MRI Nano-Contrast Agent Using Polymer Ion Complex
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Solution Overview
Problem
Current MRI contrast agents, particularly iron oxide nanoparticles, face challenges in sensitivity and specificity due to low particle size, surface crystallinity, and lack of functional groups for target-specific labeling, leading to inadequate contrast effects in distinguishing between normal and abnormal tissues.
Innovation Solution
A nano-composite is developed by encapsulating iron oxide-based nanoparticles in a polymer composite formed by an ionic bond between poly-gamma-glutamic acid (γPGA) and chitosan, leveraging their biocompatibility and ionic self-assembly properties to enhance magnetic resonance signals and increase label sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If iron oxide nanoparticles are synthesized in aqueous solution with dextran coating, then biocompatibility is improved, but magnetic resonance signal amplification effect deteriorates due to small particle size and low surface crystallinity
Solution Approach 1:
The patent changes the synthesis parameters by using organic solvent (1-octadecene) at high temperature (300°C) instead of aqueous solution at room temperature. This parameter change enables the formation of nanoparticles with larger size (10-20 nm) and high surface crystallinity, significantly improving magnetic resonance signal amplification while maintaining biocompatibility through subsequent polymer coating
Solution Approach 2:
The patent creates a composite structure by coating the inorganic iron oxide nanoparticle core with organic polymer materials (poly-gamma-glutamic acid and chitosan). This composite structure combines the high magnetic resonance signal amplification of the inorganic core with the biocompatibility and water solubility of the organic polymer coating, resolving the contradiction between signal amplification and biocompatibility
2Measurement precision
If iron oxide nanoparticles are synthesized at high temperature in organic solvent, then signal amplification effect is improved, but hydrophobicity increases making body injection difficult
Solution Approach 1:
The patent uses polymer materials (poly-gamma-glutamic acid and chitosan) as intermediary substances that bridge the hydrophobic iron oxide nanoparticle core and the aqueous biological environment. These polymers form a hydrophilic coating layer that enables water solubility and biocompatibility while preserving the core's high signal amplification properties, effectively mediating between the hydrophobic nanoparticle and hydrophilic biological system
3Ease of manufacture
If conventional iron oxide nanoparticles are used, then manufacturing simplicity is maintained, but contrast effect deteriorates due to lack of functional groups for target-specific labeling
Solution Approach 1:
The patent applies local quality modification by introducing specific functional groups (carboxyl groups from poly-gamma-glutamic acid and amine groups from chitosan) at the surface of the nanoparticle. These localized functional groups enable target-specific labeling and selective binding to specific sites in the human body, significantly improving contrast effect and diagnostic precision while maintaining the overall simplicity of the manufacturing process through ionic self-assembly
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
The nano-composite significantly amplifies MRI signals, improving the contrast effect and enabling more effective labeling of specific cells or organs, with enhanced biocompatibility and stability compared to traditional methods.
Implementation Method 1
a poly-gamma-glutamic acid (γ-PGA)/chitosan/manganese iron oxide nanoparticle composite prepared by encapsulating iron oxide-based nanoparticles in a γ-PGA/chitosan polymer composite using the ionic self-assembly properties of poly-gamma-glutamic acid (γ-PGA) and chitosan
Implementation Method 2
Magnetic resonance imaging (MRI) is a technique that obtains images by placing the human body inside a large magnet tube that generates a magnetic field, resonating hydrogen atom nucleus in the body by generating high frequency waves
Data Source
AI summary
The present invention relates to a nano-composite containing anionic and cationic polymers and a method for preparing thereof, and more particularly to a poly-gamma-glutamic acid (γ-PGA)/chitosan/manganese iron oxide nanoparticle composite prepared by encapsulating iron oxide-based nanoparticles in a γ-PGA/chitosan polymer composite using the ionic self-assembly properties of poly-gamma-glutamic acid (γ-PGA) and chitosan, which are biocompatible polymer materials, and to a method for preparing thereof.The present invention provides a magnetic resonance imaging nano-contrast agent based on a nanoparticle composite including iron oxide-based nanoparticles encapsulated in a self-assembled composite of anionic poly-gamma-glutamic acid (γPGA) and cationic chitosan. The iron oxide-based nanoparticles encapsulated in the composite interact with each other to produce a synergistic effect on the amplification of magnetic resonance signals, and thus have an relatively excellent contrast effect compared to when they exist as single particles.