Magnetosome-like structures for MRI contrast
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for cellular imaging, particularly using MRI, face limitations in achieving sufficient iron contrast for effective tracking and diagnostics due to the need for exogenously introduced iron particles, which can be toxic and have limitations in signal enhancement.
Innovation Solution
The co-expression of magnetotactic bacterial genes with mammalian iron handling genes, such as ferritin subunits lacking iron response elements, to enhance iron uptake and biomineralization within cells, creating magnetosome-like structures that improve iron contrast for imaging technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If exogenously introduced iron particles (SPIO) are used for MRI contrast, then iron contrast is provided for cell tracking, but toxicity and limitations in signal enhancement occur
Solution Approach 1:
The cell is engineered to produce its own iron contrast agents endogenously through expression of magnetosome genes and iron handling proteins, eliminating the need for exogenous iron particle introduction and thereby avoiding associated toxicity while maintaining MRI contrast capability
Solution Approach 2:
The harmful aspect (exogenous iron particle introduction) is removed from the system by replacing it with endogenous iron utilization through genetically engineered iron metabolism pathways that safely incorporate cellular iron into magnetosome-like structures
2Measurement precision
If exogenously introduced iron particles are used, then contrast is achieved, but signal enhancement is limited
Solution Approach 1:
The iron content and organization within the cell are modified by overexpressing magnetosome genes and iron handling proteins, transforming the quantity and structural organization of iron into optimized magnetosome-like structures that provide superior MRI signal enhancement compared to exogenous particles
3Quantity of substance
If standard ferritin is used for iron storage, then iron pool is augmented, but iron response elements regulate expression causing variability
Solution Approach 1:
The iron response elements (IRE) are removed from the ferritin gene construct, eliminating the regulatory mechanism that causes variable expression based on cellular iron levels, thereby achieving stable and constitutive iron storage capacity regardless of physiological iron conditions
Solution Approach 2:
By removing IRE-mediated regulation, the ferritin expression operates continuously and constitutively, ensuring stable iron storage capacity is maintained at constant levels independent of fluctuations in cellular iron availability
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
This approach allows for enhanced cellular tracking and imaging by increasing the iron content and biomineralization within cells, providing a safer and more effective contrast agent that maintains long-term imaging capabilities without dilution, even during cell growth and replication.
Implementation Method 1
one or more bacterial magnetotactic genes to amplify iron uptake, compartmentalization and biomineralization in cells
Implementation Method 2
magnetosome-like structures that impart magnetic properties to the cell that may be clinically useful
Data Source
AI summary
The invention provides an improved modified magnetosome that contains more iron therein with the combination of the expressed genes. This is achieved by co-expression of (a) one or more bacterial magnetotactic genes to amplify iron uptake, compartmentalization and biomineralization in cells, with (b) one or more mammalian iron handling proteins that together augment(s) and/or regulate the cells iron pool. As a result, mammalian cells or bacterial cells that are transfected or transformed, respectively, can be more effectively tracked using various imaging technologies.