increasing the expression of proteins or bioactive RNA molecules in the presence of specific compounds and targets, enabling effective diagnostic and therapeutic applications.

Implementation Method 1

the compound is internalized within the cell by the outer membrane transport protein

Methodology Applied

Scientific EffectActive transport:

Implementation Method 2

an inducible promoter which is operably linked to a polynucleotide encoding a repressor protein, wherein said promoter is induced by a compound

Methodology Applied

Scientific EffectInducible promoter activation:

Implementation Method 3

a repressible promoter which is operably linked to a polynucleotide encoding a protein and/or a bioactive RNA molecule of interest, wherein said repressible promoter can be repressed by the repressor protein

Methodology Applied

Scientific EffectTranscriptional repression:

Implementation Method 4

internalization of the compound is inhibited by the presence of a target which binds to the heterologous target-specific binding peptide

Methodology Applied

Scientific EffectSpecific binding: Adsorption

Data Source

PatentUS12560604B2Bacterial biosensor system

Publication Date: 2026.02.24 REGENTS OF THE UNIVERSITY OF MINNESOTA

AI summary

The disclosure relates to a biosensor on the bacterial cell surface for sensing and responding to extracellular molecules. Related methods of using the bacterial cells to inducibly express a protein of interest and/or a bioactive RNA molecule in a subject are disclosed. Related methods of using the bacterial cells to inducibly express a protein of interest or to detect a target of interest in a sample are also disclosed.